id
stringlengths 12
12
| format
stringclasses 2
values | title_ko
stringlengths 0
811
⌀ | title_en
stringlengths 0
1.26k
⌀ | journal
dict | authors
listlengths 0
15
| abstract_ko
stringlengths 0
4k
⌀ | abstract_en
stringclasses 100
values | keywords
stringclasses 157
values | citation_count
stringclasses 5
values | doi
stringlengths 0
127
⌀ | url
stringclasses 101
values | file_source
stringlengths 23
23
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|
ART001359308
|
oai_dc
|
Modeling slump of concrete with fly ash and superplasticizer
|
Modeling slump of concrete with fly ash and superplasticizer
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"I-Cheng Yeh(Chung Hua University)"
] |
The effects of fly ash and superplasticizer (SP) on workability of concrete are quite difficult to predict because they are dependent on other concrete ingredients. Because of high complexity of the relations between workability and concrete compositions, conventional regression analysis could be not
sufficient to build an accurate model. In this study, a workability model has been built using artificial neural networks (ANN). In this model, the workability is a function of the content of all concrete ingredients, including cement, fly ash, blast furnace slag, water, superplasticizer, coarse aggregate, and fine aggregate.
The effects of water/binder ratio (w/b), fly ash-binder ratio (fa/b), superplasticizer-binder ratio (SP/b), and water content on slump were explored by the trained ANN. This study led to the following conclusions:
(1) ANN can build a more accurate workability model than polynomial regression. (2) Although the water content and SP/b were kept constant, a change in w/b and fa/b had a distinct effect on the workability properties. (3) An increasing content of fly ash decreased the workability, while raised the slump upper limit that can be obtained.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001359321
|
oai_dc
|
Neuro-fuzzy based prediction of the durability of self-consolidating concrete to various sodium sulfate exposure regimes
|
Neuro-fuzzy based prediction of the durability of self-consolidating concrete to various sodium sulfate exposure regimes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. T. Bassuoni(Queen’s University of Belfast); M. L. Nehdi(The University of Western Ontario)"
] |
Among artificial intelligence-based computational techniques, adaptive neuro-fuzzy inference systems (ANFIS) are particularly suitable for modelling complex systems with known input-output data sets.
Such systems can be efficient in modelling non-linear, complex and ambiguous behaviour of cement-based materials undergoing single, dual or multiple damage factors of different forms (chemical, physical and structural). Due to the well-known complexity of sulfate attack on cement-based materials, the current work investigates the use of ANFIS to model the behaviour of a wide range of self-consolidating concrete (SCC)
mixture designs under various high-concentration sodium sulfate exposure regimes including full immersion, wetting-drying, partial immersion, freezing-thawing, and cyclic cold-hot conditions with or without sustained flexural loading. Three ANFIS models have been developed to predict the expansion, reduction in elastic dynamic modulus, and starting time of failure of the tested SCC specimens under the various highconcentration sodium sulfate exposure regimes. A fuzzy inference system was also developed to predict the
level of aggression of environmental conditions associated with very severe sodium sulfate attack based on temperature, relative humidity and degree of wetting-drying. The results show that predictions of the ANFIS and fuzzy inference systems were rational and accurate, with errors not exceeding 5%. Sensitivity analyses
showed that the trends of results given by the models had good agreement with actual experimental results
and with thermal, mineralogical and micro-analytical studies.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001438489
|
oai_dc
|
A quantitative measurement of concrete air content using image analyses
|
A quantitative measurement of concrete air content using image analyses
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"C.L. Hwang(National Taiwan University of Science and Technology); E. Wang(National Taiwan University of Science and Technology); S.H. Lin(National Taiwan University of Science and Technology); S.L. Huang(Technology and Science Institute of Northern Taiwan); S.S. Peng(National Taiwan University of Science and Technology)"
] |
A proposed topology method is introduced to measure the air content of fresh cement paste and hardened concrete. The method takes advantage of chromatographic analysis in void areas that are highlighted using different color schemes and later calculated using built-in computer software. The air content measured by the topology method is compared with results obtained from the conventional ASTM methods. It is concluded that the proposed method is reliable, and costs less and is easier to operate compared with the ASTM methods. In addition, 3 dimensional pore models can be created using image post-processing techniques. The proposed method helps researchers in understanding the formation and existence of concrete pores. This paper reports a detailed test program demonstrating the standard operating procedure used for the proposed method and presents a comparison of results between the proposed method and conventional ASTM Specifications. It is also concluded that the air content increases with increasing size of pores and increasing percentage of coarse aggregates.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001438491
|
oai_dc
|
The use of neural networks in concrete compressive strength estimation
|
The use of neural networks in concrete compressive strength estimation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Bilgehan(Harran University); P. Turgut(Harran University)"
] |
Testing of ultrasonic pulse velocity (UPV) is one of the most popular and actual non-destructive techniques used in the estimation of the concrete properties in structures. In this paper, artificial neural network (ANN) approach has been proposed for the evaluation of relationship between concrete compressive strength, UPV, and density values by using the experimental data obtained from many cores taken from different reinforced concrete structures with different ages and unknown ratios of concrete mixtures. The presented approach enables to find practically concrete strengths in the reinforced concrete structures, whose records of concrete mixture ratios are not yet available. Thus, researchers can easily evaluate the compressive strength of concrete specimens by using UPV values. The method can be used in conditions including too many numbers of the structures and examinations to be done in restricted time duration. This method also contributes to a remarkable reduction of the computational time without any significant loss of accuracy. Statistic measures are used to evaluate the performance of the models. The comparison of the results clearly shows that the ANN approach can be used effectively to predict the compressive strength of concrete by using UPV and density data. In addition, the model architecture can be used as a non-destructive procedure for health monitoring of structural elements.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001438487
|
oai_dc
|
Numerical analysis of under-designed reinforced concrete beam-column joints under cyclic loading
|
Numerical analysis of under-designed reinforced concrete beam-column joints under cyclic loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Saptarshi Sasmal(Universitaet Stuttgart); Balthasar Novák(Universitaet Stuttgart); K. Ramanjaneyulu(SERC)"
] |
In the present study, exterior beam-column sub-assemblage from a regular reinforced concrete (RC) building has been considered. Two different types of beam-column sub-assemblages from existing RC building have been considered, i.e., gravity load designed (‘GLD’), and seismically designed but without any ductile detailing (‘NonDuctile’). Hence, both the cases represent the under-designed structure at different time frame span before the introduction of ductile detailing. For designing ‘NonDuctile’ structure, Eurocode and Indian Standard were considered. Non-linear finite element (FE) program has been employed for analysing the sub-assemblages under cyclic loading. FE models were developed using quadratic concrete brick elements with embedded truss elements to represent reinforcements. It has been found that the results obtained from the numerical analysis are well corroborated with that of experimental results. Using the validated numerical models, it was proposed to correlate the energy dissipation from numerical analysis to that from experimental analysis. Numerical models would be helpful in practice to evaluate the seismic performance of the critical sub-assemblages prior to design decisions. Further, using the numerical studies, performance of the sub-assemblages with variation of axial load ratios (ratio is defined by applied axial load divided by axial strength) has been studied since many researchers have brought out inconsistent observations on role of axial load in changing strength and energy dissipation under cyclic load.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001438490
|
oai_dc
|
Investigation of a management framework for condition assessment of concrete structures based on reusable knowledge and inspection
|
Investigation of a management framework for condition assessment of concrete structures based on reusable knowledge and inspection
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Faramarz Moodi(Amirkabir University of Technology)"
] |
Managing and reusing knowledge in engineering and construction sectors can lead to greater competitive advantage, improved designs, and more effective management of constructed facilities. The use of Information Technology (IT) in design and construction can exploit strategic opportunities for new ways of integration, sharing and facilitating information and knowledge in any field of engineering. The integrating of separate areas of IT can be used to bring a group of experts and specialists in any field of engineering closer together by allowing them to communicate and exchange information and expertise that facilitate knowledge capture, sharing, and reuse. A lack of an advisory management system and a need to marshal all available data in a common format has indicated the need for an integrated engineering computing environment to investigate concrete repair problems. The research described in this paper is based upon an evaluation management system (EMS) which comprising a database management system (REPCON) alongside visualisation technologies and evaluation system (ECON) is developed to produce an innovative platform which will facilitate and encourage the development of knowledge in educational,evolution and evaluation modes of concrete repair. This allows us to create assessment procedures that will allow the current condition of the concrete structure and its components to be expressed numerically using a confidence level (CL) so as to take the best course of action in the repair and maintenance management. The explained rating system, which is related to structural integrity and serviceability of the structure, allows the confidence level to be determined by visual inspection and the descriptive information and pictures taken from an available REPair of CONcrete (REPCON) database.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001438488
|
oai_dc
|
Cost optimization of high strength concretes by soft computing techniques
|
Cost optimization of high strength concretes by soft computing techniques
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Erdogan Ozbay(Mustafa Kemal University); Ahmet Oztas(Epoka University); Adil Baykasoglu(University of Gaziantep)"
] |
In this study 72 different high strength concrete (HSC) mixes were produced according to the Taguchi design of experiment method. The specimens were divided into four groups based on the range of their compressive strengths 40-60, 60-80, 80-100 and 100-125 MPa. Each group included 18 different concrete mixes. The slump and air-content values of each mix were measured at the production time. The compressive strength, splitting tensile strength and water absorption properties were obtained at 28 days. Using this data the Genetic Programming technique was used to construct models to predict mechanical properties of HSC based on its constituients. These models, together with the cost data, were then used with a Genetic Algorithm to obtain an HSC mix that has minimum cost and at the same time meets all the strength and workability requirements. The paper describes details of the experimental results, model development, and optimization results.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001364219
|
oai_dc
|
Modelling inelastic hinges using CDM for nonlinear analysis of reinforced concrete frame structures
|
Modelling inelastic hinges using CDM for nonlinear analysis of reinforced concrete frame structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J. Rajasankar(CSIR); Nagesh R. Iyer(CSIR); A. Meher Prasad(Indian Institute of Technology Madras)"
] |
A new formulation based on lumped plasticity and inelastic hinges is presented in this paper for nonlinear analysis of Reinforced Concrete (RC) frame structures. Inelastic hinge behaviour is described using the principles of Continuum Damage Mechanics (CDM). Member formulation contains provisions to model stiffness degradation due to cracking of concrete and yielding of reinforcing steel. Depending on its nature, cracking is classified as concentrated or distributed. Concentrated cracking is accounted through a
damage variable and its growth is defined based on strain energy principles. Presence of distributed flexural cracks in a member is taken care of by modelling it as non-prismatic. Plasticity theory supported by effective stress concept of CDM is applied to describe the post-yield response. Nonlinear quasi-static analysis is carried out on a RC column and a wide two-storey RC frame to verify the formulation. The column is subjected to constant axial load and monotonic lateral load while the frame is subjected to only lateral load. Computed results are compared with those due to experiments or other numerical methods to validate the performance of the formulation and also to highlight the contribution of distributed cracking on global response.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001364217
|
oai_dc
|
A fuzzy expert system for diagnosis assessment of reinforced concrete bridge decks
|
A fuzzy expert system for diagnosis assessment of reinforced concrete bridge decks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ali Akbar Ramezanianpour(Amirkabir University); Vahid Shahhosseini(Amirkabir University); Faramarz Moodi(Amirkabir University)"
] |
The lack of safety of bridge deck structures causes frequent repair and strengthening of such structures. The repair induces great loss of economy, not only due to direct cost by repair, but also due to stopping the public use of such structures during repair. The major reason for this frequent repair is
mainly due to the lack of realistic and accurate assessment system for the bridge decks. The purpose of the present research was to develop a realistic expert system, called Bridge Slab-Expert which can evaluate reasonably the condition as well as the service life of concrete bridge decks, based on the
deterioration models that are derived from both the structural and environmental effects. The diagnosis assessment of deck slabs due to structural and environmental effects are developed based on the cracking
in concrete, surface distress and structural distress. Fuzzy logic is utilized to handle uncertainties and imprecision involved. Finally, Bridge Slab-Expert is developed for prediction of safety and remaining service life based on the chloride ions penetration and fick’s second law. Proposed expert system is based on user-friendly GUI environment. The developed expert system will allow the correct diagnosis of concrete decks, realistic prediction of service life, the determination of confidence level, the description of condition and the proposed action for repair.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001364216
|
oai_dc
|
Strength and durability of concrete in hot spring environments
|
Strength and durability of concrete in hot spring environments
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"How-Ji Chen(Nat. Chung-Hsing University); Tsung-Yueh Yang(National Chung-Hsing University); Chao-Wei Tang(Cheng-Shiu University)"
] |
In this paper an experimental study of the influence of hot springs curing upon concrete properties was carried out. The primary variables of the investigation include water-to-binder ratio (W/B), pozzolanic material content and curing condition. Three types of hot springs, in the range 40-90oC, derived from different regions in Taiwan were adopted for laboratory testing of concrete curing. In addition, to compare with the laboratory results, compressive strength and durability of practical concrete were conducted in a tunnel construction site. The experimental results indicate that when concrete
comprising pozzolanic materials was cured by a hot spring with high temperature, its compressive strength increased rapidly in the early ages due to high temperature and chloride ions. In the later ages, the trend
of strength development decreased obviously and the strength was even lower than that of the standard cured one. The results of durability test show that concrete containing 30-40% Portland cement replacement by pozzolanic materials and with W/B lower than 0.5 was cured in a hot spring environment,
then it had sufficient durability to prevent steel corrosion. Similar to the laboratory results, the cast-inplace concrete in a hot spring had a compressive strength growing rapidly at the earlier age and slowly at
the later age. The results of electric resistance and permeability tests also show that concrete in a hot spring had higher durability than those cured in air. In addition, there was no neutralization reaction being observed after the 360-day neutralization test. This study demonstrates that the concrete with enough compressive strength and durability is suitable for the cast-in-place structure being used in hot spring areas.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001364220
|
oai_dc
|
Genetic algorithm-based yield stress equations for concrete at high temperature and prolonged mixing time
|
Genetic algorithm-based yield stress equations for concrete at high temperature and prolonged mixing time
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Al Martini(The University of Western Ontario); M. Nehdi(The University of Western Ontario)"
] |
Experiments were designed to investigate the flow behavior of portland cement paste and concrete incorporating superplasticizers. The paste and concrete mixtures were subjected to prolonged mixing for up to 110 min at high temperature. The yield stress values of concrete and that of the
corresponding cement paste were measured using a rotating rheometer and viscometer, respectively. The results reveal a weak linear correlation between the yield stress of concrete mixtures and that of the corresponding cement pastes. Results also indicate that the yield stress of concrete varies in a linear
fashion with the elapsed time, while its variations with the temperature and superplasticizer dosage follow power and inverse power functions, respectively. In this study, the genetic algorithms (GA) technique was
used to predict the yield stress of concrete considering various parameters, such as the mixing time, ambient temperature, and superplasticizer dosage. A sensitivity study was conducted to evaluate the ability of the GA equations thus developed to capture the effects of test parameters on the yield stress of
concrete. It was found that the GA equations were sensitive to the effects of test parameters and provided yield stress predictions that compared well with corresponding experimental data.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001364218
|
oai_dc
|
Blast analysis of concrete arch structures for FRP retrofitting design
|
Blast analysis of concrete arch structures for FRP retrofitting design
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jin-Won Nam(University of California); Hyung-Jin Choi(Karagozian & Case); 김장호(연세대학교); In-Soon Kim(yonsei univ.); 이나현(연세대학교); Ho-Jin Kim(ATMACS Co., Ltd.)"
] |
Fiber Reinforced Polymer (FRP) is widely used for retrofitting concrete structures for various purposes. Especially, for the retrofitting of concrete structures subjected to blast loads, FRP is proven to be a very effective retrofitting material. However, a systematic design procedure to implement FRP for concrete structure retrofitting against blast loads does not exist currently. In addition, in case of concrete structures with inarticulate geometrical boundary conditions such as arch structures, an effective analysis
technique is needed to obtain reliable results based on minimal analytical assumptions. Therefore, in this study, a systematic and efficient blast analysis procedure for FRP retrofitting design of concrete arch structure is suggested. The procedure is composed of three sequential parts of preliminary analysis, breach and debris analysis, and retrofit-material analysis. Based on the suggested procedure, blast analyses are carried out by using explicit code, LS-DYNA. The study results are discussed in detail.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001353026
|
oai_dc
|
Reliability of underground concrete barriers against normal missile impact
|
Reliability of underground concrete barriers against normal missile impact
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"N. A. Siddiqui(King Saud University); F. H. Khan(Aligarh Muslim University); A. Umar(Aligarh Muslim University)"
] |
In the present paper, a methodology has been presented for the reliability assessment of concrete barriers that lie at a certain depth in the soil, and a missile (a rigid projectile) impacts the top of the soil cover normally, and subsequently after penetrating the soil cover completely it hits the barrier with certain striking velocity. For this purpose, using expressions available in the literature, striking velocity of missile at any depth of soil has been derived and then expressions for the depths of penetration in crater and tunnel region of concrete barrier have been deduced. These depths of penetration have been employed for the derivation of limit state functions. Using the derived limit state functions reliability assessment of underground concrete barrier has then been carried out through First Order Reliability Method (FORM). To study the influence of various random variables on barrier reliability, sensitivity analysis has also been carried out. In addition, a number of parametric studies is conducted to obtain the results of practical interest.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352991
|
oai_dc
|
Reliability analysis of concrete bridges designed with material and member resistance factors
|
Reliability analysis of concrete bridges designed with material and member resistance factors
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"백인열(가천대학교); Eui-Seung Hwang(Kyunghee University); 신수봉(인하대학교)"
] |
Reliability analysis for a proposed limit state bridge design code is performed. In order to introduce reliability concept to design code, the proposed live load model is based on truck weight survey. Test data of domestic material strengths are collected to model statistical properties of member strengths.
Sample RC and PSC girder sections are designed following the safety factor format of the proposed code and compared with the current design practice. Reliability indexes are calculated and examined for material and member resistance factor formats and sample calibrations of safety factors are presented. It is concluded that the proposed code provides reasonable level of reliability compared to the international design standards.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352975
|
oai_dc
|
Experimental, numerical and analytical studies on a novel external prestressing technique for concrete structural components
|
Experimental, numerical and analytical studies on a novel external prestressing technique for concrete structural components
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"N. Lakshmanan(CSIR); S. Saibabu(CSIR); A. Rama Chandra Murthy(CSIR); S. Chitra Ganapathi(CSIR); R. Jayaraman(CSIR); R. Senthil(Anna University)"
] |
This paper presents the details of a novel external prestressing technique for strengthening of concrete members. In the proposed technique, transfer of external force is in shear mode on the end block thus creating a complex stress distribution and the required transverse prestressing force is lesser
compared to conventional techniques. Steel brackets are provided on either side of the end block for transferring external prestressing force and these are connected to the anchor blocks by expansion type anchor bolts. In order to validate the technique, an experimental investigation has been carried out on
post-tensioned end blocks. Performance of the end blocks have been studied for design, cracking and ultimate loads. Slip and slope of steel bracket have been recorded at various stages during the experiment. Finite element analysis has been carried out by simulating the test conditions and the responses have been compared. From the analysis, it has been observed that the computed slope and slip of the steel bracket are in good agreement with the corresponding experimental observations. A simplified analytical model has been proposed to compute load-deformation of the loaded steel bracket with respect to the end block. Yield and ultimate loads have been arrived at based on force/moment equilibrium equations at critical sections. Deformation analysis has been carried out based on the assumption that the ratio of axial deformation to vertical deformation of anchor bolt would follow the same ratio at the corresponding forces such as yield and ultimate. It is observed that the computed forces, slip and slopes are in good agreement with the corresponding experimental observations.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352897
|
oai_dc
|
Modified heat of hydration and strength models for concrete containing fly ash and slag
|
Modified heat of hydration and strength models for concrete containing fly ash and slag
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zhi Ge(North Dakota State University); Kejin Wang(Iowa State University)"
] |
This paper describes the development of modified heat of hydration and maturity-strength models for concrete containing fly ash and slag. The modified models are developed based on laboratory and literature test results, which include different types of cement, fly ash, and slag. The new models
consider cement type, water-to-cementitious material ratio (w/cm), mineral admixture, air content, and curing conditions. The results show that the modified models well predict heat evolution and compressive strength development of concrete made with different cementitious materials. Using the newly developed models, the sensitivity analysis was also performed to study the effect of each parameter on the hydration and strength development. The results illustrate that comparing with other parameters studied, w/cm, air
content, fly ash, and slag replacement level have more significantly influence on concrete strength at both early and later age.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352859
|
oai_dc
|
Simple approach to calculate chloride diffusivity of concrete considering carbonation
|
Simple approach to calculate chloride diffusivity of concrete considering carbonation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"In-Seok Yoon(Induk Institute of Technology)"
] |
Chloride diffusivity of concrete is a crucial material parameter for service life determination and durability designing of marine concrete. Many research works on this issue have been conducted, varying from empirical solutions obtained experimentally to image analysis, based on multi-scale modeling. One of the simple approaches is to express the chloride diffusivity of concrete by a multi-factor function, however, the influences of various factors on the chloride diffusivity are ambiguous. Furthermore, the majority of these research works have not dealt with the carbonation process of concrete, although this
process affects the chloride diffusivity of concrete significantly. The purpose of this study is to establish a simple approach to calculate the chloride diffusivity of (non)carbonated concrete. The chloride diffusivity of concrete should be defined, based on engineering and scientific knowledge of cement and concrete materials. In this paper, a lot of parameters affecting the chloride diffusivity, such as the diffusivity in pore solution, tortuosity, micro-structural properties of hardened cement paste, volumetric portion of aggregate, are taken into consideration in the calculation of the chloride diffusivity of noncarbonated concrete. For carbonated concrete, reduced porosity due to carbonation is calculated and used for calculating the chloride diffusivity. The results are compared with experimental data and previous research works.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352744
|
oai_dc
|
Finite element impact analysis for the design of structurally dissipating rock-shed
|
Finite element impact analysis for the design of structurally dissipating rock-shed
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yi Zhang(Spie batignolles TPCI); François Toutlemonde(Université Paris Est-LCPC); Philippe Lussou(Université Paris Est-LCPC)"
] |
This paper presents finite element impact analysis for the design of Structurally Dissipating Rock-shed (SDR), an innovative design of reinforced concrete rock-shed. By using an appropriate finite element impact algorithm, the SDR structure is modelled in a simplified but efficient way. The numerical
results are firstly verified through comparisons with the results of the experiments recently realized by ESIGEC and TONELLO I.C. It is shown that, using this impact algorithm, it is possible to correctly predict the SDR structural behaviour under different rock-fall impact conditions. Moreover, the numerical results show that the slab centre is the critical impact location for reinforced concrete slab design. The impact analyses have thus been focused on the impacts at the slab centre for the SDR structural optimization. Several series of parametric studies have been carried out with respect to load cases and engineering parameters choices. These numerical results support the robustness of the new SDR concept, and serve to optimize SDR structure and improve its conventional engineering design, especially for
ensuring the slab punching shear resistance.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352773
|
oai_dc
|
Clustering-based identification for the prediction of splitting tensile strength of concrete
|
Clustering-based identification for the prediction of splitting tensile strength of concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Bulent Tutmez(Inonu University)"
] |
Splitting tensile strength (STS) of high-performance concrete (HPC) is one of the important mechanical properties for structural design. This property is related to compressive strength (CS), water/ binder (W/B) ratio and concrete age. This paper presents a clustering-based fuzzy model for the prediction
of STS based on the CS and (W/B) at a fixed age (28 days). The data driven fuzzy model consists of three main steps: fuzzy clustering, inference system, and prediction. The system can be analyzed directly by the model from measured data. The performance evaluations showed that the fuzzy model is more accurate than the other prediction models concerned.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352717
|
oai_dc
|
Displacement-based seismic design of reinforced concrete columns strengthened by FRP jackets using a nonlinear flexural model
|
Displacement-based seismic design of reinforced concrete columns strengthened by FRP jackets using a nonlinear flexural model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"조창근(Chosun University); Hee-Cheon Yun(Chungnam National University); 김윤용(Chungnam National University)"
] |
In the current research, a displacement-based seismic design scheme to retrofit reinforced concrete columns using FRP composite materials has been proposed. An accurate prediction for the nonlinear flexural analysis of FRP jacketed concrete members has been presented under multiaxial constitutive laws of concrete and composite materials. Through modification of the displacement coefficient method (DCM) and the direct displacement-based design method (DDM) of reinforced concrete structures, two algorithms
for a performance-based seismic retrofit design of reinforced concrete columns with a FRP jacket have been newly introduced. From applications to retrofit design it is known that two methods are easy to apply in retrofit design and the DCM procedure underestimates the target displacement to compare with the DDM procedure.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352787
|
oai_dc
|
Shrinkage movement analysis of reinforced concrete floors constructed in stages
|
Shrinkage movement analysis of reinforced concrete floors constructed in stages
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.K.H. Kwan(University of Hong Kong); P.L. Ng(The University of Hong Kong)"
] |
Reinforced concrete floors constructed between movement restraints often crack seriously due to shrinkage after completion. One common mitigation measure is to construct the concrete floors in stages to allow part of the shrinkage movement to take place before completion. However, shrinkage movement analysis of concrete floors constructed in stages is quite cumbersome, as the structural configuration changes during construction, thus necessitating reanalysis of the partially completed structure at each
stage. Herein, a finite element method for shrinkage movement analysis of concrete floors constructed in stages is developed. It analyses the whole structure, including the completed and uncompleted portions, at all stages. The same mesh is used all the time and therefore re-meshing and location matching are no longer necessary. This is achieved by giving negligibly small stiffness to the uncompleted portions, which in reality do not exist yet. In the analysis, the locked-in strains due to increase in elastic modulus as the
concrete hardens and the creep of the hardened concrete are taken into account. Most important of all, this method would enable fully automatic shrinkage movement analysis for the purpose of construction control.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352762
|
oai_dc
|
On the usefulness of discrete element computer modeling of particle packing for material characterization in concrete technology
|
On the usefulness of discrete element computer modeling of particle packing for material characterization in concrete technology
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"P. Stroeven(Delft University of Technology); M. Stroeven(Delft University of Technology); J. Hu(Delft University of Technology)"
] |
Discrete element modeling (DEM) in concrete technology is concerned with design and use of models that constitute a schematization of reality with operational potentials. This paper discusses the material science principles governing the design of DEM systems and evaluates the consequences for their operational potentials. It surveys the two families in physical discrete element modeling in concrete technology, only touching upon probabilistic DEM concepts as alternatives. Many common DEM systems are based on random sequential addition (RSA) procedures; their operational potentials are limited to low configuration-sensitivity features of material structure, underlying material performance characteristics of low structure-sensitivity. The second family of DEM systems employs concurrent algorithms, involving particle interaction mechanisms. Static and dynamic solutions are realized to solve particle overlap. This second family offers a far more realistic schematization of reality as to particle configuration. The operational potentials of this family involve valid approaches to structure-sensitive mechanical or durability properties. Illustrative 2D examples of fresh cement particle packing and pore formation during maturation are elaborated to demonstrate this. Mainstream fields of present day and expected application of DEM are sketched. Violation of the scientific knowledge of to day underlying these operational potentials will give rise to unreliable solutions.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352691
|
oai_dc
|
An integrated approach for optimum design of HPC mix proportion using genetic algorithm and artificial neural networks
|
An integrated approach for optimum design of HPC mix proportion using genetic algorithm and artificial neural networks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rattapoohm Parichatprecha(Naresuan Universit); Pichai Nimityongskul(Asian Institute of Technology)"
] |
This study aims to develop a cost-based high-performance concrete (HPC) mix optimization system based on an integrated approach using artificial neural networks (ANNs) and genetic algorithms (GA). ANNs are used to predict the three main properties of HPC, namely workability, strength and durability, which are used to evaluate fitness and constraint violations in the GA process. Multilayer back-propagation neural networks are trained using the results obtained from experiments and previous research. The correlation between concrete components and its properties is established. GA is employed to arrive at an optimal mix proportion of HPC by minimizing its total cost. A system prototype, called High Performance Concrete Mix-Design System using Genetic Algorithm and Neural Networks (HPCGANN), was developed in MATLAB. The architecture of the proposed system consists of three main parts: 1) User interface; 2) ANNs prediction models software; and 3) GA engine software. The validation of the proposed system is carried out by comparing the results obtained from the system with the trial batches. The results indicate that the proposed system can be used to enable the design of HPC mix which corresponds to its required performance. Furthermore, the proposed system takes into account the influence of the fluctuating unit
price of materials in order to achieve the lowest cost of concrete, which cannot be easily obtained by traditional methods or trial-and-error techniques.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352670
|
oai_dc
|
Predicting the flexural capacity of RC beam with partially unbonded steel reinforcement
|
Predicting the flexural capacity of RC beam with partially unbonded steel reinforcement
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xiao-Hui Wang(Shanghai Jiaotong University); Xi-La Liu(Shanghai Jiaotong University)"
] |
Due to the reduction of bond strength resulting from the high corrosion level of reinforcing bars, influence of this reduction on flexural capacity of reinforced concrete (RC) beam should be considered. An extreme case is considered, where bond strength is complete lost and/or the tensile steel are exposed due to heavy corrosion over a fraction of the beam length. A compatibility condition of deformations of the RC beam with partially unbonded length is proposed. Flexural capacity of this kind of RC beam is predicted by combining the proposed compatibility condition of deformations with equilibrium condition of forces. Comparison between the model’s predictions with the experimental results published in the literature shows the practicability of the proposed model. Finally, influence of some parameters on the flexural capacity of RC beam with partially unbonded length is discussed. It is concluded that the flexural capacity of the beam may not be influenced by the completely loss of bond of the whole beam span as long as the tensile steel can yield; whether or not the reduction of the flexural capacity of the beam resulting from the loss of bond over certain length may occur depends on the detailed parameters of the given beam.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352613
|
oai_dc
|
Finite element computational modeling of externally bonded CFRP composites flexural behavior in RC beams
|
Finite element computational modeling of externally bonded CFRP composites flexural behavior in RC beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"André Luís Gamino(University of Campinas); Túlio Nogueira Bittencourt(University of Sao Paulo); José Luiz Antunes de Oliveira e Sousa(University of Campinas)"
] |
This paper focuses on the flexural behavior of RC beams externally strengthened with Carbon Fiber Reinforced Polymers (CFRP) fabric. A non-linear finite element (FE) analysis strategy is proposed to support the beam flexural behavior experimental analysis. A development system(QUEBRA2D/FEMOOP programs) has been used to accomplish the numerical simulation. Appropriate constitutive models for concrete, rebars, CFRP and bond-slip interfaces have been implemented and adjusted to represent the composite system behavior. Interface and truss finite elements have been implemented (discrete and embedded approaches) for the numerical representation of rebars, interfaces and composites.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352662
|
oai_dc
|
Homogeneity of lightweight aggregate concrete assessed using ultrasonic-echo sensing
|
Homogeneity of lightweight aggregate concrete assessed using ultrasonic-echo sensing
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H. Y. Wang(National Kaohsiung University of Applied Sciences); L. S. Li(Hwa Hsia Institute of Technology); S. H. Chen(National Kaohsiung University of Applied Sciences); C. F. Weng(National Kaohsiung University of Applied Sciences)"
] |
Dredged silt from reservoirs in southern Taiwan was sintered to make lightweight aggregates (LWA), which were then used to produce lightweight aggregate concrete (LWAC).This study aimed to assess the compressive strength and homogeneity of LWAC using ultrasonic-echo sensing. Concrete specimens were prepared using aggregates of four different particle density, namely 800, 1100, 1300 and 2650 kg/m3. The LWAC specimens were cylindrical and a square wall with core specimens drilled. Besides compressive strength test, ultrasonic-echo sensing was employed to examine the ultrasonic pulse velocity and homogeneity of the wall specimens and to explore the relationship between compressive strength and ultrasonic pulse
velocity. Results show that LWA, due to its lower relative density, causes bloating, thus resulting in uneven distribution of aggregates and poor homogeneity. LWAC mixtures using LWA of particle density 1300 kg/m3
show the most even distribution of aggregates and hence best homogeneity as well as highest compressive strength of 63.5 MPa. In addition, measurements obtained using ultrasonic-echo sensing and traditional
ultrasonic method show little difference, supporting that ultrasonic-echo sensing can indeed perform nondestructive, fast and accurate assessment of LWAC homogeneity.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001352635
|
oai_dc
|
Modeling strength of high-performance concrete using genetic operation trees with pruning techniques
|
Modeling strength of high-performance concrete using genetic operation trees with pruning techniques
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chien-Hua Peng(Chung Hua University); I-Cheng Yeh(Chung Hua University); Li-Chuan Lien(National Taiwan University of Science and Technology)"
] |
Regression analysis (RA) can establish an explicit formula to predict the strength of High-Performance Concrete (HPC); however, the accuracy of the formula is poor. Back-Propagation Networks (BPNs) can establish a highly accurate model to predict the strength of HPC, but cannot generate an
explicit formula. Genetic Operation Trees (GOTs) can establish an explicit formula to predict the strength of HPC that achieves a level of accuracy in between the two aforementioned approaches. Although GOT can produce an explicit formula but the formula is often too complicated so that unable to explain the substantial meaning of the formula. This study developed a Backward Pruning Technique (BPT) to simplify the complexity of GOT formula by replacing each variable of the tip node of operation tree with the median of the variable in the training dataset belonging to the node, and then pruning the node with the most accurate test dataset. Such pruning reduces formula complexity while maintaining the accuracy. 404 experimental datasets were used to compare accuracy and complexity of three model building techniques, RA, BPN and GOT. Results show that the pruned GOT can generate simple and accurate formula for predicting the strength of HPC.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001376299
|
oai_dc
|
Failure analysis of reinforced concrete frames with short column effect
|
Failure analysis of reinforced concrete frames with short column effect
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Naci Caglar(University of Sakarya); Mahir Mutlu(University of Sakarya)"
] |
Short column effect is cause to failure of columns which may result in severe damages or even collapse during earthquakes. The scope of the study is mainly to reveal the effect of short column on the holistic behaviour of the buildings. The nonlinear analysis of 31 different frame buildings containing short column problem are carried out using finite element method. The finite element models were selected by 2 bays and 3 stories. Since the short columns are generally seen in the first storey of the buildings, in the
study, they are only constructed in the same storey. The adverse effect of the short column on the response of buildings was shown in terms of the total load factor and displacement capacity of building. The response of buildings in terms of ground storey displacements is presented in figures and discussed. It is revealed that if the window openings are constructed along the bays, the total load capacity is decreased 85% compared with reference model in which all of bays are filled with infill walls.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001376296
|
oai_dc
|
Maximum axial load level and minimum confinement for limited ductility design of high-strength concrete columns
|
Maximum axial load level and minimum confinement for limited ductility design of high-strength concrete columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J.Y.K. Lam(The University of Hong Kong); J.C.M. Ho(The University of Hong Kong); A.K.H. Kwan(The University of Hong Kong)"
] |
In the design of concrete columns, it is important to provide some nominal flexural ductility even for structures not subjected to earthquake attack. Currently, the nominal flexural ductility is provided by imposing empirical deemed-to-satisfy rules, which limit the minimum size and maximum spacing of the confining reinforcement. However, these existing empirical rules have the major shortcoming that the actual level of flexural ductility provided is not consistent, being generally lower at higher concrete strength or higher axial load level. Hence, for high-strength concrete columns subjected to high axial
loads, these existing rules are unsafe. Herein, the combined effects of concrete strength, axial load level, confining pressure and longitudinal steel ratio on the flexural ductility are evaluated using nonlinear moment-curvature analysis. Based on the numerical results, a new design method that provides a consistent level of nominal flexural ductility by imposing an upper limit to the axial load level or a lower limit to the confining pressure is developed. Lastly, two formulas and one design chart for direct evaluation of the maximum axial load level and minimum confining pressure are produced.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001376297
|
oai_dc
|
Analysis of RC beams subjected to shock loading using a modified fibre element formulation
|
Analysis of RC beams subjected to shock loading using a modified fibre element formulation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hamid R. Valipour(The University of New South Wales); Luan Huynh(The University of New South Wales); Stephen J. Foster(The University of New South Wales)"
] |
In this paper an improved one-dimensional frame element for modelling of reinforced concrete beams and columns subjected to impact is presented. The model is developed in the framework of a flexibility fibre element formulation that ignores the shear effect at material level. However, a simple
shear cap is introduced at section level to take account of possible shear failure. The effect of strain rate at the fibre level is taken into account by using the dynamic increase factor (DIF) concept for steel and concrete. The capability of the formulation for estimating the element response history is demonstrated by some numerical examples and it is shown that the developed 1D element has the potential to be used for dynamic analysis of large framed structures subjected to impact of air blast and rigid objects.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001376298
|
oai_dc
|
Strength and chloride penetration of Portland cement mortar containing palm oil fuel ash and ground river sand
|
Strength and chloride penetration of Portland cement mortar containing palm oil fuel ash and ground river sand
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Sumrerng Rukzon(Khon Kaen University); Prinya Chindaprasirt(Khon Kaen University)"
] |
This paper presents a study of the strength and chloride penetration of blended Portland cement mortar containing ground palm oil fuel ash (POA) and ground river sand (GS). Ordinary Portland cement (OPC) was partially replaced with POA and GS. Compressive strength, rapid chloride penetration
test (RCPT) and chloride penetration depth of mortars were determined. The GS only asserted the packing effect and its incorporation reduced the strength and the resistance to chloride penetration of mortar. The POA asserted both packing and pozzolanic effects. The use of the blend of equal portion of POA and GS also produced high strength mortars, save cost and excellent resistance to chloride penetration owing to the synergic effect of the blend of POA and GS. For chloride depth, the mathematical model correlates
well with the experimental results. The computer graphics of chloride depth of the ternary blended mortars are also constructed and can be used to aid the understanding and the proportioning of the blended system.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001376300
|
oai_dc
|
Simulation of chloride penetration into concrete structures subjected to both cyclic flexural loads and tidal effects
|
Simulation of chloride penetration into concrete structures subjected to both cyclic flexural loads and tidal effects
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Tran Van Mien(Chulalongkorn University); Boonchai Stitmannaithum(Chulalongkorn University); Toyoharu Nawa(Hokkaido University)"
] |
Chloride induced corrosion is a concern that governs the durability of concrete structures in marine environments, especially in tidal environments. During the service lives of concrete structures, internal cracks in the concrete cover may appear due to imposed loads, accelerating chloride penetration
because of the simultaneous action of environmental and service structural loads. This paper investigated the effects of cyclic flexural loads on chloride diffusion characteristics of plain concretes, and proposed a model to predict the chloride penetration into plain concretes subjected to both tidal environments and different cyclic flexural load levels. Further, a new experiment was performed to verify the model. Results of the model using Finite Difference Method (FDM) showed that the durability of concretes in tidal
environments was reduced as cyclic flexural load levels, SR, increased, and the modeling results fitted well with the experimental results.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356104
|
oai_dc
|
A new strength model for the high-performance fiber reinforced concrete
|
A new strength model for the high-performance fiber reinforced concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"P. Ramadoss(Anna University); K. Nagamani(Anna University)"
] |
Steel fiber reinforced concrete is increasingly used day by day in various structural applications.
An extensive experimentation was carried out with w/cm ratio ranging from 0.25 to 0.40, and fiber content ranging from zero to1.5 percent by volume with an aspect ratio of 80 and silica fume replacement at 5%, 10% and 15%. The influence of steel fiber content in terms of fiber reinforcing index on the compressive strength of high-performance fiber reinforced concrete (HPFRC) with strength ranging from 45 85 MPa is presented. Based on the test results, equations are proposed using statistical methods to predict 28-day
strength of HPFRC effecting the fiber addition in terms of fiber reinforcing index. A strength model proposed by modifying the mix design procedure, can utilize the optimum water content and efficiency factor of pozzolan. To examine the validity of the proposed strength model, the experimental results were compared with the values predicted by the model and the absolute variation obtained was within 5 percent.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356283
|
oai_dc
|
Mathematical model of strength and porosity of ternary blend Portland rice husk ash and fly ash cement mortar
|
Mathematical model of strength and porosity of ternary blend Portland rice husk ash and fly ash cement mortar
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Sumrerng Rukzon(Khon Kaen University); Prinya Chindaprasirt(Khon Kaen University)"
] |
This paper presents a mathematical model for strength and porosity of mortars made with ternary blends of ordinary Portland cement (OPC), ground rice husk ash (RHA) and classified fly ash (FA). The mortar mixtures were made with Portland cement Type I containing 0-40% FA and RHA. FA and RHA with 1-3% by weight retained on a sieve No. 325 were used. Compressive strength and porosity of the blended cement mortar at the age of 7, 28 and 90 days were determined. The use of ternary blended cements of RHA and FA produced mixes with good strength and low porosity of mortar.
A mathematical analysis and two–parameter polynomial model were presented for the strength and porosity estimation with FA and RHA contents as parameters. The computer graphics of strength and porosity of the ternary blend were also constructed to aid the understanding and the proportioning of the blended system.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356241
|
oai_dc
|
A methodology for spatial distribution of grain and voids in self compacting concrete using digital image processing methods
|
A methodology for spatial distribution of grain and voids in self compacting concrete using digital image processing methods
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Okan Önal(Dokuz Eylul University); Gürkan Özden(Dokuz Eylul University); Burak Felekog˘ lu(Dokuz Eylul University)"
] |
Digital image processing algorithms for the analysis and characterization of grains and voids in cemented materials were developed using toolbox functions of a mathematical software package. Utilization of grayscale, color and watershed segmentation algorithms and their performances were demonstrated on artificially prepared self-compacting concrete (SCC) samples. It has been found that color segmentation was more advantageous over the gray scale segmentation for the detection of voids whereas the latter
method provided satisfying results for the aggregate grains due to the sharp contrast between their colors and the cohesive matrix. The watershed segmentation method, on the other hand, appeared to be very efficient while separating touching objects in digital images.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356094
|
oai_dc
|
Prediction of workability of concrete using design of experiments for mixtures
|
Prediction of workability of concrete using design of experiments for mixtures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"I-Cheng Yeh(Chung Hua University)"
] |
In this study, the effects and the interactions of water content, SP-binder ratio, and waterbinder ratio on the workability performance of concrete were investigated. The experiments were designed based on flatted simplex-centroid experiment design modified from standard simplex-centroid one. The
data gotten from the design was used to build the concrete slump model using neural networks. Research reported in this paper shows that a small number of slump experiments can be performed and meaningful data obtained with the experiment design. Such data would be suitable for building slump model using neural networks. The trained network can be satisfactorily used for exploring the effects of the components and their interactions on the workability of concrete. It has found that a high water content and a high SP/b ratio is essential for high workability, but achieving this by increasing these parameters will not in itself guarantee high workability. The w/b played a very important role in producing workability and had rather profound effects; however, the medium value about 0.4 is the best w/b to reach high slump without too much effort on trying to find the appropriate water content and SP/b.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356126
|
oai_dc
|
Identification of reinforced concrete beam-like structures subjected to distributed damage from experimental static measurements
|
Identification of reinforced concrete beam-like structures subjected to distributed damage from experimental static measurements
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"N. Lakshmanan(CSIR); B. K. Raghuprasad(Indian Institute of Science); K. Muthumani(CSIR); N. Gopalakrishnan(CSIR); D. Basu(CSIR)"
] |
Structural health monitoring of existing infrastructure is currently an important field of research, where elaborate experimental programs and advanced analytical methods are used in identifying the current state of health of critical and important structures. The paper outlines two methods of system
identification of beam-like reinforced concrete structures representing bridges, through static measurements, in a distributed damage scenario. The first one is similar to the stiffness method, re-cast and the second one to flexibility method. A least square error (LSE) based solution method is used for the estimation of flexural rigidities and damages of simply supported, cantilever and propped cantilever beam from the measured deformation values. The performance of both methods in the presence of measurement
errors is demonstrated. An experiment on an un-symmetrically damaged simply supported reinforced concrete beam is used to validate the developed method. A method for damage prognosis is demonstrated using a generalized, indeterminate, propped cantilever beam.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356496
|
oai_dc
|
Compaction process in concrete during missile impact: a DEM analysis
|
Compaction process in concrete during missile impact: a DEM analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wenjie Shiu(Université Joseph Fourier); Laurent Daudeville(Université Joseph Fourier); Frédéric-Victor Donzé(Université Joseph Fourier)"
] |
A local behavior law, which includes elasticity, plasticity and damage, is developed in a three dimensional numerical model for concrete. The model is based on the Discrete Element Method (DEM) and the computational implementation has been carried out in the numerical Code YADE. This model was used to study the response of a concrete slab impacted by a rigid missile, and focuses on the extension of the compacted zone. To do so, the model was first used to simulate compression and hydrostatic tests.
Once the local constitutive law parameters of the discrete element model were calibrated, the numerical model simulated the impact of a rigid missile used as a reference case to be compared to an experimental data set. From this reference case, simulations were carried out to show the importance of compaction during an impact and how it expands depending on the different impact conditions. Moreover, the numerical results were compared to empirical predictive formulae for penetration and perforation cases,
demonstrating the importance of taking into account the local compaction process in the local interaction law between discrete elements.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356481
|
oai_dc
|
Numerical analysis of spalling of concrete cover at high temperature
|
Numerical analysis of spalling of concrete cover at high temperature
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Joško Ožbolt(Institute for Construction Materials Stuttgart); Goran Periškic(Institute for Construction Materials Stuttgart); Hans-Wolf Reinhardt(Institute for Construction Materials Stuttgart); Rolf Eligehausen(Institute for Construction Materials Stuttgart)"
] |
In the present paper a 3D thermo-hygro-mechanical model for concrete is used to study explosive spalling of concrete cover at high temperature. For a given boundary conditions the distribution of moisture, pore pressure, temperature, stresses and strains are calculated by employing a threedimensional transient finite element analysis. The used thermo-hygro-mechanical model accounts for the interaction between hygral and thermal properties of concrete. Moreover, these properties are coupled with
the mechanical properties of concrete, i.e., it is assumed that the mechanical properties (damage) have an effect on distribution of moisture (pore pressure) and temperature. Stresses in concrete are calculated by employing temperature dependent microplane model. To study explosive spalling of concrete cover, a 3D finite element analysis of a concrete slab, which was locally exposed to high temperature, is performed. It is shown that relatively high pore pressure in concrete can cause explosive spalling. The numerical results indicate that the governing parameter that controls spalling is permeability of concrete. It is also shown that possible buckling of a concrete layer in the spalling zone increases the risk for explosive spalling.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356582
|
oai_dc
|
Anisotropic damage modelling of biaxial behaviour and rupture of concrete structures
|
Anisotropic damage modelling of biaxial behaviour and rupture of concrete structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F. Ragueneau(LMT-Cachan); R. Desmorat(LMT-Cachan); F. Gatuingt(LMT-Cachan)"
] |
This paper deals with damage induced anisotropy modeling for concrete-like materials. A thermodynamics based constitutive relationship is presented coupling anisotropic damage and elasticity, the main idea of the model being that damage anisotropy is responsible for the dissymmetry tension/compression.
A strain written damage criterion is considered (Mazars criterion extended to anisotropy in the initial model). The biaxial behavior of a family of anisotropic damage model is analyzed through the effects of yield surface modifications by the introduction of new equivalent strains.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356547
|
oai_dc
|
A parametric study of the meso-scale modelling of concrete subjected to cyclic compression
|
A parametric study of the meso-scale modelling of concrete subjected to cyclic compression
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rasmus Rempling(Chalmers University of Technology); Peter Grassl(University of Glasgow)"
] |
The present parametric study deals with the meso-scale modelling of concrete subjected to cyclic compression, which exhibits hysteresis loops during unloading and reloading. Concrete is idealised as a two-dimensional three-phase composite made of aggregates, mortar and interfacial transition zones (ITZs). The meso-scale modelling approach relies on the hypothesis that the hysteresis loops are caused by localised permanent displacements, which result in nonlinear fracture processes during unloading and
reloading. A parametric study is carried out to investigate how aggregate density and size, amount of permanent displacements in the ITZ and the mortar, and the ITZ strength influence the hysteresis loops obtained with the meso-scale modelling approach.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356537
|
oai_dc
|
Damage prediction in the vicinity of an impact on a concrete structure: a combined FEM/DEM approach
|
Damage prediction in the vicinity of an impact on a concrete structure: a combined FEM/DEM approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jessica Rousseau(Universit Joseph Fourier); Emmanuel Frangin(Universit Joseph Fourier); Philippe Marin(Universit Joseph Fourier); Laurent Daudeville(Université Joseph Fourier)"
] |
This article focuses on concrete structures submitted to impact loading and is aimed at predicting local damage in the vicinity of an impact zone as well as the global response of the structure. The Discrete Element Method (DEM) seems particularly well suited in this context for modeling fractures. An
identification process of DEM material parameters from macroscopic data (Young’s modulus, compressive and tensile strength, fracture energy, etc.) will first be presented for the purpose of enhancing reproducibility and reliability of the simulation results with DE samples of various sizes. The modeling of a large structure by means of DEM may lead to prohibitive computation times. A refined discretization becomes required in the vicinity of the impact, while the structure may be modeled using a coarse FE mesh further from the impact area, where the material behaves elastically. A coupled discrete-finite element approach is thus proposed: the impact zone is modeled by means of DE and elastic FE are used on the rest of the
structure. The proposed approach is then applied to a rock impact on a concrete slab in order to validate the coupled method and compare computation times.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356564
|
oai_dc
|
Cohesive modeling of dynamic fracture in reinforced concrete
|
Cohesive modeling of dynamic fracture in reinforced concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rena C. Yu(Universidad de Castilla-La Mancha); Xiaoxin Zhang(Universidad de Castilla-La Mancha,); Gonzalo Ruiz(Universidad de Castilla-La Mancha)"
] |
In this work we simulate explicitly the dynamic fracture propagation in reinforced concrete beams. In particular, adopting cohesive theories of fracture with the direct simulation of fracture and fragmentation, we
represent the concrete matrix, the steel re-bars and the interface between the two materials explicitly.
Therefore the crack nucleation within the concrete matrix, through and along the re-bars, the deterioration of the concrete-steel interface are modeled explicitly. The numerical simulations are validated against experiments of three-point-bend beams loaded dynamically under various strain rates. By extracting the crack-tip positions and the crack mouth opening displacement history, a two-stage crack propagation, marked by the attainment of the peak load, is observed. The first stage corresponds to the stable crack advance, the second one, the unstable collapse of the beam.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356577
|
oai_dc
|
A mixture theory based method for three-dimensional modeling of reinforced concrete members with embedded crack finite elements
|
A mixture theory based method for three-dimensional modeling of reinforced concrete members with embedded crack finite elements
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"O. L. Manzoli(Sao Paulo State University (UNESP)); J. Oliver(Technical University of Catalonia (UPC)); A. E. Huespe(CIMEC/Intec); G. Diaz(Technical University of Catalonia (UPC))"
] |
The paper presents a methodology to model three-dimensional reinforced concrete members by means of embedded discontinuity elements based on the Continuum Strong Discontinuous Approach (CSDA). Mixture theory concepts are used to model reinforced concrete as a 3D composite material
constituted of concrete with long fibers (rebars) bundles oriented in different directions embedded in it.
The effects of the rebars are modeled by phenomenological constitutive models devised to reproduce the axial non-linear behavior, as well as the bond-slip and dowel action. The paper presents the constitutive
models assumed for the components and the compatibility conditions chosen to constitute the composite.
Numerical analyses of existing experimental reinforced concrete members are presented, illustrating the applicability of the proposed methodology.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356488
|
oai_dc
|
A multiscale creep model as basis for simulation of early-age concrete behavior
|
A multiscale creep model as basis for simulation of early-age concrete behavior
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ch. Pichler(Vienna University of Technology); R. Lackner(Technical University of Munich)"
] |
A previously published multiscale model for early-age cement-based materials [Pichler, et al. 2007. “A multiscale micromechanics model for the autogenous-shrinkage deformation of early-age cement-based materials.” Engineering Fracture Mechanics, 74, 34-58] is extended towards upscaling of viscoelastic properties. The obtained model links macroscopic behavior, i.e., creep compliance of concrete samples, to the composition of concrete at finer scales and the (supposedly) intrinsic material properties of distinct phases at these scales. Whereas finer-scale composition (and its history) is accessible through recently developed hydration models for the main clinker phases in ordinary Portland cement (OPC), viscous properties of the creep active constituent at finer scales, i.e., calcium-silicate-hydrates (CSH) are identified
from macroscopic creep tests using the proposed multiscale model. The proposed multiscale model is assessed by different concrete creep tests reported in the open literature. Moreover, the model prediction is compared to a commonly used macroscopic creep model, the so-called B3 model.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356558
|
oai_dc
|
Extraction of a crack opening from a continuous approach using regularized damage models
|
Extraction of a crack opening from a continuous approach using regularized damage models
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Frédéric Dufour(Institut GeM, Ecole Centrale Nantes); Gilles Pijaudier-Cabot(Université de Pau et des Pays de l’Adour); Marta Choinska(Université de Nantes); Antonio Huerta(Politècnica de Catalunya)"
] |
Crack opening governs many transfer properties that play a pivotal role in durability analyses. Instead of trying to combine continuum and discrete models in computational analyses, it would be attractive to derive from the continuum approach an estimate of crack opening, without considering the
explicit description of a discontinuous displacement field in the computational model. This is the prime objective of this contribution. The derivation is based on the comparison between two continuous variables: the distribution if the effective non local strain that controls damage and an analytical distribution of the effective non local variable that derives from a strong discontinuity analysis. Close to complete failure, these distributions should be very close to each other. Their comparison provides two quantities: the displacement jump across the crack [U] and the distance between the two profiles. This
distance is an error indicator defining how close the damage distribution is from that corresponding to a crack surrounded by a fracture process zone. It may subsequently serve in continuous/discrete models in order to define the threshold below which the continuum approach is close enough to the discrete one in order to switch descriptions. The estimation of the crack opening is illustrated on a one-dimensional example and the error between the profiles issued from discontinuous and FE analyses is found to be of a
few percents close to complete failure.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356383
|
oai_dc
|
Characteristic features of concrete behaviour: Implications for the development of an engineering finite-element tool
|
Characteristic features of concrete behaviour: Implications for the development of an engineering finite-element tool
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Michael D. Kotsovos(National Technical University of Athens); Demetrios M. Cotsovos(Imperial College); Milija N. Pavlovic(Imperial College)"
] |
The present article summarises the fundamental characteristics of concrete behaviour which underlie the formulation of an engineering finite element model capable of realistically predicting the behaviour of (plain or reinforced) concrete structural forms in a wide range of problems ranging from static to impact loading without the need of any kind of re-calibration. The already published evidence supporting the proposed formulation is complemented by four additional typical case studies presented herein; for each case, a comparative study is carried out between numerical predictions and the experimental data which reveals good agreement. Such evidence validates the material characteristics upon which the FE model’s formulation is based and provides an alternative explanation regarding the behaviour of structural concrete and how it should be modelled which contradicts the presently (widely) accepted assumptions adopted in the majority of FE models used to predict the behaviour of concrete.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356371
|
oai_dc
|
A total strain-based hysteretic material model for reinforced concrete structures: theory and verifications
|
A total strain-based hysteretic material model for reinforced concrete structures: theory and verifications
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Gun Jin Yun(The University of Akron); Thomas G. Harmon(Washington University); Shirley J. Dyke(Washington University); Migeum So(Washington University)"
] |
In this paper, a total strain-based hysteretic material model based on MCFT is proposed for non-linear finite element analysis of reinforced concrete structures. Although many concrete models have been proposed for simulating behavior of structures under cyclic loading conditions, accurate simulations remain challenging due to uncertainties in materials, pitfalls of crude assumptions of existing models, and limited understanding of failure mechanisms. The proposed model is equipped with a fully generalized
hysteresis rule and is formulated for 2D plane stress non-linear finite element analysis. The proposed model has been formulated in a tangent stiffness-based finite element scheme so that it can be used for most general finite element analysis packages. Moreover, it eliminates the need to check that tensile stresses can be transmitted across a crack. The tension stiffening model is a function of the bar orientation and any orientation can be accommodated. The proposed model has been verified with a series of
experimental results of 2D RC planar panels. This study also demonstrates how parameters of the proposed model associated with cyclic damage modeling influences the pinched cyclic shear behavior.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356427
|
oai_dc
|
A methodology for remaining life prediction of concrete structural components accounting for tension softening effect
|
A methodology for remaining life prediction of concrete structural components accounting for tension softening effect
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Rama Chandra Murthy(CSIR); Smitha Gopinath(CSIR); G.S. Palani(CSIR); Nagesh R. Iyer(CSIR)"
] |
This paper presents methodologies for remaining life prediction of plain concrete structural components considering tension softening effect. Non-linear fracture mechanics principles (NLFM) have been used for crack growth analysis and remaining life prediction. Various tension softening models such
as linear, bi-linear, tri-linear, exponential and power curve have been presented with appropriate expressions. A methodology to account for tension softening effects in the computation of SIF and remaining life prediction of concrete structural components has been presented. The tension softening effects has been represented by using any one of the models mentioned above. Numerical studies have been conducted on three point bending concrete structural component under constant amplitude loading. Remaining life has been predicted for different loading cases and for various tension softening models. The predicted values have been compared with the corresponding experimental observations. It is observed that the predicted
life using bi-linear model and power curve model is in close agreement with the experimental values.
Parametric studies on remaining life prediction have also been conducted by using modified bilinear model. A suitable value for constant ‘k’ of modified bilinear model is suggested based on parametric studies.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356343
|
oai_dc
|
Numerical modeling of heterogeneous material
|
Numerical modeling of heterogeneous material
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"W. Puatatsananon(Ubon Ratchathani University); V. Saouma(University of Colorado at Boulder); V. Slowik(Wirtschaft and Kultur Leipzig (FH))"
] |
Increasingly numerical (finite element) modeling of concrete hinges on our ability to develop a representative volume element with all its heterogeneity properly discretized. Yet, despite all the sophistication of the ensuing numerical models, the initial discretization has been for the most part
simplistic. Whenever the heterogeneity of the concrete is to be accounted for, a mesh is often manually crafted through the arbitrary inclusion of the particles (aggregates and/or voids) in an ad-hoc manner. This paper develops a mathematical strategy to precisely address this limitation. Algorithms for the random generation and placement of elliptical (2D) or ellipsoid (3D) inclusions, with possibly radiating cracks, in a virtual concrete model are presented. Collision detection algorithms are extensively used.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356353
|
oai_dc
|
Hypoelastic modeling of reinforced concrete walls
|
Hypoelastic modeling of reinforced concrete walls
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mohsen A. Shayanfar(Iran University of Science and Technology); Amir Safiey(Moshanir Consultants Engineering Inc.)"
] |
This paper presents a new hypoelasticity model which was implemented in a nonlinear finite element formulation to analyze reinforced concrete (RC) structures. The model includes a new hypoelasticity constitutive relationship utilizing the rotation of material axis through successive iterations. The model can account for high nonlinearity of the stress-strain behavior of the concrete in the pre-peak regime, the softening behavior of the concrete in the post-peak regime and the irrecoverable volume dilatation at high levels of compressive load. This research introduces the modified version of the common application orthotropic stress-strain relation developed by Darwin and Pecknold. It is endeavored not to violate the principal of “simplicity” by improvement of the “capability”. The results of analyses of experimental
reinforced concrete walls are presented to confirm the abilities of the proposed relationships.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356311
|
oai_dc
|
A computational platform for seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars
|
A computational platform for seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"T.H. Kim(Daewoo Institute of Construction Technology); J.G. Park(성균관대학교); Y.J. Kim(Daewoo Institute of Construction Technology); H. M. Shin(Sungkyunkwan University)"
] |
This paper presents a nonlinear finite element analysis procedure for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars. A computer program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) is used to analyze reinforced concrete structures; this program was also used in our study. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used account for material nonlinearity of reinforced concrete. The smeared crack approach was incorporated. To represent the interaction between unbonded reinforcing or prestressing bar and concrete, an unbonded reinforcing or
prestressing bar element based on the finite element method was developed in this study. The proposed numerical method for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars is verified by comparison of its results with reliable experimental results.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356296
|
oai_dc
|
Strategies for finding the adequate air void threshold value in computer assisted determination of air void characteristics in hardened concrete
|
Strategies for finding the adequate air void threshold value in computer assisted determination of air void characteristics in hardened concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"David Duh(University of Ljubljana); Roko Žarnic(University of Ljubljana); Violeta Bokan-Bosiljkov(University of Ljubljana)"
] |
The microscopic determination of air void characteristics in hardened concrete, defined in EN 480-11 as the linear-traverse method, is an extremely time-consuming and tedious task. Over past decades, several researchers have proposed relatively expensive mechanical automated systems which could replace the human operator in this procedure. Recently, the appearance of new high-resolution flatbed scanners has made it possible for the procedure to be automated in a fully-computerized and thus cost-effective
way. The results of our work indicate the high sensitivity of such image analysis automated systems firstly to the quality of sample surface preparation, secondly to the selection of the air void threshold value, and
finally to the selection of the probe system. However, it can be concluded that in case of careful validation and the use of the approach which is proposed in the paper, such automated systems can give very good estimate of the air void system parameters, defined in EN 480-11. The amount of time saved
by using such a procedure is immense, and there is also the possibility of using alternative stereological methods to assess other, perhaps also important, characteristics of air void system in hardened concrete.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356320
|
oai_dc
|
A new approach for nonlinear finite element analysis of reinforced concrete structures with corroded reinforcements
|
A new approach for nonlinear finite element analysis of reinforced concrete structures with corroded reinforcements
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mohsen A. Shayanfar(Iran University of Science and Technology); Amir Safiey(Moshanir Consultants Engineering Inc.)"
] |
A new approach for nonlinear finite element analysis of corroded reinforcements in reinforced concrete (RC) structures is elaborated in the article. An algorithmic procedure for producing the tensionstiffening
curve of RC elements taking into consideration most of effective parameters, e.g.: the rate of steel bar corrosion, bond-slip behavior, concrete cover and amount of reinforcement, is illustrated. This has been established on both experimental and analytical bases. This algorithm is implemented into a nonlinear finite element analysis program. The abilities of the resulted program have been studied by modeling some experimental specimens showing a reasonable agreement between the analytical and experimental findings.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356303
|
oai_dc
|
Deep-beams with indirect supports: numerical modelling and experimental assessment
|
Deep-beams with indirect supports: numerical modelling and experimental assessment
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mário Pimentel(University of Porto); Paulo Cachim(University of Aveiro); Joaquim Figueiras(University of Porto)"
] |
An experimental and numerical research was conducted to gain a deeper insight on the structural behaviour of deep-beams with indirect supports and to assess the size effects in the ultimate state behaviour.
The experimental campaign focused on the influence of the reinforcement tie distribution height on the compression check of the support region and on the benefits of using unbonded prestressing steel. Three reduced scale specimens were tested and used to validate the results obtained with a nonlinear finite element model. As a good agreement could be found between the numerical and the experimental results, the numerical model was then further used to perform simulations in large scale deep-beams, with dimensions similar to the ones to be adopted in a practical case. Two sources of size effects were identified from the simulation results. Both sources are related to the concrete quasi-brittle behaviour and are responsible for increasing failure brittleness with increasing structural size. While in the laboratory models failure occurred both in the experimental tests as well as in the numerical simulations after reinforcement yielding, the numerically analysed large scale models exhibited shear failures with reinforcement still operating in the elastic range.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001356288
|
oai_dc
|
Effect of elevated temperatures on properties and color intensities of fly ash mortar
|
Effect of elevated temperatures on properties and color intensities of fly ash mortar
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Her-Yung Wang(National Kaohsiung University of Applied Sciences)"
] |
This research examines the engineering properties and color intensities of mortar containing different amounts of fly ash (0, 5, 10 and 20%) mixed at different water-to-binder ratios (w/b = 0.23, 0.47 and 0.59) and exposed at different temperatures (T = 25, 100, 200, 400, 600 and 800oC). Results show
that there is greater mass loss on ignition with high w/b and higher temperatures. In addition, the color channel image analyzer (Windows software written in Delphi) is utilized to study the relationship between
the curing temperature and intensity of three primary colors, red, green and blue (RGB), of the fly ash mortar specimens. The results show that the RGB intensities on the specimen surface increases from that at 25oC. The mortar specimen becomes white with increase in w/b but without the addition of fly ash.
Moreover, for mortar specimens with greater content of fly ash, red on the specimen surface has the greatest increase in intensity at elevated temperature. Observation the variations in color on the specimen surface may help estimate the highest elevated temperatures that concrete structures can withstand.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001960846
|
oai_dc
|
Bending and buckling analyses of functionally graded material (FGM) size-dependent nanoscale beams including the thickness stretching effect
|
Bending and buckling analyses of functionally graded material (FGM) size-dependent nanoscale beams including the thickness stretching effect
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Fouzia Larbi Chaht(University of Sidi Bel Abbes); Abdelouahed Tounsi(University of Sidi Bel Abbes); Abdelhakim Kaci(University of Sidi Bel Abbes); Mohammed Sid Ahmed Houari(Université de Sidi Bel Abbes); S. R. Mahmoud(King Abdulaziz University); O. Anwar Bég(Gort Engovation- Propulsion)"
] |
This paper addresses theoretically the bending and buckling behaviors of size-dependent nanobeams made of functionally graded materials (FGMs) including the thickness stretching effect. The size-dependent FGM nanobeam is investigated on the basis of the nonlocal continuum model. The nonlocal elastic behavior is described by the differential constitutive model of Eringen, which enables the present model to become effective in the analysis and design of nanostructures. The present model incorporates the length scale parameter (nonlocal parameter) which can capture the small scale effect, and furthermore accounts for both shear deformation and thickness stretching effects by virtue of a sinusoidal variation of all displacements through the thickness without using shear correction factor. The material properties of FGM nanobeams are assumed to vary through the thickness according to a power law. The governing equations and the related boundary conditions are derived using the principal of minimum total potential energy. A Navier-type solution is developed for simply-supported boundary conditions, and exact expressions are proposed for the deflections and the buckling load. The effects of nonlocal parameter, aspect ratio and various material compositions on the static and stability responses of the FGM nanobeam are discussed in detail. The study is relevant to nanotechnology deployment in for example aircraft structures.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.425
|
kci_detailed_000100.xml
|
||
ART001960847
|
oai_dc
|
Thermal buckling analysis of FG plates resting on elastic foundation based on an efficient and simple trigonometric shear deformation theory
|
Thermal buckling analysis of FG plates resting on elastic foundation based on an efficient and simple trigonometric shear deformation theory
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wafa Tebboune(University of Sidi Bel Abbes); Abdelouahed Tounsi(University of Sidi Bel Abbes); Kouider Halim Benrahou(University of Sidi Bel Abbes); Mohammed Sid Ahmed Houari(Université de Sidi Bel Abbes)"
] |
In this paper, an efficient and simple trigonometric shear deformation theory is presented for thermal buckling analysis of functionally graded plates. It is assumed that the plate is in contact with elastic foundation during deformation. The theory accounts for sinusoidal distribution of transverse shear stress, and satisfies the free transverse shear stress conditions on the top and bottom surfaces of the plate without using shear correction factor. Unlike the conventional trigonometric shear deformation theory, the proposed sinusoidal shear deformation theory contains only four unknowns. It is assumed that the mechanical and thermal non-homogeneous properties of functionally graded plate vary smoothly by distribution of power law across the plate thickness. Using the non-linear strain-displacement relations, the equilibrium and stability equations of plates made of functionally graded materials are derived. The boundary conditions for the plate are assumed to be simply supported on all edges. The elastic foundation is modelled by two-parameters Pasternak model, which is obtained by adding a shear layer to the Winkler model. The effects of thermal loading types and variations of power of functionally graded material, aspect ratio, and thickness ratio on the critical buckling temperature of functionally graded plates are investigated and discussed.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.443
|
kci_detailed_000100.xml
|
||
ART001960848
|
oai_dc
|
Mechanical characteristics of hollow shear connectors under direct shear force
|
Mechanical characteristics of hollow shear connectors under direct shear force
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kojiro Uenaka(Kobe City College of Technology Gakuenhigashimachi); Hiroshi Higashiyama(Kinki University)"
] |
The steel-concrete composite decks have high fatigue durability and deformability in comparison with ordinary RC slabs. Withal, the steel-concrete composite deck is mostly heavier than the RC slabs. We have proposed herein a new type of steel-concrete composite deck which is lighter than the typical steel-concrete composite decks. This can be achieved by arranging hollow sectional members as shear connectors, namely, half-pipe or channel shear connectors. The present study aims to experimentally investigate mechanical characteristics of the half-pipe shear connectors under the direct shear force. The shear bond capacity and deformability of the half-pipe shear connectors are strongly affected by the thickness-to-diameter ratio. Additionally, the shear strengths of the hollow shear connectors (i.e. the half-pipe and the channel shear connectors) are compared. Furthermore, shear capacities of the hollow shear connectors equivalent to headed stud connectors are also discussed.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.467
|
kci_detailed_000100.xml
|
||
ART001960849
|
oai_dc
|
Experimental study on lead extrusion damper and its earthquake mitigation effects for large-span reticulated shell
|
Experimental study on lead extrusion damper and its earthquake mitigation effects for large-span reticulated shell
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M.F. Yang(Southeast University); Z.D. Xu(Southeast University); X.C. Zhang(Southeast University)"
] |
A Lead Extrusion Damper (LED) is experimentally studied under various frequencies and displacement amplitudes. Experimental results show that the force-displacement hysteresis loops of the LED are close to rectangular and the force-velocity hysteresis loops exhibit nonlinear hysteretic characteristic. Also, the LED can provide consistent energy dissipation without any stiffness degradation. Based on the experimental results, a mathematical model is then proposed to describe the effects of frequency and displacement on property of LED. It can be proved from the comparison between experimental and numerical results that the mathematical model can accurately describe the mechanical behavior of LED. Subsequently, the seismic responses of the Schwedler reticulated shell structure with LEDs are analyzed by ANSYS software, in which three different installation forms of LEDs are considered. It can be concluded that the LED can effectively reduce the displacement and acceleration responses of this type of structures.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.481
|
kci_detailed_000100.xml
|
||
ART001960850
|
oai_dc
|
Shear resistance characteristic and ductility of Y-type perfobond rib shear connector
|
Shear resistance characteristic and ductility of Y-type perfobond rib shear connector
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"김상효(연세대학교); 박세준(연세대학교); 허원호(연세대학교); 정치영(부산대학교)"
] |
This study evaluates behavior of the Y-type perfobond rib shear connector proposed by Kim et al. (2013). In addition, an empirical shear resistance formula is developed based on push-out tests. Various types of the proposed Y-type perfobond rib shear connectors are examined to evaluate the effects of design variables such as concrete strength, number of transverse rebars, and thickness of rib. It is verified that higher concrete strength increases shear resistance but decreases ductility. Placing transverse rebars significantly increases both the shear resistance and ductility. As the thickness of the ribs increases, the shear resistance increases but the ductility decreases. The experimental results indicate that a Y-type perfobond rib shear connector has higher shear resistance and ductility than the conventional stud shear connector. The effects of the end bearing resistance, resistance by transverse rebars, concrete dowel resistance by holes, and concrete dowel resistance by Y-shape ribs on the shear resistance are estimated empirically based on the push-out test results and the additional push-out test results by Kim et al. (2013). An empirical shear resistance formula is suggested to estimate the shear resistance of a Y-type perfobond shear connector for design purposes. The newly developed shear resistance formula is in reasonable agreement with the experimental results because the average ratio of measured shear resistance to estimated shear resistance is 1.024.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.497
|
kci_detailed_000100.xml
|
||
ART001960851
|
oai_dc
|
Statistical-based evaluation of design codes for circular concrete-filled steel tube columns
|
Statistical-based evaluation of design codes for circular concrete-filled steel tube columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Na Li(School of Civil Engineering); Yi-Yan Lu(Wuhan University); Shan Li(Wuhan University); Hong-Jun Liang(Wuhan University)"
] |
This study addresses the load capacity prediction of circular concrete-filled steel tube (CFST) columns under axial compression using current design codes. Design methods given in the Chinese code CECS 28:2012 (2012), American code AISC 360-10 (2010) and EC4 (2004) are presented and described briefly. A wide range of experimental data of 353 CFST columns is used to evaluate the applicability of CECS 28:2012 in calculating the strength of circular CFST columns. AISC 360-10 and EC4 (2004) are also compared with the test results. The comparisons indicate that all three codes give conservative predictions for both short and long CFST columns. The effects of concrete strength, steel strength and diameter-to-thickness ratio on the accuracy of prediction according to CECS 28:2012 are discussed, which indicate a possibility of extending the limitations on the material strengths and diameter-to-thickness ratio to higher values. A revised equation for slenderness reduction factor in CECS 28:2012 is given.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.519
|
kci_detailed_000100.xml
|
||
ART001960838
|
oai_dc
|
Subspace search mechanism and cuckoo search algorithm for size optimization of space trusses
|
Subspace search mechanism and cuckoo search algorithm for size optimization of space trusses
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Kaveh(Iran University of Science and Technology); T. Bakhshpoori(Iran University of Science and Technolog)"
] |
This study presents a strategy so-called Subspace Search Mechanism (SSM) for reducing the computational time for convergence of population based metaheusristic algorithms. The selected metaheuristic for this study is the Cuckoo Search algorithm (CS) dealing with size optimization of trusses. The complexity of structural optimization problems can be partially due to the presence of high-dimensional design variables. SSM approach aims to reduce dimension of the problem. Design variables are categorized to predefined groups (subspaces). SSM focuses on the multiple use of the metaheuristic at hand for each subspace. Optimizer updates the design variables for each subspace independently. Updating rules require candidate designs evaluation. Each candidate design is the assemblage of responsible set of design variables that define the subspace of interest. SSM is incorporated to the Cuckoo Search algorithm for size optimizing of three small, moderate and large space trusses. Optimization results indicate that SSM enables the CS to work with less number of population (42%), as a result reducing the time of convergence, in exchange for some accuracy (1.5%). It is shown that the loss of accuracy can be lessened with increasing the order of complexity. This suggests its applicability to other algorithms and other complex finite element-based engineering design problems.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.289
|
kci_detailed_000100.xml
|
||
ART001960839
|
oai_dc
|
Optimum design of laterally-supported castellated beams using CBO algorithm
|
Optimum design of laterally-supported castellated beams using CBO algorithm
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Kaveh(Iran University of Science and Technology); F. Shokohi(Iran University of Science and Technolog)"
] |
In this study, two common types of laterally supported castellated beams are considered as design problems: beams with hexagonal openings and beams with circular openings. The main goal of manufacturing these beams is to increase the moment of inertia and section modulus, which results in greater strength and rigidity. These types of open-web beams have found widespread use, primarily in buildings, because of great savings in materials and construction costs. Hence, the minimum cost is taken as the design objective function and the Colliding Bodies Optimization (CBO) method is utilized for obtaining the solution of the design problem. The design methods used in this study are consistent with BS5950 Part 1 and Part 3, and Euro Code 3. A number of design examples are considered to optimize by CBO algorithm. Comparison of the optimal solution of the CBO algorithm with those of the Enhanced Charged System Search (ECSS) method demonstrate the capability of CBO in solving the present type of design problem. It is also observed that optimization results obtained by the CBO algorithm for three design examples have less cost in comparison to the results of the ECSS algorithm. From the results obtained in this paper, it can be concluded that the use of beam with hexagonal opening requires smaller amount of steel material and it is superior to the cellular beam from the cost point of view.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.305
|
kci_detailed_000100.xml
|
||
ART001960840
|
oai_dc
|
Elastic rotational restraint of web-post in cellular beams with sinusoidal openings
|
Elastic rotational restraint of web-post in cellular beams with sinusoidal openings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Sébastien Durif(Clermont Université); Abdelhamid Bouchaïr(Clermont Université); Claude Bacconnet(Clermont Université)"
] |
Experimental tests on cellular beams with sinusoidal openings showed two main failure modes around the openings. They concern the formation of four plastic hinges and the local instability of the sinusoidal part of the opening. In parallel, numerical analysis of the sinusoidal part of the opening revealed the existence of an elastic rotational restraint between the intermediate web-post and the adjacent opening panel. The aim of the present study is to present an approach to quantify this rotational restraint. Through the response surface method, a mathematical model is proposed. It shows a great ability to predict the rotational restraint value as a function of the geometrical parameters of the opening. This model can be used to perform an extensive study with various geometrical configurations of beams with the aim to develop a reliable and realistic analytical model predicting the resistance of the sinusoidal openings.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.325
|
kci_detailed_000100.xml
|
||
ART001960841
|
oai_dc
|
Effect of some welding parameters on nugget size in electrical resistance spot welding
|
Effect of some welding parameters on nugget size in electrical resistance spot welding
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ömer Savaş(Yildiz Technical University)"
] |
In this study, the effects of weld parameters on nugget size and tensile-shear strength of welding joint in electrical resistance spot welding of galvanized DP 600 steel sheets having 1.2 mm were investigated. Taguchi design method has been employed to examine the effects of five parameters of welding current, electrode pressure, welding time, clamping time and holding time by using the L27 (53) orthogonal array. Results showed that the most effective parameters on tensile shear strength and the nugget size ratio (hn/dn) were found as welding current and welding time, whereas electrode pressure, clamping time and holding time were less effective factors. Max. 545 MPa strength was obtained through proposed optimum conditions by Taguchi technique.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.345
|
kci_detailed_000100.xml
|
||
ART001960842
|
oai_dc
|
Recommended properties of elastic wearing surfaces on orthotrotropic steel decks
|
Recommended properties of elastic wearing surfaces on orthotrotropic steel decks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Abdullah Fettahoglu(Yildiz Technical University)"
] |
Orthotropic decks composed of deck plate, ribs, cross beams and wearing surface are frequently used in industry to span long distances due to their light structures and load carrying capacities. As a result they are broadly preferred in industry and there are a lot of bridges of this type exist in the world. Nevertheless, some of them cannot sustain the anticipated service life and damages in form of cracks develop in steel components and wearing surface. Main reason to these damages is seen as the repetitive wheel loads, namely the fatigue loading. Solutions to this problem could be divided into two categories: qualitative and quantitative. Qualitative solutions may be new design methodologies or innovative materials, whereas quantitative solution should be arranging dimensions of deck structure in order to resist wheel loads till the end of service life. Wearing surface on deck plate plays a very important role to avoid or mitigate these damages, since it disperses the load coming on deck structure and increases the bending stiffness of deck plate by forming a composite structure together with it. In this study the effect of Elastic moduli, Poisson ratio and thickness of wearing surface on the stresses emerged in steel deck and wearing surface itself is investigated using a FE-model developed to analyze orthotropic steel bridges.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.357
|
kci_detailed_000100.xml
|
||
ART001960843
|
oai_dc
|
Non-uniform shrinkage in simply-supported composite steel-concrete slabs
|
Non-uniform shrinkage in simply-supported composite steel-concrete slabs
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Safat Al-Deen(UNSW Canberra); Gianluca Ranzi(The University of Sydney); Brian Uy(School of Civil and Environmental Engineering, The University of New South Wales)"
] |
This paper presents the results of four long-term experiments carried out to investigate the time-dependent behaviour of composite floor slabs with particular attention devoted to the development of non-uniform shrinkage through the slab thickness. This is produced by the presence of the steel deck which prevents moisture egress to occur from the underside of the slab. To observe the influence of different drying conditions on the development of shrinkage, the four 3.3 m long specimens consisted of two composite slabs cast on Stramit Condeck HPⓡ steel deck and two reinforced concrete slabs, with the latter ones having both faces exposed for drying. During the long-term tests, the samples were maintained in a simply-supported configuration subjected to their own self-weight, creep and shrinkage for four months. Separate concrete samples were prepared and used to measure the development of shrinkage through the slab thickness over time for different drying conditions. A theoretical model was used to predict the time-dependent behaviour of the composite and reinforced concrete slabs. This approach was able to account for the occurrence of non-uniform shrinkage and comparisons between numerical results and experimental measurements showed good agreement. This work highlights the importance of considering the shrinkage gradient in predicting shrinkage deformations of composite slabs. Further comparisons with experimental results are required to properly validate the adequacy of the proposed approach for its use in routine design.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.375
|
kci_detailed_000100.xml
|
||
ART001960844
|
oai_dc
|
Vibration analysis of functionally graded material (FGM) grid systems
|
Vibration analysis of functionally graded material (FGM) grid systems
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kutlu Darılmaz(İstanbul Technical University)"
] |
The paper considers the free vibration analysis of FGM grid systems. Up to now, very little work has been done on this type of system and the paper aspires to fill this gap. Based on the hybrid-stress finite element formulation free vibration solutions for FGM grid systems of various aspect ratios, different types of gradations functions, and support conditions are determined. The tabulation of these results, not available thus far, should be useful to designers and researchers who may use them.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.395
|
kci_detailed_000100.xml
|
||
ART001960845
|
oai_dc
|
A new simple shear and normal deformations theory for functionally graded beams
|
A new simple shear and normal deformations theory for functionally graded beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mohamed Bourada(University of Sidi Bel Abbes); Abdelouahed Tounsi(University of Sidi Bel Abbes); Abdelhakim Kaci(University of Sidi Bel Abbes); Mohammed Sid Ahmed Houari(Université de Sidi Bel Abbes)"
] |
In the present work, a simple and refined trigonometric higher-order beam theory is developed for bending and vibration of functionally graded beams. The beauty of this theory is that, in addition to modeling the displacement field with only 3 unknowns as in Timoshenko beam theory, the thickness stretching effect (εz= 0) is also included in the present theory. Thus, the present refined beam theory has fewer number of unknowns and equations of motion than the other shear and normal deformations theories, and it considers also the transverse shear deformation effects without requiring shear correction factors. The neutral surface position for such beams in which the material properties vary in the thickness direction is determined. Based on the present refined trigonometric higher-order beam theory and the neutral surface concept, the equations of motion are derived from Hamilton's principle. Numerical results of the present theory are compared with other theories to show the effect of the inclusion of transverse normal strain on the deflections and stresses.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.2.409
|
kci_detailed_000100.xml
|
||
ART001991710
|
oai_dc
|
Modeling and simulation of partially delaminated composite beams
|
Modeling and simulation of partially delaminated composite beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Mahieddine(Khemis Miliana University); M. Ouali(Saad Dahleb University); A. Mazouz(Khemis Miliana University)"
] |
A finite-element model for beams with partially delaminated layers is used to investigate their behavior. In this formulation account is taken of lateral strains and the first-order shear deformation theory is used. Both displacement continuity and force equilibrium conditions are imposed between the regions with and without delamination. Numerical results of the present model are presented and its performance is evaluated for static and dynamic problems.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1119
|
kci_detailed_000100.xml
|
||
ART001991716
|
oai_dc
|
Adopting flexibility of the end-plate connections in steel moment frames
|
Adopting flexibility of the end-plate connections in steel moment frames
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Ghassemieh(University of Tehran); M. Baei(University College Dublin); A. Kari(Qom University of Technology); A. Goudarzi(University of Tehran); D.F. Laefer(University College Dublin)"
] |
The majority of connections in moment resisting frames are considered as being fully-rigid. Consequently, the real behavior of the connection, which has some level of flexibility, is ignored. This may result in inaccurate predictions of structural response. This study investigates the influence of flexibility of the extended end-plate connections in the steel moment frames. This is done at two levels. First, the actual micro-behavior of extended end-plate moment connections is explored with respect to joint flexibility. Then, the macro-behavior of frames with end-plate moment connections is investigated using modal, nonlinear static pushover and incremental dynamic analyses. In all models, the P-Delta effects along with material and geometrical nonlinearities were included in the analyses. Results revealed considerable differences between the behavior of the structural frame with connections modeled as fully-rigid versus those when flexibility was incorporated, specifically difference occurred in the natural periods, strength, and maximum inter-story drift angle.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1215
|
kci_detailed_000100.xml
|
||
ART001991717
|
oai_dc
|
Simulating the construction process of steel-concrete composite bridges
|
Simulating the construction process of steel-concrete composite bridges
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jie Wu(Tongji University); Dan M. Frangopol(Lehigh University); Mohamed Soliman(Lehigh University)"
] |
This paper presents a master-slave constraint method, which may substitute the conventional transformed-section method, to account for the changes in cross-sectional properties of composite members during construction and to investigate the time-dependent performance of steel-concrete composite bridges. The time-dependent effects caused by creep and shrinkage of concrete are considered by combining the age-adjusted effective modulus method and finite element analysis. An efficient computational tool which runs in AutoCAD environment is developed to simulate the construction process of steel-concrete composite bridges. The major highlight of the developed tool consists in a very convenient and user-friendly interface integrated in AutoCAD environment. The accuracy of the proposed method is verified by comparing its results with those provided by using the transformed-section method. Furthermore, the computational efficiency of the developed tool is demonstrated by applying it to a steel-concrete composite bridge.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1239
|
kci_detailed_000100.xml
|
||
ART001991718
|
oai_dc
|
Behavior and design of perforated steel storage rack columns under axial compression
|
Behavior and design of perforated steel storage rack columns under axial compression
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Bassel El Kadi(Fatih University); G. Kiymaz(Antalya International University)"
] |
The present study is focused on the behavior and design of perforated steel storage rack columns under axial compression. These columns may exhibit different types of behavior and levels of strength owing to their peculiar features including their complex cross-section forms and perforations along the member. In the present codes of practice, the design of these columns is carried out using analytical formulas which are supported by experimental tests described in the relevant code document. Recently proposed analytical approaches are used to estimate the load carrying capacity of axially compressed steel storage rack columns. Experimental and numerical studies were carried out to verify the proposed approaches. The experimental study includes compression tests done on members of different lengths, but of the same cross-section. A comparison between the analytical and the experimental results is presented to identify the accuracy of the recently proposed analytical approaches. The proposed approach includes modifications in the Direct Strength Method to include the effects of perforations (the so-called reduced thickness approach). CUFSM and CUTWP software programs are used to calculate the elastic buckling parameters of the studied members. Results from experimental and analytical studies compared very well. This indicates the validity of the recently proposed approaches for predicting the ultimate strength of steel storage rack columns.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1259
|
kci_detailed_000100.xml
|
||
ART001991719
|
oai_dc
|
Study on uplift performance of stud connector in steel-concrete composite structures
|
Study on uplift performance of stud connector in steel-concrete composite structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xiaochen Ju(China Academy of Railway Sciences); Zhibin Zeng(China Academy of Railway Sciences)"
] |
The main role of studs, which act as connectors of the steel-concrete composite structures, is to ensure that the steel and the concrete work together as a whole. The studs in steel-concrete composite structures bear the shearing force in the majority of cases, but in certain locations, such as the mid-span of a simply supported composite beam, the studs bear axial uplift force. The previous studies mainly focused on the shearing performance of the stud by some experimental and theoretical effort. However, rare studies involved the uplift performance of studs. In this paper, the single stud uplift test on 10 composite specimens was performed. Meanwhile, based on the test, numerical analysis was introduced to simulate the concrete damage process due to the stud uplifted from concrete. The static ultimate bearing capacity, under which the stud connector was pulled out from the damaged reinforced concrete, is much larger than the cyclic ultimate bearing capacity, under which the weld joint between stud and steel plate fractured. According to the fatigue test results of 7 specimens, the fatigue S-N curve of the construction detail after minus 2 times standard deviation is logN = 24.011 - 9.171 logΔσ, the fatigue strength corresponding to 2 x 10 6 cycles is 85.33 MPa.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1279
|
kci_detailed_000100.xml
|
||
ART001991720
|
oai_dc
|
A study on different failure criteria to predict damage in glass/polyester composite beams under low velocity impact
|
A study on different failure criteria to predict damage in glass/polyester composite beams under low velocity impact
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Manizheh Aghaei(Isfahan University of Technology); Mohammad R. Forouzan(Isfahan University of Technology); Mehdi Nikforouz(Isfahan University of Technology); Elham Shahabi(Isfahan University of Technology)"
] |
Damage caused by low velocity impact is so dangerous in composites because although in most cases it is not visible to the eye, it can greatly reduce the strength of the composite material. In this paper, damage development in U-section glass/polyester pultruded beams subjected to low velocity impact was considered. Different failure criteria such as Maximum stress, Maximum strain, Hou, Hashin and the combination of Maximum strain criteria for fiber failure and Hou criteria for matrix failure were programmed and implemented in ABAQUS software via a user subroutine VUMAT. A suitable degradation model was also considered for reducing material constants due to damage. Experimental tests, which performed to validate numerical results, showed that Hashin and Hou failure criteria have better accuracy in predicting force-time history than the other three criteria. However, maximum stress and Hashin failure criteria had the best prediction for damage area, in comparison with the other three criteria. Finally in order to compare numerical model with the experimental results in terms of extent of damage, bending test was performed after impact and the behavior of the beam was considered.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1291
|
kci_detailed_000100.xml
|
||
ART001991721
|
oai_dc
|
A component method model for blind-bolts with headed anchors in tension
|
A component method model for blind-bolts with headed anchors in tension
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Theodoros Pitrakkos(The University of Nottingham); Walid Tizani(The University of Nottingham)"
] |
The successful application of the component-based approach - widely used to model structural joints - requires knowledge of the mechanical properties of the constitutive joint components, including an appropriate assembly procedure to derive the joint properties. This paper presents a component-method model for a structural joint component that is located in the tension zone of blind-bolted connections to concrete-filled tubular steel profiles. The model relates to the response of blind-bolts with headed anchors under monotonic loading, and the blind-bolt is termed the "Extended Hollo-bolt". Experimental data is used to develop the model, with the data being collected in a manner such that constitutive models were characterised for the principal elements which contribute to the global deformability of the connector. The model, based on a system of spring elements, incorporates pre-load and deformation from various parts of the blind-bolt: (i) the internal bolt elongation; (ii) the connector's expanding sleeves element; and (iii) the connector's mechanical anchorage element. The characteristics of these elements are determined on the basis of piecewise functions, accounting for basic geometrical and mechanical properties such as the strength of the concrete applied to the tube, the connection clamping length, and the size and class of the blind-bolt's internal bolt. An assembly process is then detailed to establish the model for the elastic and inelastic behaviour of the component. Comparisons of model predictions with experimental data show that the proposed model can predict with sufficient accuracy the response of the component. The model furthers the development of a full and detailed design method for an original connection technology.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1305
|
kci_detailed_000100.xml
|
||
ART001991708
|
oai_dc
|
Shear strength analyses of internal diaphragm connections to CFT columns
|
Shear strength analyses of internal diaphragm connections to CFT columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Liping Kang(Tongji University); Roberto T. Leon(Virginia Tech); Xilin Lu(Tongji University)"
] |
Previous theoretical equations for the shear capacity of steel beam to concrete filled steel tube (CFT) column connections vary in the assumptions for the shear deformation mechanisms and adopt different equations for calculating shear strength of each component (steel tube webs, steel tube flanges, diaphragms, and concrete etc.); thus result in different equations for calculating shear strength of the joint. Besides, shear force-deformation relations of the joint, needed for estimating building drift, are not well developed at the present. This paper compares previously proposed equations for joint shear capacity, discusses the shear deformation mechanism of the joint, and suggests recommendations for obtaining more accurate predictions. Finite element analyses of internal diaphragm connections to CFT columns were carried out in ABAQUS. ABAQUS results and theoretical estimations of the shear capacities were then used to calibrate rotational springs in joint elements in OpenSEES simulating the shear deformation behavior of the joint. The ABAQUS and OpenSEES results were validated with experimental results available. Results show that: (1) shear deformation of the steel tube dominates the deformation of the joint; while the thickness of the diaphragms has a negligible effect; (2) in OpenSEES simulation, the joint behavior is highly dependent on the yielding strength given to the rotational spring; and (3) axial force ratio has a significant effect on the joint deformation of the specimen analyzed. Finally, modified joint shear force-deformation relations are proposed based on previous theory.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1083
|
kci_detailed_000100.xml
|
||
ART001991709
|
oai_dc
|
Determination of displacement distributions in welded steel tension elements using digital image techniques
|
Determination of displacement distributions in welded steel tension elements using digital image techniques
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Sahin Sozen(Gaziosmanpasa University)"
] |
It is known that material properties, connection quality and manufacturing methods are among the important factors directly affecting the behavior of steel connections and hence steel structures. The possible performance differences between a fabricated connection and its computer model may cause critical design problems for steel structures. Achieving a reliable design depends, however, on how accurately the material properties and relevant constitutive models are considered to characterize the behavior of structures. Conventionally, the stress and strain fields in structural steel connections are calculated using the finite elements method with assumed material properties and constitutive models. Because the conventional strain gages allow the measurement of deformation only at one point and direction for specific time duration, it is not possible to determine the general characteristics of stress-strain distributions in connections after the laboratory performance tests. In this study, a new method is introduced to measure displacement distribution of simple steel welded connections under tension tests. The method is based on analyzing digital images of connection specimens taken periodically during the laboratory tension test. By using this method, displacement distribution of steel connections can be calculated with an acceptable precision for the tested connections. Calculated displacements based on the digital image correlation method are compared with those calculated using the finite elements method.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1103
|
kci_detailed_000100.xml
|
||
ART001991711
|
oai_dc
|
Experimental study on flexural behavior of splicing concrete-filled GFRP tubular composite members connected with steel bars
|
Experimental study on flexural behavior of splicing concrete-filled GFRP tubular composite members connected with steel bars
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"B.L. Chen(Northeastern University); L.G. Wang(Northeastern University)"
] |
Based on the experiment, this paper focuses on studying flexural behavior of splicing concrete-filled glass fiber reinforced polymer (GFRP) tubular composite members connected with steel bars. The test results indicated the confinement effects of GFRP tubes on the concrete core in compression zone began to produce, when the load reached about 50%<i>P<sub>u</sub></i> (<i>P<sub>u</sub></i>-ultimate load), but the confinement effects in tensile zone was unobvious. In addition, the failure modes of composite members were influenced by the steel ratio of the joint. For splicing unreinforced composite members, the steel ratio more than 1.96% could satisfy the splicing requirements and the steel ratio 2.94% was ideal comparatively. For splicing reinforced specimen, the bearing capacity of specimen with 3.92% steel ratio was higher 21.4% than specimen with 2.94% steel ratio and the latter was higher 21.2% than the contrast non-splicing specimen, which indicated that the steel ratio more than 2.94% could satisfy the splicing requirements and both splicing ways used in the experiment were feasible. So, the optimal steel ratio 2.94% was suggested economically. The experimental results also indicated that the carrying capacity and ductility of splicing concrete-filled GFRP tubular composite members could be improved by setting internal longitudinal rebars.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1129
|
kci_detailed_000100.xml
|
||
ART001991712
|
oai_dc
|
Steel-CFRP composite and their shear response as vertical stirrup in beams
|
Steel-CFRP composite and their shear response as vertical stirrup in beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Faris A. Uriayer(Jamia Millia Islamia); Mehtab Alam(Jamia Millia Islamia)"
] |
An experimental study was conducted for the effectiveness of steel-CFRP composite (CFRP laminates sandwiched between two steel strips) as stirrups in concrete beam to carry shearing force and comparison was made with conventional steel bar stirrups. A total numbers of 8 concrete beams were tested under four point loads. Each beam measured 1,600 mm long, 160 mm width and 240 mm depth. The beams were composed of same grade of concrete, with same amount of flexural steel but different shear reinforcements. The main variables include, type of stirrups (shape of stirrups and number of CFRP layers used in each stirrup) and number of stirrups used in shear spans. After getting on an excellent closeness between the values of ultimate shear resistance and ultimate tensile load of steel-CFRP stirrups, it could be concluded that the steel-CFRP stirrups represent the effective solution of premature failure of FRP stirrups at the bends.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1145
|
kci_detailed_000100.xml
|
||
ART001991713
|
oai_dc
|
Energy dissipation of steel-polymer composite beam-column connector
|
Energy dissipation of steel-polymer composite beam-column connector
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yun-Che Wang(National Cheng Kung University); Chih-Chin Ko(National Cheng Kung University)"
] |
The connection between a column and a beam is of particular importance to ensure the safety of civil engineering structures, such as high-rise buildings and bridges. While the connector must bear sufficient force for load transmission, increase of its ductility, toughness and damping may greatly enhance the overall safety of the structures. In this work, a composite beam-column connector is proposed and analyzed with the finite element method, including effects of elasticity, linear viscoelasticity, plasticity, as well as geometric nonlinearity. The composite connector consists of three parts: (1) soft steel; (2) polymer; and (3) conventional steel to be connected to beam and column. It is found that even in the linear range, the energy dissipation capacity of the composite connector is largely enhanced by the polymer material. Since the soft steel exhibits low yield stress and high ductility, hence under large deformation the soft steel has the plastic deformation to give rise to unique energy dissipation. With suitable geometric design, the connector may be tuned to exhibit different strengths and energy dissipation capabilities for real-world applications.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1161
|
kci_detailed_000100.xml
|
||
ART001991714
|
oai_dc
|
Cyclic test for beam-to-column abnormal joints in steel moment-resisting frames
|
Cyclic test for beam-to-column abnormal joints in steel moment-resisting frames
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zu Q. Liu(Xi’an University of Architecture and Technology); Jian Y. Xue(Xi’an University of Architecture and Tec); Xiu N. Peng(Guangxi University); Liang Gao(Xi’an University of Architecture and Technology)"
] |
Six specimens are tested to investigate the cyclic behavior of beam-to-column abnormal joints in steel moment-resisting frames, which are designed according to the principle of strong-member and weak-panel zone. Key parameters include the axial compression ratio of column and the section depth ratio of beams. Experimental results indicate that four types of failure patterns occurred during the loading process. The P-hysteretic loops are stable and plentiful, but have different changing tendency at the positive and negative direction in the later of loading process due to mechanical behaviors of specimens. The ultimate strength tends to increase with the decrease of the section depth ratio of beams, but it is not apparent relationship to the axial compression ratio of column, which is less than 0.5. The top panel zone has good deformation capacity and the shear rotation can reach to 0.04 rad. The top panel zone and the bottom panel zone don't work as a whole. Based on the experimental results, the equation for shear strength of the abnormal joint panel zone is established by considering the restriction of the bottom panel zone to the top panel zone, which is suitable for the abnormal joint of H-shaped or box column and beams with different depths.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1177
|
kci_detailed_000100.xml
|
||
ART001991715
|
oai_dc
|
Nonlinear time-varying analysis algorithms for modeling the behavior of complex rigid long-span steel structures during construction processes
|
Nonlinear time-varying analysis algorithms for modeling the behavior of complex rigid long-span steel structures during construction processes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Li-Min Tian(Xi’an University of Architecture and Technology); Ji-Ping Hao(Xi’an University of Architecture and Tec)"
] |
There is a great difference in mechanical behavior between design model one-time loading and step-by-step construction process. This paper presents practical computational methods for simulating the structural behavior of long-span rigid steel structures during construction processes. It introduces the positioning principle of node rectification for installation which is especially suitable for rigid long-span steel structures. Novel improved nonlinear analytical methods, known as element birth and death of node rectification, are introduced based on several calculating methods, as well as a forward iteration of node rectification method. These methods proposed in this paper can solve the problem of element's 'floating' and can be easily incorporated in commercial finite element software. These proposed methods were eventually implemented in the computer simulation and analysis of the main stadium for the Universiade Sports Center during the construction process. The optimum construction scheme of the structure is determined by the improved algorithm and the computational results matched well with the measured values in the project, thus indicating that the novel nonlinear time-varying analysis approach is effective construction simulation of complex rigid long-span steel structures and provides useful reference for future design and construction.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.5.1197
|
kci_detailed_000100.xml
|
||
ART002011428
|
oai_dc
|
Probabilistic sensitivity analysis of multi-span highway bridges
|
Probabilistic sensitivity analysis of multi-span highway bridges
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Bayat(Tarbiat Modares University); F. Daneshjoo(Tarbiat Modares University); N. Nisticò(Università degli Studi di Roma “La Sapie)"
] |
In this study, we try to compare different intensity measures for evaluating nonlinear response of bridge structure. This paper presents seismic analytic fragility of a three-span concrete girder highway bridge. A complete detail of bridge modeling parameters and also its verification has been presented. Fragility function considers the relationship of intensities of the ground motion and probability of exceeding certain state of damage. Incremental dynamic analysis (IDA) has been subjected to the bridge from medium to strong ground motions. A suite of 20 earthquake ground motions with different range of PGAs are used in nonlinear dynamic analysis of the bridge. Complete sensitive analyses have been done on the response of bridge and also efficiency and practically of them are studied to obtain a proficient intensity measure for these types of structure by considering its sensitivity to the period of the bridge. Three dimensional finite element (FE) model of the bridge is developed and analyzed. The numerical results show that the bridge response is very sensitive to the earthquake ground motions when PGA and Sa (Ti, 5%) are used as intensity measure (IM) and also indicated that the failure probability of the bridge system is dominated by the bridge piers.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.237
|
kci_detailed_000100.xml
|
||
ART002011415
|
oai_dc
|
Buckling of non-homogeneous orthotropic conical shells subjected to combined load
|
Buckling of non-homogeneous orthotropic conical shells subjected to combined load
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. H. Sofiyev(Suleyman Demirel University); N. Kuruoglu(Bahcesehir University)"
] |
The buckling analysis is presented for non-homogeneous (NH) orthotropic truncated conical shells subjected to combined loading of axial compression and external pressure. The governing equations have been obtained for the non-homogeneous orthotropic truncated conical shell, the material properties of which vary continuously in the thickness direction. By applying Superposition and Galerkin methods to the governing equations, the expressions for critical loads (axial, lateral, hydrostatic and combined) of non-homogeneous orthotropic truncated conical shells with simply supported boundary conditions are obtained. The results are verified by comparing the obtained values with those in the existing literature. Finally, the effects of non-homogeneity, material orthotropy, cone semi-vertex angle and other geometrical parameters on the values of the critical combined load have been studied.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.001
|
kci_detailed_000100.xml
|
||
ART002011416
|
oai_dc
|
Push-out tests and bond strength of rectangular CFST columns
|
Push-out tests and bond strength of rectangular CFST columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xiushu Qu(Beijing University of Civil Engineering and Architecture); Zhi-Hua Chen(Tianjin University); David A. Nethercot(Imperial College London); Leroy Gardner(Imperial College London); Marios Theofanous(University of Birmingham)"
] |
Push-out tests have been conducted on 18 rectangular concrete-filled steel tubular (CFST) columns with the aim of studying the bond behaviour between the steel tube and the concrete infill. The obtained load-slip response and the distribution of the interface bond stress along the member length and around the cross-section for various load levels, as derived from measured axial strain gradients in the steel tube, are reported. Concrete compressive strength, interface length, cross-sectional dimensions and different interface conditions were varied to assess their effect on the ultimate bond stress. The test results indicate that lubricating the steel-concrete interface always had a significant adverse effect on the interface bond strength. Among the other variables considered, concrete compressive strength and cross-section size were found to have a pronounced effect on the bond strength of non-lubricated specimens for the range of cross-section geometries considered, which is not reflected in the European structural design code for composite structures, EN 1994-1-1 (2004). Finally, based on nonlinear regression of the test data generated in the present study, supplemented by additional data obtained from the literature, an empirical equation has been proposed for predicting the average ultimate bond strength for SHS and RHS filled with normal strength concrete.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.021
|
kci_detailed_000100.xml
|
||
ART002011417
|
oai_dc
|
Cost minimization of prestressed steel trusses considering shape and size variables
|
Cost minimization of prestressed steel trusses considering shape and size variables
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zekeriya Aydın(Namık Kemal University); Ebru Cakir(Namık Kemal University)"
] |
There are many studies on the optimization of steel trusses in literature; and, a large number of them include a shape optimization. However, only a few of these studies are focused on the prestressed steel trusses. Therefore, this paper aims to determine the amounts of the material and cost savings in steel plane trusses in the case of prestressing. A parallel-chord simply supported steel truss is handled as an example to evaluate the used approach. It is considered that prestressing tendon is settled under the bottom bar, between two end supports, using deviators. Cross-sections of the truss members and height of the truss are taken as the design variables. The prestress losses are calculated in two steps as instantaneous losses and time-dependent losses. Tension increment in prestressing tendon due to the external loads is also considered. A computer program based on genetic algorithm is developed to solve the optimization problem. The handled truss is optimized for different span lengths and different tendon eccentricities using the coded program. The effects of span length and eccentricity of tendon on prestressed truss optimization are investigated. The results of different solutions are compared with each other and those of the non-prestressed solution. It is concluded that the amounts of the material and the cost of a steel plane truss can be reduced up to 19.9% and 14.6%, respectively, by applying prestressing.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.043
|
kci_detailed_000100.xml
|
||
ART002011418
|
oai_dc
|
Non-linear performance analysis of existing and concentric braced steel structures
|
Non-linear performance analysis of existing and concentric braced steel structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"R. Tuğrul Erdem(Celal Bayar University)"
] |
Since there are several places located in active seismic zones in the world, serious damages and losses have happened due to major scaled earthquakes. Especially, structures having different irregularities have been severely damaged or collapsed during these seismic events. Behavior of existing structures under several loading conditions is not completely determined due to some uncertainties. This situation reveals the importance of design and analysis of structures under seismic effects. Several non-linear static procedures have been developed in recent years. Determination of the seismic safety of the existing structures and strengthening techniques are significant civil engineering problems Non-linear methods are defined in codes to determine the performance levels of structures more accurately. However, displacement based ones give more realistic results. These methods provide more reliable evaluation possibilities for existing structures with developing computer technology. In this study, non-linear performance analysis of existing and strengthened steel structures by X shaped bracing members with 3, 5 and 7 stories which have soft story irregularity is performed according to FEMA-356 and Turkish Earthquake Code-2007. Damage ratios of the structural members and global performance levels are determined as well as modal properties and story drift ratios after non-linear finite elements analysis for each structure.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.059
|
kci_detailed_000101.xml
|
||
ART002011419
|
oai_dc
|
Minimum-weight design of stiffened shell under hydrostatic pressure by genetic algorithm
|
Minimum-weight design of stiffened shell under hydrostatic pressure by genetic algorithm
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.R. Ghasemi(University of Kashan); M.H. Hajmohammad(University of Kashan)"
] |
In this paper, optimization of cylindrical shells under external pressure to minimize its weight has been studied. Buckling equations are based on standard of ABS underwater vehicles. Dimension and type of circumferential stiffeners, and its distance from each other are assumed as variables of optimization problem. Considering the extent of these variables, genetic algorithms have been used for optimization. To study the effect of hydrostatic pressure on the shell and its fabrication according to the existing standards, geometrical and construction as well as stress and buckling constraints have been used in optimization algorithm and also penalty functions are applied to eliminate weak model. Finally, the best model which has the minimum weight considering the applied pressure has been presented.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.075
|
kci_detailed_000101.xml
|
||
ART002011427
|
oai_dc
|
Fatigue tests of damaged tubes under flexural loading
|
Fatigue tests of damaged tubes under flexural loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Tohid Ghanbari Ghazijahani(University of Tasmania); Hui Jiao(University of Tasmania); Damien Holloway(University of Tasmania)"
] |
Despite the proliferation of the industrial application of steel tubes, the effect of collision on the surface of steel tubes subject to cyclic loading has largely remained untouched. This paper studies the fatigue behavior of steel tubes which are impacted by an external object. A dent imperfection caused by a collision was modeled and fatigue tests were conducted using a MTS machine. Fatigue life as well as the failure modes were thoroughly discussed in a way that the fatigue life of the dented tubes with similar geometrical specifications at full-scale can be generalized.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.223
|
kci_detailed_000101.xml
|
||
ART002011420
|
oai_dc
|
Thermomechanical effects on the bending of antisymmetric cross-ply composite plates using a four variable sinusoidal theory
|
Thermomechanical effects on the bending of antisymmetric cross-ply composite plates using a four variable sinusoidal theory
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F. Chattibi(University of Sidi Bel Abbes); Abdelouahed Tounsi(University of Sidi Bel Abbes); Kouider Halim Benrahou(University of Sidi Bel Abbes); Abdelkader Benachour(University of Sidi Bel Abbes); K. Nedri(University of Sidi Bel Abbes)"
] |
The thermomechanical bending response of anti-symmetric cross-ply composite plates is investigated by the use of the simple four variable sinusoidal plate theory. The theory accounts for sinusoidal distribution of transverse shear stress, and satisfies the free transverse shear stress conditions on the top and bottom surfaces of the plate without using shear correction factor. By dividing the transverse displacement into bending and shear parts, the number of unknowns and governing equations for the present theory is reduced, significantly facilitating engineering analysis. The validity of the present theory is demonstrated by comparison with solutions available in the literature. Numerical results are presented to demonstrate the behavior of the system. The influences of aspect ratio, side-to-thickness ratio, thermal expansion coefficients ratio and stacking sequence on the thermally induced response are studied. The present study is relevant to aerospace, chemical process and nuclear engineering structures which may be subjected to intense thermal loads.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.093
|
kci_detailed_000101.xml
|
||
ART002011421
|
oai_dc
|
Creep performance of concrete-filled steel tubular (CFST) columns and applications to a CFST arch bridge
|
Creep performance of concrete-filled steel tubular (CFST) columns and applications to a CFST arch bridge
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Meng-Gang Yang(Central South University); C. S. Cai(Louisiana State University); Yong Chen(Shanghai Municipal Engineering Design Institute (Group) Co. Ltd.)"
] |
This paper first presents an experimental study of twelve specimens for their creep performance, including nine concrete-filled steel tubular (CFST) columns and three plain concrete columns, subjected to three levels of sustained axial loads for 1710 days. Then, the creep strain curves are predicted from the existing creep models including the ACI 209 model, the MC 78 model, and the MC 90 model, and further a fitted creep model is obtained by experimental data. Finally, the creep effects of a CFST arch bridge are analyzed to compare the accuracy of the existing creep models. The experimental results show that the creep strains in CFST specimens are far less than in the plain concrete specimens and still increase after two years. The ACI 209 model outperforms the MC 78 model and the MC 90 model when predicting the creep behavior of the CFST specimens. Analysis results indicate that the creep effects in the CFST arch bridge are significant. The deflections and stresses calculated by the ACI 209 model are the closest to the fitted model in the three existing models, demonstrating that the ACI 209 model can be used for creep analysis of CFST arch bridges and can meet the engineering accuracy requirement when lack of experimental data.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.111
|
kci_detailed_000101.xml
|
||
ART002011422
|
oai_dc
|
Detection of tube defect using the autoregressive algorithm
|
Detection of tube defect using the autoregressive algorithm
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zakiah A. Hali(Universiti Teknikal Malaysia Melaka); Nordin Jamaludin(Universiti Kebangsaan Malaysia); Syarif Junaidi(Universiti Kebangsaan Malaysia); Syed Yusainee Syed Yahya(Universiti Teknologi MARA)"
] |
Easy detection and evaluation of defect in the tube structure is a continuous problem and remains a significant demand in tube inspection technologies. This study is aimed to automate defect detection using the pattern recognition approach based on the classification of high frequency stress wave signals. The stress wave signals from vibrational impact excitation on several tube conditions were captured to identify the defect in ASTM A179 seamless steel tubes. The variation in stress wave propagation was captured by a high frequency sensor. Stress wave signals from four tubes with artificial defects of different depths and one reference tube were classified using the autoregressive (AR) algorithm. The results were demonstrated using a dendrogram. The preliminary research revealed the natural arrangement of stress wave signals were grouped into two clusters. The stress wave signals from the healthy tube were grouped together in one cluster and the signals from the defective tubes were classified in another cluster. This approach was effective in separating different stress wave signals and allowed quicker and easier defect identification and interpretation in steel tubes.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.131
|
kci_detailed_000101.xml
|
||
ART002011423
|
oai_dc
|
Effect of fibers and welded-wire reinforcements on the diaphragm behavior of composite deck slabs
|
Effect of fibers and welded-wire reinforcements on the diaphragm behavior of composite deck slabs
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Salah Altoubat(University of Sharjah); Hisseine Ousmane(University of Sharjah); Samer Barakat(University of Sharjah)"
] |
Twelve large-scale composite deck slabs were instrumented and tested in a cantilever diaphragm configuration to assess the effect of fibers and welded wire mesh (WWM) on the in-plane shear capacity of composite deck slabs. The slabs were constructed with reentrant decking profile and reinforced with different types and dosages of secondary reinforcements: Conventional welded wire mesh (A142 and A98); synthetic macro-fibers (dosages of 3 kg/m<sup>3</sup> and 5.3 kg/m<sup>3</sup>); and hooked-end steel fibers with a dosage of 15 kg/m<sup>3</sup>. The deck orientation relative to the main beam (strong and weak) was also considered in this study. Fibers and WWM were found efficient in distributing the applied load to the whole matrix, inducing multiple cracking, thereby enhancing the strength and ductility of composite deck slabs. The test results indicate that fibers increased the slab’s ultimate in-plane shear capacity by up to 29% and 50% in the strong and weak directions, respectively. WWM increased the ultimate in-plane shear capacity by up to 19% in the strong direction and 9% in the weak direction. The results suggest that discrete fibers can provide comparable diaphragm behavior as that with the conventional WWM.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.153
|
kci_detailed_000101.xml
|
||
ART002011424
|
oai_dc
|
Fragility assessment of buckling-restrained braced frames under near-field earthquakes
|
Fragility assessment of buckling-restrained braced frames under near-field earthquakes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ahmad F. Ghowsi(Indian Institute of Technology Delhi); Dipti R. Sahoo(Indian Institute of Technology Delhi)"
] |
This study presents an analytical investigation on the seismic response of a medium-rise buckling-restrained braced frame (BRBF) under the near-fault ground motions. A seven-story BRBF is designed as per the current code provisions for five different combinations of brace configurations and beam-column connections. Two types of brace configurations (i.e., Chevron and Double-X) are considered along with a combination of the moment-resisting and the non-moment-resisting beam-to-column connections for the study frame. Nonlinear dynamic analyses are carried out for all study frames for an ensemble of forty SAC near-fault ground motions. The main parameters evaluated are the interstory and residual drift response, brace displacement ductility, and plastic hinge mechanisms. Fragility curves are developed using log-normal probability density functions for all study frames considering the interstory drift ratio and residual drift ratio as the damage parameters. The average interstory drift response of BRBFs with Double-X brace configurations significantly exceeded the allowable drift limit of 2%. The maximum displacement ductility characteristics of BRBs is efficiently utilized under the seismic loading if these braces are arranged in the Double-X configurations instead of Chevron configurations in BRBFs located in the near-fault regions. However, BRBFs with the Double-X brace configurations exhibit the higher interstory drift and residual drift response under near-fault ground motions due to the formation of plastic hinges in the columns and beams at the intermediate story levels.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.173
|
kci_detailed_000101.xml
|
||
ART002011425
|
oai_dc
|
Damage detection using finite element model updating with an improved optimization algorithm
|
Damage detection using finite element model updating with an improved optimization algorithm
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yalan Xu(Xidian University); Yu Qian(Xidian University); Gangbing Song(University of Houston); Kongming Guo(University of Houston)"
] |
The sensitivity-based finite element model updating method has received increasing attention in damage detection of structures based on measured modal parameters. Finding an optimization technique with high efficiency and fast convergence is one of the key issues for model updating-based damage detection. A new simple and computationally efficient optimization algorithm is proposed and applied to damage detection by using finite element model updating. The proposed method combines the Gauss- Newton method with region truncation of each iterative step, in which not only the constraints are introduced instead of penalty functions, but also the searching steps are restricted in a controlled region. The developed algorithm is illustrated by a numerically simulated 25-bar truss structure, and the results have been compared and verified with those obtained from the trust region method. In order to investigate the reliability of the proposed method in damage detection of structures, the influence of the uncertainties coming from measured modal parameters on the statistical characteristics of detection result is investigated by Monte-Carlo simulation, and the probability of damage detection is estimated using the probabilistic method.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.191
|
kci_detailed_000101.xml
|
||
ART002011426
|
oai_dc
|
Experimental research on seismic behavior of novel composite RCS joints
|
Experimental research on seismic behavior of novel composite RCS joints
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jinjie Men(Xi’an University of Architecture & Technology); Zhifeng Guo(Xi’an University of Architecture & Technology); Qingxuan Shi(Xi’an University of Architecture & Technology)"
] |
Results from an experimental study on the seismic response of six composite reinforced concrete column-to-steel beam interior joints are presented. The primary variable investigated is the details in the joint. For the basic specimen, the main subassemblies of the beam and column are both continuous, and the steel beam flanges extended to the joint are partly cut off. Transverse beam, steel band plates, cove plates, X shape reinforcement bars and end plates are used in the other five specimens, respectively. After the joint steel panel yielded, two failure modes were observed during the test: local failure in Specimens 1, 2 and 4, shear failure in Specimens 3, 5 and 6. Specimens 6, 3, 5 and 4 have a better strength and deformation capacity than the other two specimens for the effectiveness of their subassemblies. For Specimens 2 and 4, though the performance of strength degradation and stiffness degradation are not as good as the other four specimens, they all have excellent energy dissipation capacity comparing to the RC joint, or the Steel Reinforced Concrete (SRC) joint. Based on the test result, some suggestions are presented for the design of composite RCS joint.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.19.1.209
|
kci_detailed_000101.xml
|
||
ART001998558
|
oai_dc
|
Mid-length lateral deflection of cyclically-loaded braces
|
Mid-length lateral deflection of cyclically-loaded braces
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Therese Sheehan(University of Bradford); Tak-Ming Chan(The Hong Kong Polytechnic University); Dennis Lam(University of Bradford)"
] |
This study explores the lateral deflections of diagonal braces in concentrically-braced earthquakeresisting frames. The performance of this widely-used system is often compromised by the flexural buckling of slender braces in compression. In addition to reducing the compressive resistance, buckling may also cause these members to undergo sizeable lateral deflections which could damage surrounding structural components. Different approaches have been used in the past to predict the mid-length lateral deflections of cyclically loaded steel braces based on their theoretical deformed geometry or by using experimental data. Expressions have been proposed relating the mid-length lateral deflection to the axial displacement ductility of the member. Recent experiments were conducted on hollow and concrete-filled circular hollow section (CHS) braces of different lengths under cyclic loading. Very slender, concrete-filled tubular braces exhibited a highly ductile response, undergoing large axial displacements prior to failure. The presence of concrete infill did not influence the magnitude of lateral deflection in relation to the axial displacement, but did increase the number of cycles endured and the maximum axial displacement achieved. The corresponding lateral deflections exceeded the deflections observed in the majority of the previous experiments that were considered. Consequently, predictive expressions from previous research did not accurately predict the mid-height lateral deflections of these CHS members. Mid-length lateral deflections were found to be influenced by the member non-dimensional slenderness (λ) and hence a new expression was proposed for the lateral deflection in terms of member slenderness and axial displacement ductility.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.6.1569
|
kci_detailed_000101.xml
|
||
ART001998545
|
oai_dc
|
Experimental testing of cold-formed built-up members in pure compression
|
Experimental testing of cold-formed built-up members in pure compression
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kenneth A. Biggs(The University of Oklahoma); 강현구(서울대학교); Chris Ramseyer(The University of Oklahoma); Suhyun Ree(Seoul National University)"
] |
Cold-formed built-up members are compression members that are common in multiple areas of steel construction, which include cold-formed steel joints and stud walls. These members are vulnerable to unique buckling behaviors; however, limited experimental research has been done in this area. Give this gap, experimental testing of 71 built-up members was conducted in this study. The variations of the test specimens include multiple lengths, intermediate welds, orientations, and thicknesses. The experimental testing was devised to observe the different buckling modes of the built-up C-channels and the effects of the geometrical properties; to check for applicability of multiple intermediate welding patterns; and to evaluate both the 2001 and 2007 editions of the American Iron and Steel Institute (AISI) Specification for built-up members in pure compression. The AISI-2001 and AISI-2007 were found to give inconsistent results that at times were un-conservative or overly conservative in terms of axial strength. It was also found that orientation of the member has an important impact on the maximum failure load on the member.
|
토목공학
| null |
http://dx.doi.org/10.12989/scs.2015.18.6.1331
|
kci_detailed_000101.xml
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.