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ART001474292
|
oai_dc
|
Effect of damage on permeability and hygro-thermal\r\nbehaviour of HPCs at elevated temperatures: Part 1. Experimental results
|
Effect of damage on permeability and hygro-thermal\r\nbehaviour of HPCs at elevated temperatures: Part 1. Experimental results
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"D. Gawin(Technical University of Lodz); C. Alonso(Istituto de Ciencias de la Construccion Eduardo Torroja); C. Andrade(Istituto de Ciencias de la Construccion Eduardo Torroja); C. E. Majorana(University of Padua); F. Pesavento(University of Padua)"
] |
This paper presents an analysis of some experimental results concerning micro-structural tests,permeability measurements and strain-stress tests of four types of High-Performance Concrete, exposed toelevated temperatures (up to 700oC). These experimental results, obtained within the ?ITECO?research programme are discussed and interpreted in the context of a recently developed mathematical model of hygro-thermal behaviour and degradation of concrete at high temperature, which is briefly presented in the Part 2 paper (Gawin, et al. 2005). Correlations between concrete permeability and porosity microstructure, as well as between damage and cracks?volume, are found. An approximate decomposition of the thermally induced material damage into two parts, a chemical one related to cement dehydration process, and a thermal one due to micro-cracks?development caused by thermal strains at micro- and meso-scale, is performed. Constitutive relationships describing influence of temperature and material damage upon its intrinsic permeability at high temperature for 4 types of HPC are deduced. In the Part II of this paper (Gawin, et al. 2005) effect of two different damage-permeability coupling formulations on the results of computer simulations concerning hygro-thermo-mechanical performance of concrete wall during standard fire, is numerically analysed.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474317
|
oai_dc
|
Effect of damage on permeability and hygro-thermal\r\nbehaviour of HPCs at elevated temperatures: Part 2. Numerical analysis
|
Effect of damage on permeability and hygro-thermal\r\nbehaviour of HPCs at elevated temperatures: Part 2. Numerical analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"D. Gawin(Technical University of Lodz); C. E. Majorana(University of Padua); F. Pesavento(University of Padua); B. A. Schrelfer(University of Padua)"
] |
In the Part 1 paper (Gawin, et al. 2005) some experimental results concerning micro-structuraltests, permeability measurements and stress-strain tests of four types of High Performance Concrete, exposed to elevated temperatures (up to 700oC) are presented and discussed. On the basis of these experimental results parameters of the constitutive relationships describing influence of damage and temperature upon material intrinsic permeability at high temperature were determined. In this paper the effects of various formulations of damage-permeability coupling on results of computer simulations are analysed and compared with the results obtained by means of the previously proposed approach, that does not take into account thethermo-chemical concrete damage directly. Numerical solutions are obtained using the recently developedfully coupled model of hygro-thermal and damage phenomena in concrete at elevated temperatures. Hightemperature effects are considered by means of temperature and pressure dependence of several material parameters. Based on the mathematical model, the computer code HITECOSP was developed. Materialparameters of the model were measured by several European laboratories, which participated in the?ITECO?research project. A model problem, concerning hygro-thermal behaviour and degradation of a HPC structure during fire, is solved. The influence of two different constitutive descriptions of the concrete permeability changes at high temperature, including thermo-chemical and mechanical damage effects, upon the results of computer simulations is analysed and discussed.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474277
|
oai_dc
|
Inelastic analysis of concrete beams strengthened with various fiber reinforced polymer (FRP) systems
|
Inelastic analysis of concrete beams strengthened with various fiber reinforced polymer (FRP) systems
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. J. Terro(Kuwait University); M. M. El-Hawary(Kuwait Institute for Scientific Research); S. A. Hamoush(A & T State University)"
] |
This paper presents a numerical model developed to evaluate the load-deflection and moment curvature relationship for concrete beams strengthened externally with four different Fiber Reinforced Polymer (FRP) composite systems. The developed model considers the inelastic behavior of concrete section subjected to a combined axial force and bending moment. The model accounts for tensile strength of concrete as defined by the modulus of rupture of concrete. Based on the adopted material constitutiverelations, the model evaluates the sectional curvature as a function of the applied axial load and bending moment. Deflections along the beam are evaluated using a finite difference technique taking into account support conditions. The developed numerical technique has been tested on a cantilever beam with a transverse load applied at its end. A study of the behavior of the beam with tension reinforcement compared to that with FRP areas giving an equivalent ultimate moment has been carried out. Moreover, cracking of the section in the tensile region at ultimate load has also been considered. The results indicated that beams reinforced with FRP systems possess more ductility than those reinforced with steel. This ductility, however, can be tuned by increasing the area of FRP or by combining different FRP layers.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474325
|
oai_dc
|
Numerical investigation of RC structural walls subjected to cyclic loading
|
Numerical investigation of RC structural walls subjected to cyclic loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"D.M. Cotsovos(Concept Engineering Consultants); M.N. Pavlovic(Imperial College)"
] |
This work is based on a nonlinear finite-element model with proven capacity for yieldingrealistic predictions of the response of reinforced-concrete structures under static monotonically-increasing loading. In it, the material description relies essentially on the two key properties of triaxiality and brittleness and, thus, is simpler than those of most other material models in use. In this article, the finiteelement program is successfully used in investigating the behaviour of a series of RC walls under static cyclic loading. This type of loading offers a more strenuous test of the validity of the proposed program since cracks continuously form and close during each load cycle. Such a test is considered to be essentialbefore attempting to use the program for the analysis of concrete structures under seismic excitation inorder to ensure that the solution procedure adopted is numerically stable and can accurately predict thebehaviour of RC structures under such earthquake-loading conditions. This is achieved through acomparative study between the numerical predictions obtained presently from the program and availableexperimental data.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474231
|
oai_dc
|
Seismic performance of 1/4-scale RC frames subjected to axial and cyclic reversed lateral loads
|
Seismic performance of 1/4-scale RC frames subjected to axial and cyclic reversed lateral loads
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hakim Bechtoula(Kyoto University); Masanobu Sakashita(Kyoto University); Susumu Kono(Kyoto University); Fumio Watanabe(Kyoto University)"
] |
This paper summarizes an experimental study on the seismic behavior of lower stories of a mid-rise reinforced concrete frame building. Two reinforced concrete frames with two stories and one span were tested and each frame represents lower two stories of an 11-story RC frame building. Both frames were designed in accordance with Japanese design guidelines and were identical except in the variation of axial force. The tests demonstrated that the overall load-displacement relations of the two frames were nearly the same and the first-story column shear was closely related to the column axial load. The columns and beams elongated during both of the tests, with the second-floor beam elongation exceeding 1.5% of the beam clear span length. The frame with higher axial loads developed more cracks that the frame under moderate axial load.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474253
|
oai_dc
|
Crack propagation simulation of concrete with the regular triangular lattice model
|
Crack propagation simulation of concrete with the regular triangular lattice model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"조병완(한양대학교); 태기호(부천 대학교 ); Erik Schlangen(Delft University Technology); 김창현(한양대학교)"
] |
This paper discusses 2D lattice models of beams for simulating the fracture of brittle materials. A simulation of an experiment on a concrete beam subjected to bending, in which two overlapping cracks occur, is used to study the effect of individual beam characteristics and different arrangements of the beams in the overall lattice. It was found that any regular orientation of the beams influences the resulting crack patterns. Methods to implement a wide range of Poisson뭩 ratios are also developed, and the use of the lattice to study arbitrary micro-structures is outlined. The crack patterns that are obtained with lattice are in good agreement with the experimental results. Also, numerical simulations of the tests were performed by means of a lattice model, and non-integer dimensions were measured on the predicted lattice damage patterns.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474214
|
oai_dc
|
A method to evaluate the frequencies of free transversal vibrations in self-anchored cable-stayed bridges
|
A method to evaluate the frequencies of free transversal vibrations in self-anchored cable-stayed bridges
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Pietro Monaco(Polytechnic of Bari); Alessandra Fiore(Polytechnic of Bari)"
] |
The objective of this paper is setting out, for a cable-stayed bridge with a curtain suspension, a method to determine the modes of vibration of the structure. The system of differential equations governing the vibrations of the bridge, derived by means of a variational formulation in a nonlinear field, is reported in Appendix C. The whole analysis results from the application of Hamilton's principle, using the expressions of potential and kinetic energies and of the virtual work made by viscous damping forces of the various parts of the bridge (Monaco and Fiore 2003). This paper focuses on the equation concerning the transversal motion of the girder of the cable-stayed bridge and in particular on its final form obtained, restrictedly to the linear case, neglecting some quantities affecting the solution in a non-remarkable way. In the hypotheses of normal mode of vibration and of steady-state, we propose the resolution of this equation by a particular method based on a numerical approach. Respecting the boundary conditions, we derive, for each mode of vibration, the corresponding frequency, both natural and damped, the shape-function of the girder axis and the exponential function governing the variability of motion amplitude in time. Finally the results so obtained are compared with those deriving from the dynamic analysis performed by a finite elements calculation program.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474178
|
oai_dc
|
Modelling the rheological behaviour of fresh concrete: An elasto-viscoplastic finite element approach
|
Modelling the rheological behaviour of fresh concrete: An elasto-viscoplastic finite element approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. E. Chidiac(McMaster University); F. Habibbeigi(McMaster University)"
] |
Rheological behaviour of fresh concrete is an important factor in controlling concrete quality. It is recognized that the measurement of the slump is not a sufficient test method to adequately characterize the rheology of fresh concrete. To further understand the slump measurement and its relationship to the rheological properties, an elasto-viscoplastic, 2-D axisymmetric finite element (FE) model is developed. The FE model employs the Bingham material model to simulate the flow of a slump test. An experimental program is carried out using the Slump Rate Machine (SLRM_II) to evaluate the finite element simulation results. The simulated slump-versus-time curves are found to be in good agreement with the measured data. A sensitivity study is performed to evaluate the effects of yield stress, plastic viscosity and cone withdrawal rate on the measured flow curve using the FE model. The results demonstrate that the computed yield stress compares well with reported experimental data. The flow behaviour is shown to be influenced by the yield stress, plastic viscosity and the cone withdrawal rate. Further, it is found that the value of the apparent plastic viscosity is different from the true viscosity, with the difference depending on the cone withdrawal rate. It is also confirmed that the value of the final slump is most influenced by the yield stress.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474197
|
oai_dc
|
Ductility enhancement of reinforced concrete thin walls
|
Ductility enhancement of reinforced concrete thin walls
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"김장훈(아주대학교)"
] |
The ductility of reinforced concrete bearing walls subjected to high axial loading and moment can be enhanced by improving the deformability of the compression zone or by reducing the neutral axis depth. The current state-of-the-art procedure evaluating the confinement effect prompts a consideration of the spaces between the transverse and longitudinal reinforcing bars, and a provision of tie bars. At the same time, consideration must also be given to the thickness of the walls. However, such considerations indicate that the confinement effect cannot be expected with the current practice of detailing wall ends in Korea. As an alternative, a comprehensive method for dimensioning boundary elements is proposed so that the entire section of a boundary element can stay within the compression zone when the full flexural strength of the wall is developed. In this comprehensive method, the once predominant code approach for determining the compression zone has been advanced by considering the rectangular stress block parameters varying with the extreme compression fiber strain. Moreover, the size of boundary elements can also be determined in relation to the architectural requirement.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473577
|
oai_dc
|
Closed form interaction surfaces for nonlinear design codes of RC columns with MC 90
|
Closed form interaction surfaces for nonlinear design codes of RC columns with MC 90
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. H. F. M. Barros(University of Coimbra); C. C. Ferreira(University of Coimbra); A. F. M. Barros(IDMEC/IST)"
] |
The closed form solution of the equilibrium equations in the ultimate design of reinforced concrete sections under biaxial bending is presented. The stresses in the materials are described by the Model Code 1990 equations. Computation of the integral equations is performed generally in terms of all variables. The deformed shape of the section in the ultimate conditions is defined by Heaviside functions. The procedure is convenient for the use of mathematical manipulation programs and the results are easily included into nonlinear analysis codes. The equations developed for rectangular sections can be applied for other sections, such as T, L, I for instance, by decomposition into rectangles. Numerical examples of the developed model for rectangular sections and composed sections are included.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473516
|
oai_dc
|
Relation between total degradation of steel concrete bond and degree of corrosion of RC beams experimental and computational studies
|
Relation between total degradation of steel concrete bond and degree of corrosion of RC beams experimental and computational studies
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Olivier Maurel(Universite de Reims); Mickael Dekoster(Universite des Sciences et Technologies de Lille); Francois Buyle-Bodin(Universite des Sciences et Technologies de Lille)"
] |
This paper presents a study on the effects of localized steel-concrete bond degradation on the flexural behaviour of RC beams. A finite element analysis is undertaken to complete the experimental analysis. The first part deals with an experimental study on beams where bond was removed by using plastic tube at different locations and for various lengths. The flexural behaviour was studied at global scale (load-deflection) and local scale (moment-curvature). The second part, a numerical study using a simplified special finite element (rust element) modelling the rust layer occurring between reinforcement
and concrete with corrosion was conducted in order to find the relation between the degree of corrosion and the degradation of the steel-concrete bond. The computed value of the corrosion degree corresponding
to the total degradation of bond has been used in a second time to model the tests, in order to evaluate the influence of the loss of bond, the steel cross section reduction, and the combination of both. The results enable to evaluate the influence of the different corrosion effects on the flexural behaviour,according to the length and the location of the corroded zone.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473524
|
oai_dc
|
Kinetics of the water absorption in GGBS-concretes: A capillary-diffusive model
|
Kinetics of the water absorption in GGBS-concretes: A capillary-diffusive model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"E. Villar-Cocina(Central University of Las Villas); E. Valencia-Morales(Central University of Las Villas); J. Vega-Leyva(Central University of Las Villas); J. Antiquera Munoz(University of Magallanes)"
] |
We study the kinetics of absorption of water in Portland cement concretes added with 60, 70 and 80% of granulated blast furnace slag (GGBS) cured in water and at open air and preheated at 50 and
100oC. A mathematical model is presented that allows describing the process not only in early ages where the capillary sorption is predominant but also for later and long times where the diffusive processes
through the finer and gel pores are considered. The fitting of the model by computerized methods enables us to determine the parameters that characterize the process: i.e., the sorptivity coefficient (S) and
diffusion coefficient (D). This allows the description of the process for all times and offers the possibility to know the contributions of both, the diffusive and capillary processes. The results show the influence of
the curing regime and the preheating temperature on the behavior of GGBS mortars.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473537
|
oai_dc
|
A partial factors methodology for structural safety assessment in non-linear analysis
|
A partial factors methodology for structural safety assessment in non-linear analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Paula M. R. P. Castro(Porto University); Raimundo M. Delgado(Porto University); Jose M. A. Cesar de Sa(Porto University)"
] |
In the present structural codes the safety verification is based on a linear analysis of the structure and the satisfaction of ultimate and serviceability limit states, using a semi-probabilistic security
format through the consideration of partial safety factors, which affect the action values and the characteristic values of the material properties. In this context, if a non-linear structural analysis is wanted
a difficulty arises, because the global safety coefficient, which could be obtained in a straightforward way from the non-linear analysis, is not directly relatable to the different safety coefficient values usually used
for the different materials, as is the case for reinforced concrete structures. The work here presented aims to overcome this difficulty by proposing a methodology that generalises the format of safety verification
based on partial safety factors, well established in structural codes within the scope of linear analysis, for cases where non-linear analysis is needed. The methodology preserves the principal assumptions made in
the codes as well as a reasonable simplicity in its use, including a realistic definition of the material properties and the structural behaviour, and it is based on the evaluation of a global safety coefficient.
Some examples are presented aiming to clarify and synthesise all the options that were taken in the application of the proposed methodology, namely how to transpose the force distributions obtained with a
non-linear analysis into design force distributions. One of the most important features of the proposed methodology, the ability for comparing the simplified procedures for second order effects evaluation
prescribed in the structural codes, is also presented in a simple and systematic way. The potential of the methodology for the development and assessment of alternative and more accurate procedures to those
already established in codes of practice, where non-linear effects must be considered, is also indicated.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473586
|
oai_dc
|
Predicting shear capacity of NSC and HSC slender beams without stirrups using artificial intelligence
|
Predicting shear capacity of NSC and HSC slender beams without stirrups using artificial intelligence
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H. El-Chabib(The University of Western Ontario); M. Nehdi(The University of Western Ontario); A. Said(The University of Western Ontario)"
] |
The use of high-strength concrete (HSC) has significantly increased over the last decade, especially in offshore structures, long-span bridges, and tall buildings. The behavior of such concrete is noticeably different from that of normal-strength concrete (NSC) due to its different microstructure and mode of failure. In particular, the shear capacity of structural members made of HSC is a concern and must be carefully evaluated. The shear fracture surface in HSC members is usually trans-granular (propagates across coarse aggregates) and is therefore smoother than that in NSC members, which reduces the effect of shear transfer mechanisms through aggregate interlock across cracks, thus reducing the ultimate shear strength. Current code provisions for shear design are mainly based on experimental results obtained on NSC members having compressive strength of up to 50MPa. The validity of such methods to calculate the shear strength of HSC members is still questionable. In this study, a new approach based on artificial neural networks (ANNs) was used to predict the shear capacity of NSC and HSC beams without shear reinforcement. Shear capacities predicted by the ANN model were compared to those of five other methods commonly used in shear investigations: the ACI method, the CSA simplified method, Response 2000, Eurocode-2, and Zsutty's method. A sensitivity analysis was conducted to evaluate the ability of ANNs to capture the effect of main shear design parameters (concrete compressive strength, amount of longitudinal reinforcement, beam size, and shear span to depth ratio) on the shear capacity of reinforced NSC and HSC beams. It was found that the ANN model outperformed all other considered methods, providing more accurate results of shear capacity, and better capturing the effect of basic shear design parameters. Therefore, it offers an efficient alternative to evaluate the shear capacity of NSC and HSC members without stirrups.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474655
|
oai_dc
|
Nonlinear finite element analysis of four-pile caps supporting columns subjected to generic loading
|
Nonlinear finite element analysis of four-pile caps supporting columns subjected to generic loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rafael Alves de Souza(Universidade Estadual de Maringa); Daniel Alexander Kuchma(University of Illinois at Urbana-Champaign); Jung Woong Park(University of Illinois at Urbana-Champaign); Tulio Nogueira Bittencourt(Escola Politecnica da Universidade de Sao Paulo)"
] |
The paper presents the development of an adaptable strut-and-tie model that can be applied to the design or analysis of four-pile caps that support axial compression and biaxial flexure from a supported rectangular column. Due to an absence of relevant test data, the model is validated using nonlinear finite element analyses (NLFEA). The results indicate that the use of the proposed model would lead to safe and economical designs. The proposed model can be easily extended to any number of piles, providing a rational procedure for the design of wide range of pile caps.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474651
|
oai_dc
|
Modeling mesoscale uncertainty for concrete in tension
|
Modeling mesoscale uncertainty for concrete in tension
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Nathan Tregger(Northwestern University); David Corr(Exponent Failure Analysis Associates Inc.); Lori Graham-Brady(Johns Hopkins University); Surendra Shah(Northwestern University)"
] |
Due to heterogeneities at all scales, concrete exhibits significant variability in mechanical behavior from sample to sample. An understanding of the fundamental mechanical performance of concrete must therefore be embedded in a stochastic framework. The current work attempts to address the connection between a two-dimensional concrete mesostructure and the random local material properties associated within that mesostructure. This work builds on previous work that has focused on the random configuration of concrete mesostructures. This was accomplished by developing an understanding of the effects of variations in the mortar strength and the mortar-aggregate interfacial strength in given deterministic mesostructural configurations. The results are assessed through direct tension tests that are validated by comparing experimental results of two different, pre-arranged mesostructures, with the intent of isolating the effect of local variations in strength. Agreement is shown both in mechanical property values as well as the qualitative nature of crack initiation and propagation.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474881
|
oai_dc
|
Simulations of spacing of localized zones in reinforced concrete beams using elasto-plasticity and damage mechanics with non-local softening
|
Simulations of spacing of localized zones in reinforced concrete beams using elasto-plasticity and damage mechanics with non-local softening
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"I. Marzec(Gdansk University of Technology); J. Bobinski(Gdansk University of Technology); J. Tejchman(Gdansk University of Technology)"
] |
The paper presents quasi-static plane strain FE-simulations of strain localization in reinforced concrete beams without stirrups. The material was modeled with two different isotropic continuum crack models: an elasto-plastic and a damage one. In case of elasto-plasticity, linear Drucker-Prager criterion with a non-associated flow rule was defined in the compressive regime and a Rankine criterion with an associated flow rule was adopted in the tensile regime. In the case of a damage model, the degradation of the material due to micro-cracking was described with a single scalar damage parameter. To ensure the mesh-independence and to capture size effects, both criteria were enhanced in a softening regime by nonlocal terms. Thus, a characteristic length of micro-structure was included. The effect of a characteristic length, reinforcement ratio, bond-slip stiffness, fracture energy and beam size on strain localization was investigated. The numerical results with reinforced concrete beams were quantitatively compared with corresponding laboratory tests by Walraven (1978).
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474681
|
oai_dc
|
Corrosion effects on tension stiffening behavior of reinforced concrete
|
Corrosion effects on tension stiffening behavior of reinforced concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. A. Shayanfar(Iran University of Science and Technology); M. Ghalehnovi(Iran University of Science and Technology); A. Safiey(Moshanir Power Engineering Consultants)"
] |
The investigation of corrosion effects on the tensile behavior of reinforced concrete (RC) members is very important in region prone to high corrosion conditions. In this article, an experimental study concerning corrosion effects on tensile behavior of RC members is presented. For this purpose, a comprehensive experimental program including 58 cylindrical reinforced concrete specimens under various levels of corrosion is conducted. Some of the specimens (44) are located in large tub containing water and salt (5% salt solution); an electrical supplier has been utilized for the accelerated corrosion program. Afterwards, the tensile behavior of the specimens was studied by means of the direct tension tests. For each specimen, the tension stiffening curve is plotted, and their behavior at various load levels is investigated. Average crack spacing, loss of cross-section area due to corrosion, the concrete contribution to the tensile response for different strain levels, and maximum bond stress developed at each corrosion level are studied, and their appropriate relationships are proposed. The main parameters considered in this investigation are: degree of corrosion (Cw), reinforcement diameter (d), reinforcement ratio (?), clear concrete cover (c), ratio of clear concrete cover to rebar diameter (c/d), and ratio of rebar diameter to reinforcement percentage (d/?).
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474645
|
oai_dc
|
Performance analysis tool for reinforced concrete members
|
Performance analysis tool for reinforced concrete members
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Asad Esmaeily(Kansas State University); Robert J. Peterman(Kansas State University)"
] |
A computer program was developed to analyze the non-linear, cyclic flexural performance of reinforced concrete structural members under various types of loading paths including non-sequential variations in axial load. This performance is significantly affected by the loading history. Different monotonic material models as well as hysteresis rules for confined and unconfined concrete and steel, some developed and calibrated against test results on material samples, were implemented in a fiber-based moment-curvature and in turn force-deflection analysis. One of the assumptions on curvature distribution along the member was based on a method developed to address the variation of the plastic hinge length as a result of loading pattern. Functionality of the program was verified by reproduction of analytical results obtained by others for several cases, and accuracy of the analytical process and the implemented models were evaluated against the experimental results from large-scale reinforced concrete columns tested under the analyzed loading cases. While the program can be used to predict the response of a member under a certain loading pattern, it can also be used to examine various analytical models and methods or refine a custom material model against test data.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474546
|
oai_dc
|
Reinforced concrete beams under drop-weight impact loads
|
Reinforced concrete beams under drop-weight impact loads
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ian M. May(Heriot-Watt University); Yi Chen(Heriot-Watt University); D. Roger J. Owen(University of Wales Swansea); Y. T. Feng(University of Wales Swansea); Philip J. Thiele(University of Wales Swansea)"
] |
This paper describes the results of an investigation into high mass-low velocity impact behaviour of reinforced concrete beams. Tests have been conducted on fifteen 2.7 m or 1.5 m span beams under drop-weight loads. A high-speed video camera has been used at rates of up to 4,500 frames per second in order to record the crack formation, propagation, particle spallation and scabbing. In some tests the strain in the reinforcement has been recorded using 밆urham?strain gauged bars, a technique developed by Scott and Marchand (2000) in which the strain gauges are embedded in the bars, so that the strains in the reinforcement can be recorded without affecting the bond between the concrete and the reinforcement. The impact force acting on the beams has been measured using a load cell placed within the impactor. A high-speed data logging system has been used to record the impact load, strains, accelerations, etc., so that time histories can be obtained. This research has led to the development of computational techniques based on combined continuum/discontinuum methods (finite/discrete element methods) to permit the simulation of impact loaded reinforced concrete beams. The implementation has been within the software package ELFEN (2004). Beams, similar to those tested, have been analysed using ELFEN a good agreement has been obtained for both the load-time histories and the crack patterns.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474566
|
oai_dc
|
Fuzzy inference based cover thickness estimation of reinforced concrete structure quantitatively \r\nconsidering salty environment impact
|
Fuzzy inference based cover thickness estimation of reinforced concrete structure quantitatively \r\nconsidering salty environment impact
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"도정윤(군산대학교)"
] |
This article involves architecting prototype-fuzzy expert system for designing the nominal cover thickness by means of fuzzy inference for quantitatively representing the environment affecting factor to reinforced concrete in chloride-induced corrosion environment. In this work, nominal cover thickness to reinforcement in concrete was determined by the sum of minimum cover thickness and tolerance to that defined from skill level, constructability and the significance of member. Several variables defining the quality of concrete and environment affecting factor (EAF) including relative humidity, temperature, cyclic wet and dry, and the distance from coast were treated as fuzzy variables. To qualify EAF the environment conditions of cycle degree of wet-dry, relative humidity, distance from coast and temperature were used as input variables. To determine the nominal cover thickness a qualified EAF, concrete grade, and water-cement ratio were used. The membership functions of each fuzzy variable were generated from the engineering knowledge and intuition based on some references as well as some international codes of practice.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474568
|
oai_dc
|
Development of a computer aided program for slipforming operations incorporating maturity approach
|
Development of a computer aided program for slipforming operations incorporating maturity approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"K.M.A. Hossain(Ryerson University); C. Anagnostopoulos(Colt Engineering); M. Lachemi(Ryerson University)"
] |
Slipforming is a construction method in which the forms move continuously during the placement of concrete. This paper presents the development of a computer aided program designated as 밅ADSLIPFORM?for slipforming operations. The program incorporates maturity methods for the prediction of initial setting times of slipform concrete layers using laboratory data (time-temperature histories and setting times of concrete mixtures at different temperatures) and generates slipform mock-up times. The performance of CADSLIPFORM is validated by comparing simulated mock-up times with those estimated in the field through conventional hard front by rod (R) method. Moreover, the program versatility is demonstrated by illustrating mock-up simulations for different cases with variable slipform parameters such as: number and thickness of concrete layers, concrete temperature (simulating variable setting times) and slipform speed. The program also incorporates the choice of Freiesleben Hansen & Pederson (FHP) and Carino & Tank (CT) maturity functions. CADSLIPFORM can assist user to develop reliable schedule of slipforming operation suitable for a specific project by optimizing various slipform parameters.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474558
|
oai_dc
|
The coupling effect of drying shrinkage and moisture diffusion in concrete
|
The coupling effect of drying shrinkage and moisture diffusion in concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Suwito(University of Colorado at Boulder); Ayman Ababneh(Clarkson University); Yunping Xi(University of Colorado at Boulder); Kaspar Willam(University of Colorado at Boulder)"
] |
Drying shrinkage of concrete occurs due to the loss of moisture and thus, it is controlled by moisture diffusion process. On the other hand, the shrinkage causes cracking of concrete and affects its moisture diffusion properties. Therefore, moisture diffusion and drying shrinkage are two coupled processes and their interactive effect is important for the durability of concrete structures. In this paper, the two material parameters in the moisture diffusion equation, i.e., the moisture capacity and humidity diffusivity, are modified by two different methods to include the effect of drying shrinkage on the moisture diffusion. The effect of drying shrinkage on the humidity diffusivity is introduced by the scalar damage parameter. The effect of drying shrinkage on the moisture capacity is evaluated by an analytical model based on non-equilibrium thermodynamics and minimum potential energy principle for a two-phase composite. The mechanical part of drying shrinkage is modeled as an elastoplastic damage problem. The coupled problem of moisture diffusion and drying shrinkage is solved using a finite element method. The present model can predict that the drying shrinkage accelerates the moisture diffusion in concrete, and in turn, the accelerated drying process increases the shrinkage strain. The coupling effects are demonstrated by a numerical example.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474561
|
oai_dc
|
Nonlinear finite element analysis of reinforced concrete corbels at both deterministic and probabilistic levels
|
Nonlinear finite element analysis of reinforced concrete corbels at both deterministic and probabilistic levels
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Alfred Strauss(University of Natural Resources and Applied Life Sciences); Andrea Mordini(University of Parma); Konrad Bergmeister(University of Natural Resources and Applied Life Sciences)"
] |
Reinforced concrete corbels are structural elements widely used in practical engineering. The complex response of these elements is described in design codes in a simplified manner. These formulations are not sufficient to show the real behavior, which, however, is an essential prerequisite for the manufacturing of numerous elements. Therefore, a deterministic and probabilistic study has been performed, which is described in this contribution. Real complex structures have been modeled by means of the finite element method supported primarily by experimental works. The main objective of this study was the detection of uncertainties effects and safety margins not captured by traditional codes. This aim could be fulfilled by statistical considerations applied to the investigated structures. The probabilistic study is based on advanced Monte Carlo simulation techniques and sophisticated nonlinear finite element formulations.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474567
|
oai_dc
|
The effects of different cement dosages, slumps and pumice aggregate ratios on the freezing and thawing of concrete
|
The effects of different cement dosages, slumps and pumice aggregate ratios on the freezing and thawing of concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ibrahim Turkmen(Ataturk University); Ramazan Demirboga(Ataturk University); Rustem Gul(Ataturk University)"
] |
This research was conducted to determine effect of pumice aggregate ratio, cement dosage and slumps on freeze-thaw resistance, density, water absorption and elasticity of concrete. In the first batch, 300 kg/m3 cement dosage were kept constant and pumice ratios were changed as 25%, 50%, 75% and 100% of replacement for normal aggregate by volume for 3? cm, 5? cm and 7? cm slumps. Other batches were prepared with 200 kg/m3, 250 kg/m3, 350 kg/m3, 400 kg/m3 and 500 kg/m3 cement dosages and 25% pumice aggregate +75% normal aggregate at a constant slump. Test results showed that when pumice-aggregate ratio decreased the density and freeze-thaw resistance of concretes increased. With increasing of cement dosage in the mixtures, density of the concretes increased, however, freeze-thaw resistance of concretes decreased. Water absorption of the concrete decreased with increasing cement dosage but increased with the pumice ratio. Water absorption of the concrete also decreased after freeze-thaw cycles. Freeze-thaw resistance of concretes was decreased with increasing the slumps.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474553
|
oai_dc
|
Nonlinear analysis of connectors applied on concrete composite constructions
|
Nonlinear analysis of connectors applied on concrete composite constructions
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"B. Winkler(Hilti Corporation); P. Bianchi(Hilti Corporation); M. Siemers(Hilti Corporation)"
] |
To place concrete overlays has become a standard application in the strengthening and rehabilitation of concrete structures such as bridges, tunnels, parking decks and industrial buildings. In general, connectors are used to ensure a monolithic behavior of the two concrete layers. Within the framework of the development of a new connector wedge splitting tests and shear tests were performed, in addition nonlinear finite element analyses were applied to investigate the load transfer behavior of the connectors for different prototypes. The numerical simulation results were compared to experimental data. The computed load-displacement curve demonstrates good correspondence with the curves obtained in the experiments, and the experimental crack patterns are reasonably simulated by the computed crack propagation. Both numerical and experimental investigations on the wedge splitting test and on the shear test served as basis for the development of new type of connectors.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001520011
|
oai_dc
|
Application of computational technologies to R/C structural analysis
|
Application of computational technologies to R/C structural analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Takashi Hara(Tokuyama College of Technology)"
] |
In this paper, FEM procedure is applied to the static and dynamic analyses of R/C structures. Simple R/C shell structure is solved by using FEM procedures and the experimental evaluations are performed to represent the applicability of FEM procedure to R/C structures. Also, R/C columns are analyzed numerically and experimentally. On the basis of these results, FEM procedures are applied to the R/C cooling tower structures assembled by huge R/C shell structure and a lot of discrete R/C columns. In this analysis, the parallel computing procedures are introduced into these analyses to reduce the computational effort. The dynamic performances of R/C cooling tower are also solved by the application of parallel computations as well. From the numerical analyses, the conventional FEM procedures combined with computational technologies enables us to design the huge R/C structures statically and dynamically.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001520006
|
oai_dc
|
Force-deformation behaviour modelling of cracked reinforced concrete by EXCEL spreadsheets
|
Force-deformation behaviour modelling of cracked reinforced concrete by EXCEL spreadsheets
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Nelson Lam(University of Melbourne); John Wilson(Swinburne University of Technology); Elisa Lumantarna(Swinburne University of Technology)"
] |
Force-deformation modelling of cracked reinforced concrete is essential for a displacementbased seismic assessment of structures and can be achieved by fibre-element analysis of the cross-section of the major lateral resisting elements. The non-linear moment curvature relationship obtained from fibreelement analysis takes into account the significant effects of axial pre-compression and contributions by the longitudinal reinforcement. Whilst some specialised analysis packages possess the capability of incorporating fibre-elements into the modelling (e.g., RESPONSE 2000), implementation of the analysis on EXCEL is illustrated in this paper. The outcome of the analysis is the moment-curvature relationship of the wall cross-section, curvature at yield and at damage control limit states specified by the user. Few software platforms can compete with EXCEL in terms of its transparencies, versatility and familiarity to the computer users. The program has the capability of handling arbitrary cross-sections that are without an axis of symmetry. Application of the program is illustrated with examples of typical cross-sections of structural walls. The calculated limiting curvature for the considered cross-sections were used to construct displacement profiles up the height of the wall for comparison with the seismically induced displacement demand.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001520004
|
oai_dc
|
A numerical tension-stiffening model for ultra high strength fiber-reinforced concrete beams
|
A numerical tension-stiffening model for ultra high strength fiber-reinforced concrete beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"나채국(한국과학기술원); 곽효경(한국과학기술원)"
] |
A numerical model that can simulate the nonlinear behavior of ultra high strength fiberreinforced concrete (UHSFRC) structures subject to monotonic loadings is introduced. Since engineering material properties of UHSFRC are remarkably different from those of normal strength concrete and engineered cementitious composite, classification of the mechanical characteristics related to the biaxial behavior of UHSFRC, from the designation of the basic material properties such as the uniaxial stressstrain relationship of UHSFRC to consideration of the bond stress-slip between the reinforcement and surrounding concrete with fiber, is conducted in this paper in order to make possible accurate simulation of the cracking behavior in UHSFRC structures. Based on the concept of the equivalent uniaxial strain, constitutive relationships of UHSFRC are presented in the axes of orthotropy which coincide with the principal axes of the total strain and rotate according to the loading history. This paper introduces a criterion to simulate the tension-stiffening effect on the basis of the force equilibriums, compatibility conditions, and bond stress-slip relationship in an idealized axial member and its efficiency is validated by comparison with available experimental data. Finally, the applicability of the proposed numerical model is established through correlation studies between analytical and experimental results for idealized UHSFRC beams.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001520010
|
oai_dc
|
Analysis of side-plated reinforced concrete beams with partial interaction
|
Analysis of side-plated reinforced concrete beams with partial interaction
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"R.K.L. Su(The University of Hong Kong); W.H. Siu(The University of Hong Kong)"
] |
Existing reinforced concrete (RC) beams can be strengthened with externally bolted steel plates to the sides of beams. The effectiveness of this type of bolted side-plate (BSP) beam can however be affected by partial interaction between the steel plates and RC beams due to the mechanical slip of bolts. To avoid over-estimation of the flexural strength and ensure accurate prediction of the loaddeformation response of the beams, the effect of partial interaction has to be properly considered. In this paper, a special non-linear macro-finite-element model that takes into account the effects of partial interaction is proposed. The RC beam and the steel plates are modelled as two different elements, interacting through discrete groups of bolts. A layered method is adopted for the formulation of the RC beam and steel plate elements, while a special non-linear model based on a kinematic hardening assumption for the bolts is used to simulate the bolt group effect. The computer program SiBAN was developed based on the proposed approach. Comparison with the available experimental results shows that SiBAN can accurately predict the partial interaction behaviour of the BSP beams. Further numerical simulations show that the interaction between the RC beam and the steel plates is greatly reduced by the formation of plastic hinges and should be considered in analyses of the strengthened beams.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001520008
|
oai_dc
|
Predicting shear strength of RC exterior beam-column joints by modified rotating-angle softened-truss model
|
Predicting shear strength of RC exterior beam-column joints by modified rotating-angle softened-truss model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Simon H.F. Wong(Hyder Consulting (Hong Kong) Ltd); J.S. Kuang(Hong Kong University of Science and Technology)"
] |
A theoretical model known as the modified rotating-angle softened-truss model (MRA-STM), which is a modification of Rotating-Angle Softened-Truss Model and Modified Compression Field Theory, is presented for the analysis of reinforced concrete membranes in shear. As an application, shear strength and behaviour of reinforced concrete exterior beam-column joints are analysed using the MRA-STM combining with the deep beam analogy. The joints are considered as RC panels and subjected to vertical and horizontal shear stresses from adjacent columns and beams. The strut and truss actions in a beamcolumn joint are represented by the effective transverse compression stresses and a softened concrete truss in the proposed model. The theoretical predictions of shear strength of reinforced concrete exterior beamcolumn joints from the proposed model show good agreement with the experimental results.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001520013
|
oai_dc
|
Numerical study on concrete penetration/perforation under high velocity impact by ogive-nose steel projectile
|
Numerical study on concrete penetration/perforation under high velocity impact by ogive-nose steel projectile
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Md. Jahidul Islam(National University of Singapore); Somsak Swaddiwudhipong(National University of Singapore); Zishun Liu(Institute of High Performance Computing)"
] |
Severe element distortion problem is observed in finite element mesh while performing numerical simulations of high velocity steel projectiles penetration/perforation of concrete targets using finite element method (FEM). This problem of element distortion in Lagrangian formulation of FEM can be resolved by using element erosion methodology. Element erosion approach is applied in the finite element program by defining failure parameters as a condition for element elimination. In this study strain parameters for both compression and tension at failure are used as failure criteria. Since no direct method exists to determine these values, a calibration approach is used to establish suitable failure strain values while performing numerical simulations of ogive-nose steel projectile penetration/perforation into concrete target. A range of erosion parameters is suggested and adopted in concrete penetration/perforation tests to validate the suggested values. Good agreement between the numerical and field data is observed.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001520005
|
oai_dc
|
Numerical simulation of concrete confined by transverse reinforcement
|
Numerical simulation of concrete confined by transverse reinforcement
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yong Lu(The University of Edinburgh); Zhenhuan Song(The University of Edinburgh)"
] |
The behaviour of concrete confined by transverse reinforcement is a classical topic. Numerous studies have been conducted to establish the stress-strain relationships for concrete under various confining reinforcement arrangements. Many empirical and semi-empirical formulas exist. Simplified analytical models have also been proposed to evaluate the increase in the strength and ductility of confined concrete. However, relatively few studies have been conducted to utilise advanced computational models for a realistic simulation of the behaviour of concrete confined by transverse reinforcement. As a matter of fact, high fidelity simulations using the latest numerical solvers in conjunction with advanced material constitutive models can be a powerful means to investigating the mechanisms underlying the confining effects of different reinforcement schemes. This paper presents a study on the use of high fidelity finite element models for the investigation of the behaviour of concrete confined by stirrups, as well as the interpretation of the numerical results. The development of the models is described in detail, and the essential modelling considerations are discussed. The models are then validated by simulating representative experimental studies on short columns with different confining reinforcement schemes. The development and distribution of the confining stress and the subsequent increase in the axial strength are examined. The models are shown to be capable of reproducing the behaviour of the confined concrete realistically, paving a way for systematic parametric studies and investigation into complicated confinement, load combination, and dynamic loading situations.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474477
|
oai_dc
|
Concrete bridge deck deterioration model using belief networks
|
Concrete bridge deck deterioration model using belief networks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hrodny Njardardottir(University of Toronto); Brenda McCabe(University of Toronto); Michael D. A. Thomas(University of New Brunswick)"
] |
When deterioration of concrete is observed in a structure, it is highly desirable to determine the cause of such deterioration. Only by understanding the cause can an appropriate repair strategy be implemented to address both the cause and the symptom. In colder climates, bridge deck deterioration is often caused by chlorides from de-icing salts, which penetrate the concrete and depassivate the embedded reinforcement, causing corrosion. Bridge decks can also suffer from other deterioration mechanisms, such as alkali-silica reaction, freeze-thaw, and shrinkage. There is a need for a comprehensive and integrative system to help with the inspection and evaluation of concrete bridge deck deterioration before decisions are made on the best way to repair it. The purpose of this research was to develop a model to help with the diagnosis of concrete bridge deck deterioration that integrates the symptoms observed during an inspection, various deterioration mechanisms, and the probability of their occurrence given the available data. The model displays the diagnosis result as the probability that one of four deterioration mechanisms, namely shrinkage, corrosion of reinforcement, freeze-thaw and alkali-silica reaction, is at fault. Sensitivity analysis was performed to determine which probabilities in the model require refinement. Two case studies are included in this investigation.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474470
|
oai_dc
|
Evaluation of seismic response of soft-storey infilled frames
|
Evaluation of seismic response of soft-storey infilled frames
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Helen Santhi(Anna University); G. M. Samuel Knight(Anna University); K. Muthumani(Structural Engineering Research Centre)"
] |
In this study two single-bay, three-storey space frames, one with brick masonry infill in the second and third floors representing a soft-storey frame and the other without infill were designed and their 1:3 scale models were constructed according to non-seismic detailing and the similitude law. The models were excited with an intensity of earthquake motion as specified in the form of response spectrum in Indian seismic code IS 1893-2002 using a shake table. The seismic responses of the soft-storey frame such as fundamental frequency, mode shape, base shear and stiffness were compared with that of the bare frame. It was observed that the presence of open ground floor in the soft-storey infilled frame reduced the natural frequency by 30%. The shear demand in the soft-storey frame was found to be more than two and a half times greater than that in the bare frame. From the mode shape it was found that, the bare frame vibrated in the flexure mode whereas the soft-storey frame vibrated in the shear mode. The frames were tested to failure and the damaged soft-storey frame was retrofitted with concrete jacketing and, subjected to same earthquake motions as the original frames. Pushover analysis was carried out using the software package SAP 2000 to validate the test results. The performance point was obtained for all the frames under study, therefore the frames were found to be adequate for gravity loads and moderate earthquakes. It was concluded that the global nonlinear seismic response of reinforced concrete frames with masonry infill can be adequately simulated using static nonlinear pushover analysis.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474482
|
oai_dc
|
Nonlinear finite element analysis of reinforced concrete structures subjected to transient thermal loads
|
Nonlinear finite element analysis of reinforced concrete structures subjected to transient thermal loads
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"C. E. Zhou(University of Toronto); F. J. Vecchio(University of Toronto)"
] |
This paper describes a 2D nonlinear finite element analysis (NLFEA) platform that combines heat flow analysis with realistic analysis of cracked reinforced concrete structures. The behavior models included in the structural analysis are mainly based on the Modified Compression Field Theory and the Distributed Stress Field Model. The heat flow analysis takes into account time-varying thermal loads and temperature-dependent material properties. The capability of 2D nonlinear transient thermal analysis is then implemented into a nonlinear finite element analysis program VecTor2?for 2D reinforced concrete membranes. Analyses of four numerical examples are performed using VecTor2, and results obtained indicate that the suggested nonlinear finite element analysis procedure is capable of modeling the complete response of a concrete structure to thermal and mechanical loads.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474486
|
oai_dc
|
Damage detection in beams and plates using wavelet transforms
|
Damage detection in beams and plates using wavelet transforms
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Rajasekaran(PSG College of Technology); S. P. Varghese(PSG College of Technology)"
] |
A wavelet based approach is proposed for structural damage detection in beams, plate and delamination of composite plates. Wavelet theory is applied here for crack identification of a beam element with a transverse on edge non-propagating open crack. Finite difference method was used for generating a general displacement equation for the cracked beam in the first example. In the second and third example, damage is detected from the deformed shape of a loaded simply supported plate applying the wavelet theory. Delamination in composite plate is identified using wavelet theory in the fourth example. The main concept used is the breaking down of the dynamic signal of a structural response into a series of local basis function called wavelets, so as to detect the special characteristics of the structure by scaling and transformation property of wavelets. In the light of the results obtained, limitations of the proposed method as well as suggestions for future work are presented. Results show great promise of wavelet approach for damage detection and structural health monitoring.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474492
|
oai_dc
|
Simulation of fracture in plain concrete modeled as a composite material
|
Simulation of fracture in plain concrete modeled as a composite material
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Thanh T. Bui(University of New South Wales); Mario M. Attard(University of New South Wales)"
] |
A composite model is used to represent the heterogeneity of plain concrete consisting of coarse aggregates, mortar matrix and the mortar-aggregate interface. The composite elements of plain concrete are modeled using triangular finite element units which have six interface nodes along the sides. Fracture is captured through a constitutive single branch softening-fracture law at the interface nodes, which bounds the elastic domain inside each triangular unit. The inelastic displacement at an interface node represents the crack opening or sliding displacement and is conjugate to the internodal force. The path-dependent softening behaviour is developed within a quasi-prescribed displacement control formulation. The crack profile is restricted to the interface boundaries of the defined mesh. No re-meshing is carried out. Solutions to the rate formulation are obtained using a mathematical programming procedure in the form of a linear complementary problem. An event by event solution strategy is adopted to eliminate solutions with simultaneous formation of softening zones in symmetric problems. The composite plain concrete model is compared to experimental results for the tensile crack growth in a Brazilian test and three-point bending tests on different sized specimens. The model is also used to simulate wedge-type shear-compression failure directly under the loading platen of a Brazilian test.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474414
|
oai_dc
|
An expert system for making durable concrete for chemical exposure
|
An expert system for making durable concrete for chemical exposure
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Md. Nazrul Islam(Universiti Kebangsaan Malaysia); Muhammad Fauzi Mohd. Zain(Universiti Kebangsaan Malaysia); Hassan Basri(Universiti Kebangsaan Malaysia)"
] |
The development and the main features of an expert system for modeling the requirements of durable concrete in chemical exposure, called the Durable Concrete Advisor for Chemical Exposure (DCACE), are described. The system was developed to help improve the quality of concrete exposed to chemical environment by minimizing mistakes and deficiencies in selecting concrete constituents. Using Kappa-PC expert system shell, an object-oriented model was developed where the rule-based reasoning operates on or across objects. The American Concrete Institute manual of concrete practice was chosen as the main source of knowledge. Other textual sources were also consulted for knowledge acquisition. The major objectives of the research were acquisition and formalization of the relevant knowledge and building an expert system for making durable concrete for chemical exposure regarding sulfate attack, acid attack, seawater attack and carbonation. Similar to most expert systems, this system has explanation facilities, can be incrementally expanded, and has an easy to understand knowledge base. The performance of the system is demonstrated by an example session. The system is user-friendly and can be used as an educational tool.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474424
|
oai_dc
|
Fuzzy methodology application for modeling uncertainties in chloride ingress models of RC building structure
|
Fuzzy methodology application for modeling uncertainties in chloride ingress models of RC building structure
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"도정윤(군산대학교); 송훈(한국건설기술연구원); 소승영(전북대학교); 소양섭(전북대학교)"
] |
Chloride ingress is a common cause of deterioration of reinforced concrete located in coastal zone. Modeling the chloride ingress is an important basis for designing reinforced concrete structures and for assessing the reliability of an existing structure. The modeling is also needed for predicting the deterioration of a reinforced structure. The existing deterministic solution for prediction model of corrosion initiation cannot reflect uncertainties which input variables have. This paper presents an approach to the fuzzy arithmetic based modeling of the chloride-induced corrosion of reinforcement in concrete structures that takes into account the uncertainties in the physical models of chloride penetration into concrete and corrosion of steel reinforcement, as well as the uncertainties in the governing parameters, including concrete diffusivity, concrete cover depth, surface chloride concentration and critical chloride level for corrosion initiation. There are a lot of prediction model for predicting the time of reinforcement corrosion of structures exposed to chloride-induced corrosion environment. In this work, RILEM model formula and Crank뭩 solution of Fick뭩 second law of diffusion is used. The parameters of the models are regarded as fuzzy numbers with proper membership function adapted to statistical data of the governing parameters instead of random variables of probabilistic modeling of Monte Carlo Simulation and the fuzziness of the time to corrosion initiation is determined by the fuzzy arithmetic of interval arithmetic and extension principle. An analysis is implemented by comparing deterministic calculation with fuzzy arithmetic for above two prediction models.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474420
|
oai_dc
|
Complete moment-curvature relationship of reinforced normal- and high-strength concrete beams\r\nexperiencing complex load history
|
Complete moment-curvature relationship of reinforced normal- and high-strength concrete beams\r\nexperiencing complex load history
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F. T. K. Au(The University of Hong Kong); B. Z. Z. Bai(The University of Hong Kong); A. K. H. Kwan(The University of Hong Kong)"
] |
The moment-curvature relationship of reinforced concrete beams made of normal- and high-strength concrete experiencing complex load history is studied using a numerical method that employs the actual stress-strain curves of the constitutive materials and takes into account the stress-path dependence of the concrete and steel reinforcement. The load history considered includes loading, unloading and reloading. From the results obtained, it is found that the complete moment-curvature relationship, which is also path-dependent, is similar to the material stress-strain relationship with stress-path dependence. However, the unloading part of the moment-curvature relationship of the beam section is elastic but not perfectly linear, although the unloading of both concrete and steel is assumed to be linearly elastic. It is also observed that when unloading happens, the variation of neutral axis depth has different trends for under- and over-reinforced sections. Moreover, even when the section is fully unloaded, there are still residual curvature and stress in the section in some circumstances. Various issues related to the post-peak behavior of reinforced concrete beams are also discussed.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474411
|
oai_dc
|
Strut-tie model evaluation of behavior and strength of pre-tensioned concrete deep beams
|
Strut-tie model evaluation of behavior and strength of pre-tensioned concrete deep beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"윤영묵(경북대학교)"
] |
To date, many studies have been conducted for the analysis and design of reinforced concrete members with disturbed regions. However, prestressed concrete deep beams have not been the subject of many investigations. This paper presents an evaluation of the behavior and strength of three pre-tensioned concrete deep beams failed by shear and bond slip of prestressing strands using a nonlinear strut-tie model approach. In this approach, effective prestressing forces represented by equivalent external loads are gradually introduced along strand's transfer length in the nearest strut-tie model joints, the friction at the interface of main diagonal shear cracks is modeled by the aggregate interlock struts along the direction of the cracks in strut-tie model, and an algorithm considering the effect of bond slip of prestressing strands in the strut-tie model analysis and design of pre-tensioned concrete members is implemented. Through the strut-tie model analysis of pre-tensioned concrete deep beams, the nonlinear strut-tie model approach proved to present effective solutions for predicting the essential aspects of the behavior and strength of pre-tensioned concrete deep beams. The nonlinear strut-tie model approach is capable of predicting the strength and failure modes of pre-tensioned concrete deep beams including the anchorage failure of prestressing strands and, accordingly, can be employed in the practical and precise design of pre-tensioned concrete deep beams.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474393
|
oai_dc
|
Three-dimensional FE analysis of headed stud anchors exposed to fire
|
Three-dimensional FE analysis of headed stud anchors exposed to fire
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Josko Ozbolt(University of Stuttgart); Ivica Kozar(University of Rijeka); Rolf Eligehausen(University of Stuttgart); Goran Periskic(University of Stuttgart)"
] |
In the present paper a transient three-dimensional thermo-mechanical model for concrete is presented. For given boundary conditions, temperature distribution is calculated by employing a three-dimensional transient thermal finite element analysis. Thermal properties of concrete are assumed to be constant and independent of the stress-strain distribution. In the thermo-mechanical model for concrete the total strain tensor is decomposed into pure mechanical strain, free thermal strain and load induced thermal strain. The mechanical strain is calculated by using temperature dependent microplane model for concrete (Ozbolt, et al. 2001). The dependency of the macroscopic concrete properties (Young's modulus, tensile and compressive strengths and fracture energy) on temperature is based on the available experimental database. The stress independent free thermal strain is calculated according to the proposal of Nielsen, et al. (2001). The load induced thermal strain is obtained by employing the bi-parabolic model, which was recently proposed by Nielsen, et al. (2004). It is assumed that the total load induced thermal strain is irrecoverable, i.e., creep component is neglected. The model is implemented into a three-dimensional FE code. The performance of headed stud anchors exposed to fire was studied. Three-dimensional transient thermal FE analysis was carried out for three embedment depths and for four thermal loading histories. The results of the analysis show that the resistance of anchors can be significantly reduced if they are exposed to fire. The largest reduction of the load capacity was obtained for anchors with relatively small embedment depths. The numerical results agree well with the available experimental evidence.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474433
|
oai_dc
|
Cyclic load testing and numerical modeling of concrete columns with substandard seismic details
|
Cyclic load testing and numerical modeling of concrete columns with substandard seismic details
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mohammad S. Marefat(University of Tehran); Mohammad Khanmohammadi(University of Tehran); Mohammad K. Bahrani(University of Tehran); Ali Goli(University of Tehran)"
] |
Recent earthquakes have shown that many of existing buildings in Iran sustain heavy damage due to defective seismic details. To assess vulnerability of one common type of buildings, which consists of low rise framed concrete structures, three defective and three standard columns have been tested under reversed cyclic load. The substandard specimens suffered in average 37% loss of strength and 45% loss of energy dissipation capacity relative to standard specimens, and this was mainly due to less lateral and longitudinal reinforcement and insufficient sectional dimensions. A relationship has been developed to introduce variation of plastic length under increasing displacement amplitude. At ultimate state, the length of plastic hinge is almost equal to full depth of section. Using calibrated hysteresis models, the response of different specimens under two earthquakes has been analyzed. The analysis indicated that the ratio between displacement demand and capacity of standard specimens is about unity and that of deficient ones is about 1.7.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474429
|
oai_dc
|
Assessment of computational performance for a vector parallel implementation: 3D probabilistic model discrete cracking in concrete
|
Assessment of computational performance for a vector parallel implementation: 3D probabilistic model discrete cracking in concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Carmen N. M. Paz(LAMCE/COPPE/UFRJ); Jose L. D. Alves(LAMCE/COPPE/UFRJ); Nelson F. F. Ebecken(LAMCE/COPPE/UFRJ)"
] |
This work presents an assessment of the computational performance of a vector-parallel implementation of probabilistic model for concrete cracking in 3D. This paper shows the continuing efforts towards code optimization as reported in earlier works Paz, et al. (2002a,b and 2003). The probabilistic crack approach is based on the direct Monte Carlo method. Cracking is accounted by means of 3D interface elements. This approach considers that all nonlinearities are restricted to interface elements modeling cracks. The heterogeneity governs the overall cracking behavior and related size effects on concrete fracture. Computational kernels in the implementation are the inexact Newton iterative driver to solve the non-linear problem and a preconditioned conjugate gradient (PCG) driver to solve linearized equations, using an element by element (EBE) strategy to compute matrix-vector products. In particular the paper analyzes code behavior using OpenMP directives in parallel vector processors (PVP), such as the CRAY SV1 and CRAY T94. The impact of the memory architecture on code performance, and also some strategies devised to circumvent this issue are addressed by numerical experiment.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474436
|
oai_dc
|
Performance evaluation of binary blends of Portland cement and fly ash with complex admixture for durable concrete structures
|
Performance evaluation of binary blends of Portland cement and fly ash with complex admixture for durable concrete structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dingyi Yang(Southeast University); Wei Sun(Yangzhou University); Yongquan Tan(Suzhou Concrete and Cement Products Research Institute)"
] |
This paper presents the results of a study on binary blends of Portland cement and fly ash with complex admixture used for the concrete structures to meet specific performance objectives in east coastal area of China. The concretes were evaluated for workability, strength, water permeability, drying shrinkage, sulfate resistance and electrical resistance. Environmental Scanning Electron Microscopy (ESEM) was used to examine the microstructure of concrete made by complex admixture compared with control batches without complex admixture. The combined efforts of fly ash and complex admixture led to an improvement in the workability, strength and durability.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474463
|
oai_dc
|
Optimal proportioning of concrete aggregates using a self-adaptive genetic algorithm
|
Optimal proportioning of concrete aggregates using a self-adaptive genetic algorithm
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Adil Amirjanov(Near East University); Konstantin Sobolev(Universidad Autonoma de Nuevo Leon)"
] |
A linear programming problem of the optimal proportioning of concrete aggregates is discussed; and a self-adaptive genetic algorithm is developed to solve this problem. The proposed method is based on changing a range of variables for capturing the feasible region of the optimum solution. A computational verification of this method is compared with the results of the linear programming.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474873
|
oai_dc
|
Finite element modeling methodologies for FRP strengthened RC members
|
Finite element modeling methodologies for FRP strengthened RC members
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Sangdon Park(Syracuse University); Riyad Aboutaha(Syracuse University)"
] |
The Finite Element Analysis (FEA) is evidently a powerful tool for the analysis of structural concrete having nonlinearity and brittle failure properties. However, the result of FEA of structural concrete is sensitive to two modeling factors: the shear transfer coefficient (STC) for an open concrete crack and force convergence tolerance value (CONVTOL). Very limited work has been done to find the optimal FE Modeling (FEM) methodologies for structural concrete members strengthened with externally bonded FRP sheets. A total of 22 experimental deep beams with or without FRP flexure or/and shear strengthening systems are analyzed by nonlinear FEA using ANAYS program. For each experimental beams, an FE model with a total of 16 cases of modeling factor combinations are developed and analyzed to find the optimal FEM methodology. Two elements the SHELL63 and SOLID46 representing the material properties of FRP laminate are investigated and compared. The results of this research suggest that the optimal combination of modeling factor is STC of 0.25 and CONVTOL of 0.2. A SOLID 46 element representing the FRP strengthening system leads to better results than a SHELL 63 element does.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473687
|
oai_dc
|
Framework for a general section designer software component
|
Framework for a general section designer software component
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Naveed Anwar(Naveed Anwar and Worsak Kanok-NukulchaiAsian Institute of Technology (AIT)); Worsak Kanok-Nukulchai(Naveed Anwar and Worsak Kanok-NukulchaiAsian Institute of Technology (AIT))"
] |
The Component-Based Software Development (CBSD) has established itself as a sound paradigm in the software engineering discipline and has gained wide spread acceptance in the industry. The CBSD relies on the availability of standard software components for encapsulation of specific functionality. This paper presents the framework for the development of a software component for the design of general member cross-sections. The proposed component can be used in component-based structural engineering software or as a stand-alone program developed around the component. This paper describes the use-case scenarios for the component, its design patterns, object models, class hierarchy, the integrated and unified handling of cross-section behavior and implementation issue. It is expected that acomponent developed using the proposed patterns and model can be used in analysis, design and detailing packages to handle reinforced concrete, partially prestressed concrete, steel-concrete composite and steel sections. The component can provide the entire response parameters of the cross section including determination of geometric properties, elastic stresses, flexural capacity, moment-curvature, and ductility ratios. The component can also be used as the main computational engine for stand-alone section design software. The component can be further extended to handle the retrofitting and strengthening of crosssections, shear and torsional response, determination of fire-damage parameters, etc.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473679
|
oai_dc
|
Direct frequency domain analysis of concrete arch dams based on FE-(FE-HE)-BE technique
|
Direct frequency domain analysis of concrete arch dams based on FE-(FE-HE)-BE technique
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Vahid Lotfi(Amirkabir University)"
] |
A FE-(FE-HE)-BE procedure is presented for dynamic analysis of concrete arch dams. In this technique, dam body is discretized by solid finite elements, while the reservoir domain is considered by a combination of fluid finite elements and a three-dimensional fluid hyper-element. Furthermore, foundation rock domain is handled by three- dimensional boundary element formulation. Based on thismethod, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various conditions. Moreover, the effects of canyon shape on response of dam, is also discussed
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001474884
|
oai_dc
|
Three dimensional finite element simulations of fracture tests using the Craft concrete model
|
Three dimensional finite element simulations of fracture tests using the Craft concrete model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.D. Jefferson(Cardiff University); B.I.G. Barr(Cardiff University); T. Bennett(Cardiff University); S.C. Hee(Cardiff University)"
] |
Two enhancements to a recently developed plastic-damage-contact model for concrete are presented. The model itself, which uses planes of degradation that can undergo damage and separation but that can regain contact according to a contact law, is described. The first enhancement is a new damage evolution function which provides a completely smooth transition from the undamaged to the damaged state and from pre-peak to post-peak regions. The second is an improved contact function that governs thepotential degree of contact with increasing opening on a crack plane. The use of a damage evolution function with a pre-peak has implications for the consistent tangent matrix/stress recovery algorithm developed for the model implementation, and amendments to this algorithm to accommodate the new function are described. A series of unpublished experimental tests on notched specimens undertaken in Cardiff in the mid 1990s are then described. These include notched beam tests as well as prismatic and cylindrical torsion tests. The tests are then considered in three dimensional finite element analyses using the modified Craft model implemented in the finite element program LUSAS. Comparisons between experimental and numerical data show reasonable agreement except that the numerical simulations do not fully describe the latter stages of the softening responses for the torsion examples. Finally, it is concluded that the torsion tests described provide useful benchmark examples for the validation of three-dimensional numerical models for concrete.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473603
|
oai_dc
|
An experimental-computational investigation of fracture in brittle materials
|
An experimental-computational investigation of fracture in brittle materials
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"K. De Proft(Vrije Universiteit Brussel); G. N. Wells(Delft University of Technology); L. J. Sluys(Delft University of Technology); W. P. De Wilde(Vrije Universiteit Brussel)"
] |
A combined experimental-computational study of a double edge-notched stone specimen subjected to tensile loading is presented. In the experimental part, the load-deformation response and the displacement field around the crack tip are recorded. An Electronic Speckle Pattern Interferometer (ESPI) is used to obtain the local displacement field. The experimental results are used to validate a numerical model for the description of fracture using finite elements. The numerical model uses displacement discontinuities to model cracks. At the discontinuity, a plasticity-based cohesive zone model is applied for monotonic loading and a combined damage-plasticity cohesive zone model is used for cyclic loading. Both local and global results from the numerical simulations are compared with experimental data. It is shown that local measurements add important information for the validation of the numerical model. Consequently, the numerical models are enhanced in order to correctly capture the experimentally observed behaviour.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473718
|
oai_dc
|
Finite element modeling of slab-on-beam concrete bridge superstructures
|
Finite element modeling of slab-on-beam concrete bridge superstructures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Michael D. Patrick(Tennessee Technological University); X. Sharon Huo(Tennessee Technological University)"
] |
This paper presents a study of four finite element techniques that can be used to model slabon-beam highway bridges. The feasibility and correctness of each modeling technique are examined by applying them to a prestressed concrete I-beam bridge and a prestressed concrete box-beam bridge. Other issues related to bridge modeling such as torsional constant, support conditions, and quality control check are studied in detail and discussed in the paper. It is found that, under truck loading, the bending stress distribution in a beam section depends on the modeling technique being utilized. It is observed that the behavior of the bridge superstructure can be better represented when accounting for composite behavior between the supporting beams and slab.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473705
|
oai_dc
|
Computational optimisation of a concrete model to simulate membrane action in RC slabs
|
Computational optimisation of a concrete model to simulate membrane action in RC slabs
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Khandaker M. A. Hossain(Ryerson University); Olubayo O. Olufemi(University of Aberdeen)"
] |
Slabs in buildings and bridge decks, which are restrained against lateral displacements at the edges, have ultimate strengths far in excess of those predicted by analytical methods based on yield line theory. The increase in strength has been attributed to membrane action, which is due to the in-plane forces developed at the supports. The benefits of compressive membrane action are usually not taken into account in currently available design methods developed based on plastic flow theories assuming concreteto be a rigid-plastic material. By extending the existing knowledge of compressive membrane action, it is possible to design slabs in building and bridge structures economically with less than normal reinforcement. Recent research on building and bridge structures reflects the importance of membrane action in design. This paper describes the finite element modelling of membrane action in reinforced concrete slabs through optimisation of a simple concrete model. Through a series of parametric studies using the simple concrete model in the finite element simulation of eight fully clamped concrete slabs with significant membrane action, a set of fixed numerical model parameter values is identified and computational conditions established, which would guarantee reliable strength prediction of arbitrary slabs. The reliability of the identified values to simulate membrane action (for prediction purposes) is further verified by the directsimulation of 42 other slabs, which gave an average value of 0.9698 for the ratio of experimental to predicted strengths and a standard deviation of 0.117. A ?eflection factor?is also established for the slabs, relating the predicted peak deflection to experimental values, which, (for the same level of fixity at the supports), can be used for accurate displacement determination. The proposed optimised concrete model and finite element procedure can be used as a tool to simulate membrane action in slabs in building and bridge structures having variable support and loading conditions including fire. Other practical applications of the developed finite element procedure and design process are also discussed.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001473611
|
oai_dc
|
Analysis of stress distribution in anchorage zones of pretensioned beams
|
Analysis of stress distribution in anchorage zones of pretensioned beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F. Gens(Université de Liège); J-C. Dotreppe(Université de Liège)"
] |
The stress transmission mechanism in pretensioned concrete beams, though very interesting from an economical point of view, is very complex, integrating various phenomenons such as sliding, bond, bursting. For long the complexity of this mechanism has led engineers to provide a massive rectangular anchorage zone at each end of the beam. The necessity of using such a concrete reinforcementis certainly unquestionable in post-tensioned beams. However in pretensioned elements the stresses induced in concrete in the anchorage zone are smaller than in post-tensioned elements. In this article the stress field in the end zone is calculated numerically and from this analysis the possible reduction of the cross-section of the anchorage block is examined.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464233
|
oai_dc
|
Modelling time-dependent cracking in reinforced concrete using bond-slip Interface elements
|
Modelling time-dependent cracking in reinforced concrete using bond-slip Interface elements
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kak Tien Chong(The University of New South Wales); R. Ian Gilbert(The University of New South Wales); Stephen J. Foster(The University of New South Wales)"
] |
two-dimensional nonlinear finite element model is developed to simulate time-dependent cracking of reinforced concrete members under service loads. To predict localized cracking, the crack band model is employed to model individual crack opening. In conjunction with the crack band model, a bond-interface element is used to model the slip between concrete and reinforcing steel permitting large slip displacements between the concrete element nodes and the steel truss element nodes at crack openings. The time-dependent effects of concrete creep and shrinkage are incorporated into the smeared
crack model as inelastic pre-strains in an iterative solution procedure. Two test examples are shown to verify the finite element model with good agreement between the model and the observed test results.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464198
|
oai_dc
|
Implementation of a macro model to predict seismic response of RC structural walls
|
Implementation of a macro model to predict seismic response of RC structural walls
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Matej Fischinger(University of Ljubljana); Tatjana Isakovic(University of Ljubljana); Peter Kante(University of Ljubljana)"
] |
A relatively simple multiple-vertical-line-element macro model has been incorporated into a standard computer code DRAIN-2D. It was used in blind predictions of seismic response of cantilever RC walls subjected to a series of consequent earthquakes on a shaking table. The model was able to predict predominantly flexural response with relative success. It was able to predict the stiffness and the strength of the pre-cracked specimen and time-history response of the highly nonlinear wall as well as to simulate the shift of the neutral axis and corresponding varying axial force in the cantilever wall. However, failing to identify the rupture of some brittle reinforcement in the third test, the model was not able to predict post-critical, near collapse behaviour during the subsequent response to two stronger earthquakes. The
analysed macro model seems to be appropriate for global analyses of complex building structures with RC structural walls subjected to moderate/strong earthquakes. However, it cannot, by definition, be used
in refined research analyses monitoring local behaviour in the post critical region.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464195
|
oai_dc
|
A computational setting of calcium leaching in concrete and its coupling with continuum damage mechanics
|
A computational setting of calcium leaching in concrete and its coupling with continuum damage mechanics
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"V. H. Nguyen(Institut Navier); B. Nedjar(Institut Navier); J. M. Torrenti(IRSN/DIR/Pg)"
] |
We present in this work a coupled phenomenological chemo-mechanical model that represents the degradation of concrete-like materials. The chemical behaviour is described by the nowadays well known simplified calcium leaching approach. And the mechanical damage behaviour is described by a continuum damage model which involves the gradient of the damage quantity. The coupled nonlinear problem at hand is addressed within the context of the finite element method. For the equation governing the calcium dissolution-diffusion part of the problem, special care is taken to treat the highly nonlinear calcium conductivity and solid calcium functions. The algorithmic design is based on a Newton-type iterative scheme where use is made of a recently proposed relaxed linearization procedure. And for the equation governing the damage part of the problem, an augmented Lagrangian formulation is used to take into account the damage irreversibility constraint. Finally, numerical simulations are compared with experimental results on cement paste.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464196
|
oai_dc
|
A coupled damage-viscoplasticity model for the analysis of localisation and size effects
|
A coupled damage-viscoplasticity model for the analysis of localisation and size effects
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J. F. Georgin(URGC Structures); L. J. Sluys(TU Delft); J. M. Reynouard(URGC Structures)"
] |
A coupled damage-viscoplasticity model is presented for the analysis of localisation and size effects. On one hand, viscosity helps to avoid mesh sensitivity because of the introduction of a length scale in the model and, on the other hand, enables to represent size effects. Size effects were analysed by means of three-point bending tests. Correlation between the fracture energy parameter measured experimentally and the density fracture energy modelling parameter is discussed. It has been shown that the dependence of nominal strength and fracture energy on size is determined by the ligament length in comparison with the width of the fracture process zone.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464232
|
oai_dc
|
Improved phenomenological modelling of transient thermal strains for concrete at high temperatures
|
Improved phenomenological modelling of transient thermal strains for concrete at high temperatures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Claus V. Nielsen(Danish Technological Institute); Chris J. Pearce(University of Glasgow); Nenad Bicanic(University of Glasgow)"
] |
Several extensions to the Thelandersson phenomenological model for concrete under transient high temperatures are explored. These include novel expressions for the temperature degradation of the elastic modulus and the temperature dependency of the coefficient of the free thermal strain. Furthermore, a coefficient of thermo mechanical strain is proposed as a bi-linear function of temperature. Good qualitative agreement with various test results taken from the literature is demonstrated. Further extensions
include the effects of plastic straining and temperature dependent Poisson’s ratio. The models performance is illustrated on several simple benchmark problems under uniaxial and biaxial stress states.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464192
|
oai_dc
|
A minimum ductility design method for non-rectangular high-strength concrete beams
|
A minimum ductility design method for non-rectangular high-strength concrete beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F. T. K. Au(The University of Hong Kong); A. K. H. Kwan(The University of Hong Kong)"
] |
The flexural ductility of solid rectangular reinforced concrete beams has been studied quite extensively. However, many reinforced concrete beams are neither solid nor rectangular; examples include T-, Γ-, Π- and box-shaped beams. There have been few studies on the flexural ductility of nonrectangular reinforced concrete beams and as a result little is known about the possible effect of sectional shape on flexural ductility. Herein, the effect of sectional shape on the post-peak flexural behaviour of reinforced normal and high-strength concrete beams has been studied using a newly developed analysis method that employs the actual stress-strain curves of the constitutive materials and takes into account the stress-path dependence of the stress-strain curve of the steel reinforcement. It was revealed that the
sectional shape could have significant effect on the flexural ductility of a concrete beam and that the flexural ductility of a T-, Γ-, Π- or box-shaped beam is generally lower than that of a solid rectangular beam with the same overall dimensions and the same amount of reinforcement provided. Based on the numerical results obtained, a simple method of ensuring the provision of a certain minimum level of flexural ductility to non-rectangular concrete beams has been developed.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464188
|
oai_dc
|
Computational modeling of cracking of concrete in strong discontinuity settings
|
Computational modeling of cracking of concrete in strong discontinuity settings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"J. Oliver(Technical University of Catalonia); A. Huespe(Technical University of Catalonia); M.D.G. Pulido(Technical University of Catalonia); S. Blanco(Technical University of Catalonia)"
] |
The paper is devoted to present the Continuum Strong Discontinuity Approach (CSDA) and to examine its capabilities for modeling cracking of concrete. After introducing the main ingredients of the CSDA, an isotropic continuum damage model, which distinguishes tension and compression states, is used to implicitly induce a projected traction separation-law that rules the cracking phenomena. Criteria for onset and propagation of material failure and specific finite elements with embedded discontinuities are also briefly sketched. Finally, some representative numerical simulations of cracking, in plain and
reinforced concrete specimens, using the CSDA are presented.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464166
|
oai_dc
|
Tools for forensic analysis of concrete structures
|
Tools for forensic analysis of concrete structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Frank J. Vecchio(University of Toronto); Evan C. Bentz(University of Toronto); Michael P. Collins(University of Toronto)"
] |
Computer-based analysis tools for forensic assessment of reinforced concrete structures are presented. The analysis tools, mostly in the form of nonlinear finite element procedures, are based on the concepts and formulations of the Modified Compression Field Theory. Relevant details regarding their formulation are provided. Development of realistic constitutive models and corroboration of the analysis procedures, through comprehensive experimental programs, are discussed. Also presented are graphicsbased pre- and post-processors, which are of significant aid in structural modeling, input of data, and interpretation of analysis results. The details and results of a case study, illustrating the application and value of such analytical tools, are also discussed.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464171
|
oai_dc
|
Computer aided reinforcement design of RC structures
|
Computer aided reinforcement design of RC structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xuehui An(Tsinghua University); Koichi Maekawa(The University of Tokyo)"
] |
In this study, a design process for reinforced concrete structures using the nonlinear FEM analysis is developed. Instead of using the nonlinear analysis to evaluate the required performance after design process, the nonlinear analysis is applied before designing the reinforcement arrangement inside the RC structures. An automatic reinforcement generator for computer aided reinforcement agreement is developed for this purpose. Based on a nonlinear FEM program for analyzing the reinforced concrete structure, a smart fictitious material model of steel, is proposed which can self-adjust the reinforcement to the required amount at the cracking location according to the load increment. Using this tool, the reinforcement ratio required at design load level can be decided automatically. In this paper, an example of RC beam with
opening is used to verify the proposed process. Finally, a trial design process for a real size underground RC LNG tank is introduced.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464185
|
oai_dc
|
An analytical and computational study on energy dissipation along fracture process zone in concrete
|
An analytical and computational study on energy dissipation along fracture process zone in concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yanhua Zhao(Dalian University of Technology); Shilang Xu(Dalian University of Technology); Zongjin Li(Hong Kong University of Science & Technology)"
] |
The influence of the fracture process zone (FPZ) on the fracture properties is one of the hottest topics in the field of fracture mechanics for cementitious materials. Within the FPZ in front of a traction free crack, cohesive forces are distributed in accordance with the softening stress-separation constitutive relation of the material. Therefore, further crack propagation necessitates energy dissipation, which is the work done by the cohesive forces. In this paper gf, the local fracture energy characterizing the energy consumption due to the cohesive forces, is discussed. The computational expression of gf in
the FPZ can be obtained for any stage during the material fracture process regarding the variation of FPZ, whether in terms of its length or width. Gfa, the average energy consumption along the crack extension region, has also been computed and discussed in this paper. The experimental results obtained from the wedge splitting tests on specimens with different initial notch ratios are employed to investigate the property of the local fracture energy gf and the average value Gfa over the crack extension length. These results can be used to indicate the influence of the FPZ. Additionally, changes in the length of the FPZ during the fracture process are also studied.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464175
|
oai_dc
|
Numeric simulation of near-surface moisture migration and stress development in concrete exposed to fire
|
Numeric simulation of near-surface moisture migration and stress development in concrete exposed to fire
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Gary R. Consolazio(University of Florida); Jae H. Chung(University of Florida)"
] |
A methodology is presented for computing stresses in structural concrete members exposed to fire. Coupled heat and moisture migration simulations are used to establish temperature, pore pressure, and liquid-saturation state variables within near-surface zones of heated concrete members. Particular attention is placed on the use of coupled heat and multiphase fluid flow simulations to study phenomena such as moisture-clogging. Once the state variables are determined, a procedure for combining the effects of thermal dilation, mechanical loads, pore pressure, and boundary conditions is proposed and demonstrated. Combined stresses are computed for varying displacement boundary conditions using data obtained from coupled heat and moisture flow simulations. These stresses are then compared to stresses computed from thermal analyses in which moisture effects are omitted. The results demonstrate that moisture migration has a significant influence on the development of thermal stresses.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464191
|
oai_dc
|
Performance of structural-concrete members under sequential loading and exhibiting points of inflection
|
Performance of structural-concrete members under sequential loading and exhibiting points of inflection
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"I. Jelic(Arup); M.N. Pavlovic(Imperial College); M.D. Kotsovos(National Technical University of Athens)"
] |
The article reports data on, and numerical modelling of, beams exhibiting points of inflection and subjected to sequential loading. Both tests and analysis point to inadequacies in current codes of practice. An alternative design methodology, which is strongly associated with the notion that contraflexure points should be designed as “internal supports”, is shown to produce superior performance even though it requires significantly less secondary reinforcement than that advocated by codes.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464190
|
oai_dc
|
Cracking behavior of RC shear walls subject to cyclic loadings
|
Cracking behavior of RC shear walls subject to cyclic loadings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"곽효경(한국과학기술원); 김도연(한국과학기술원)"
] |
This paper presents a numerical model for simulating the nonlinear response of reinforced concrete (RC) shear walls subject to cyclic loadings. The material behavior of cracked concrete is described by an orthotropic constitutive relation with tension-stiffening and compression softening effects defining equivalent uniaxial stress-strain relation in the axes of orthotropy. Especially in making analytical predictions for inelastic behaviors of RC walls under reversed cyclic loading, some influencing factors inducing the material nonlinearities have been considered. A simple hysteretic stress-strain relation of concrete, which crosses the tension-compression region, is defined. Modification of the hysteretic stressstrain relation of steel is also introduced to reflect a pinching effect depending on the shear span ratio and
to represent an average stress distribution in a cracked RC element, respectively. To assess the applicability of the constitutive model for RC element, analytical results are compared with idealized shear panel and shear wall test results under monotonic and cyclic shear loadings.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464391
|
oai_dc
|
On modeling of fire resistance tests on concrete and reinforced-concrete structures
|
On modeling of fire resistance tests on concrete and reinforced-concrete structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Adnan Ibrahimbegovic(LMT-Cachan); Amor Boulkertous(LMT-Cachan); Luc Davenne(LMT-Cachan); Medzid Muhasilovic(Unverisity of Ljubljana); Ahmed Pokrklic(University of Sarajevo)"
] |
In this work we first review the statistical data on large fires in urban areas, presenting a detailed list of causes of fires, the type of damage to concrete and reinforced concrete structures. We also present the modern experimental approach for studying the fire-resistance of different structural components, along with the role of numerical modeling to provide more detailed information on quantifying the temperature and heat flux fields. In the last part of this work we provide the refined models for assessment of fireinduced damage in structures built of concrete and/or reinforced-concrete. We show that the refined models of this kind are needed to provide a more thorough explanation of damage and to complete the damage assessment and post-fire evaluations.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464801
|
oai_dc
|
Some aspects of load-rate sensitivity in visco-elastic microplane material model
|
Some aspects of load-rate sensitivity in visco-elastic microplane material model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ivica Kožar(University of Rijeka); Joško Ožbolt(University of Rijeka)"
] |
The paper describes localization of deformation in a bar under tensile loading. The material of the bar is considered as non-linear viscous elastic and the bar consists of two symmetric halves. It is assumed that the model represents behavior of the quasi-brittle viscous material under uniaxial tension with different loading rates. Besides that, the bar could represent uniaxial stress-strain law on a single plane of a microplane material model. Non-linear material property is taken from the microplane material model and it is coupled with the viscous damper producing non-linear Maxwell material model.
Mathematically, the problem is described with a system of two partial differential equations with a nonlinear algebraic constraint. In order to obtain solution, the system of differential algebraic equations is transformed into a system of three partial differential equations. System is subjected to loadings of different rate and it is shown that localization occurs only for high loading rates. Mathematically, in such a case two solutions are possible: one without the localization (unstable) and one with the localization (stable one). Furthermore, mass is added to the bar and in that case the problem is described with a system of four differential equations. It is demonstrated that for high enough loading rates, it is the added mass that dominates the response, in contrast to the viscous and elastic material parameters that dominated in the case without mass. This is demonstrated by several numerical examples.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464394
|
oai_dc
|
Stress resultant model for ultimate load design of reinforced-concrete frames: combined axial force and bending moment
|
Stress resultant model for ultimate load design of reinforced-concrete frames: combined axial force and bending moment
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ba-Hung Pham(Ecole Normale Superieure de Cachan); Luc Davenne(Ecole Normale Superieure de Cachan); Delphine Brancherie(Universite de Technologie de Compiegne); Adnan Ibrahimbegovic(Ecole Normale Superieure de Cachan)"
] |
In this paper, we present a new finite Timoshenko beam element with a model for ultimate load computation of reinforced concrete frames. The proposed model combines the descriptions of the diffuse plastic failure in the beam-column followed by the creation of plastic hinges due to the failure or collapse of the concrete and or the re-bars. A modified multi-scale analysis is performed in order to identify the parameters for stress-resultant-based macro model, which is used to described the behavior of the Timoshenko beam element. The micro-scale is described by using the multi-fiber elements with embedded strain discontinuities in mode 1, which would typically be triggered by bending failure mode. A special attention is paid to the influence of the axial force on the bending moment - rotation response, especially for the columns behavior computation.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464810
|
oai_dc
|
Towards robust viscoelastic-plastic-damage material model with different hardenings/softenings capable of representing salient phenomena in seismic loading applications
|
Towards robust viscoelastic-plastic-damage material model with different hardenings/softenings capable of representing salient phenomena in seismic loading applications
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Pierre Jehel(LMT-Cachan (ENS Cachan/CNRS/UPMC/PRES UniverSud Paris)); Luc Davenne(LMT-Cachan (ENS Cachan/CNRS/UPMC/PRES UniverSud Paris)); Adnan Ibrahimbegovic(LMT-Cachan (ENS Cachan/CNRS/UPMC/PRES UniverSud Paris)); Pierre Léger(École Polytechnique de Montréal University of Montreal Campus)"
] |
This paper presents the physical formulation of a 1D material model suitable for seismic applications. It is written within the framework of thermodynamics with internal variables that is,especially, very efficient for the phenomenological representation of material behaviors at macroscale:those of the representative elementary volume. The model can reproduce the main characteristics observed for concrete, that is nonsymetric loading rate-dependent (viscoelasticity) behavior with appearance of permanent deformations and local hysteresis (continuum plasticity), stiffness degradation (continuum damage), cracking due to displacement localization (discrete plasticity or damage). The parameters have a clear physical meaning and can thus be easily identified. Although this point is not detailed in the paper,this material model is developed to be implemented in a finite element computer program. Therefore, for the benefit of the robustness of the numerical implementation, (i) linear state equations (no local iteration required) are defined whenever possible and (ii) the conditions in which the presented model can enter the generalized standard materials class − whose elements benefit from good global and local stability properties − are clearly established. To illustrate the capabilities of this model − among them for Earthquake Engineering applications − results of some numerical applications are presented.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464804
|
oai_dc
|
An embedded crack model for failure analysis of concrete solids
|
An embedded crack model for failure analysis of concrete solids
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jaka Dujc(University of Ljubljana); Boštjan Brank(University of Ljubljana); Adnan Ibrahimbegovic(École Normale Supérieure de Cachan); Delphine Brancherie(Université de Technologie de Compiègne)"
] |
We present a quadrilateral finite element with an embedded crack that can be used to model tensile fracture in two-dimensional concrete solids and the crack growth. The element has kinematics that can represent linear jumps in both normal and tangential displacements along the crack line. The cohesive law in the crack is based on rigid-plasticity with softening. The required material data for the concrete failure analysis are the constants of isotropic elasticity and the mode I softening curve. The results of two well known tests are presented in order to illustrate very satisfying performance of the presented approach to simulate failure of concrete solids.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464814
|
oai_dc
|
Obtaining equivalent fracture toughness of concrete using uniaxial compression test
|
Obtaining equivalent fracture toughness of concrete using uniaxial compression test
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zongjin Li(HongKong University of Science & Technology); Yanhua Zhao(Dalian University of Technology)"
] |
From typical stress-axial strain curve and stress-volume strain curve of a concrete under uniaxial compression, the initiation and localization of microcracks within the interior of the specimen can be identified. The occurrence of random microcrack indicates the end of the linear elasticity, and the localization of microcrack implies formation of major crack, which triggers the onset of unstable crack propagation. The interval between initiation and localization of microcracks is characterized by a stable microcrack growth. Based on fracture behavior observed from a uniaxial compressive test of a concrete cylinder, a model has been developed to extract fundamental fracture properties of a concrete, i.e. the equivalent fracture toughness and the size of fracture process zone. The introduction of cracking Poisson’s ratio accounts for tensile failure characteristics of concrete even under uniaxal compression. To justify the validity of the model proposed, tests on three-point bending have been performed to obtain the fracture toughness in accordance with two parameter fracture model and double-K fracture model. Surprisingly, it yields favorably comparable results and provides an encouraging alternative approach to determine fracture properties for concretes.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001464807
|
oai_dc
|
Enhanced solid element for modelling of reinforced concrete structures with bond-slip
|
Enhanced solid element for modelling of reinforced concrete structures with bond-slip
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Norberto Domínguez(Sección de Estudios de Posgrado e Investigación (SEPI)); Marco Aurelio Fernández(Sección de Estudios de Posgrado e Investigación (SEPI)); Adnan Ibrahimbegovic(Laboratoire de Mécanique et Technologie (LMT))"
] |
Since its invention in the 19th century, Reinforced Concrete (RC) has been widely used in the construction of a lot of different structures, as buildings, bridges, nuclear central plants, or even ships. The details of the mechanical response for this kind of structures depends directly upon the material behavior of each component: concrete and steel, as well as their interaction through the bond-slip, which makes a rigorous engineering analysis of RC structures quite complicated. Consequently, the practical calculation of RC structures is done by adopting a lot of simplifications and hypotheses validated in the elastic range. Nevertheless, as soon as any RC structural element is working in the inelastic range, it is possible to obtain the numerical prediction of its realistic behavior only through the use of non linear analysis. The aim of this work is to develop a new kind of Finite Element: the “Enhanced Solid Element (ESE)” which takes into account the complex composition of reinforced concrete, being able to handle each dissipative material behavior and their different deformations, and on the other hand, conserving a simplified shape for engineering applications. Based on the recent XFEM developments, we introduce the concept of nodal enrichment to represent kinematics of steel rebars as well as bonding. This enrichment allows to reproduce the strain incompatibility between concrete and steel that occurs because of the bond degradation and slip. This formulation was tested with a couple of simple examples and compared to the results obtained from other standard formulations.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001359111
|
oai_dc
|
Modeling properties of self-compacting concrete: support vector machines approach
|
Modeling properties of self-compacting concrete: support vector machines approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rafat Siddique(Thapar University); Paratibha Aggarwal(N.I.T. Kurukshetra); Yogesh Aggarwal(N.I.T. Kurukshetra); S. M. Gupta(N.I.T. Kurukshetra)"
] |
The paper explores the potential of Support Vector Machines (SVM) approach in predicting 28-day compressive strength and slump flow of self-compacting concrete. Total of 80 data collected from the exiting literature were used in present work. To compare the performance of the technique, prediction was also done using a back propagation neural network model. For this data-set, RBF kernel worked well in comparison to polynomial kernel based support vector machines and provide a root mean square error
of 4.688 (MPa) (correlation coefficient=0.942) for 28-day compressive strength prediction and a root mean square error of 7.825 cm (correlation coefficient=0.931) for slump flow. Results obtained for RMSE and
correlation coefficient suggested a comparable performance by Support Vector Machine approach to neural network approach for both 28-day compressive strength and slump flow prediction.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001359119
|
oai_dc
|
Modelling the performance of self-compacting SIFCON of cement slurries using genetic programming technique
|
Modelling the performance of self-compacting SIFCON of cement slurries using genetic programming technique
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Abdulkadir Cevik(University of Gaziantep); Mohammed Sonebi(Queen’s University Belfast)"
] |
The paper explores the potential of applicability of Genetic programming approach (GP), adopted in this investigation, to model the combined effects of five independent variables to predict the mini-slump, the plate cohesion meter, the induced bleeding test, the J-fiber penetration value, and the compressive strength at 7 and 28 days of self-compacting slurry infiltrated fiber concrete (SIFCON). The variables investigated were the proportions of limestone powder (LSP) and sand, the dosage rates of superplasticiser (SP) and viscosity modifying agent (VMA), and water-to-binder ratio (W/B). Twenty eight mixtures were made with 10-50% LSP as replacement of cement, 0.02-0.06% VMA by mass of cement, 0.6-1.2% SP and 50-150% sand (% mass of binder) and 0.42-0.48 W/B. The proposed genetic models of the self-compacting SIFCON offer useful modelling approach regarding the mix optimisation in predicting the fluidity, the cohesion, the bleeding, the penetration, and the compressive strength.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001359103
|
oai_dc
|
Prediction of product parameters of fly ash cement bricks using two dimensional orthogonal polynomials in the regression analysis
|
Prediction of product parameters of fly ash cement bricks using two dimensional orthogonal polynomials in the regression analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Chakraverty(B.P.P.P); Himani Saini(B.P.P.P); S. K. Panigrahi(B.P.P.P.)"
] |
This paper focuses on the application of two dimensional orthogonal polynomials in the regression analysis for the relationship of product parameters viz. compressive strength, bulk density and water absorption of fly ash cement bricks with other process parameters such as percentages of fly ash, sand and cement. The method has been validated by linear and non-linear two parameter regression models.
The use of two dimensional orthogonal system makes the analysis computationally efficient, simple and straight forward. Corresponding co-efficient of determination and F-test are also reported to show the efficacy and reliability of the relationships. By applying the evolved relationships, the product parameters of fly ash cement bricks may be approximated for the use in construction sectors.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001359084
|
oai_dc
|
Numerical modeling of drying shrinkage behavior of self-compacting concrete
|
Numerical modeling of drying shrinkage behavior of self-compacting concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"How-Ji Chen(Nat. Chung-Hsing University); Te-Hung Liu(National Chung-Hsing University,); Chao-Wei Tang(Cheng-Shiu University)"
] |
Self-compacting concrete (SCC), characterized by the high flowability and resistance to segregation, is due to the high amount of paste (including cement and mineral admixtures) in contrast with normal concrete (NC). However, the high amount of paste will limit the volume fractions of coarse aggregate, and reduce the tendency of coarse aggregate to suppress drying shrinkage deformations. For this reason, SCC tends to produce higher values of drying shrinkage than NC for the most part. In order to assess the
drying shrinkage of SCC quantitatively for application to offshore caisson foundations, the formulas presented in the literatures (ACI 209 and CEB-FIP) are used to predict the values of drying shrinkage in SCC according to the corresponding mix proportions. Additionally, a finite element (FE) model, which assumes concrete to be a homogeneous and isotropic material and follows the actual size and environmental conditions of the caisson, is utilized to simulate stress distribution situations and deformations in the SCC caisson resulting from the drying shrinkage. The probability of cracking and the behavior of drying shrinkage of the SCC caisson are drawn from the analytic results calculated by the FE model proposed in this paper.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001359137
|
oai_dc
|
Study of thin film transition liquid crystal display (TFT-LCD) optical waste glass applied in early-high-strength controlled low strength materials
|
Study of thin film transition liquid crystal display (TFT-LCD) optical waste glass applied in early-high-strength controlled low strength materials
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Her-Yung Wang(National Kaohsiung University of Applied Sciences); Jyun-Sheng Chen(National Kaohsiung University of Applied Sciences)"
] |
The present study verifies compressive strength, ultrasonic pulse velocity, electrical resistance, permeable ratio, and shrinkage from waste glass controlled low strength materials (WGCLSM) and earlyhigh-strength WGCSLM specimens, by replacing the sand with waste glass percentages of 0%, 10%,
20%, and 30%. This study reveals that increasing amounts of waste LCD glass incorporated into concrete increases WGCLSM fluidity and reduces the setting time, resulting in good working properties. By increasing the glass to sand replacement ratio, the compressive strength decreases to achieve low-strength effects. Furthermore, the electrical resistance also rises as a result of increasing the glass to sand replacement ratio. Early-high-strength WGCSLM aged 28 days has twice the electrical resistance compared to general WGCSLM. Early-high-strength WGCSLM aged 7 days has a higher ultrasonic pulse velocity similar to WGCSLM aged 28 days. The variation of length with age of different compositions is all within the tolerance range of 0.025%. This study demonstrates that the proper composition ratio of waste LCD glass to sand in early-high-strength WGCSLM can be determined by using different amounts of glass-sand. A mechanism for LCD optical waste glass usage can be established to achieve industrial waste minimization, resource recycling, and economic security.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001424704
|
oai_dc
|
Constitutive property behavior of an ultra-high-performance concrete with and without steel fibers
|
Constitutive property behavior of an ultra-high-performance concrete with and without steel fibers
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"E.M. Williams(U.S. Army Engineer Research and Development Center); S.S. Graham(U.S. Army Engineer Research and Development Center); S.A. Akers(U.S. Army Engineer Research and Development Center); P.A. Reed(U.S. Army Engineer Research and Development Center); T.S. Rushing(U.S. Army Engineer Research and Development Center)"
] |
A laboratory investigation was conducted to characterize the constitutive property behavior of Cor-Tuf, an ultra-high-performance composite concrete. Mechanical property tests (hydrostatic compression, unconfined compression (UC), triaxial compression (TXC), unconfined direct pull (DP), uniaxial strain, and uniaxial-strain-load/constant-volumetric-strain tests) were performed on specimens prepared from concrete mixtures with and without steel fibers. From the UC and TXC test results, compression failure surfaces were developed for both sets of specimens. Both failure surfaces exhibited a continuous increase in maximum principal stress difference with increasing confining stress. The DP tests results determined the unconfined tensile strengths of the two mixtures. The tensile strength of each mixture was less than the generally assumed tensile strength for conventional strength concrete, which is 10 percent of the unconfined compressive strength. Both concretes behaved similarly, but Cor-Tuf with steel fibers exhibited slightly greater strength with increased confining pressure, and Cor-Tuf without steel fibers displayed slightly greater compressibility.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001424698
|
oai_dc
|
Flexural and tensile properties of a glass fiber-reinforced ultra-high-strength concrete: an experimental, micromechanical and numerical study
|
Flexural and tensile properties of a glass fiber-reinforced ultra-high-strength concrete: an experimental, micromechanical and numerical study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Jason Roth(U.S. Army Engineer Research and Development Center); Thomas R. Slawson(U.S. Army Engineer Research and Development Center); Omar G. Flores(U.S. Army Engineer Research and Development Center)"
] |
The focus of this research effort was characterization of the flexural and tensile properties of a specific ultra-high-strength, fiber-reinforced concrete material. The material exhibited a mean unconfined compressive strength of approximately 140 MPa and was reinforced with short, randomly distributed alkali resistant glass fibers. As a part of the study, coupled experimental, analytical and numerical investigations were performed. Flexural and direct tension tests were first conducted to experimentally characterize material behavior. Following experimentation, a micromechanically-based analytical model was utilized to calculate the material’s tensile failure response, which was compared to the experimental results. Lastly, to investigate the relationship between the tensile failure and flexural response, a numerical analysis of the flexural experiments was performed utilizing the experimentally developed tensile failure function. Results of the experimental, analytical and numerical investigations are presented herein.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001424693
|
oai_dc
|
Numerical procedures for extreme impulsive loading on high strength concrete structures
|
Numerical procedures for extreme impulsive loading on high strength concrete structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kent T. Danielson(U.S. Army Engineer Research and Development Center); Mark D. Adley(U.S. Army Engineer Research and Development Center); James L. O'Daniel(U.S. Army Engineer Research and Development Center)"
] |
This paper demonstrates numerical techniques for complex large-scale modeling with microplane constitutive theories for reinforced high strength concrete, which for these applications, is defined to be around the 7000 psi (48 MPa) strength as frequently found in protective structural design. Applications involve highly impulsive loads, such as an explosive detonation or impact-penetration event. These capabilities were implemented into the authors’ finite element code, ParaAble and the PRONTO 3D code from Sandia National Laboratories. All materials are explicitly modeled with eight-noded hexahedral elements. The concrete is modeled with a microplane constitutive theory, the reinforcing steel is modeled with the Johnson-Cook model, and the high explosive material is modeled with a JWL equation of state and a programmed burn model. Damage evolution, which can be used for erosion of elements and/or for postanalysis examination of damage, is extracted from the microplane predictions and computed by a modified Holmquist-Johnson-Cook approach that relates damage to levels of inelastic strain increment and pressure. Computation is performed with MPI on parallel processors. Several practical analyses demonstrate that large-scale analyses of this type can be reasonably run on large parallel computing systems.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001424681
|
oai_dc
|
Integration of the microplane constitutive model into the EPIC code
|
Integration of the microplane constitutive model into the EPIC code
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"David Littlefield(The University of Alabama at Birmingham); Kenneth C. Walls(The University of Alabama at Birmingham); Kent T. Danielson(US Army Engineer Research and Development Center)"
] |
In this work the implementation of a production-level port of the Microplane constitutive model for concrete into the EPIC code is described. The port follows guidelines outlined in the Material Model Module (MMM) standard used in EPIC to insure a seamless interface with the existing code. Certain features of the model were not implemented using the MMM interface due to compatibility reasons; for example, a separate module was developed to initialize, store and update internal state variables. Objective strain and deformation measures for use in the material model were also implemented into the code. Example calculations were performed and illustrate the veracity of this new implementation.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001424669
|
oai_dc
|
The use of RKPM meshfree methods to compute responses to projectile impacts and blasts nearby charges
|
The use of RKPM meshfree methods to compute responses to projectile impacts and blasts nearby charges
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hyung-Jin Choi(Karagozian & Case); John Crawford(Karagozian & Case); Youcai Wu(Karagozian & Case)"
] |
This paper presents results from a study concerning the capability afforded by the RKPM (reproducing kernel particle method) meshfree analysis formulation to predict responses of concrete and UHPC components resulting from projectile impacts and blasts from nearby charges. In this paper, the basic features offered by the RKPM method are described, especially as they are implemented in the analysis code KC-FEMFRE, which was developed by Karagozian & Case (K&C).
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001424634
|
oai_dc
|
The virtual penetration laboratory: new developments for projectile penetration in concrete
|
The virtual penetration laboratory: new developments for projectile penetration in concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mark D. Adley(U.S. Army Engineer Research and Development Center); Andreas O. Frank(U.S. Army Engineer Research and Development Center); Kent T. Danielson(U.S. Army Engineer Research and Development Center); Stephen A. Akers(U.S. Army Engineer Research and Development Center); James L. O’Daniel(U.S. Army Engineer Research and Development Center)"
] |
This paper discusses new capabilities developed for the Virtual Penetration Laboratory (VPL) software package to address the challenges of determining Penetration Resistance (PR) equations for concrete materials. Specifically, the paper introduces a three-invariant concrete constitutive model recently developed by the authors. The Advanced Fundamental Concrete (AFC) model was developed to provide a fast-running predictive model to simulate the behavior of concrete and other high-strength geologic materials. The Continuous Evolutionary Algorithms (CEA) automatic fitting algorithms used to fit the new model are discussed, and then examples are presented to demonstrate the effectiveness of the new AFC model. Finally, the AFC model in conjunction with the VPL software package is used to develop a PR equation for a concrete material.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001424658
|
oai_dc
|
Comparing finite element and meshfree particle formulations for projectile penetration into fiber reinforced concrete
|
Comparing finite element and meshfree particle formulations for projectile penetration into fiber reinforced concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"James O’Daniel(US Army Engineer Research and Development Center); Mark Adley(US Air Force Research Laboratory); Kent Danielson(US Army Engineer Research and Development Center); Beverly DiPaolo(US Army Engineer Research and Development Center); Nicholas Boone(US Army Engineer Research and Development Center)"
] |
Penetration of a fragment-like projectile into Fiber Reinforced Concrete (FRC) was simulated using finite element (FE) and particle formulations. Extreme deformations and failure of the material during the penetration event were modeled with multiple approaches to evaluate how well each represented the actual physics of the penetration process and compared to experimental data. A Fragment Simulating Projectile (FSP) normally impacting a flat, square plate of FRC was modeled using two target thicknesses to examine the different levels of damage. The thinner plate was perforated by the FSP, while the thicker plate captured the FSP and only allowed penetration part way through the thickness. Full three dimensional simulations were performed, so the capability was present for non-symmetric FRC behavior and possible projectile rotation in all directions. These calculations assessed the ability of the finite element and particle formulations to calculate penetration response while assessing criteria necessary to perform the computations. The numerical code EPIC contains the element and particle formulations, as well as the explicit methodology and constitutive models, needed to perform these simulations.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001391701
|
oai_dc
|
Flexural ductility of prestressed concrete beams with unbonded tendons
|
Flexural ductility of prestressed concrete beams with unbonded tendons
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F.T.K. Au(The University of Hong Kong); K.H.E. Chan(The University of Hong Kong); A.K.H. Kwan(The University of Hong Kong); J.S. Du(Beijing Jiao Tong University)"
] |
Based on a numerical method to analyse the full-range behaviour of prestressed concrete beams with unbonded tendons, parametric studies are carried out to investigate the influence of 11 parameters on the curvature ductility of unbonded prestressed concrete (UPC) beams. It is found that, among various parameters studied, the depth to prestressing tendons, depth to non-prestressed tension steel, partial prestressing ratio, yield strength of non-prestressed tension steel and concrete compressive strength have
substantial effects on the curvature ductility. Although the curvature ductility of UPC beams is affected by a large number of factors, rather simple equations can be formulated for reasonably accurate estimation of curvature ductility. Conversion factors are introduced to cope with the difference in partial safety factors, shapes of equivalent stress blocks and the equations to predict the ultimate tendon stress in BS8110, EC2 and ACI318. The same equations can also be used to provide conservative estimates of ductility of UPC beams with compression steel.
|
토목공학
| null |
kci_detailed_000099.xml
|
|||
ART001391724
|
oai_dc
|
A systematic approach for the development of porous concrete based on axiomatic design theory
|
A systematic approach for the development of porous concrete based on axiomatic design theory
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"X.H. Tran(KAIST); R. Tawie(KAIST); 이행기(한국과학기술원)"
] |
This paper presents a design framework developed using axiomatic design (AD) theory that can be applied in the design process of porous concrete. The main contribution of this paper is the definition of an AD framework based on the needs and functional requirements of porous concrete. The
framework shows how AD theory can be used to provide guidelines for proportioning and manufacturing porous concrete. The advantage of the AD approach is that it systemizes the way to decouple design parameters and makes designers to think rationally between what we want to achieve and how we propose to satisfy the functional requirements of porous concrete. In this paper, test results of laboratorysize porous concrete specimens under compression were analyzed to evaluate the performance of the porous concrete based on the desired functional requirements.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001391731
|
oai_dc
|
Closed form ultimate strength of multi-rectangle reinforced concrete sections under axial load and biaxial bending
|
Closed form ultimate strength of multi-rectangle reinforced concrete sections under axial load and biaxial bending
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"V. Dias da Silva(University of Coimbra); C.C. Ferreira(University of Coimbra); M.H.F.M. Barros(University of Coimbra); E.N.B.S. Julio(University of Coimbra)"
] |
The analysis of prismatic members made of reinforced concrete under inclined bending, especially the computation of ultimate loads, is a pronounced non-linear problem which is frequently solved by discretizing the stress distribution in the cross-section using interpolation functions. In the approach
described in the present contribution the exact analytical stress distribution is used instead. The obtained expressions are integrated by means of a symbolic manipulation package and automatically converted to optimized Fortran code. The direct problem-computation of ultimate internal forces given the position of the neutral axis-is first described. Subsequently, two kinds of inverse problem are treated: the computation of rupture envelops and the dimensioning of reinforcement, given design internal forces. An iterative
Newton-Raphson procedure is used. Examples are presented.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001391704
|
oai_dc
|
Load carrying capacity of deteriorated reinforced concrete columns
|
Load carrying capacity of deteriorated reinforced concrete columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mucip Tapan(Yuzuncu Yil University); Riyad S. Aboutaha(Syracuse University)"
] |
This paper presents a new methodology to evaluate the load carrying capacity of deteriorated non-slender concrete bridge pier columns by construction of the full P-M interaction diagrams. The proposed method incorporates the actual material properties of deteriorated columns, and accounts for amount of corrosion and exposed corroded bar length, concrete loss, loss of concrete confinement and strength due to stirrup deterioration, bond failure, and type of stresses in the corroded reinforcement. The
developed structural model and the damaged material models are integrated in a spreadsheet for evaluating the load carrying capacity for different deterioration stages and/or corrosion amounts. Available experimental and analytical data for the effects of corrosion on short columns subject to axial loads combined with moments (eccentricity induced) are used to verify the accuracy of proposed model. It was observed that, for the limited available experimental data, the proposed model is conservative and is capable of predicting the load carrying capacity of deteriorated reinforced concrete columns with reasonable accuracy. The proposed analytical method will improve the understanding of effects of deterioration on structural members, and allow engineers to qualitatively assess load carrying capacity of
deteriorated reinforced concrete bridge pier columns.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001391694
|
oai_dc
|
Influence of extreme curing conditions on compressive strength and pulse velocity of lightweight pumice concrete
|
Influence of extreme curing conditions on compressive strength and pulse velocity of lightweight pumice concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Khandaker M. Anwar Hossain(Ryerson University)"
] |
The effect of six different curing conditions on compressive strength and ultrasonic pulse velocity (UPV) of volcanic pumice concrete (VPC) and normal concrete (NC) has been studied. The curing conditions include water, air, low temperature (4℃) and different elevated temperatures of up to 110℃.
The curing age varies from 3 days to 91 days. The development in the pulse velocity and the compressive strength is found to be higher in full water curing than the other curing conditions. The reduction of pulse velocity and compressive strength is more in high temperature curing conditions and also more in VPC compared to NC. Curing conditions affect the relationship between pulse velocity and compressive strength of both VPC and NC.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001416480
|
oai_dc
|
Performance characteristics of dredged silt and high-performance lightweight aggregate concrete
|
Performance characteristics of dredged silt and high-performance lightweight aggregate concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H.Y. Wang(National Kaohsiung University of Applied Sciences); Y.N. Sheen(National Kaohsiung University of Applied Sciences); M.F. Hung(De-Lin Institute of Technology)"
] |
Dredged silt from reservoirs in southern Taiwan was sintered to make lightweight aggregates (LWA), which were then used to produce high-performance lightweight aggregate concrete (HPLWC). The HPLWC was manufactured using different amounts of mixing water (140, 150, and 160 kg/m³) and LWA of different particle densities (700, 1100, and 1500 kg/m³) at different W/b ratios (0.28, 0.32, and 0.4). Results show that the lightweight aggregates of dredged silt taken in southern Taiwan perform better than the general lightweight aggregates. In addition, the HPLWC possessed high workability with a slump of 230-270 mm, and a slump flow of 450-610 mm, high compressive strength of over 40 MPa after 28 days of curing, good strength efficiency of cement exceeding 0.1MPa/kg/㎥, low thermal conductivity of 0.4-0.8 kcal/mh℃, shrinkage of less than 4.8 × 10⁻⁴, and high electrical resistivity of above 40 kΩ-cm. The above findings prove that HPLWC made from dredged silt can help enhance durability of concrete and provide and an ecological alternative use of dredged silt.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001416482
|
oai_dc
|
Dynamic tensile behaviour of reactive powder concrete by Hopkinson bar experiments and numerical simulation
|
Dynamic tensile behaviour of reactive powder concrete by Hopkinson bar experiments and numerical simulation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jianzhong Lai(Nanjing University of Science and Technology); Wei Sun(Southeast University)"
] |
토목공학
| null |
kci_detailed_000100.xml
|
||||
ART001416479
|
oai_dc
|
Simulation of brittle fracture of autoclaved aerated concrete
|
Simulation of brittle fracture of autoclaved aerated concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"I. Kadashevich(Otto-von-Guericke-Universitat Magdeburg); D. Stoyan(Institut fur Stochastik)"
] |
The system of pores of autoclaved aerated concrete (AAC) is described by the so-called cherry-pit model, a random system of partially interpenetrating spheres. For the simulation of fracture processes, the solid phase is approximated by an irregular spatial network of beams obtained by means of the so-called radical tessellation with respect to the pore spheres. FE calculations using standard software (ANSYS) yield the strain energies of the beams. These energies are used as fracture criterion according to which highly loaded beams are considered as broken and are removed from the network. The paper investigates the relationship between mean fracture strength and microstructure for structures close to real AAC samples and virtual structures with particular geometrical properties.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001416477
|
oai_dc
|
Deflection prediction for reinforced concrete deep beams
|
Deflection prediction for reinforced concrete deep beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wen-Yao Lu(China University of Technology); Shyh-Jiann Hwang(National Taiwan University); Ing-Jaung Lin(National Taiwan University of Science and Technology)"
] |
A simplified method, developed from the softened strut-and-tie model, for determining the mid-span deflection of deep beams at ultimate state is proposed. The mid-span deflection and shear strength predictions of the proposed model are compared with the experimental data collected from 70 simply supported reinforced concrete deep beams, loaded with concentrated loads located at a distance a from an end reaction. The comparison shows that the proposed model can accurately predict the mid-span deflection and shear strength of deep beams with different shear span-to-depth ratios, different concrete strengths, and different horizontal and vertical hoops.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001416478
|
oai_dc
|
Hydration properties of cement pastes containing high-volume mineral admixtures
|
Hydration properties of cement pastes containing high-volume mineral admixtures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chao-Wei Tang(Cheng-Shiu University)"
] |
This research aimed to investigate the influence of high-volume mineral admixtures (MAs), i.e., fly ash and slag, on the hydration characteristics and microstructures of cement pastes. Degree of cement hydration was quantified by the loss-on-ignition technique and degree of pozzolanic reaction was determined by a selective dissolution method. The influence of MAs on the pore structure of paste was measured by mercury intrusion porosimetry. The results showed that the hydration properties of the blended pastes were a function of water to binder ratio, cement replacement level by MAs, and curing age. Pastes containing fly ash exhibited strongly reduced early strength, especially for mix with 45% fly ash. Moreover, at a similar cement replacement level, slag incorporated cement paste showed higher degrees of cement hydration and pozzolanic reaction than that of fly ash incorporated cement paste. Thus, the present study demonstrates that high substitution rates of slag for cement result in better effects on the short- and long-term hydration properties of cement pastes.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001416481
|
oai_dc
|
Shape determination of 3-D reinforcement corrosion in concrete based on observed temperature on concrete surface
|
Shape determination of 3-D reinforcement corrosion in concrete based on observed temperature on concrete surface
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Takahiko Kurahashi( Nagaoka University of Technology); Hideki Oshita(Chuo University)"
] |
We present the shape determination method of 3-D reinforcement corrosion based on observed temperature on concrete surface. The non-destructive testing for reinforcement corrosion in concrete using a heat image on concrete surface have been proposed by Oshita. The position of the reinforcement of corrosion or the cavity can be found using that method. However, the size of those defects can not be precisely measured based on the heat image. We therefore proposed the numerical determination system of the shape for the reinforcement corrosion using the observed temperature on the concrete surface. The adjoint variable method is introduced to formulate the shape determination problem, and the finite element method is employed to simulate the heat transfer problem. Some numerical experiments and the examination for the number of the observation points are shown in this paper.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001359302
|
oai_dc
|
Analysis on IBEM for consideration on reinforced concrete slab resistance
|
Analysis on IBEM for consideration on reinforced concrete slab resistance
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"경제운(Korea Institute of Construction & Transportation Technology Evaluation); 태성호(한양대학교); 이한승(한양대학교); 이성복(대한주택공사주택도시연구원)"
] |
The corrosion of RC structures demonstrates very complicated forms of deterioration intermingled together but all pointing to a decrease in the durability of RC structures due to the corrosion of reinforcing bars. Until now, nondestructive techniques, such as half-cell potential and polarization resistance, have been widely available in the world. The former provides information on the probability of corrosion while the latter is associated with information concerning corrosion rates. Inversion by the boundary element
method (IBEM) was developed for considering concrete resistivity. The applicability of the procedure was examined through a numerical analysis and electrolytic tests for RC slabs. A distribution in such concrete resistivity is relatively inhomogeneous including cracks on the surface of slabs. Regarding cracks in concrete, the relative coefficient of concrete resistance was introduced to perform its analysis. Further, the procedure will be developed to identify the corroded region visually using 3-D VRML.
|
토목공학
| null |
kci_detailed_000100.xml
|
|||
ART001359244
|
oai_dc
|
Seismic behavior of post-tensioned precast reinforced concrete beam-to-column connections
|
Seismic behavior of post-tensioned precast reinforced concrete beam-to-column connections
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chin-Tung Cheng(National Kaohsiung First University of Science & Technology)"
] |
In this research, the self-centering effect in precast and prestressed reinforced concrete structures was investigated experimentally. The reinforced concrete beams and columns were precast and connected
by post-tensioning tendons passing through the center of the beams as well as the panel zone of the connections. Three beam-to-interior-column connections were constructed to investigate parameters such as beam to column interfaces (steel on steel or plastic on plastic), energy dissipating devices (unbonded buckling restrained steel bars or steel angles) and the spacing of hoops in the panel zone. In addition to the self-centering effect, the shear strength in the panel zone of interior column connections was
experimentally and theoretically evaluated, since the panel zone designed by current code provisions may not be conservative enough to resist the panel shear increased by the post-tensioning force.
|
토목공학
| null |
kci_detailed_000100.xml
|
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