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ART001557993
|
oai_dc
|
Curved laminate analysis
|
Curved laminate analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yih-Cherng Chiang(Chinese Culture University)"
] |
This paper is devoted to the development of the equations which describe the elastic response of a curved laminate subjected to in-plane loads and bending moments. Similar to the classic 6 × 6 ABD matrix constitutive relation of a flat laminate, a new 6 × 6 matrix constitutive relation between force resultants, moment resultants, mid-plane strains and deformed curvatures for a curved laminate is formulated. This curved lamination theory will provide the fundamental basis for the analyses of curved laminated structures. The stress predictions by the present curved lamination theory are compared to those by the curved laminate analysis that neglected the nonlinear terms in the derivation of the constitutive relation. The results show that the curved laminate analysis that neglected the nonlinear terms cannot reflect the effect of curvature and can no longer predict the stresses accurately as the curvature becomes noticeable. In this paper, a curved lamination theory that retains the nonlinear terms and, therefore, accounts for the effect of the non-flat geometry of the structure will be developed.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557999
|
oai_dc
|
Pressure impulse diagrams for simply-supported steel columns based on residual load-carrying capacities
|
Pressure impulse diagrams for simply-supported steel columns based on residual load-carrying capacities
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"박종일(Joint Modeling and Simulation Center); Theodor Krauthammer(University of Florida)"
] |
This paper is focused on the residual capacity of steel columns, as a damage criterion. Load-Impulse (P-I) diagrams are frequently used for analysis, design, or assessment of blast resistant structures. The residual load carrying capacity of a simply supported steel column was derived as a damage criterion based on a SDOF computational approach. Dimensionless P-I diagrams were generated numerically with this quantitative damage criterion. These numerical P-I diagrams were used to show that traditional constant ductility ratios adopted as damage criteria are not appropriate for either the design or damage assessment of blast resistant steel columns, and that the current approach could be a much more appropriate alternative.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557998
|
oai_dc
|
Prediction of moments in composite frames considering cracking and time effects using neural network models
|
Prediction of moments in composite frames considering cracking and time effects using neural network models
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Umesh Pendharkar(Ujjain Engineering College); Sandeep Chaudhary(Malaviya National Institute of Technology); A.K. Nagpal(Indian Institute of Technology Delhi)"
] |
There can be a significant amount of moment redistribution in composite frames consisting of steel columns and composite beams, due to cracking, creep and shrinkage of concrete. Considerable amount of computational effort is required for taking into account these effects for large composite frames. A methodology has been presented in this paper for taking into account these effects. In the methodology that has been demonstrated for moderately high frames, neural network models are developed for rapid prediction of the inelastic moments (typically for 20 years, considering instantaneous cracking, and time effects, i.e., creep and shrinkage, in concrete) at a joint in a frame from the elastic moments (neglecting instantaneous cracking and time effects). The proposed models predict the inelastic moment ratios (ratio of elastic moment to inelastic moment) using eleven input parameters for interior joints and seven input parameters for exterior joints. The training and testing data sets are generated using a hybrid procedure developed by the authors. The neural network models have been validated for frames of different number of spans and storeys. The models drastically reduce the computational effort and predict the inelastic moments, with reasonable accuracy for practical purposes, from the elastic moments, that can be obtained from any of the readily available software.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557995
|
oai_dc
|
Experimental behavior of eccentrically loaded R.C. short columns strengthened using GFRP wrapping
|
Experimental behavior of eccentrically loaded R.C. short columns strengthened using GFRP wrapping
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S.K. Elwan(The Higher Institute of Engineering); A.S. Rashed(The Higher Institute of Engineering)"
] |
This paper aims to study the behavior of short reinforced concrete columns confined with external glass Fiber Reinforced Polymers (GFRP) sheets under eccentric loads. The experimental part of the study was achieved by testing 9 specimens under eccentric compression. Three eccentricity ratios corresponding to e/t = 0, 0.10, 0.50 in one direction of the column were used. Specimens were divided into three groups. The first group was the control one without confinement. The second group was fully wrapped with GFRP laminates before loading. The third group was wrapped under loading after reaching 75% of failure loads of the control specimens. The third group was investigated in order to represent the practical case of strengthening a loaded column with FRP laminates. All specimens were loaded until failure. The results show that GFRP laminates enhances both failure load and ductility response of eccentrically loaded column. Moreover, the study also illustrates the effect of confinement on the first crack load, lateral deformation, strain in reinforcement and failure pattern. Based on the analysis of the experimental results, a simple model has been proposed to predict the improvement of load carrying capacity under different eccentricity ratios. The predicted equation takes into consideration the eccentricity to cross section depth ratio, the ultimate strength of GFRP, the thickness of wrapping laminate, and the time of wrapping (before loading and under loading). A good correlation was obtained between experimental and analytical results.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557994
|
oai_dc
|
Damage detection in truss bridges using vibration based multi-criteria approach
|
Damage detection in truss bridges using vibration based multi-criteria approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H.W. Shih(Queensland University of Technology); D.P. Thambiratnam(Queensland University of Technology); T.H.T. Chan(Queensland University of Technology)"
] |
This paper uses dynamic computer simulation techniques to develop and apply a multicriteria procedure using non-destructive vibration-based parameters for damage assessment in truss bridges. In addition to changes in natural frequencies, this procedure incorporates two parameters, namely the modal flexibility and the modal strain energy. Using the numerically simulated modal data obtained through finite element analysis of the healthy and damaged bridge models, algorithms based on modal flexibility and modal strain energy changes before and after damage are obtained and used as the indices for the assessment of structural health state. The application of the two proposed parameters to truss-type structures is limited in the literature. The proposed multi-criteria based damage assessment procedure is therefore developed and applied to truss bridges. The application of the approach is demonstrated through numerical simulation studies of a single-span simply supported truss bridge with eight damage scenarios corresponding to different types of deck and truss damage. Results show that the proposed multi-criteria method is effective in damage assessment in this type of bridge superstructure.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608561
|
oai_dc
|
The effects of uncertainties in structural analysis
|
The effects of uncertainties in structural analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. F. Pellissetti(Leopold-Franzens University); G. I. Schuëller(Leopold-Franzens University)"
] |
Model-based predictions of structural behavior are negatively affected by uncertainties of various type and in various stages of the structural analysis. The present paper focusses on dynamic analysis and addresses the effects of uncertainties concerning material and geometric parameters, mainly
in the context of modal analysis of large-scale structures. Given the large number of uncertain parameters arising in this case, highly scalable simulation-based methods are adopted, which can deal with possibly
thousands of uncertain parameters. In order to solve the reliability problem, i.e., the estimation of very small exceedance probabilities, an advanced simulation method called Line Sampling is used. In combination with an efficient algorithm for the estimation of the most important uncertain parameters, the method provides good estimates of the failure probability and enables one to quantify the error in the estimate. Another aspect here considered is the uncertainty quantification for closely-spaced eigenfrequencies. The solution here adopted represents each eigenfrequency as a weighted superposition of the full set of eigenfrequencies. In a case study performed with the FE model of a satellite it is shown that the effects of uncertain parameters can be very different in magnitude, depending on the considered response quantity. In particular, the uncertainty in the quantities of interest (eigenfrequencies) turns out to be mainly caused by very few of the uncertain parameters, which results in sharp estimates of the failure
probabilities at low computational cost.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608554
|
oai_dc
|
On procedures for reliability assessment of mechanical systems and structures
|
On procedures for reliability assessment of mechanical systems and structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"G. I. Schuëller(Leopold-Franzens University)"
] |
In this paper a brief overview of methods to assess the reliability of mechanical systems and structures is presented. A selection of computational procedures, stochastic structural dynamics, stochastic fatigue crack growth and reliability based optimization are discussed. It is shown that reliability based methods may form the basis for a rational decision making.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608558
|
oai_dc
|
Ground strain estimation for lifeline earthquake engineering
|
Ground strain estimation for lifeline earthquake engineering
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Takeshi Koike(Tokyo City University); Osamu Maruyama(Musashi Institute of Technology); Lessandro Estelito Garciano(Musashi Institute of Technology)"
] |
Current seismic design guidelines in Japan are diverse in the seismic ground strain estimates, because the concepts on a horizontally propagating wave model are not consistent in various seismic design guidelines including gas, water and other underground structures. The purpose of this study is (a)
to derive the analytical methods to estimate the ground strains for incident seismic waves, (b) to develop a statistical estimation technique of the ground strains, and finally (c) to compare the theoretical estimation with the observed data which was measured at 441 sites in the 1999 Chi-Chi Earthquake in
Taiwan.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608565
|
oai_dc
|
Probabilistic assessment on the basis of interval data
|
Probabilistic assessment on the basis of interval data
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ben H. Thacker(Southwest Research Institute); Luc J. Huyse(Southwest Research Institute)"
] |
Uncertainties enter a complex analysis from a variety of sources: variability, lack of data, human errors, model simplification and lack of understanding of the underlying physics. However, for many important engineering applications insufficient data are available to justify the choice of a particular probability density function (PDF). Sometimes the only data available are in the form of interval estimates which represent, often conflicting, expert opinion. In this paper we demonstrate that Bayesian estimation techniques can successfully be used in applications where only vague interval measurements are available. The proposed approach is intended to fit within a probabilistic framework, which is established and widely accepted. To circumvent the problem of selecting a specific PDF when only little or vague data are available, a hierarchical model of a continuous family of PDF’s is used. The classical Bayesian estimation methods are expanded to make use of imprecise interval data. Each of the expert opinions (interval data) are interpreted as random interval samples of a parent PDF. Consequently, a partial conflict between experts is automatically accounted for through the likelihood function.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608576
|
oai_dc
|
Auxiliary domain method for solving multi-objective dynamic reliability problems for nonlinear structures
|
Auxiliary domain method for solving multi-objective dynamic reliability problems for nonlinear structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Lambros Katafygiotis(Hong Kong University of Science and Technology); Sai Hung Cheung(California Institute of Technology); Torgeir Moan(NTNU)"
] |
A novel methodology, referred to as Auxiliary Domain Method (ADM), allowing for a very efficient solution of nonlinear reliability problems is presented. The target nonlinear failure domain is first populated by samples generated with the help of a Markov Chain. Based on these samples an auxiliary failure domain (AFD), corresponding to an auxiliary reliability problem, is introduced. The criteria for selecting the AFD are discussed. The emphasis in this paper is on the selection of the auxiliary linear failure domain in the case where the original nonlinear reliability problem involves multiple objectives rather than a single objective. Each reliability objective is assumed to correspond to a particular response quantity not exceeding a corresponding threshold. Once the AFD has been specified the method proceeds with a modified subset simulation procedure where the first step involves the direct simulation of samples in the AFD, rather than standard Monte Carlo simulation as required in standard subset simulation. While the method is applicable to general nonlinear reliability problems herein the focus is on the calculation of
the probability of failure of nonlinear dynamical systems subjected to Gaussian random excitations. The method is demonstrated through such a numerical example involving two reliability objectives and a very large number of random variables. It is found that ADM is very efficient and offers drastic improvements over standard subset simulation, especially when one deals with low probability failure events.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608570
|
oai_dc
|
Milling tool wear forecast based on the partial least-squares regression analysis
|
Milling tool wear forecast based on the partial least-squares regression analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xu Chuangwen(Xi’an Jiaotong University, Lanzhou Polytechnic College); Chen Hualing(Xi’an Jiaotong University)"
] |
Power signals resulting from spindle and feed motor, present a rich content of physical information, the appropriate analysis of which can lead to the clear identification of the nature of the tool wear. The partial least-squares regression (PLSR) method has been established as the tool wear analysis
method for this purpose. Firstly, the results of the application of widely used techniques are given and their limitations of prior methods are delineated. Secondly, the application of PLSR is proposed. The singular value theory is used to noise reduction. According to grey relational degree analysis, sample
variable is filtered as part sample variable and all sample variables as independent variables for modelling,and the tool wear is taken as dependent variable, thus PLSR model is built up through adapting to several
experimental data of tool wear in different milling process. Finally, the prediction value of tool wear is compare with actual value, in order to test whether the model of the tool wear can adopt to new measuring data on the independent variable. In the new different cutting process, milling tool wear was predicted by the methods of PLSR and MLR (Multivariate Linear Regression) as well as BPNN (BP Neural Network) at the same time. Experimental results show that the methods can meet the needs of the
engineering and PLSR is more suitable for monitoring tool wear.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608581
|
oai_dc
|
Free vibrations of delaminated beams in prebuckled states: Lower and upper bounds
|
Free vibrations of delaminated beams in prebuckled states: Lower and upper bounds
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dong Wei Shu(Nanyang Technological University); Christian N. Della(Nanyang Technological University)"
] |
토목공학
| null |
kci_detailed_000077.xml
|
||||
ART001608551
|
oai_dc
|
Effect of elevated temperature on physico-mechanical properties of metakaolin blended cement mortar
|
Effect of elevated temperature on physico-mechanical properties of metakaolin blended cement mortar
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. M. Rashad(Housing & Building National Research Center); M. S. Morsy(Housing & Building National Research Center); H. A. El-Nouhy(Housing & Building National Research Center)"
] |
An experimental investigation was conducted to evaluate the performance of mortars with and without Metakaolin (MK) exposed to elevated temperatures 200oC, 400oC, 600oC and 800oC for two hours. The binder to sand ratio was kept constant (1:5.23). The ordinary Portland cement (OPC) was replaced with MK at 0%, 5%, 10% 20% and 30%. All mixtures were designed to have a flow of 94 ±5%. The compressive strength of mortars before and after exposure to elevated temperature was determined. The formation of various decomposition phases were identified using X-ray diffractometry
(XRD) and differential thermal analysis (DTA). The microstructure of the mortars was examined using scanning electron microscope (SEM). Test results indicated that MK improves the compressive strength before and after exposure to elevated temperature and that the 20% cement replacement of MK is the optimum percentage.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608579
|
oai_dc
|
Evaluation of seismic energy demand and its application on design of buckling-restrained braced frames
|
Evaluation of seismic energy demand and its application on design of buckling-restrained braced frames
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"김진구(성균관대학교); Hyunhoon Choi(Sungkyunkwan University)"
] |
In this study seismic analyses of steel structures were carried out to examine the effect of ground motion characteristics and structural properties on energy demands using 100 earthquake ground motions recorded in different soil conditions, and the results were compared with those of previous works.
Analysis results show that ductility ratios and the site conditions have significant influence on input energy. The ratio of hysteretic to input energy is considerably influenced by the ductility ratio and the strong motion duration. It is also observed that as the predominant periods of the input energy spectra are significantly larger than those of acceleration response spectra used in the strength design, the strength demand on a structure designed based on energy should be checked especially in short period structures.
For that reason framed structures with buckling-restrained-braces (BRBs) were designed in such a way that all the input energy was dissipated by the hysteretic energy of the BRBs, and the results were compared with those designed by conventional strength-based design procedure.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608575
|
oai_dc
|
Investigation of linear and nonlinear of behaviours of reinforced concrete cantilever retaining walls according to the earthquake loads considering soil-structures interactions
|
Investigation of linear and nonlinear of behaviours of reinforced concrete cantilever retaining walls according to the earthquake loads considering soil-structures interactions
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Senol Gürsoy(Karadeniz Technical University); Ahmet Durmus(Karadeniz Technical University)"
] |
It is known that retaining walls were severely damaged as well in the most recent earthquakes having occurred in the countries in the active seismic belts of the world. This damage can be ascribed to the calculation methods used for the designs of retaining walls in the event of their constructions and
employment having been accurately carried out. Generally simplified pseudo-static methods are used in the analysis of retaining walls with analytical methods and soil-structure interaction are not considered. In view of these circumstances, in this article by taking soil interaction into consideration, linear and nonlinear behaviours of retaining walls are analyzed with the assistance of LUSAS which is one of the structural analysis programs. This investigations are carried out per LUSAS which employs the finite element method as to the Erzincan (1992) Earthquake North-South component and the obtained findings are compared with the ones obtained from the method suggested in Eurocode-8, which is still effective today, and Mononobe-Okabe method. Not only do the obtained results indicate the distribution and
magnitude of soil pressures are depend on the filling soil but on the foundation soil as well and nonlinear effects should be considered in designs of these walls.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608564
|
oai_dc
|
Closed-loop active vibration control of a typical nose landing gear with torsional MR fluid based damper
|
Closed-loop active vibration control of a typical nose landing gear with torsional MR fluid based damper
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dipak K. Maiti(Indian Institute of Technology); Sateesh B.(Indian Institute of Technology)"
] |
Vibration is an undesirable phenomenon in a dynamic system like lightly damped aerospace structures and active vibration control has gradually been employed to suppress vibration. The objective of the current investigation is to introduce an active torsional magneto-rheological (MR) fluid based damper
for vibration control of a typical nose landing gear. They offer the adaptability of active control devices without requiring the associated large power sources. A torsional damper is designed and developed based
on Bingham plastic shear flow model. The numerical analysis is carried out to estimate the damping coefficient and damping force. The designed damper is fabricated and an experimental setup is also established to characterize the damper and these results are compared with the analytical results. A typical
FE model of Nose landing gear is developed to study the effectiveness of the damper. Open loop response analysis has been carried out and response levels are monitored at the piston tip of a nose landing gear for various loading conditions without damper and with MR-damper as semi-active device. The closedloop full state feedback control scheme by the pole-placement technique is also applied to control the landing gear instability of an aircraft.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608560
|
oai_dc
|
Local response of W-shaped steel columns under blast loading
|
Local response of W-shaped steel columns under blast loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"김진구(성균관대학교); Taejin Kim(Sungkyunkwan University); Kyungkoo Lee(Seoul National University)"
] |
Local failure of a primary structural component induced by direct air-blast loading may be itself a critical damage and lead to the partial or full collapse of the building. As an extensive research to mitigate blast-induced hazards in steel frame structure, a state-of-art analytical approach or high-fidelity
computational nonlinear continuum modeling using computational fluid dynamics was described in this paper. The capability of the approach to produce reasonable blast pressures on a steel wide-flange section
column was first evaluated. Parametric studies were conducted to observe the effects of section sizes and boundary conditions on behavior and failure of columns in steel frame structures. This study shows that the analytical approach is reasonable and effective to understand the nature of blast wave and complex interaction between blast loading and steel column behavior.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608556
|
oai_dc
|
Minimum life-cycle cost design of ice-resistant offshore platforms
|
Minimum life-cycle cost design of ice-resistant offshore platforms
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Da-yong Zhang(Dalian University of Tech); Gang Li(Dalian University of Tech); Qian-jin Yue(Dalian University of Tech)"
] |
In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, maintenance of offshore platforms as uncertain events may occur within
the life-cycle of a platform under the extreme ice load. In this study, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on cost-effectiveness criterion is proposed.
Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death and injury as well as discounting cost over time are considered. An efficient approximate method of the global reliability analysis for the offshore platforms is provided, which converts the implicit nonlinear performance function in the conventional reliability analysis to linear explicit one. The proposed life-cycle optimum design formula are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared to the conventional design.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608580
|
oai_dc
|
Prediction of force reduction factor (R) of prefabricated industrial buildings using neural networks
|
Prediction of force reduction factor (R) of prefabricated industrial buildings using neural networks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Hakan Arslan(Selcuk University); Murat Ceylan(Selcuk University); M. Yasar Kaltakci(Selcuk University); Yüksel Ozbay(Selcuk University); Fatma Gulten Gulay(Istanbul Technical University)"
] |
The force (load) reduction factor, R, which is one of the most important parameters in earthquake load calculation, is independent of the dimensions of the structure but is defined on the basis of the load bearing system of the structure as defined in earthquake codes. Significant damages and failures were experienced on prefabricated reinforced concrete structures during the last three major earthquakes in Turkey (Adana 1998, Kocaeli 1999, Duzce 1999) and the experts are still discussing the main reasons of those failures. Most of them agreed that they resulted mainly from the earthquake force
reduction factor, R that is incorrectly selected during design processes, in addition to all other detailing errors. Thus this wide spread damages caused by the earthquake to prefabricated structures aroused suspicion about the correctness of the R coefficient recommended in the current Turkish Earthquake Codes (TEC - 98). In this study, an attempt was made for an approximate determination of R coefficient for widely utilized prefabricated structure types (single-floor single-span) with variable dimensions.
According to the selecting variable dimensions, 140 sample frames were computed using pushover analysis. The force reduction factor R was calculated by load-displacement curves obtained pushover analysis for each frame. Then, formulated artificial neural network method was trained by using 107 of the 140 sample frames. For the training various algorithms were used. The method was applied and used for the prediction of the R rest 33 frames with about 92% accuracy. The paper also aims at proposing the authorities to change the R coefficient values predicted in TEC - 98 for prefabricated concrete structures.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608590
|
oai_dc
|
Seismic behavior of strengthened reinforced concrete coupling beams by bolted steel plates, Part 1: Experimental study
|
Seismic behavior of strengthened reinforced concrete coupling beams by bolted steel plates, Part 1: Experimental study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Y. Zhu(The University of Guang Zhou); R. K. L. Su(The University of Hong Kong); F. L. Zhou(The University of Guang Zhou)"
] |
An experimental study of five full-scale coupling beam specimens has been conducted to investigate the seismic behavior of strengthened RC coupling beams by bolted side steel plates using a reversed cyclic loading procedure. The strengthened coupling beams are fabricated with different plate
thicknesses and shear connector arrangements to study their respective effects on load-carrying capacity, strength retention, stiffness degradation, deformation capacity, and energy dissipation ability. The study revealed that putting shear connectors along the span of coupling beams produces no significant improvement to the structural performance of the strengthened beams. Translational and rotational partial interactions of the shear connectors that would weaken the load-carrying capacity of the steel plates were observed and measured. The hierarchy of failure of concrete, steel plates, and shear connectors was identified. Furthermore, detailed effects of plate buckling and various arrangements of shear connectors on the post-peak behavior of the strengthened beams are discussed.
|
토목공학
| null |
kci_detailed_000077.xml
|
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ART001608585
|
oai_dc
|
Determination of collapse safety of shear wall-frame structures
|
Determination of collapse safety of shear wall-frame structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Emel Yükseli Cengiz(Istanbul Metropolitan Municipality); Ahmet Isin Saygun(Istanbul Technical University)"
] |
A new finite shear wall element model and a method for calculation of 3D multi-storied only shear walled or shear walled – framed structures using finite shear wall elements assumed ideal elasto –plastic material are developed. The collapse load of the system subjected to factored constant gravity
loads and proportionally increasing lateral loads is calculated with a method of load increments. The shape functions over the element are determined as a cubic variation along the story height and a linear variation in horizontal direction because of the rigid behavior of the floor slab. In case shear walls are chosen as only one element in every floor, correct solutions are obtained by using this developed element. Because of the rigid behavior of the floor slabs, the number of unknowns are reduced substantially. While in framed structures, classical plastic hinge hypothesis is used, in nodes of shear wall elements when vertical deformation parameter is exceeded εe, this node is accepted as a plastic node. While the system is calculated with matrix displacement method, for determination of collapse safety, plastic displacements and plastic deformations are taken as additional unknowns. Rows and columns are added to the system stiffness matrix for additional unknowns.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608568
|
oai_dc
|
Duality in non-linear programming for limit analysis of not resisting tension bodies
|
Duality in non-linear programming for limit analysis of not resisting tension bodies
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"O. Corbi(University of Naples “Federico II”); A. Baratta(University of Naples “Federico II”)"
] |
In the paper, one focuses on the problem of duality in non-linear programming, applied to the solution of no-tension problems by means of Limit Analysis (LA) theorems for Not Resisting Tension (NRT) models. In details, one demonstrates that, starting from the application of the duality theory to the
non-linear program defined by the static theorem approach for a discrete NRT model, this procedure results in the definition of a dual problem that has a significant physical meaning: the formulation of the kinematic theorem.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608582
|
oai_dc
|
An elliptical fracture criterion for mixed mode fracture I+II emanating from notches
|
An elliptical fracture criterion for mixed mode fracture I+II emanating from notches
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H. El Minor(Université Sidi Mohemed Ben Abdelah Fes); G. Pluvinage(Université de Metz); Z. Azari(Université de Picardie Jules Verne)"
] |
Some mixed mode fracture criterion may be converted in to elliptical or ellipsoidal formula with the aid of mathematical translation. Hence, the crack initiation in mixed mode fracture I+II emanating from notches, has been studied using notched circular ring specimens. On the basis of Irwin (1957) theory, a new criteria in mixed mode fracture I+II, based fracture elliptic criterion and notch stress intensity factors has been developed.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608574
|
oai_dc
|
Bilinear plate bending element for thin and moderately thick plates using Integrated Force Method
|
Bilinear plate bending element for thin and moderately thick plates using Integrated Force Method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H. R. Dhananjaya(Manipal Institute of Technology); J. Nagabhushanam(Indian Institute of Science); P. C. Pandey(Indian Institute of Science)"
] |
Using the Mindlin-Reissner plate theory, many quadrilateral plate bending elements have been developed so far to analyze thin and moderately thick plate problems via displacement based finite element method. Here new formulation has been made to analyze thin and moderately thick plate problems using force based finite element method called Integrated Force Method (IFM). The IFM is a novel matrix formulation developed in recent years for analyzing civil, mechanical and aerospace engineering structures.
In this method all independent/internal forces are treated as unknown variables which are calculated by simultaneously imposing equations of equilibrium and compatibility conditions. In this paper the force
based new bilinear quadrilateral plate bending element (MQP4) is proposed to analyze the thin and moderately thick plate bending problems using Integrated Force Method. The Mindlin-Reissner plate theory has been used in the formulation of this element which accounts the effect of shear deformation. Standard plate bending benchmark problems are analyzed using the proposed element MQP4 via Integrated Force Method to study its performance with respect to accuracy and convergence, and results are compared with those of displacement based 4-node quadrilateral plate bending finite elements available in the literature. The results are also compared with the exact solutions. The proposed element MQP4 is free from shear locking and works satisfactorily in both thin and moderately thick plate bending situations.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608586
|
oai_dc
|
Stress intensity factors for an interface crack between an epoxy and aluminium composite plate
|
Stress intensity factors for an interface crack between an epoxy and aluminium composite plate
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Itou(Kanagawa University)"
] |
A cracked composite specimen, comprised of an epoxy and an aluminium plate, was fractured under a tensile load. In this paper, two crack configurations were investigated. The first was an artificial center crack positioned in the epoxy plate parallel to the material interface. The other was for two edge cracks in the epoxy plate, again, parallel to the interface. A tensile test was carried out by gradually increasing the applied load and it was verified that the cracks always moved suddenly in an outward direction from the interface. The d/a ratio was gradually reduced to zero, and it was confirmed that the maximum stress intensity factor value for the artificial center crack, , approached that of an artificial interface crack, (where: 2a is the crack length and d is the offset between the crack and interface). The same phenomenon was also verified for the edge cracks. Specifically, when the offset, d, was reduced to zero, the maximum stress intensity factor value, , approached that of an artificial interface edge crack.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608578
|
oai_dc
|
Alternative plate finite elements for the analysis of thick plates on elastic foundations
|
Alternative plate finite elements for the analysis of thick plates on elastic foundations
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"K. Ozgan(Yüksel Proje Uluslararas); Ayse T. Daloglu(Karadeniz Technical University)"
] |
A four-noded plate bending quadrilateral (PBQ4) and an eight-noded plate bending quadrilateral (PBQ8) element based on Mindlin plate theory have been adopted for modeling the thick plates on elastic foundations using Winkler model. Transverse shear deformations have been included, and
the stiffness matrices of the plate elements and the Winkler foundation stiffness matrices are developed using Finite Element Method based on thick plate theory. A computer program is coded for this purpose. Various loading and boundary conditions are considered, and examples from the literature are solved for comparison. Shear locking problem in the PBQ4 element is observed for small value of subgrade reaction and plate thickness. It is noted that prevention of shear locking problem in the analysis of the thin plate is
generally possible by using element PBQ8. It can be concluded that, the element PBQ8 is more effective and reliable than element PBQ4 for solving problems of thin and thick plates on elastic foundations.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608571
|
oai_dc
|
The unsymmetric finite element formulation and variational incorrectness
|
The unsymmetric finite element formulation and variational incorrectness
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"G. Prathap(CSIR Centre for Mathematical Modelling and Computer Simulation); S. Manju(National Aerospace Laboratories); V. Senthilkumar(CSIR Centre for Mathematical Modelling and Computer Simulation)"
] |
The unsymmetric finite element formulation has been proposed recently to improve predictions from distorted finite elements. Studies have also shown that this special formulation using parametric functions for the test functions and metric functions for the trial functions works surprisingly well because the former satisfy the continuity conditions while the latter ensure that the stress representation during finite element computation can retrieve in a best-fit manner, the actual variation of stress in the metric space. However, a question that remained was whether the unsymmetric formulation
was variationally correct. Here we determine that it is not, using the simplest possible element to amplify the principles.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608562
|
oai_dc
|
Free vibration analysis of a Timoshenko beam carrying multiple spring-mass systems with the effects of shear deformation and rotary inertia
|
Free vibration analysis of a Timoshenko beam carrying multiple spring-mass systems with the effects of shear deformation and rotary inertia
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Der-Wei Chen(National Defense University); Jee-Ray Wang(ChienKuo Technology University); Tsung-Lung Liu(National Defense University)"
] |
Because of complexity, the literature regarding the free vibration analysis of a Timoshenko beam carrying “multiple” spring-mass systems is rare, particular that regarding the “exact” solutions. As to the “exact” solutions by further considering the joint terms of shear deformation and rotary inertia in
the differential equation of motion of a Timoshenko beam carrying multiple concentrated attachments, the information concerned is not found yet. This is the reason why this paper aims at studying the natural frequencies and mode shapes of a uniform Timoshenko beam carrying multiple intermediate spring-mass systems using an exact as well as a numerical assembly method. Since the shear deformation and rotary inertia terms are dependent on the slenderness ratio of the beam, the shear coefficient of the cross-section,
the total number of attachments and the support conditions of the beam, the individual and/or combined effects of these factors on the result are investigated in details. Numerical results reveal that the effect of
the shear deformation and rotary inertia joint terms on the lowest five natural frequencies of the combined vibrating system is somehow complicated.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608559
|
oai_dc
|
Numerical stability and parameters study of an improved bi-directional evolutionary structural optimization method
|
Numerical stability and parameters study of an improved bi-directional evolutionary structural optimization method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"X. Huang(RMIT University); Y. M. Xie(RMIT University)"
] |
This paper presents a modified and improved bi-directional evolutionary structural optimization (BESO) method for topology optimization. A sensitivity filter which has been used in other optimization methods is introduced into BESO so that the design solutions become mesh-independent. To improve the convergence of the optimization process, the sensitivity number considers its historical information. Numerical examples show the effectiveness of the modified BESO method in obtaining convergent and mesh-independent solutions. A study of the effects of various BESO parameters on the solution is then conducted to determine the appropriate values for these parameters.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608572
|
oai_dc
|
Behavior of tunnel form buildings under quasi-static cyclic lateral loading
|
Behavior of tunnel form buildings under quasi-static cyclic lateral loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Bahadir Yuksel(Selcuk University); Erol Kalkan(California Geological Survey)"
] |
In this paper, experimental investigations on the inelastic seismic behavior of tunnel form buildings (i.e., box-type or panel systems) are presented. Two four-story scaled building specimens were tested under quasi-static cyclic lateral loading in longitudinal and transverse directions. The experimental
results and supplemental finite element simulations collectively indicate that lightly reinforced structural walls of tunnel form buildings may exhibit brittle flexural failure under seismic action. The global tension/ compression couple triggers this failure mechanism by creating pure axial tension in outermost shearwalls. This type of failure takes place due to rupturing of longitudinal reinforcement without crushing of concrete, therefore is of particular interest in emphasizing the mode of failure that is not routinely considered during seismic design of shear-wall dominant structural systems.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608557
|
oai_dc
|
Reliability of articulated tower joint against random base shear
|
Reliability of articulated tower joint against random base shear
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Nazrul Islam(Jamia Millia Islamia University); Suhail Ahmad(Indian Institute of Technology)"
] |
An Articulated tower is one of the compliant offshore structures connected to the sea-bed through a universal joint which is the most vulnerable location of the tower that sustains the randomly fluctuating shear stresses. The time history response of the bottom hinge shear is obtained and presented
in the spectral form. The fatigue and fracture reliability assessment of the tower joint against randomly varying shear stresses have been carried out. Non-linear limit state functions are derived in terms of important random variables using S-N curve and fracture mechanics approaches. Advanced First Order Reliability Method is used for reliability assessment. Sensitivity analysis shows the influence of various variables on the hinge safety. Fatigue life estimation has been made using probabilistic approach.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608567
|
oai_dc
|
Pre-earthquake fuzzy logic and neural network based rapid visual screening of buildings
|
Pre-earthquake fuzzy logic and neural network based rapid visual screening of buildings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"V. J. Moseley(University of Patras); S. E. Dritsos(University of Patras)"
] |
When assessing buildings that may collapse during a large earthquake, conventional rapid visual screening procedures generally provide good results when identifying buildings for further investigation. Unfortunately, their accuracy at identify buildings at risk is not so good. In addition, there
appears to be little room for improvement. This paper investigates an alternative screening procedure based on fuzzy logic and artificial neural networks. Two databases of buildings damaged during the Athens earthquake of 1999 are used for training purposes. Extremely good results are obtained from one database and not so good results are obtained from the second database. This finding illustrates the importance of specifically collecting data tailored to the requirements of the fuzzy logic based rapid visual screening procedure. In general, results demonstrate that the trained fuzzy logic based rapid visual screening procedure represents a marked improvement when identifying buildings at risk. In particular, when smaller percentages of the buildings with high damage scores are extracted for further investigation,
the proposed fuzzy screening procedure becomes more efficient. This paper shows that the proposed procedure has a significant optimisation potential, is worth pursuing and, to this end, a strategy that outlines the future development of the fuzzy logic based rapid visual screening procedure is proposed.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608553
|
oai_dc
|
Non-linear vibration and stability analysis of a partially supported conveyor belt by a distributed viscoelastic foundation
|
Non-linear vibration and stability analysis of a partially supported conveyor belt by a distributed viscoelastic foundation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. H. Ghayesh(Tarbiat Modarres University); S. E. Khadem(Tarbiat Modarres University)"
] |
The main source of transverse vibration of a conveyor belt is frictional contact between pulley and belt. Also, environmental characteristics such as natural dampers and springs affect natural frequencies, stability and bifurcation points of system. These phenomena can be modeled by a small velocity fluctuation about mean velocity. Also, viscoelastic foundation can be modeled as the dampers and springs with continuous characteristics. In this study, non-linear vibration of a conveyor belt supported partially by a distributed viscoelastic foundation is investigated. Perturbation method is applied to obtain a closed form analytic solutions. Finally, numerical simulations are presented to show stiffness, damping coefficient, foundation length, non-linearity and mean velocity effects on location of bifurcation points,
natural frequencies and stability of solutions.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608552
|
oai_dc
|
Stability and vibration analysis of composite plates using spline finite strips with higher-order shear deformation
|
Stability and vibration analysis of composite plates using spline finite strips with higher-order shear deformation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"G. Akhras(Royal Military College of Canada); W. Li(Royal Military College of Canada)"
] |
In the present study, a spline finite strip with higher-order shear deformation is formulated for the stability and free vibration analysis of composite plates. The analysis is conducted based on Reddy’s third-order shear deformation theory, Touratier’s “Sine” model, Afaq’s exponential model and Cho’s higher-order zigzag laminate theory. Consequently, the shear correction coefficients are not required in the analysis, and an improved accuracy for thick laminates is achieved. The numerical results, based on different shear deformation theories, are presented in comparison with the three-dimensional elasticity
solutions. The effects of length-to-thickness ratio, fibre orientation, and boundary conditions on the critical buckling loads and natural frequencies are investigated through numerical examples.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001608563
|
oai_dc
|
Comparison of code provisions on lap splices
|
Comparison of code provisions on lap splices
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Erdem Canbay(Middle East Technical University)"
] |
The code provisions on lap splices are critically assessed in the light of 203 beams without transverse reinforcement and 278 beams with transverse reinforcement. For comparison, the provisions given in the ACI 318, Eurocode 2, and TS 500 Codes are considered. The ACI Committee 408 recommended provision and a new proposal are also taken into account throughout the assessment. The comparison with real beam tests where the splice region was subjected to constant moment indicates that current provisions in the Codes do not agree acceptably with test results. The steel stress prediction
graphs calculated by means of the Code provisions show high scatter and remain unsafe especially for test data without transverse reinforcement. Both the recent recommended provision by ACI Committee 408 and a new design expression proposed by the author have much less scatter with fewer unsafe predictions. The simplified design provision proposed by ACI Committee 408 does not yield similar results to that of the advanced design provision proposed by the same committee and therefore it could conveniently be
replaced with the simpler equation proposed by the author.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557233
|
oai_dc
|
Study on damage detection software of beam-like structures
|
Study on damage detection software of beam-like structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jiawei Xiang(Guilin University of Electronic Technology); Zhansi Jiang(Guilin University of Electronic Technology); Yanxue Wang(Guilin University of Electronic Technology); Xuefeng Chen(Xi'an Jiaotong University)"
] |
A simply structural damage detection software is developed to identification damage in beams. According to linear fracture mechanics theory, the localized additional flexibility in damage vicinity can be represented by a lumped parameter element. The damaged beam is modeled by waveletbased elements to gain the first three frequencies precisely. The first three frequencies influencing functions of damage location and depth are approximated by means of surface-fitting techniques to gain damage detection database of forward problem. Then the first three measured natural frequencies are employed as inputs to solve inverse problem and the intersection of the three frequencies contour lines predict the damage location and depth. The DLL (Dynamic Linkable Library) file of damage detection method is coded by C++ and the corresponding interface of software is coded by virtual instrument software LabVIEW. Finally, the software is tested on beams and shafts in engineering. It is shown that the presented software can be used in actual engineering structures.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557234
|
oai_dc
|
Geodesic shape finding of membrane structure with geodesic string by the dynamic relaxation method
|
Geodesic shape finding of membrane structure with geodesic string by the dynamic relaxation method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"K.S. Lee(Inha University); 한상을(인하대학교)"
] |
The explicit nonlinear dynamic relaxation method (DRM) is applied to the nonlinear geodesic shape finding analysis by introducing fictional tensioned ‘strings’ along the desired seams with a three or four-node membrane element. A number of results from the numerical example for the nonlinear geodesic shape finding and patterning analysis are obtained by the proposed method to demonstrate the accuracy and efficiency of the developed method. Therefore, the proposed geodesic shape finding algorithm may improve the applicability of a four-node membrane element to membrane structural engineering and design analysis simultaneously for the shape finding, stress, and patterning analysis.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557243
|
oai_dc
|
Capacity design by developed pole placement structural control
|
Capacity design by developed pole placement structural control
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Fereidoun Amini(Iran University of Science); Kaveh Karami(Iran University of Science)"
] |
To ensure safety and long term performance, structural control has rapidly matured over the past decade into a viable means of limiting structural responses to strong winds and earthquakes. Nonlinear response history analysis requires rigorous procedure to compute seismic demands. Therefore the simplified nonlinear analysis procedures are useful to determine performance of the structure. In this investigation, application of improved capacity demand diagram method in the control of structural system is presented for the first time. Developed pole assignment method (DPAM) in structural systems control is introduced. Genetic algorithm (GA) is employed as an optimization tool for minimizing a target function that defines values of coefficient matrices providing the placement of actuators and optimal control forces. The ground acceleration is modified under induced control forces. Due to this, performance of structure based on improved nonlinear demand diagram is selected to threshold of nonlinear behavior of structure. With small energy consumption characteristics, semi-active devices are especially attractive solutions for limiting earthquake effects. To illustrate the efficiency of DPAM, a 30-story steel moment frame structure employing the semi-active control devices is applied. In comparison to the widely used linear quadratic regulation (LQR), the DPAM controller was shown to be just as effective and better in the reduction of structural responses during large earthquakes.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557236
|
oai_dc
|
A note on buckling and vibration of clamped orthotropic plates under in-plane loads
|
A note on buckling and vibration of clamped orthotropic plates under in-plane loads
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"D.H. Felix(Universidad Nacional del Sur); D.V. Bambill(Universidad Nacional del Sur); C.A. Rossit(Universidad Nacional del Sur)"
] |
The present work deals with obtaining the critical buckling load and the natural frequencies of clamped, orthotropic, rectangular thin plates subjected to different linear distributed in-plane forces. An analytical solution is proposed. Using the Ritz method, the dependence between in-plane forces and natural frequencies are estimated for various plate sizes, and some results are compared with finite element solutions and where possible, comparison is made with previously published results. Beam functions are used as admissible functions in the Ritz method.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557219
|
oai_dc
|
Applications of Hilbert-Huang transform to structural damage detection
|
Applications of Hilbert-Huang transform to structural damage detection
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dung-Jiang Chiou(National Central University Jhung-li); Wen-Ko Hsu(National Central University Jhung-li); Cheng-Wu Chen(National Kaohsiung Marine University); Chih-Min Hsieh(National Kaohsiung Marine University); Jhy-Pyng Tang(National Central University Jhung-li); Wei-Ling Chiang(National Central University Jhung-li)"
] |
This study investigates the feasibility of detecting structural damage using the HHT method. A damage detection index, the ratio of bandwidth (RB) is proposed. This index is highly correlated or approximately equal to the change of equivalent damping ratio for an intact structure incurring damage from strong ground motions. Based on an analysis of shaking table test data from benchmark models subjected to adjusted Kobe and El Centro earthquakes, the damage detection index is evaluated using the Hilbert-Huang Transform (HHT) and the Fast Fourier Transform (FFT) methods, respectively. Results indicate that, when the response of the structure is in the elastic region, the RB value only slightly changes in both the HHT and the FFT spectra. Additionally, RB values estimated from the HHT spectra vs. the PGA values change incrementally when the structure response is nonlinear i.e., member yielding occurs, but not in the RB curve from the FFT spectra. Moreover, the RB value of the top floor changes more than those from the other floors. Furthermore, structural damage is detected only when using the acceleration response data from the top floor. Therefore, the ratio of bandwidth RB estimated from the smoothed HHT spectra is an effective and sensitive damage index for detecting structural damage. Results of this study also demonstrate that the HHT is a powerful method in analyzing the nonlinear responses of steel structures to strong ground motions.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557228
|
oai_dc
|
An accurate substructural synthesis approach to random responses
|
An accurate substructural synthesis approach to random responses
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Z.G. Ying(Zhejiang University); W.Q. Zhu(Zhejiang University); S.Q. Ye(The Hong Kong Polytechnic University); Y.Q. Ni(The Hong Kong Polytechnic University)"
] |
An accurate substructural synthesis method including random responses synthesis, frequencyresponse functions synthesis and mid-order modes synthesis is developed based on rigorous substructure description, dynamic condensation and coupling. An entire structure can firstly be divided into several substructures according to different functions, geometric and dynamic characteristics. Substructural displacements are expressed exactly by retained mid-order fixed-interfacial normal modes and residual constraint modes. Substructural interfacial degree-of-freedoms are eliminated by interfacial displacements compatibility and forces equilibrium between adjacent substructures. Then substructural mode vibration equations are coupled to form an exact-condensed synthesized structure equation, from which structural mid-order modes are calculated accurately. Furthermore, substructural frequency-response function equations are coupled to yield an exact-condensed synthesized structure vibration equation in frequency domain, from which the generalized structural frequency-response functions are obtained. Substructural frequency-response functions are calculated separately by using the generalized frequency-response functions, which can be assembled into an entire-structural frequency-response function matrix. Substructural power spectral density functions are expressed by the exact-synthesized substructural frequency-response functions, and substructural random responses such as correlation functions and meansquare responses can be calculated separately. The accuracy and capacity of the proposed substructure synthesis method is verified by numerical examples.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557242
|
oai_dc
|
Experimental and analytical investigation on seismic behavior of RC framed structure by pushover method
|
Experimental and analytical investigation on seismic behavior of RC framed structure by pushover method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Akanshu Sharma(Bhabha Atomic Research Centre); G.R. Reddy(Bhabha Atomic Research Centre); R. Eligehausen(University of Stuttgart); K.K. Vaze(Bhabha Atomic Research Centre)"
] |
Pushover analysis has gained significant popularity as an analytical tool for realistic determination of the inelastic behaviour of RC structures. Though significant work has been done to evaluate the demands realistically, the evaluation of capacity and realistic failure modes has taken a back seat. In order to throw light on the inelastic behaviour and capacity evaluation for the RC framed structures, a 3D Reinforced concrete frame structure was tested under monotonically increasing lateral pushover loads, in a parabolic pattern, till failure. The structure consisted of three storeys and had 2 bays along the two orthogonal directions. The structure was gradually pushed in small increments of load and the corresponding displacements were monitored continuously, leading to a pushover curve for the structure as a result of the test along with other relevant information such as strains on reinforcement bars at critical locations, failure modes etc. The major failure modes were observed as flexural failure of beams and columns, torsional failure of transverse beams and joint shear failure. The analysis of the structure was by considering all these failure modes. In order to have a comparison, the analysis was performed as three different cases. In one case, only the flexural hinges were modelled for critical locations in beams and columns; in second the torsional hinges for transverse beams were included in the analysis and in the third case, joint shear hinges were also included in the analysis. It is shown that modelling and capturing all the failure modes is practically possible and such an analysis can provide the realistic insight into the behaviour of the structure.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001557224
|
oai_dc
|
Physics based basis function for vibration analysis of high speed rotating beams
|
Physics based basis function for vibration analysis of high speed rotating beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"R. Ganesh(Indian Institute of Science); Ranjan Ganguli(Indian Institute of Science)"
] |
The natural frequencies of continuous systems depend on the governing partial differential equation and can be numerically estimated using the finite element method. The accuracy and convergence of the finite element method depends on the choice of basis functions. A basis function will generally perform better if it is closely linked to the problem physics. The stiffness matrix is the same for either static or dynamic loading, hence the basis function can be chosen such that it satisfies the static part of the governing differential equation. However, in the case of a rotating beam, an exact closed form solution for the static part of the governing differential equation is not known. In this paper, we try to find an approximate solution for the static part of the governing differential equation for an uniform rotating beam. The error resulting from the approximation is minimized to generate relations between the constants assumed in the solution. This new function is used as a basis function which gives rise to shape functions which depend on position of the element in the beam, material, geometric properties and rotational speed of the beam. The results of finite element analysis with the new basis functions are verified with published literature for uniform and tapered rotating beams under different boundary conditions. Numerical results clearly show the advantage of the current approach at high rotation speeds with a reduction of 10 to 33% in the degrees of freedom required for convergence of the first five modes to four decimal places for an uniform rotating cantilever beam.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001489645
|
oai_dc
|
Damage detection for beam structures using an angle-between-string-and-horizon flexibility matrix
|
Damage detection for beam structures using an angle-between-string-and-horizon flexibility matrix
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Guirong Yan(University of Western Sydney); Zhongdong Duan(Harbin Institute of Technology); Jinping Ou(Dalian University of Technology)"
] |
The classical flexibility difference method detects damage by observing the difference of conventional deflection flexibility matrices between pre- and post-damaged states of a structure. This method is not able to identify multiple damage scenarios, and its criteria to identify damage depend upon the boundary conditions of structures. The key point behind the inability and dependence is revealed in this study. A more feasible flexibility for damage detection, the Angle-between-String-and-Horizon (ASH) flexibility, is proposed. The physical meaning of the new flexibility is given, and synthesis of the new flexibility matrix by modal frequencies and translational mode shapes is formulated. The damage indicators are extracted from the difference of ASH flexibility matrices between the pre- and postdamaged structures. One feature of the ASH flexibility is that the components in the ASH flexibility matrix are associated with elements instead of Nodes or DOFs. Therefore, the damage indicators based on the ASH flexibility are mapped to structural elements directly, and thus they can pinpoint the damaged elements, which is appealing to damage detection for complex structures. In addition, the change in the ASH flexibility caused by damage is not affected by boundary conditions, which simplifies the criteria to identify damage. Moreover, the proposed method can determine relatively the damage severity. Because the proposed damage indicator of an element mainly reflects the deflection change within the element itself, which significantly reduces the influence of the damage in one element on the damage indicators of other damaged elements, the proposed method can identify multiple damage locations. The viability of the proposed approach has been demonstrated by numerical examples and experimental tests on a cantilever beam and a simply supported beam.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001489627
|
oai_dc
|
Thermal post-buckling analysis of uniform slender functionally graded material beams
|
Thermal post-buckling analysis of uniform slender functionally graded material beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"K. Sanjay Anandrao(Advanced Systems Laboratory); R.K. Gupta(Advanced Systems Laboratory); P. Ramchandran(Defense Research and Development Laboratory); G. Venkateswara Rao(Sreenidhi Institute of Science and Technology)"
] |
Two or more distinct materials are combined into a single functionally graded material (FGM) where the microstructural composition and properties change gradually. Thermal post-buckling behavior of uniform slender FGM beams is investigated independently using the classical Rayleigh-Ritz (RR) formulation and the versatile Finite Element Analysis (FEA) formulation developed in this paper. The von-Karman strain-displacement relations are used to account for moderately large deflections of FGM beams. Bending-extension coupling arising due to heterogeneity of material through the thickness is included. Simply supported and clamped beams with axially immovable ends are considered in the present study. Post-buckling load versus deflection curves and buckled mode shapes obtained from both the RR and FEA formulations for different volume fraction exponents show an excellent agreement with the available literature results for simply supported ends. Response of the FGM beam with clamped ends is studied for the first time and the results from both the RR and FEA formulations show a very good agreement. Though the response of the FGM beam could have been studied more accurately by FEA formulation alone, the authors aim to apply the RR formulation is to find an approximate closed form post-buckling solutions for the FGM beams. Further, the use of the RR formulation clearly demonstrates the effect of bending-extension coupling on the post-buckling response of the FGM beams.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001489630
|
oai_dc
|
Passive control of seismically excited structures by the liquid column vibration absorber
|
Passive control of seismically excited structures by the liquid column vibration absorber
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Tanmoy Konar(Bengal Engineering and Science University); Aparna (Dey) Ghosh(Bengal Engineering and Science University)"
] |
The potential of the liquid column vibration absorber (LCVA) as a seismic vibration control device for structures has been explored in this paper. In this work, the structure has been modeled as a linear, viscously damped single-degree-of-freedom (SDOF) system. The governing differential equations of motion for the damper liquid and for the coupled structure-LCVA system have been derived from dynamic equilibrium. The nonlinear orifice damping in the LCVA has been linearized by a stochastic equivalent linearization technique. A transfer function formulation for the structure-LCVA system has been presented. The design parameters of the LCVA have been identified and by applying the transfer function formulation the optimum combination of these parameters has been determined to obtain the most efficient control performance of the LCVA in terms of the reduction in the root-mean-square (r.m.s.) displacement response of the structure. The study has been carried out for an example structure subjected to base input characterized by a white noise power spectral density function (PSDF). The sensitivity of the performance of the LCVA to the coefficient of head loss and to the tuning ratio have also been examined and compared with that of the liquid column damper (LCD). Finally, a simulation study has been carried out with a recorded accelerogram, to demonstrate the effectiveness of the LCVA.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001489634
|
oai_dc
|
Crack tip plastic zone under Mode I, Mode II and mixed mode (I+II) conditions
|
Crack tip plastic zone under Mode I, Mode II and mixed mode (I+II) conditions
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M.R. Ayatollahi(Iran University of Science and Technology); Karo Sedighiani(Iran University of Science and Technology)"
] |
The shape and size of the plastic zone around the crack tip are analyzed under pure mode I, pure mode II and mixed mode (I+II) loading for small scale yielding and for both plane stress and plane strain conditions. A new analytical formulation is presented to determine the radius of the plastic zone in a non-dimensional form. In particular, the effect of T-stress on the plastic zone around the crack tip is studied. The results of this investigation indicate that the stress field with a T-stress always yields a larger plastic zone than the field without a T-stress. It is found that under predominantly mode I loading, the effect of a negative T-stress on the size of the plastic zone is more dramatic than a positive T-stress. However, when mode II portion of loading is dominating the effect of both positive and negative Tstresses on the size of the plastic zone is almost equal. For validating the analytical results, several finite element analyses were performed. It is shown that the results obtained by the proposed analytical formulation are in very good agreements with those obtained from the finite element analyses.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001489624
|
oai_dc
|
Large strain analysis of two-dimensional frames by the normal flow algorithm
|
Large strain analysis of two-dimensional frames by the normal flow algorithm
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Tabatabaei, R.(Islamic Azad University); Saffari, H(Shahid Bahonar University)"
] |
Nonlinear equations of structures are generally solved numerically by the iterative solution of linear equations. However, this iterative procedure diverges when the tangent stiffness is ill-conditioned which occurs near limit points. In other words, a major challenge with simple iterative methods is failure caused by a singular or near singular Jacobian matrix. In this paper, using the Newton-Raphson algorithm based on Davidenko’s equations, the iterations can traverse the limit point without difficulty. It is argued that the propose algorithm may be both more computationally efficient and more robust compared to the other algorithm when tracing path through severe nonlinearities such as those associated with structural collapse. Two frames are analyzed using the proposed algorithm and the results are compared with the previous methods. The ability of the proposed method, particularly for tracing the limit points, is demonstrated by those numerical examples.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001489637
|
oai_dc
|
Basis of design and numerical modeling of offshore wind turbines
|
Basis of design and numerical modeling of offshore wind turbines
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Francesco Petrini(University of Rome “La Sapienza”); Hui Li(Harbin Institute of Technology); Franco Bontempi(University of Rome “La Sapienza”)"
] |
Offshore wind turbines are relatively complex structural and mechanical systems located in a highly demanding environment. In the present paper the fundamental aspects and the major issues related to the design of these special structures are outlined. Particularly, a systemic approach is proposed for a global design of such structures, in order to handle coherently their different parts: the decomposition of these structural systems, the required performance and the acting loads are all considered under this philosophy. According to this strategy, a proper numerical modeling requires the adoption of a suitable technique in order to organize the qualitative and quantitative assessments in various sub-problems, which can be solved by means of sub-models at different levels of detail, for both structural behavior and loads simulation. Specifically, numerical models are developed to assess the safety performances under aerodynamic and hydrodynamic actions. In order to face the problems of the actual design of a wind farm in the Mediterranean Sea, in this paper, three schemes of turbines support structures have been considered and compared: the mono pile, the tripod and the jacket support structure typologies.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001489642
|
oai_dc
|
New twelve node serendipity quadrilateral plate bending element based on Mindlin-Reissner theory using Integrated Force Method
|
New twelve node serendipity quadrilateral plate bending element based on Mindlin-Reissner theory using Integrated Force Method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H.R. Dhananjaya(University of Malaya); J. Nagabhushanam(Indian Institute of Science Bangalore); P.C. Pandey(Indian Institute of Science Bangalore); Mohd. Zamin Jumaat(University of Malaya)"
] |
The Integrated Force Method (IFM) is a novel matrix formulation developed for analyzing the civil, mechanical and aerospace engineering structures. In this method all independent/internal forces are treated as unknown variables which are calculated by simultaneously imposing equations of equilibrium and compatibility conditions. This paper presents a new 12-node serendipity quadrilateral plate bending element MQP12 for the analysis of thin and thick plate problems using IFM. The Mindlin-Reissner plate theory has been employed in the formulation which accounts the effect of shear deformation. The performance of this new element with respect to accuracy and convergence is studied by analyzing many standard benchmark plate bending problems. The results of the new element MQP12 are compared with those of displacement-based 12-node plate bending elements available in the literature. The results are also compared with exact solutions. The new element MQP12 is free from shear locking and performs excellent for both thin and moderately thick plate bending situations.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001501429
|
oai_dc
|
New prismatic solid-shell element: assumed strain formulation and hourglass mode analysis
|
New prismatic solid-shell element: assumed strain formulation and hourglass mode analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Farid Abed-Meraim(Arts et Métiers ParisTech); Alain Combescure(INSA de Lyon)"
] |
토목공학
| null |
kci_detailed_000077.xml
|
||||
ART001501421
|
oai_dc
|
Mesoscale modelling of concrete for static and dynamic response analysis Part 1: model development and implementation
|
Mesoscale modelling of concrete for static and dynamic response analysis Part 1: model development and implementation
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zhenguo Tu(IKM Ocean Design As); Yong Lu(The University of Edinburgh)"
] |
Concrete is a heterogeneous material exhibiting quasi-brittle behaviour. While homogenization of concrete is commonly accepted in general engineering applications, a detailed description of the material heterogeneity using a mesoscale model becomes desirable and even necessary for problems where drastic spatial and time variation of the stress and strain is involved, for example in the analysis of local damages under impact, shock or blast load. A mesoscale model can also assist in an investigation into the underlying mechanisms affecting the bulk material behaviour under various stress conditions.Extending from existing mesoscale model studies, where use is often made of specialized codes with limited capability in the material description and numerical solutions, this paper presents a mesoscale computational model developed under a general-purpose finite element environment. The aim is to facilitate the utilization of sophisticated material descriptions (e.g., pressure and rate dependency) and advanced numerical solvers to suit a broad range of applications, including high impulsive dynamic analysis. The whole procedure encompasses a module for the generation of concrete mesoscale structure; a process for the generation of the FE mesh, considering two alternative schemes for the interface transition zone (ITZ); and the nonlinear analysis of the mesoscale FE model with an explicit time integration approach. The development of the model and various associated computational considerations are discussed in this paper (Part 1). Further numerical studies using the mesoscale model for both quasistatic and dynamic loadings will be presented in the companion paper (Part 2).
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001501427
|
oai_dc
|
Seismic performance of concrete moment resisting frame buildings in Canada
|
Seismic performance of concrete moment resisting frame buildings in Canada
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Omar El Kafrawy(El Kafrawy Consulting Co.); Ashutosh Bagchi(Concordia University); Jag Humar(Carleton University)"
] |
The seismic provisions of the current edition (2005) of the National Building Code of Canada (NBCC) differ significantly from the earlier edition. The current seismic provisions are based on the uniform hazard spectra corresponding to 2% probability of exceedance in 50 years, as opposed to the seismic hazard level with 10% probablity of exeedance in 50 years used in the earlier edition. Moreover, the current code is presented in an objective-based format where the design is performed based on an acceptable solution. In the light of these changes, an assessment of the expected performance of the buildings designed according to the requirements of the current edition of NBCC would be very useful. In this paper, the seismic performance of a set of six, twelve, and eighteen story buildings of regular geometry and with concrete moment resisting frames, designed for Vancouver western Canada, has been evaluated. Although the effects of non-structural elements are not considered in the design, the nonstructural elements connected to the lateral load resisting systems affect the seismic performance of a building. To simulate the non-structural elements, infill panels are included in some frame models. Spectrum compatible artificial ground motion records and scaled actual accelerograms have been used for evaluating the dynamic response. The performance has been evaluated for each building under various of seismic hazard with different probabilities of exceedance. From the study it has been observed that, although all the buildings achieved the life-safety performance as assumed in the design provisions of the building code, their performance characteristics are found to be non-uniform.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001501413
|
oai_dc
|
A comparative study for beams on elastic foundation models to analysis of mode-I delamination in DCB specimens
|
A comparative study for beams on elastic foundation models to analysis of mode-I delamination in DCB specimens
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mahmood Mehrdad Shokrieh(Iran University of Science and Technology); Mohammad Heidari-Rarani(Iran University of Science and Technology)"
] |
The aim of this research is a comprehensive review and evaluation of beam theories resting on elastic foundations that used to model mode-I delamination in multidirectional laminated composite by DCB specimen. A compliance based approach is used to calculate critical strain energy release rate (SERR). Two well-known beam theories, i.e. Euler-Bernoulli (EB) and Timoshenko beams (TB), on Winkler and Pasternak elastic foundations (WEF and PEF) are considered. In each case, a closed-form solution is presented for compliance versus crack length, effective material properties and geometrical dimensions. Effective flexural modulus (E_fx) and out-of-plane extensional stiffness (E_z) are used in all models instead of transversely isotropic assumption in composite laminates. Eventually, the analytical solutions are compared with experimental results available in the literature for unidirectional ([0˚]_6) and antisymmetric angle-ply ([±30˚]_5, and [±45˚]_5) lay-ups. TB on WEF is a simple model that predicts more accurate results for compliance and SERR in unidirectional laminates in comparison to other models. TB on PEF, in accordance with Williams (1989) assumptions, is too stiff for unidirectional DCB specimens, whereas in angle-ply DCB specimens it gives more reliable results. That it shows the effects of transverse shear deformation and root rotation on SERR value in composite DCB specimens.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001501425
|
oai_dc
|
Mesoscale modelling of concrete for static and dynamic response analysis Part 2: numerical investigations
|
Mesoscale modelling of concrete for static and dynamic response analysis Part 2: numerical investigations
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yong Lu(The University of Edinburgh); Zhenguo Tu(IKM Ocean Design As)"
] |
As a brittle and heterogeneous material, concrete behaves differently under different stress conditions and its bulk strength is loading rate dependent. To a large extent, the varying behavioural properties of concrete can be explained by the mechanical failure processes at a mesoscopic level. The development of a computational mesoscale model in a general finite element environment, as presented in the preceding companion paper (Part 1), makes it possible to investigate into the underlying mechanisms governing the bulk-scale behaviour of concrete under a variety of loading conditions and to characterise the variation in quantitative terms. In this paper, we first present a series of parametric studies on the behaviour of concrete material under quasi-static compression and tension conditions. The loading-face friction effect, the possible influences of the non-homogeneity within the mortar and ITZ phases, and the effect of randomness of coarse aggregates are examined. The mesoscale model is then applied to analyze the dynamic behaviour of concrete under high rate loading conditions. The potential contribution of the mesoscopic heterogeneity towards the generally recognized rate enhancement of the material compressive strength is discussed.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001501412
|
oai_dc
|
Application of joint time-frequency distribution for estimation of time-varying modal damping ratio
|
Application of joint time-frequency distribution for estimation of time-varying modal damping ratio
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H. Bucher(COPPE/Federal University); C. Magluta(COPPE/Federal University); W.J. Mansur(COPPE/Federal University)"
] |
The logarithmic decrement method has been long used to estimate damping ratios in systems with only one modal component such as linear single degree of freedom (SDOF) mechanical systems. This paper presents an application of a methodology that uses joint time-frequency distribution (JTFD) as input, instead of the raw signal, to systems with several vibration modes. A most important feature of the present approach is that it can be applied to a system with time-varying damping ratio. Initially the precision and robustness of the method is determined using a synthetic model with multiple harmonic components, one of them displaying a time-varying damping ratio, subsequently the results obtained from experiments with a reduced model are presented. A comparison is made between the results obtained with this methodology and those using the classical technique of Least Squares Complex Exponential Method (LSCE) in order to highlight the advantages of the former, such as, good precision, robustness and excellent performance in extreme cases, e.g., when very low frequency components and time varying damping ratio are present.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001501415
|
oai_dc
|
Beams affected by corrosion influence of reinforcement placement in the cracking
|
Beams affected by corrosion influence of reinforcement placement in the cracking
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Néstor F. Ortega(Universidad Nacional del Sur); Irene E. Rivas(Universidad Nacional del Centro de la Prov); Raquel R. Aveldaño(Universidad Nacional del Sur); María H. Peralta(Universidad Nacional del Centro de la Prov)"
] |
The results of experimental and numerical investigations on reinforced concrete beams, with different longitudinal rebars affected by corrosive processes are presented in this paper. Different diameters and/or different distributions of longitudinal rebars were employed keeping constant the total section in each analyzed case, (maintaining a constant stirrup diameter and distribution). The rebars were subjected to accelerated corrosion in the experimental study. Electrochemical monitoring of the process, periodic measuring of the cover cracking and gravimetry of the rebars were performed through the test. Some building recommendations are obtained in order to be considered by designers of concrete structures. The numerical simulation was carried out through the application of the Finite Element Method (FEM), employing plane models, and using linear-elastic material model. The cracking process was associated with the evolution of the tensile stresses that were originated. This numerical methodology allows the monitoring of the mechanical behavior until the beginning of the cracking.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001501418
|
oai_dc
|
Strengthening of deficient RC frames with high strength concrete panels: an experimental study
|
Strengthening of deficient RC frames with high strength concrete panels: an experimental study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mehmet Baran(Kirikkale University); Melih Susoy(OM Engineering Services, Inc.); Tugrul Tankut(Middle East Technical University)"
] |
An economic, structurally effective and practically applicable strengthening technique was developed for reinforced concrete (RC) framed buildings. The idea of the technique is to convert the existing hollow brick infill wall into a load carrying system acting as a cast-in-place RC infill wall by bonding relatively thin high strength precast concrete PC panels to the plastered hollow brick infill. For this purpose, a total of eight one-third scale, one bay, one story frames were tested under reversed-cyclic lateral loads. Test frames were designed and constructed with common deficiencies observed in practice. Four different panel types were used for strengthening. Test results showed that both strength and stiffness of the frames were significantly improved by the introduction of PC panels. Experimental results were compared with the analytical approaches suggested by the authors.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001497731
|
oai_dc
|
Response of lap splice of reinforcing bars confined by FRP wrapping: application to nonlinear analysis of RC column
|
Response of lap splice of reinforcing bars confined by FRP wrapping: application to nonlinear analysis of RC column
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Amorn Pimanmas(Thammasat University); Dam Xuan Thai(The National University of Civil Engineering)"
] |
This paper presents a nonlinear analysis of reinforced concrete column with lap splice confined by FRP wrapping in the critical hinging zone. The steel stress-slip model derived from the triuniform bond stress model presented in the companion paper is included in the nonlinear frame analysis to simulate the response of reinforced concrete columns subjected to cyclic displacement reversals. The nonlinear modeling is based on a fiber discretization of an RC column section. Each fiber is modeled as either nonlinear concrete or steel spring, whose load-deformation characteristics are calculated from the section of fiber and material properties. The steel spring that models the reinforcing bars consists of three sub-springs, i.e., steel bar sub-spring, lap splice spring, and anchorage bond-slip spring connected in series from top to bottom. By combining the steel stress versus slip of the lap splice, the stress-deformation of steel bar and the steel stress-slip of bars anchored into the footing, the nonlinear steel spring model is derived. The analytical responses are found to be close to experimental ones. The analysis without lap splice springs included may result in an erroneous overestimation in the strength and ductility of columns.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001497723
|
oai_dc
|
An Internet-based computing framework for the simulation of multi-scale response of structural systems
|
An Internet-based computing framework for the simulation of multi-scale response of structural systems
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hung-Ming Chen(National Taiwan University of Science and Technology); Yu-Chih Lin(National Taiwan University of Science and Technology)"
] |
This paper presents a new Internet-based computational framework for the realistic simulation of multi-scale response of structural systems. Two levels of parallel processing are involved in this framework: multiple local distributed computing environments connected by the Internet to form a clusterto-cluster distributed computing environment. To utilize such a computing environment for a realistic simulation, the simulation task of a structural system has been separated into a simulation of a simplified global model in association with several detailed component models using various scales. These related multi-scale simulation tasks are distributed amongst clusters and connected to form a multi-level hierarchy. The Internet is used to coordinate geographically distributed simulation tasks. This paper also presents the development of a software framework that can support the multi-level hierarchical simulation approach, in a cluster-to-cluster distributed computing environment. The architectural design of the program also allows the integration of several multi-scale models to be clients and servers under a single platform. Such integration can combine geographically distributed computing resources to produce realistic simulations of structural systems.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001497728
|
oai_dc
|
Response of a completely free beam on a tensionless Pasternak foundation subjected to dynamic load
|
Response of a completely free beam on a tensionless Pasternak foundation subjected to dynamic load
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Z. Celep(Istanbul Technical University); K. Güler(Istanbul Technical University); F. Demir(Süleyman Demirel University)"
] |
Static and dynamic responses of a completely free elastic beam resting on a two-parameter tensionless Pasternak foundation are investigated by assuming that the beam is symmetrically subjected to a uniformly distributed load and concentrated load at its middle. Governing equations of the problem are obtained and solved by paying attention on the boundary conditions of the problem including the concentrated edge foundation reaction in the case of complete contact and lift-off condition of the beam in a two-parameter foundation. The nonlinear governing equation of the problem is evaluated numerically by adopting an iterative procedure. Numerical results are presented in figures to demonstrate the non-linear behavior of the beam-foundation system for various values of the parameters of the problem comparatively by considering the static and dynamic loading cases.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001497730
|
oai_dc
|
Response of lap splice of reinforcing bars confined by FRP wrapping: modeling approach
|
Response of lap splice of reinforcing bars confined by FRP wrapping: modeling approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dam Xuan Thai(The National University of Civil Engineering); Amorn Pimanmas(Thammasat University)"
] |
This paper presents a tri-uniform bond stress model for predicting the lap splice strength of reinforcing bar at the critical bond splitting failure. The proposed bond distribution model consists of three zones, namely, splitting zone, post-splitting zone and yielding zone. In each zone, the bond stress is assumed to be constant. The models for bond strength in each zone are adopted from previous studies. Combining the equilibrium, strain-slip relation and the bond strength model in each zone, the steel stressslip model can be derived, which can be used in the nonlinear frame analysis of the column. The proposed model is applied to derive explicit equations for predicting the strength of the lap splice strengthened by fiber reinforced polymer (FRP) in both elastic and post-yield ranges. For design purpose, a procedure to calculate the required FRP thickness and the number of FRP sheets is also presented. A parametric investigation was conducted to study the relation between lap splice strength and lap splice length, number and thickness of FRP sheets and the ratio of concrete cover to bar diameter. The study shows that the lap splice strength can be enhanced by increasing one of these parameters: lap splice length, number or thickness of FRP sheets and concrete cover to bar diameter ratio. Verification of the model has been conducted using experimental data available in literature.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001497729
|
oai_dc
|
Modeling of progressive collapse of a multi-storey structure using a spring-mass-damper system
|
Modeling of progressive collapse of a multi-storey structure using a spring-mass-damper system
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Weifeng Yuan(Nanyang Technological University); Kang Hai Tan(Nanyang Technological University)"
] |
A simple mechanical model is proposed to demonstrate qualitatively the pancake progressive collapse of multi-storey structures. The impact between two collapsed storeys is simulated using a simple algorithm that builds on virtual mass-spring-damper system. To analyze various collapse modes, columns and beams are considered separately. Parametric studies show that the process of progressive collapse involves a large number of complex mechanisms. However, the proposed model provides a simple numerical tool to assess the overall behavior of collapse arising from a few initiating causes. Unique features, such as beam-to-beam connection failure criterion, and beam-to-column connection failure criterion are incorporated into the program. Besides, the criterion of local failure of structural members can also be easily incorporated into the proposed model.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001497726
|
oai_dc
|
Shear strength analysis and prediction of reinforced concrete transfer beams in high-rise buildings
|
Shear strength analysis and prediction of reinforced concrete transfer beams in high-rise buildings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"R.S. Londhe(Government College of Engineering)"
] |
Results of an experimental investigation on the behavior and ultimate shear capacity of 27 reinforced concrete Transfer (deep) beams are summarized. The main variables were percent longitudinal (tension) steel (0.28 to 0.60%), percent horizontal web steel (0.60 to 2.40%), percent vertical steel (0.50to 2.25%), percent orthogonal web steel, shear span-to-depth ratio (1.10 to 3.20) and cube concrete compressive strength (32 MPa to 48 MPa).The span of the beam has been kept constant at 1000 mm with 100 mm overhang on either side of the supports. The result of this study shows that the load transfer capacity of transfer (deep) beam with distributed longitudinal reinforcement is increased significantly. Also, the vertical shear reinforcement is more effective than the horizontal reinforcement in increasing the shear capacity as well as to transform the brittle mode of failure in to the ductile mode of failure. It has been observed that the orthogonal web reinforcement is highly influencing parameter to generate the shear capacity of transfer beams as well as its failure modes. Moreover, the results from the experiments have been processed suitably and presented an analytical model for design of transfer beams in high-rise buildings for estimating the shear capacity of beams.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001497718
|
oai_dc
|
Elucidating the mechanical behavior of ultra-high-strength concrete under repeated impact loading
|
Elucidating the mechanical behavior of ultra-high-strength concrete under repeated impact loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yuh-Shiou Tai(ROC Military Academy); Iau-Teh Wang(ROC Military Academy)"
] |
The response of concrete to transient dynamic loading has received extensive attention for both civil and military applications. Accordingly, thoroughly understanding the response and failure modes of concrete subjected to impact or explosive loading is vital to the protection provided by fortifications. Reactive powder concrete (RPC), as developed by Richard and Cheyrezy (1995) in recent years, is a unique mixture that is cured such that it has an ultra-high compressive strength. In this work, the concrete cylinders with different steel fiber volume fractions were subjected to repeated impact loading by a split Hopkinson Pressure Bar (SHPB) device. Experimental results indicate that the ability of repeated impact resistance of ultra-high-strength concrete was markedly superior to that of other specimens. Additionally, the rate of damage was decelerated and the energy absorption of ultra-high-strength concrete improved as the steel fiber volume fraction increased.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001526942
|
oai_dc
|
Compressive behavior of short fibrous reinforced concrete members with square cross-section
|
Compressive behavior of short fibrous reinforced concrete members with square cross-section
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"G. Campione(Univ. di Palermo)"
] |
In this paper an analytical model is presented that addresses the compressive response of short-fiber reinforced concrete members (FRC) with hooked steel fibers. This model is applicable to a wide range of concrete strengths and accounts for the interaction between the cover spalling and the concrete core confinement induced by transverse steel stirrups and also for buckling of longitudinal reinforcing bars. The load-shortening curves generated here analytically fit existing experimental data well.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001526945
|
oai_dc
|
A custom building deterioration model
|
A custom building deterioration model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"O.A. Hosny(The American University in Cairo); A.A. Elhakeem(The American University in Cairo); T. Hegazy(University of Waterloo)"
] |
Developing accurate prediction models for deterioration behavior represents a challenging but essential task in comprehensive Infrastructure Management Systems. The challenge may be a result of the lack of historical data, impact of unforeseen parameters, and/or the past repair/maintenance practices.
These realities contribute heavily to the noticeable variability in deterioration behavior even among similar components. This paper introduces a novel approach to predict the deterioration of any infrastructure component. The approach is general as it fits any component, however the prediction is custom for a specific item to consider the inherent impacts of expected and unexpected parameters that affect its unique deterioration behavior.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001526944
|
oai_dc
|
A new method for optimal selection of sensor location on a high-rise building using simplified finite element model
|
A new method for optimal selection of sensor location on a high-rise building using simplified finite element model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ting-Hua Yi(Dalian University of Technology); Hong-Nan Li(Dalian University of Technology); Ming Gu(Tongji University)"
] |
Deciding on an optimal sensor placement (OSP) is a common problem encountered in many engineering applications and is also a critical issue in the construction and implementation of an effective structural health monitoring (SHM) system. The present study focuses with techniques for selecting optimal sensor locations in a sensor network designed to monitor the health condition of Dalian World Trade Building which is the tallest in the northeast of China. Since the number of degree-of-freedom (DOF) of the building structure is too large, multi-modes should be selected to describe the dynamic behavior of a structural system with sufficient accuracy to allow its health state to be determined effectively. However, it’s difficult to accurately distinguish the translational and rotational modes for the flexible structures with closely spaced modes by the modal participation mass ratios. In this paper, a new method of the OSP that computing the mode shape matrix in the weak axis of structure by the simplified multi-DOF system was presented based on the equivalent rigidity parameter identification method. The initial sensor assignment was obtained by the QR-factorization of the structural mode shape matrix. Taking the maximum off-diagonal element of the modal assurance criterion (MAC) matrix as a target function, one more sensor was added each time until the maximum off-diagonal element of the MAC reaches the threshold. Considering the economic factors, the final plan of sensor placement was determined. The numerical example demonstrated the feasibility and effectiveness of the proposed scheme.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001526938
|
oai_dc
|
Investigation of water length effects on the modal behavior of a prototype arch dam using operational and analytical modal analyses
|
Investigation of water length effects on the modal behavior of a prototype arch dam using operational and analytical modal analyses
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Baris Sevim(Gümüshane University); Alemdar Bayraktar(Karadeniz Technical University); Ahmet Can Altunisik(Karadeniz Technical University)"
] |
This study determines the water length effects on the modal behavior of a prototype arch dam using Operational and Analytical Modal Analyses. Achievement of this purpose involves construction of a prototype arch dam-reservoir-foundation model under laboratory conditions. In the model, reservoir length was taken to be as much as three times the dam height. To determine the experimental dynamic characteristics of the arch dam using Operational Modal Analysis, ambient vibration tests were implemented for empty reservoir and three different reservoir water lengths. In the ambient vibration tests,the dam was vibrated by natural excitations provided from small impact effects and the response signals were measured using sensitive accelerometers. Operational Modal Analysis software process signals collected from the ambient vibration tests, and Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification techniques estimated modal parameters of the dams. To validate the experimental results, 3D finite element model of the prototype arch dam was modeled by ANSYS software for empty reservoir and three different reservoir water lengths, and dynamic characteristics of each model were determined analytically. At the end of the study, experimentally and analytically identified dynamic characteristics compared to each other. Also, changes on the natural frequencies along to water length are plotted as graphs. Results suggest that reservoir water complicates the modal behavior of the arch dam significantly.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001526935
|
oai_dc
|
Application of neural networks and an adapted wavelet packet for generating artificial ground motion
|
Application of neural networks and an adapted wavelet packet for generating artificial ground motion
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Asadi(Yazd University); M. Fadavi(Shomal University); A. Bagheri(Iran University of Science & Technology); G. Ghodrati Amiri(Iran University of Science & Technology)"
] |
For seismic resistant design of critical structures, a dynamic analysis, either response spectrum or time history is frequently required. Owing to the lack of recorded data and the randomness of earthquake ground motion that may be experienced by structure in the future, usually it is difficult to obtain recorded data which fit the requirements (site type, epicenteral distance, etc.) well. Therefore, the artificial seismic records are widely used in seismic designs, verification of seismic capacity and seismic assessment of structures. The purpose of this paper is to develop a numerical method using Artificial Neural Network (ANN) and wavelet packet transform in best basis method which is presented for the decomposition of artificial earthquake records consistent with any arbitrarily specified target response spectra requirements. The ground motion has been modeled as a non-stationary process using wavelet packet. This study shows that the procedure using ANN-based models and wavelet packets in best-basis method are applicable to generate artificial earthquakes compatible with any response spectra. Several numerical examples are given to verify the developed model.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001526939
|
oai_dc
|
FOA (first-order-analysis) model of an expandable lattice structure for vehicle crash energy absorption of an inflatable morphing body
|
FOA (first-order-analysis) model of an expandable lattice structure for vehicle crash energy absorption of an inflatable morphing body
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Dong Wook Lee(Samsung Techwin); Zheng-Dong Ma(University of Michigan); Noboru Kikuchi(University of Michigan)"
] |
A concept of crash energy absorbing (CEA) lattice structure for an inflatable morphing vehicle body (Lee et al. 2008) has been investigated as a method of providing rigidity and energy absorption capability during a vehicular collision (Lee et al. 2007). A modified analytical model for the CEA lattice structure design is described in this paper. The modification of the analytic model was made with a stiffness approach for the elastic region and updated plastic limit analysis with a pure plastic bending deformation concept and amended elongation factors for the plastic region. The proposed CEA structure is composed of a morphing lattice structure with movable thin-walled members for morphing purposes, members that will be locked in designated positions either before or during the crash. What will be described here is how to model the CEA structure analytically based on the energy absorbed by the CEA structure.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001526941
|
oai_dc
|
A technique to avoid aspect-ratio locking in QUAD8 element for extremely large aspect-ratios
|
A technique to avoid aspect-ratio locking in QUAD8 element for extremely large aspect-ratios
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Rajendran(Nanyang Technological University)"
] |
This paper investigates the aspect-ratio locking of the isoparametric 8-node quadrilateral (QUAD8) element. An important finding is that, if finite element solution is carried out with in exact arithmetic (i.e., with no truncation and round off errors), the locking tendency of the element is completely avoided even for aspect-ratios as high as 100000. The current finite element codes mostly use floating point arithmetic. Thus, they can only avoid this locking for aspect-ratios up to 100 or 1000. A novel method is proposed in the paper to avoid aspect-ratio locking in floating point computations. In this method, the offending terms of the strain-displacement matrix (i.e., B-matrix) are multiplied by suitable scaling factors to avoid ill-conditioning of stiffness matrix. Numerical examples are presented to demonstrate the efficacy of the method. The examples reveal that aspect-ratio locking is avoided even for aspect-ratios as high as 100000.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001470710
|
oai_dc
|
Parametric study of pile groups subjected to lateral load
|
Parametric study of pile groups subjected to lateral load
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H.S. Chore(Datta Meghe College of Engineering); R.K. Ingle(Visvesvaraya National Institute of Technology); V.A. Sawant(Indian Institute of Technology (IIT))"
] |
토목공학
| null |
kci_detailed_000077.xml
|
||||
ART001470702
|
oai_dc
|
A case study of reinforced concrete short column under earthquake using experimental and theoretical investigations
|
A case study of reinforced concrete short column under earthquake using experimental and theoretical investigations
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chen-Yuan Chen(National Pingtung University of Education); Kuo-Chiang Liu(Yung-Ta Institute of Technology & Commerce); Yuh-Wehn Liu(Chia-Nan University of Pharmacy and Science); Wehn-Jiunn Huang(National Cheng-Kung University)"
] |
The purpose of this paper is to carry out both experimental and theoretical investigations of R.C. short column subjected to horizontal forces under constant compressive loading. Eight specimens with section of 40 cm × 40 cm, height 40 cm and 50 cm and different type hoop were used of the steel cage to detect the seismic behavior of reinforced concrete short columns. Hoop spacing of column, strength of concrete, and the axial load of experiments were the three main parameters in this test. A series of equations were derived to reveal the theory could be used on analysis short column, too.
Through test failure model of R.C short column being established, the type of hoop affects the behavior R.C short column in ductility rather than in strength. And the effect of analysis by Truss Model is evident and reliable in shear failure model of short column.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001470707
|
oai_dc
|
Modeling of compressive strength of HPC mixes using a combined algorithm of genetic programming and orthogonal least squares
|
Modeling of compressive strength of HPC mixes using a combined algorithm of genetic programming and orthogonal least squares
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S.M. Mousavi(Sharif University of Technology); A.H. Gandomi(Tafresh University); A.H. Alavi(Iran University of Science and Technology); M. Vesalimahmood(Iran University of Science and Technology)"
] |
In this study, a hybrid search algorithm combining genetic programming with orthogonal least squares (GP/OLS) is utilized to generate prediction models for compressive strength of high performance concrete (HPC) mixes. The GP/OLS models are developed based on a comprehensive database containing 1133 experimental test results obtained from previously published papers. A multiple least squares regression (LSR) analysis is performed to benchmark the GP/OLS models. A subsequent parametric study is carried out to verify the validity of the models. The results indicate that the proposed models are effectively capable of evaluating the compressive strength of HPC mixes. The derived formulas are very simple, straightforward and provide an analysis tool accessible to practicing engineers.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001470692
|
oai_dc
|
Nonlinear vibrations of axially moving beams with multiple concentrated masses Part I: primary resonance
|
Nonlinear vibrations of axially moving beams with multiple concentrated masses Part I: primary resonance
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Sar gül(Celal Bayar University); H. Boyaci(Celal Bayar University)"
] |
Transverse vibrations of axially moving beams with multiple concentrated masses have been investigated. It is assumed that the beam is of Euler-Bernoulli type, and both ends of it have simply supports. Concentrated masses are equally distributed on the beam. This system is formulated mathematically and then sought to find out approximately solutions of the problem. Method of multiple scales has been used. It is assumed that axial velocity of the beam is harmonically varying around a mean-constant velocity. In case of primary resonance, an analytical solution is derived. Then, the effects of both magnitude and number of the concentrated masses on nonlinear vibrations are investigated numerically in detail.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001470690
|
oai_dc
|
Simple geometrical model to analyze the motion detection of bridges based-GPS technique: case study Yonghe Bridge
|
Simple geometrical model to analyze the motion detection of bridges based-GPS technique: case study Yonghe Bridge
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mosbeh R. Kaloop(Mansoura University); Hui Li(Harbin Institute of Technology)"
] |
This study deals with the viability of using a designed geometrical model consists of plane, polar coordinates (PC) and span length in the determination of bridges deformation. The data of a Tianjin Yonghe bridge located in the southern part of China as collected by RTK-DGPS technique and Accelerometer were used in the analysis. Kalman filter and fast Fourier transformation (FFT) analyses were used to determine the frequency. The results indicate that the designed plane and PC geometrical model are easy to calculate the long-time structural deformation monitoring. In addition, the observed frequency using GPS with the rate of 20 Hz doesn’t give correction natural frequency of the observation structures.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001470698
|
oai_dc
|
Control of a building complex with Magneto-Rheological Dampers and Tuned Mass Damper
|
Control of a building complex with Magneto-Rheological Dampers and Tuned Mass Damper
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"F. Amini(Science and Technology University); R. Doroudi(Science and Technology University)"
] |
Coupled building control is a viable method to protect tall buildings from seismic excitation. In this study, the semi-active control of a building complex is investigated for mitigating seismic responses. The building complex is formed of one main building and one podium structure connected through Magneto-Rheological (MR) Dampers and Tuned Mass Damper. The conventional semi-active control techniques require a primary controller as a reference to determine the desired control force, and modulate the input voltage of the MR damper by comparing the desired control force. The fuzzy logic directly determines the input voltage of an MR damper from the response of the MR damper. The control performance of the proposed fuzzy control technique for the MR damper is evaluated for the control problem of a seismically-excited building complex. In this paper, a building complex that include a 14-story main building and an 8-story podium structure is applied as a numerical example to demonstrate the effectiveness of semi-active control with Magneto-Rheological dampers and its comparison with the passive control with the Tuned Mass Damper and two uncoupled buildings and hybrid semi-active control including the Tuned Mass Damper and Magneto-Rheological dampers while they are subject to the earthquake excitation. The numerical results show that semi-active control and hybrid semi-active control can significantly mitigate the seismic responses of both buildings, such as displacement and shear force responses, and fuzzy control technique can effectively mitigate the seismic response of the building complex.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001470695
|
oai_dc
|
Neural networks for inelastic mid-span deflections in continuous composite beams
|
Neural networks for inelastic mid-span deflections in continuous composite beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Umesh Pendharkar(Ujjain Engineering College); Sandeep Chaudhary(Malaviya National Institute of Technology); A.K. Nagpal(Indian Institute of Technology Delhi)"
] |
Maximum deflection in a beam is a design criteria and occurs generally at or close to the mid-span. Neural networks have been developed for the continuous composite beams to predict the inelastic mid-span deflections (typically for 20 years, considering cracking, and time effects, i.e., creep and shrinkage, in concrete) from the elastic moments and elastic mid-span deflections (neglecting instantaneous cracking and time effects). The training and testing data for the neural networks is generated using a hybrid analytical-numerical procedure of analysis. The neural networks have been validated for four example beams and the errors are shown to be small. This methodology, of using networks enables a rapid estimation of inelastic mid-span deflections and requires a computational effort almost equal to that required for the simple elastic analysis. The neural networks can be extended for the composite building frames that would result in huge saving in computational time.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001470705
|
oai_dc
|
Construction stage analysis of Kömürhan Highway Bridge using time dependent material properties
|
Construction stage analysis of Kömürhan Highway Bridge using time dependent material properties
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ahmet Can Altunisik(Karadeniz Technical University); Alemdar Bayraktar(Karadeniz Technical University); Süleyman Adanur(Karadeniz Technical University); Arman Domaniç(Yüksel Domaniç Engineering Company); Baris Sevim(Karadeniz Technical University)"
] |
The aim of this study concerns with the construction stage analysis of highway bridges constructed with balanced cantilever method using time dependent material properties. Kömürhan Highway Bridge constructed with balanced cantilever method and located on the 51st km of Elaz-Malatya, Turkey, highway over F rat River is selected as an application. Finite element models of the bridge are modelled using SAP2000 program. Geometric nonlinearity is taken into consideration in the analysis using P-Delta plus large displacement criterion. The time dependent material strength variations and geometric variations are included in the analysis. Elasticity modulus, creep and shrinkage are computed for different stages of the construction process. The structural behaviour of the bridge at different construction stages has been examined. Two different finite element analyses with and without construction stages are carried out and results are compared with each other. As analyses result, variation of internal forces such as bending moment, axial forces and shear forces for bridge deck and column are given with detail. It is seen that construction stage analysis has remarkable effect on the structural behaviour of the bridge.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001463851
|
oai_dc
|
Geometrically non-linear static analysis of a simply supported beam made of hyperelastic material
|
Geometrically non-linear static analysis of a simply supported beam made of hyperelastic material
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"T. Kocatürk(Yildiz Technical University); S..D. Akbas(Yildiz Technical University)"
] |
This paper focuses on geometrically non-linear static analysis of a simply supported beam made of hyperelastic material subjected to a non-follower transversal uniformly distributed load. As it is known, the line of action of follower forces is affected by the deformation of the elastic system on which they act and therefore such forces are non-conservative. The material of the beam is assumed as isotropic and hyperelastic. Two types of simply supported beams are considered which have the following boundary conditions: 1) There is a pin at left end and a roller at right end of the beam (pinned-rolled beam). 2) Both ends of the beam are supported by pins (pinned-pinned beam). In this study, finite element model of the beam is constructed by using total Lagrangian finite element model of two dimensional continuum for a twelve-node quadratic element. The considered highly non-linear problem is solved by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. In order to use the solution procedures of Newton-Raphson type, there is need to linearized equilibrium equations, which can be achieved through the linearization of the principle of virtual work in its continuum form. In the study, the effect of the large deflections and rotations on the displacements and the normal stress and the shear stress distributions through the thickness of the beam is investigated in detail. It is known that in the failure analysis, the most important quantities are the principal normal stresses and the maximum shear stress. Therefore these stresses are investigated in detail. The convergence studies are performed for various numbers of finite elements. The effects of the geometric non-linearity and pinned-pinned and pinned-rolled support conditions on the displacements and on the stresses are investigated. By using a twelve-node quadratic element, the free boundary conditions are satisfied and very good stress diagrams are obtained. Also, some of the results of the total Lagrangian finite element model of two dimensional continuum for a twelve-node quadratic element are compared with the results of SAP2000 packet program. Numerical results show that geometrical nonlinearity plays very important role in the static responses of the beam.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001463857
|
oai_dc
|
Sensitivity analysis of responses for vibration control systems
|
Sensitivity analysis of responses for vibration control systems
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yudong Chen(Jilin University); Suhuan Chen(Jilin University)"
] |
토목공학
| null |
kci_detailed_000077.xml
|
||||
ART001463850
|
oai_dc
|
Development of new finite elements for fatigue life prediction in structural components
|
Development of new finite elements for fatigue life prediction in structural components
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wasim Tarar(The Ohio State University); Onome Scott-Emuakpor(The Ohio State University); M.-H. Herman Shen(The Ohio State University)"
] |
An energy-based fatigue life prediction framework was previously developed by the authors for prediction of axial and bending fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. In this study, the energy expressions that construct the new constitutive law are integrated into minimum potential energy formulation to develop new finite elements for uniaxial and bending fatigue life prediction. The comparison of finite element method (FEM) results to existing experimental fatigue data, verifies the new finite elements for fatigue life prediction. The final output of this finite element analysis is in the form of number of cycles to failure for each element in ascending or descending order. Therefore, the new finite element framework can provide the number of cycles to failure for each element in structural components. The performance of the fatigue finite elements is demonstrated by the fatigue life predictions from Al6061-T6 aluminum and Ti-6Al-4V. Results are compared with experimental results and analytical predictions.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001463855
|
oai_dc
|
Numerical assessment of seismic safety of liquid storage tanks and performance of base isolation system
|
Numerical assessment of seismic safety of liquid storage tanks and performance of base isolation system
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mohammad Ali Goudarzi(Lorestan University); Saeed Alimohammadi(University of Science and Culture)"
] |
Seismic isolation is a well-known method to mitigate the earthquake effects on structures by increasing their fundamental natural periods at the expense of larger displacements in the structural system. In this paper, the seismic response of isolated and fixed base vertical, cylindrical, liquid storage tanks is investigated using a Finite Element Model (FEM), taking into account fluid-structure interaction effects. Three vertical, cylindrical tanks with different ratios of height to radius (H/R = 2.6, 1.0 and 0.3) are numerically analyzed and the results of response-history analysis, including base shear, overturning moment and free surface displacement are reported for isolated and non-isolated tanks. Isolated tanks equipped by lead rubber bearings isolators and the bearing are modeled by using a non-linear spring in FEM model. It is observed that the seismic isolation of liquid storage tanks is quite effective and the response of isolated tanks is significantly influenced by the system parameters such as their fundamental frequencies and the aspect ratio of the tanks. However, the base isolation does not significantly affect the surface wave height and even it can causes adverse effects on the free surface sloshing motion.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001463856
|
oai_dc
|
Time domain identification of multiple cracks in a beam
|
Time domain identification of multiple cracks in a beam
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Z.Y. He(South China University of Technology); Z.R. Lu(Sun Yat-sen University)"
] |
It is well known that the analytical vibration characteristic of a cracked beam depends largely on the crack model. In the forward analysis, an improved and simplified approach in modeling discrete open cracks in beams is presented. The effective length of the crack zone on both sides of a crack with stiffness reduction is formulated in terms of the crack depth. Both free and forced vibrations of cracked beams are studied in this paper and the results from the proposed modified crack model and other existing models are compared. The modified crack model gives very accurate predictions in the modal frequencies and time responses of the beams particularly with overlaps in the effective lengths with reduced stiffness. In the inverse analysis, the response sensitivity with respect to damage parameters (the location and depth of crack, etc.) is derived. And the dynamic response sensitivity is used to update the damage parameters. The identified results from both numerical simulations and experiment work illustrate the effectiveness of the proposed method.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001463854
|
oai_dc
|
Comparative study on damage identification from Iso-Eigen-Value-Change contours and smeared damage model
|
Comparative study on damage identification from Iso-Eigen-Value-Change contours and smeared damage model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"N. Lakshmanan(Structural Engineering Research Centre); B.K. Raghuprasad(Indian Institute of Science); N. Gopalakrishnan(Structural Engineering Research Centre); R. Sreekala(Structural Engineering Research Centre); G.V. Rama Rao(Structural Engineering Research Centre)"
] |
The paper proposes two methodologies for damage identification from measured natural frequencies of a contiguously damaged reinforced concrete beam, idealised with distributed damage model. The first method identifies damage from Iso-Eigen-Value-Change contours, plotted between pairs of different frequencies. The performance of the method is checked for a wide variation of damage positions and extents. The method is also extended to a discrete structure in the form of a five-storied shear building and the simplicity of the method is demonstrated. The second method is through smeared damage model, where the damage is assumed constant for different segments of the beam and the lengths and centres of these segments are the known inputs. First-order perturbation method is used to derive the relevant expressions. Both these methods are based on distributed damage models and have been checked with experimental program on simply supported reinforced concrete beams, subjected to different stages of symmetric and un-symmetric damages. The results of the experiments are encouraging and show that both the methods can be adopted together in a damage identification scenario.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001463852
|
oai_dc
|
Plastification procedure of laterally-loaded steel bars under a rising temperature
|
Plastification procedure of laterally-loaded steel bars under a rising temperature
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zhan-fei Huang(AECOM Singapore Pte Ltd.); Kang-hai Tan(Nanyang Technological University); George L. England(Imperial College)"
] |
This paper investigates the structural responses of axially restrained steel beams under fire conditions by a nonlinear finite element method. The axial restraint is represented by a linear elastic spring. Different parameters which include beam slenderness ratio, external load level and axial restraint ratio are investigated. The process of forming a mid-span plastic hinge at the mid-span under a rising temperature is studied. In line with forming a fully plastic hinge at mid-span, the response of a restrained beam under rising temperature can be divided into three stages, viz. no plastic hinge, hinge forming and rotating, and catenary action stage. During catenary action stage, the axial restraint pulls the heated beam and prevents it from failing. This study introduces definitions of beam limiting temperature Tlim, catenary temperature Tctn and warning time twn. Influences of slenderness ratio, load level and axial restraint ratio on Tlim, Tctn and twn are examined.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001463853
|
oai_dc
|
Dynamic stiffness matrix of an axially loaded slender double-beam element
|
Dynamic stiffness matrix of an axially loaded slender double-beam element
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Li Jun(Shanghai Jiao Tong University); Hua Hongxing(Shanghai Jiao Tong University); Li Xiaobin(Wuhan University of Technology)"
] |
The dynamic stiffness matrix is formulated for an axially loaded slender double-beam element in which both beams are homogeneous, prismatic and of the same length by directly solving the governing differential equations of motion of the double-beam element. The Bernoulli-Euler beam theory is used to define the dynamic behaviors of the beams and the effects of the mass of springs and axial force are taken into account in the formulation. The dynamic stiffness method is used for calculation of the exact natural frequencies and mode shapes of the double-beam systems. Numerical results are given for a particular example of axially loaded double-beam system under a variety of boundary conditions, and the exact numerical solutions are shown for the natural frequencies and normal mode shapes. The effects of the axial force and boundary conditions are extensively discussed.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001451696
|
oai_dc
|
Energy approach for dynamic buckling of shallow fixed arches under step loading with infinite duration
|
Energy approach for dynamic buckling of shallow fixed arches under step loading with infinite duration
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yong-Lin Pi(University of Technology, Sydney); Mark Andrew Bradford(University of Technology, Sydney); Weilian Qu(Wuhan University of Technology)"
] |
Shallow fixed arches have a nonlinear primary equilibrium path with limit points and an unstable postbuckling equilibrium path, and they may also have bifurcation points at which equilibrium bifurcates from the nonlinear primary path to an unstable secondary equilibrium path. When a shallow fixed arch is subjected to a central step load, the load imparts kinetic energy to the arch and causes the arch to oscillate. When the load is sufficiently large, the oscillation of the arch may reach its unstable equilibrium path and the arch experiences an escaping-motion type of dynamic buckling. Nonlinear dynamic buckling of a two degree-of-freedom arch model is used to establish energy criteria for dynamic buckling of the conservative systems that have unstable primary and/or secondary equilibrium paths and then the energy criteria are applied to the dynamic buckling analysis of shallow fixed arches. The energy approach allows the dynamic buckling load to be determined without needing to solve the equations of motion.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001451702
|
oai_dc
|
A new finite element procedure for fatigue life prediction of AL6061 plates under multiaxial loadings
|
A new finite element procedure for fatigue life prediction of AL6061 plates under multiaxial loadings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wasim Tarar(The Ohio State University); M.-H. Herman Shen(The Ohio State University); Tommy George(Air Force Research Laboratory Wright-Patterson AFB); Charles Cross(Air Force Research Laboratory Wright-Patterson AFB)"
] |
An energy-based fatigue life prediction framework was previously developed by the authors for prediction of axial, bending and shear fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. In the first part of this study, energy expressions that construct the constitutive law are equated in the form of total strain energy and the distortion energy dissipated in a fatigue cycle. The resulting equation is further evaluated to acquire the equivalent stress per cycle using energy based methodologies. The equivalent stress expressions are developed both for biaxial and multiaxial fatigue loads and are used to predict the number of cycles to failure based on previously developed prediction criterion. The equivalent stress expressions developed in this study are further used in a new finite element procedure to predict the fatigue life for two and three dimensional structures. In the second part of this study, a new Quadrilateral fatigue finite element is developed through integration of constitutive law into minimum potential energy formulation. This new QUAD-4 element is capable of simulating biaxial fatigue problems. The final output of this finite element analysis both using equivalent stress approach and using the new QUAD-4 fatigue element, is in the form of number of cycles to failure for each element on a scale in ascending or descending order. Therefore, the new finite element framework can provide the number of cycles to failure at each location in gas turbine engine structural components. In order to obtain experimental data for comparison, an Al6061-T6 plate is tested using a previously developed vibration based testing framework. The finite element analysis is performed for Al6061-T6 aluminum and the results are compared with experimental results.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001451711
|
oai_dc
|
Differential transform method for free vibration analysis of a moving beam
|
Differential transform method for free vibration analysis of a moving beam
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yusuf Yesilce(Dokuz Eylul University)"
] |
In this study, the Differential Transform Method (DTM) is employed in order to solve the governing differential equation of a moving Bernoulli-Euler beam with axial force effect and investigate its free flexural vibration characteristics. The free vibration analysis of a moving Bernoulli-Euler beam using DTM has not been investigated by any of the studies in open literature so far. At first, the terms are found directly from the analytical solution of the differential equation that describes the deformations of the cross-section according to Bernoulli-Euler beam theory. After the analytical solution, an efficient and easy mathematical technique called DTM is used to solve the differential equation of the motion. The calculated natural frequencies of the moving beams with various combinations of boundary conditions using DTM are tabulated in several tables and are compared with the results of the analytical solution where a very good agreement is observed.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001451709
|
oai_dc
|
The structural detailing effect on seismic behavior of steel moment resisting connections
|
The structural detailing effect on seismic behavior of steel moment resisting connections
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hooman Farrokhi(KN Toosi University of Technology); F. Ahmadi Danesh(KN Toosi University of Technology); Sassan Eshghi(International Institute of Earthquake Engineering and Seismology)"
] |
Different types of moment resisting connections are commonly used to transfer the induced seismic moments between frame elements in an earthquake resisting structure. The local connection behavior may drastically affect the global seismic response of the structure. In this study, the finite element and experimental seismic investigations are implemented on two frequently used connection type to evaluate the local behavior and to reveal the failure modes. An alternative connection type is then proposed to eliminate the unfavorable brittle fracture modes resulted from probable poor welding quality. This will develop a reliable predefined ductile plastic mechanism forming away from the critical locations. Employing this technique, the structural reliability of the moment resisting connections shall be improved by achieving a controllable energy dissipation source in form of yielding of the cover plates.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001451705
|
oai_dc
|
Seismic interaction of flexural ductility and shear capacity in reinforced concrete columns
|
Seismic interaction of flexural ductility and shear capacity in reinforced concrete columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Rachel Howser(University of Houston); A. Laskar(WorleyParsons); Y.L. Mo(University of Houston)"
] |
The seismic performance of reinforced concrete (RC) bridge columns is a significant issue because the interaction of flexural ductility and shear capacity of such columns with varied amounts of lateral reinforcement is not well established. Several relationships between flexural ductility and shear capacity have been proposed by various researchers in the past. In this paper, a parametric study on RC bridge columns is conducted using a nonlinear finite element program, “Simulation of Concrete Structures (SCS)”, developed at the University of Houston. SCS has been previously used to predict the seismic behavior of such columns. The predicted results were compared with the test results obtained from experiments available in literature. Based on the results of the parametric study performed in this paper, a set of new relationships between flexural ductility and shear capacity of RC columns is proposed for seismic design.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001451694
|
oai_dc
|
Optimum design of FRP box-girder bridges
|
Optimum design of FRP box-girder bridges
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Akhil Upadhyay(IIT Roorkee); V. Kalyanaraman(IIT Madras)"
] |
Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fibre reinforced plastics (FRP) as material and box-girders as a structural system have great scope. This combination offers various options to tailor structure and its elements but this flexibility poses greater challenge in optimum design. In this paper a procedure is derived for a generalised optimum design of FRP box-girder bridges, using genetic algorithms (GA). The formulation of the optimum design problem in the form of objective function and constraints is presented. Size, configuration and topology optimization are done simultaneously. A few optimum design studies are carried out to check the performance of the developed procedure and to get trends in the optimum design which will be helpful to the new designers.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001451710
|
oai_dc
|
Numerical analysis of second-order effects of externally prestressed concrete beams
|
Numerical analysis of second-order effects of externally prestressed concrete beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Tiejiong Lou(Politecnico di Torino); Yiqiang Xiang(Zhejiang University)"
] |
A numerical procedure for the geometrical and material nonlinear analysis of concrete beams prestressed with external tendons is described, where the effects of external prestressing are treated as the equivalent loads applied on the concrete beams. The geometrical nonlinearity is considered not only the eccentricity variations of external tendons (second-order effects) but also the large displacement effects of the structure. The numerical method can predict the nonlinear response of externally prestressed concrete beams throughout the entire loading history with considerable accuracy. An evaluation of second-order effects of externally prestressed concrete beams is carried out using the proposed analysis. The analysis shows that the second-order effects have significant influence on the response characteristics of externally prestressed concrete beams. They lead to inferior ultimate load and strength capacities and a lower ultimate stress increase in tendons. Based on the current analysis, it is recommended that, for simplysupported externally prestressed beams with straight horizontal tendons, one deviator at midspan instead of two deviators at one-third span be furnished to minimize these effects.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001535812
|
oai_dc
|
Exact dynamic stiffness matrix for a thin-walled beam-column of doubly asymmetric cross-section
|
Exact dynamic stiffness matrix for a thin-walled beam-column of doubly asymmetric cross-section
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A. Shirmohammadzade(Sahand University of Technology); B. Rafezy(Sahand University of Technology); W.P. Howson(Cardiff University)"
] |
Bernoulli-Euler beam theory is used to develop an exact dynamic stiffness matrix for the flexural-torsional coupled motion of a three-dimensional, axially loaded, thin-walled beam of doubly asymmetric cross-section. This is achieved through solution of the differential equations governing the motion of the beam including warping stiffness. The uniform distribution of mass in the member is also accounted for exactly, thus necessitating the solution of a transcendental eigenvalue problem. This is accomplished using the Wittrick-Williams algorithm. Finally, examples are given to confirm the accuracy of the theory presented, together with an assessment of the effects of axial load and loading eccentricity.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001535811
|
oai_dc
|
Time-dependent analysis of cable trusses Part II. Simulation-based reliability assessment
|
Time-dependent analysis of cable trusses Part II. Simulation-based reliability assessment
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Kmet(Technical University of Kosice); M. Tomko(Technical University of Kosice); J. Brda(Technical University of Kosice)"
] |
One of the possible alternatives of simulation-based time-dependent reliability assessment of pre-stressed biconcave and biconvex cable trusses, the Monte Carlo method, is applied in this paper. The influence of an excessive deflection of cable truss (caused by creep of cables and rheologic changes) on its time-dependent serviceability is investigated. Attention is given to the definition of the basic random variables and their statistical functions (basic, mutually dependent random variables such as the prestressing forces of the bottom and top cable, structural geometry, the Young’s modulus of elasticity of the cables, and the independent variables, such as permanent load, wind, snow and thermal actions). Then, the determination of the response of the cable truss to the loading effects, and the definition of the limiting values considering serviceability of the structure are performed. The potential of the method, using direct Monte Carlo technique for simulation-based time-dependent reliability assessment as a powerful tool, is emphasized. Results obtained by the First order reliability method (FORM) are compared with those obtained by the Monte Carlo simulation technique.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001535815
|
oai_dc
|
How to reduce short column effects in buildings with reinforced concrete infill walls on basement floors
|
How to reduce short column effects in buildings with reinforced concrete infill walls on basement floors
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Murat Bikce(Mustafa Kemal University)"
] |
Band windows are commonly used in reinforced concrete structures for the purpose of ventilation and lighting. These applications shorten the lengths of the columns and, consequently, they are subject to higher shear forces as compared with those of hollow frames. Such short columns may cause some damages during earthquakes. Hence, these effects of short columns should be minimized by choosing the dimensions of the band windows properly in order to prevent serious damages in the structure. This can be achieved by taking into account the parameters that are crucial in causing short column effect. Hence, in this study, the effects of those parameters such as the widths and heights of the band windows, the number of bays and storeys within the frame, and the heights of storeys are examined. The effects of the parameters are analyzed using time history analysis. One of the important results of these analyses, is that, the widths of the band windows should be less than 60% of the clear span between the columns, whereas, their heights should be greater than 35% of the clear storey height in order to decrease the short column effects substantially during the design of the reinforced concrete structures.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001535809
|
oai_dc
|
Active mass damper control for cable stayed bridge under construction: an experimental study
|
Active mass damper control for cable stayed bridge under construction: an experimental study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hao Chen(Tongji University); Zhi Sun(Tongji University); Limin Sun(Tongji University)"
] |
A cable stayed bridge under construction has low structural damping and is not as stable as the completed bridge. Control countermeasures, such as the installation of energy dissipating devices, are thus required. In this study, the general procedure and key issues on adopting an active control device, the active mass damper (AMD), for vibration control of cable stayed bridges under construction were studied. Taking a typical cable stayed bridge as the prototype structure; a lab-scale test structure was designed and fabricated firstly. A baseline FEM model was then setup and updated according to the modal parameters measured from vibration test on the structure. A numerical study to simulate the bridge-AMD control system was conducted and an efficient LQG-based controller was designed. Based on that, an experimental implementation of AMD control of the transverse vibration of the bridge model was performed. The results from numerical simulation and experimental study verified that the AMD-based active control was feasible and efficient for reducing dynamic responses of a complex structural system. Moreover, the discussion made in this study clarified some critical problems which should be addressed for the practical implementation of AMD control on real cable-stayed bridges.
|
토목공학
| null |
kci_detailed_000077.xml
|
|||
ART001535810
|
oai_dc
|
Time-dependent analysis of cable trusses Part I. Closed-form computational model
|
Time-dependent analysis of cable trusses Part I. Closed-form computational model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"S. Kmet(Technical University of Kosice); M. Tomko(Technical University of Kosice)"
] |
In this paper the time-dependent closed-form static solution of the suspended pre-stressed biconcave and biconvex cable trusses with unmovable, movable and elastic or viscoelastic yielding supports subjected to various types of vertical load is presented. Irvine’s forms of the deflections and the cable equations are modified because the effects of the rheological behaviour needed to be incorporated in them. The concrete cable equations in the form of the explicit relations are derived and presented. From a solution of a vertical equilibrium equation for a loaded cable truss with rheological properties, the additional vertical deflection as a time-function is determined. The time-dependent closed-form model serves to determine the time-dependent response, i.e., horizontal components of cable forces and deflection of the cable truss due to applied loading at the investigated time considering effects of elastic deformations, creep strains, temperature changes and elastic supports. Results obtained by the present closed-form solution are compared with those obtained by FEM. The derived time-dependent closed-form computational model is used for a time-dependent simulation-based reliability assessment of cable trusses as is described in the second part of this paper.
|
토목공학
| null |
kci_detailed_000078.xml
|
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