• Earthquakes and Structures
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• 제25권5호
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• pp.385-398
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• 2023

The parameters of the multiple-vertical-line-element model (MVLEM) of reinforced concrete (RC) shear walls are often empirically determined, which causes large simulation errors. To improve the simulation accuracy of the MVLEM for RC shear walls, this paper proposed a novel method to determine the MVLEM parameters using the artificial neural network (ANN). First, a comprehensive database containing 193 shear wall specimens with complete parameter information was established. And the shear walls were simulated using the classic MVLEM. The average simulation errors of the lateral force and drift of the peak and ultimate points on the skeleton curves were approximately 18%. Second, the MVLEM parameters were manually optimized to minimize the simulation error and the optimal MVLEM parameters were used as the label data of the training of the ANN. Then, the trained ANN was used to generate the MVLEM parameters of the collected shear walls. The results show that the simulation error of the predicted MVLEM was reduced to less than 13% from the original 18%. Particularly, the responses generated by the predicted MVLEM are more identical to the experimental results for the testing set, which contains both flexure-control and shear-control shear wall specimens. It indicates that establishing MVLEM for RC shear walls using ANN is feasible and promising, and that the predicted MVLEM substantially improves the simulation accuracy.

• Geomechanics and Engineering
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• 제13권4호
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• pp.601-619
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• 2017

Cantilever retaining wall movements generally depend on the intensity and duration of ground motion, the response of the soil underlying the wall, the response of the backfill, the structural rigidity, and soil-structure interaction (SSI). This paper investigates the effect of material properties on seismic response of backfill-cantilever retaining wall-soil/foundation interaction system considering SSI. The material properties varied include the modulus of elasticity, Poisson's ratio, and mass density of the wall material. A series of nonlinear time history analyses with variation of material properties of the cantilever retaining wall are carried out by using the suggested finite element model (FEM). The backfill and foundation soil are modelled as an elastoplastic medium obeying the Drucker-Prager yield criterion, and the backfill-wall interface behavior is taken into consideration by using interface elements between the wall and soil to allow for de-bonding. The viscous boundary model is used in three dimensions to consider radiational effect of the seismic waves through the soil medium. In the seismic analyses, North-South component of the ground motion recorded during August 17, 1999 Kocaeli Earthquake in Yarimca station is used. Dynamic equations of motions are solved by using Newmark's direct step-by-step integration method. The response quantities incorporate the lateral displacements of the wall relative to the moving base and the stresses in the wall in all directions. The results show that while the modulus of elasticity has a considerable effect on seismic behavior of cantilever retaining wall, the Poisson's ratio and mass density of the wall material have negligible effects on seismic response.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.291-296
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• 2000

In this paper a relatively simple and reliable wall models are investigated, which are suitable to be efficiently incorporated in a practical nonlinear seismic analysis of reinforced concrete shear wall structural systems. Four types of analogous frames have been selected for the elastic stress analysis. Three types of macro-elements model which include wide-column model, truss model and Kabeyasawa model, are chosen for the use in nonlinear analysis. A numerical analysis is carried out for six stories plane coupled wall structure. Analysis results indicate that macro-elements wall model is effective and suitable for simulating stress in elastic analysis. In inelastic analysis, the yielding strength have little effect on different wall model, and the effect on post-yielding stiffness in story shear-drift relationship depend on force-deformation properties of macro-elements.

• 한국안전학회지
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• 제23권5호
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• pp.22-29
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• 2008

This paper provides the evaluation method for the pressure vessel with internal wall-thinning defect, which is based on ASME design criteria. Pressure vessel has wall-thinning partially and patch reinforcement has been attached for reliable operating. However, present partial wall thinning could be through wall thinning at the next inspection time with present corrosion progress speed. Therefore safety margin was calculated for various conditions from present wall-thinning condition to additive patch reinforced condition via two-dimensional and three-dimensional, geometrically linear FE analyses using elastic materials.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.137.1-137.1
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• 2005

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1998년도 가을 학술발표회 논문집
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• pp.319-328
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• 1998

• 한국전산구조공학회논문집
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• 제16권1호
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• pp.43-52
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• 2003

본 논문은 콘크리트 균열방향의 회전 및 철근의 항복에 따른 2차원 R/C 구조물의 극한거동 덴 한계상태설계에 관한 연구를 다룬 것으로, 유한요소모델에 적용하여 비선형 해석 및 한계상태설계가 가능한 수치 해석 및 설계 알고리즘을 소개하였다. 철근의 설계를 위하여, 각 유한요소의 극한거동에 기초한 한계상태설계방정식이 유한요소 알고리즘에 도입되었다. 한편, 하중에 따른 콘크리트 균열방향의 회전 및 철근의 항복을 고려한 2차원 R/C 평면요소의 단순화된 실용적 비선형 응력-변형률 거동의 구성관계모델을 제시하여 비선형 유한요소해석 알고리즘을 구성하였다 제시된 해석 모델을 R/C 전단벽의 실험모델과 비교하여 검증하도록 하였으며, R/C 전단벽에 대한 설계 예를 통하여, 각각의 유한요소에서 얻어진 설계 철근비를 한계상태설계방정식으로부터 산정하였다.

• Wind and Structures
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• 제19권6호
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• pp.603-621
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• 2014

Past high speed wind events have exposed the vulnerability of the roof systems of existing light-framed wood structures to uplift loading, contributing greatly to economic and human loss. This paper further investigates the behaviour of light-framed wood structures under the uplift loading of a realistic pressure distribution. A three-dimensional finite-element model is first developed to capture the behaviour of a recently completed full-scale experiment. After describing the components used to develop the numerical model, a comparison between the numerical prediction and experimental results in terms of the deflected shape at the roof-to-wall connections is presented to gain confidence in the numerical model. The model is then used to analyze the behaviour of the truss system under realistic and equivalent uniform pressure distributions and to perform an assessment of the use of the tributary area method to calculate the withdrawal force acting on the roof-to-wall connections.

• Steel and Composite Structures
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• 제21권3호
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• pp.461-477
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• 2016

Steel-concrete-steel (SCS) sandwich composite wall has been proposed for building and offshore constructions. An ultra-lightweight cement composite with density1380 kg/m3 and compressive strength up to 60 MPa is used as core material and inter-locking J-hook connectors are welded on the steel face plates to achieve the composite action. This paper presents the numerical models using nonlinear finite element analysis to investigate the load displacement behavior of SCS sandwich walls subjected to axial compression. The results obtained from finite element analysis are verified against the test results to establish its accuracy in predicting load-displacement curves, maximum resistance and failure modes of the sandwich walls. The studies show that the inter-locking J-hook connectors are subjected to tension force due to the lateral expansion of cement composite core under compression. This signifies the important role of the interlocking effect of J-hook connectors in preventing tensile separation of the steel face plates so that the local buckling of steel face plates is prevented.

• 한국정밀공학회지
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• 제20권2호
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• pp.192-198
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• 2003

A finite element analysis of end-to-end artery/PTFE anastomosis has been presented in this study to evaluate the distribution of compliance and stresses in the vicinity of the anastomosis due to any mismatch in compliance characteristics. The artery wall was assumed to be made of linear isotropic material in this simplified model and a nonlinear analysis and convergency study with respect to increasing meshed element numbers were performed with a mean artery pressure loading of the artery-PTFE model. Also, sub-modeling method was Introduced to progress the accuracy of the finite element analysis. The results are as follow : 1. A hypercompliant zone on the artery side was observed around 4.Omm from the anastomosis and a high hoop stresses in the wall of artery and PTFE was dominant. 2. An artery displays large deformation so that nonlinear analysis and sub-modeling method was used. 3. An anastomosis with the thinner thickness and larger diameter PTFE (B type) could reduce the compliance disagreement.