• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.4018-4023
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• 2010

Various kinds of shear connector such as headed stud, channel, perforated steel plate and others are commonly used to transfer stress and present composite performance in composite structures, and many researches have been conducted to improve the characteristics of different types of shear connectors. It is focused in this study on the bending performance of steel pipe pile cap with the open type perforated shear connector for the composite connection to the spread footing. Nonlinear analysis was conducted, using ABAQUS, a finite element analysis program, to obtain information for determining the characteristics of the structure and to allow various parametric analysis for bending performance of steel pipe pile cap with the open perforated shear connector.

• Magazine of the Korea Concrete Institute
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• v.1 no.1
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• pp.105-114
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• 1989

휨을 받는 철근콘크리트 부재 단면의 연화현상은 구조물의 파괴하중 해석시 중요한 인자로 작용한다. 일반적인 탄-소성 이론에 근거한 소성한계해석법을 사용할 경우 철골 구조물에는 적합하지만 철근콘크리트 구조물에는 최대하중 이후의 연화현상으로 인하여 이 이론은 부적합하게 된다. 따라서 본 논문의 주목적은 변위제어방법을 사용하여 철근콘크리트 구조물이 파괴될 때까지의 완전한 거동을 이끌어 내는 것이다. 프로그램을 사용한 계산결과를 보다 빠르고 경제적으로 이끌어 내기 위하여 단면의 성질인 모멘트-곡률, 축력-축\ulcorner향 변형률, 그리고 전단력 변형률 곡선 등을 여러개의 직선적으로 단순화한 모델식을 사용하여 해석한다. 또한 연화현상을 고려한 유한요소의 해석결과는 사용된 요소의 크기에 따라 결과가 매우 다르게 나타나기 때문에 이를 방지하기 위하여 파괴에너지 개념을 도입하여 모멘트-곡률 곡선을 보정하여 구조계산에 적용시킨다. 이와 같이 단면을 층으로 나누어 해석하지 않고 직접 단면의 성질을 나타내는 곡선들을 적용한 본 프로그램으로 보와 골조를 해석한 결과는 실제적인 실험결과와 비교하였을 경우 거의 일치하게 나타난다.

• Journal of the Korea Concrete Institute
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• v.27 no.5
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• pp.481-488
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• 2015

The purpose of this study is to provide analytical method to reasonably predict the overall behavior up to destruction of reinforced concrete panel specimens using high-strength reinforcing bar. A total of 12 specimens of reinforced concrete panels with a wall thickness one-third the size of the actual nuclear containment structures under various loading conditions and design parameters were selected and the analysis was performed using a non-linear finite element analysis program (RCAHEST) was developed by the authors. The mean and coefficient of variation for shear strength at cracking point and maximum shear strength from the experiment and analysis results was predicted 1.03 and 12%, 0.97 and 9%, respectively. For the shear strain at the maximum shear strength from the experiment and analysis results was predicted 0.96 and 30%, respectively. Based on the results, the analysis program that was applied newly modified constitutive equation in this study is judged as having a relatively high reliability for the analysis results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.218-225
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• 2021

The purpose of this study is to present a rational analytical method for predicting the behavioral characteristics from crack occurrence to fracture for a one-way CFRP grid reinforced concrete slab specimen. A total of four specimens were selected by Zhang et al.(2004) as the main experimental variables for CFRP grid amount, material properties and loading method. Analysis was performed through the Nonlinear Finite Element analysis program(RCAHEST), which applied the newly modified constitutive relational equations by the author. The mean and coefficient of variation for maximum moment from the experiment and analysis results was predicted 1.38 and 7 %. The mean and coefficient of variation for displacement corresponding maximum moment from the experiment and analysis results was predicted 1.41and 9.8 %. The prediction results for the behavioral characteristics from crack occurrence to fracture were verified and evaluated. It is judged that additional research is needed to secure various experimental results and to develop a more reliable analytical method.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.631-633
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• 2012

본 논문은 구조용 후판 강재로 절곡되었을 때, 절곡부재의 구조연성 변화에 대한 해석 방안과 이에 따른 해석적 평가 사례를 제시하고 있다. 절곡 방법에 의한 제작과정에서 재료는 변형경화 현상이 발생한다. 이로 인해 구조연성 저하가 불가피하기 때문에 절곡부재의 휨연성 검토가 필요하다. 해석 방안은 유한요소해석 프로그램인 ABAQUS를 이용하였다. Lanczos 알고리즘을 적용한 고유치해석과 재료 비탄성-기하비선형을 고려한 비선형 해석을 하였다. 비선형해석 절곡에 의한 재료특성을 고려하였다. 극한 하중과 파괴모드를 평가하기 위해 Newton-Raphson method, modified Riks method를 적용한 단계별 하중재하 해석을 실시하였다. 본 연구를 통해 휨연성을 평가하는데 활용 될 것으로 판단된다.

• Journal of Korean Society of Steel Construction
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• v.17 no.1 s.74
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• pp.63-71
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• 2005

There were already several studies conducted on the steel-concrete (SC) composite column, which was developedcomplement the weaknesses and maintain the advantages of previous composite columns. The axial compressive capacity of the SC composite column was estimated by the tests in previous studies, but the experiments for the large-scale column could not be performed because of the limitation with the laboratory's capacity. In this study, the analytical study was performed using the general finite element analysis program to reflect the interaction of concrete and steel and the local buckling of steel flange composed of the non-compact section. The appropriateness of the analytical model was verified by the comparison between experimental and analytical results. The nonlinear behavior of full-scale SC composite column was analyzed using the verified analytical model. From these analytical studies, it was concluded that the width-to-thickness ratio of the steel cross-section of the SC composite column should not exceed 25:0. The section area of the link is best when it is over 0.025 dt, and the link distance is to be less than D/2 or 300mm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.947-954
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• 2016

A simplified analysis method is first proposed in order to determine an optimized initial shape of cable-stayed bridges including all unstrained element lengths without using complicated nonlinear FE analysis. The unstrained-length based FE method is then presented using the unstrained lengths by the simplified analysis. To demonstrate validity and accuracy of the proposed method, Incheon bridge model having the fabrication camber is constructed and initial shaping analysis is performed using the presented method and commercial finite element analysis program, MIDAS. Resultantly it is shown that the initial solutions by the proposed algorithm are well optimized and in good agreement with those by MIDAS except for axial displacements of the main member.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.6
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• pp.536-541
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• 2005

Large displacement and rigidity about rubber component are expected by nonlinear and large deformation analysis in this study. Rubber is also used by the model of Mooney-Rivlin and the self contact between rubbers is established. There is the friction between rigid body and rubber, wall and floor. The nonlinear simulation analysis used in this study is expected to be widely applied in design, analysis and development of several rubber components which are used in automotive, railroad, and mechanical elements etc. By utilizing this method, time and cost can also be saved in developing new rubber product. The analysis of rubber components requires special material modeling and non-linear finite element analysis tools that are quite different from those used for metallic parts. The objective of this study is to analyze the rubber component with large deformation and non-linear properties.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.2 s.54
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• pp.223-230
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• 2009

In this study we deal with bending behaviors of a concrete filled tubular(CFT) with various diameter-thickness ratios and concrete strengths. In finite element analysis using a commercial package(LUSAS), the bonding effect between concrete and steel in CFT structures is modeled by applying a joint element for the bonding surface. In order to consider the nonlinearity of concrete and steel tubes, stress-strain curves of the concrete and steel are used for the increased stresses in a plastic domain. The numerical results obtained from the proposed method show good agreement with the experimental data from load-displacement curves of a steel tube under distributed loads. Several parametric studies are focused on structural characteristics of CFT under bending effects for different diameter-thickness ratios and concrete strengths.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.147-155
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• 2009

The buckling and failure of filament wound thick composite cylinders under external hydrostatic pressure were investigated by the finite element analysis and test. ACOS, MSC.NASTRAN, and MSC.MARC were used for finite element analysis. T700 carbon-epoxy filament wound composite cylinders were fabricated to have winding angles of $[\pm30/90]_{FW}$, $[\pm45/90]_{FW}$, $[\pm60]_{FW}$, $[\pm60/90]_{FW}$, and tested to verify the finite element analysis. Among the softwares, ACOS predicted buckling load the best with about 1.7~14.3% deviation from test. Analysis and test shows cylinders do not recover the initial buckling pressure after buckling and directly lead to final failure.