• Computational Structural Engineering
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• v.11 no.2
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• pp.57-69
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• 1998

이번 기사에서는 반복하중 하에서의 철근 콘크리트 구조물의 비선형 유한요소해석에 관한 연구를 정리한 CEB 보고서를 소개하고자 한다. 보고서의 분량이 190쪽으로 번역기사의 내용으로는 많지만, 매우 유익한 내용이라 생각되어 선택하였으며, 구체적인 수식은 생략하고 전반적인 내용의 흐름을 위주로 정리했다. 이 보고서의 내용은 콘크리트의 압축거동, 콘크리트의 인장거동, 철근의 거동, 콘크리트와 철근의 부착, 철근과 콘크리트 혹은 콘크리트와 콘크리트의 경계면 거동, 그리고 철근콘크리트의 유한요소모델링 등으로 이루어져 있다.

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.175-181
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• 2009

An intelligent control technique using a neural network is proposed for offshore structures exposed to sea-bed earthquakes. Fluid-structure interaction effect was considered in developing controller and a training algorithm for the neural network is presented. In the numerical example, the performance of the proposed neural network controller was compared with that of a passive controller and uncontrolled structures. Based on the example, it can be concluded that the proposed neuro-control scheme can be used for offshore structures with nonlinear characteristics due to its interaction with fluid.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.2
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• pp.29-36
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• 2009

The present study emphasizes a nonlinear model to predict the shear behaviour of reinforced concrete interior beam-column joints. To model the shear behaviour of a panel zone in the beam-column joint, a modified softened truss model theory for in-plane shear prediction was introduced. This relationship was changed to define the characteristics for the rotational spring to represent the shear deformation in the joint by an equivalent moment-rotation relationship from the joint equilibrium. The analysis model was compared with experiments on reinforced concrete interior beam-column joints that were subjected to axial and shear forces, and the current model was found to accurately predict not only the shear force but also the shear deformation in the joint.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.463-469
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• 2014

Safety related devices unconstrained temporally in the process of operation of nuclear power plants could be damaged by the sliding during seismic activity. In this study sliding response of unconstrained objects to the base excitations is studied experimentally and analytically. In experiments static and dynamic tests to determine the coefficient of friction and the shaking table experiments to verify the sliding response of the analytic results were conducted. Numerical solutions by solving the nonlinear differential equations of motion governing sliding were found by the computer program using the step by step acceleration method. The exact solutions of the sliding response to the simple forms of base excitations were found to verify the computer program developed in this study. Relative displacement envelopes were suggested as a colliding criteria of the unconstrained objects.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.3
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• pp.31-38
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• 1989

This paper concentrates on the analysis of reinforced concrete(R/C) structures subjected to monotonic loading, from zero to ultimate loads. Tensile cracking, the nonlinear stress-strain relationship for concrete and reinforcement are taken into account the concrete is assumed to be elastic in tension region and elasto-hardening plastic in compression region. The Kupfer's failure criteria and associated flow rule are adopted to govern the plastic behavior of the concrete. The reinforcing bar is considered as a elasto-hardening platic material. The tension stiffening effect of the concrete between cracks is also considered. The numerical error depends on the used finite element mesh size is reduced by correcting the slope of strain softening region of the concrete according to the developed energy criteria.

• Composites Research
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• v.12 no.1
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• pp.59-67
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• 1999

The effects of fiber waviness on tensile/compressive nonlinear elastic behaviors of graphite/epoxy unidirectional composite materials are studied theoretically and experimentally. New constitutive models are proposed to predict elastic properties and tensile/compressive nonlinear behaviors of composite materials. Three types of wavy pattern are considered: uniform, graded and localized fiber waviness. Complementary energy density and incremental method are used to incorporate the material and geometrical nonlinearities due to fiber waviness. Tensile/compressive tests are conducted on the specimens with fiber waviness. It is found that the predictions are in good agreement with the experimental results.

• Journal of Korean Society of Steel Construction
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• v.15 no.3
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• pp.313-320
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• 2003

The governing equation of the post-buckling of shear-deformable uniform columns under a combined load consisting of a uniformly distributed axial load and a concentrated load at a free end was derived and the post-buckling analysis was investigated by using differential transformation. The loads were obtained for various end-slopes. The results obtained by the present method agree well with published results. In this paper, the differential transformation method was illustrated through its application to the non-linear differential equation of the post-buckling. It is expected that applications of the method to more challenging problems will are expected follow in future to ensue.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.47-54
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• 1990

Under external loads, large panel structures behave quite differently from monolithic wall structures, because of the distinct planes of weakness in the horizontal and vertical joints between panels. Study on the ultimate load and the failure mode of the large panel structures under extream lateral loads is therefore important. The purpose of this study is to predict the nonlinear behavior of the structure using the general purpose nonlinear computer program 'ANSR' being based on the quasi-static test results of the large panel structure(full scale in two story) and to examine the distribution and change mode of the internal forces which can not be obtained in the test.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.3
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• pp.11-26
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• 2011

The inelastic displacement ratio is defined as the ratio of the peak inelastic displacement to the peak linear elastic displacement. The inelastic displacement ratio allows simple evaluation of the peak inelastic displacement directly from the peak elastic displacement without computation of the inelastic response. Existing research of the inelastic displacement ratio is limited to piece-wise linear systems such as bilinear or stiffness degrading systems. In this paper, the inelastic displacement ratio is investigated for smooth hysteretic behavior systems subjected to near- and far-fault earthquakes. A simple formula of the inelastic displacement ratio is proposed by using a two step procedure of regression analysis.

• Journal of Korean Society of Steel Construction
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• v.11 no.2 s.39
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• pp.143-151
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• 1999

An analytical study on the behavior of composite beams, which are composed of cold-formed profiled steel sheeting and normal strength concrete, is described. An analytical method to trace the nonlinear behavior of a composite beam is developed to include the nonlinear material properties of steel sheeting, reinforcing steel bar and concrete. A simple Power Model has also been proposed for the nonlinear moment-curvature relation of the composite beam. The model, which has been originally used to predict the flexural capacity of the beam to column connections, is adapted to the composite beams. The load-deflection behavior of the beams has been simulated by the step-by-step numerical integration using the moment-curvature relation obtained by the Power Model. The results have been compared with test results.