• Title/Summary/Keyword: 소성이력

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Seismic Damage Assessment and Nonlinear Structural Identification Using Measured Seismic Responses (실측 지진응답을 이용한 지진손상도 평가 및 소성모형 추정)

  • 이형진;김남식
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.6
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    • pp.7-15
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    • 2002
  • In this paper, the nonlinear parameter estimation method using the estimated hysteresis of each structural members was studied for the purpose of efficient seismic damage prediction and estimation of MDOF nonlinear structural model in the shaking table test. The hysteresis of each structural members can be obtained by the conversion of measured response histories into relative motions of each structural members and member forces. These hysteresis can be used to evaluate various kinds of damage indices of each structural members. The MDOF nonlinear structural model for further analysis(re-analysis) can be easily reconstructed using estimated nonlinear structural parameters of each structural members. To demonstrate the proposed techniques, several numerical and experimental example analyses are carried out. The results indicate that the proposed method can be very useful to assess local seismic damages of structures.

A Comparative Study on Formulation of Three-Dimensional Elastic-Plastic Finite Deformation Analysis for Prediction Large Deflection (강부재의 대변형 예측을 위한 3차원 탄소성 유한변위해석의 정식화에 대한 비교연구)

  • Jang, Gab-Chul;Chang, Kyong-Ho
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.4 s.22
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    • pp.53-61
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    • 2006
  • In th is paper, to predicting the large deformation and cyclic plastic behavior of steel members under loading, 3-Dimensional elastic-plastic FE analysis method is developed by using finite deformation theory and proposed cyclic plasticity model. finite deformation theory, described the large deformation, is formulated by using Updated-lagrangian formulation and Green's strain tensor, Jaumann's derivative of Kirchoff stress. Also, cyclic plasticity model proposed by author is applied to developed analysis method. To verification of developed analysis method, analysis result of steel plate specimen compare to the analysis result using infinitesimal deformation theory and test result. Also, load-displacement and deflection shape, analysis result of pipe-section steel column, compare to test result. The good agreement between analysis result and experiment result shown that developed 3-dimensional finite element analysis can be predict the large deformation and cyclic plastic behavior of steel members.

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Design of Unbend Braces to Satisfy Given Performance Acceptance Criteria (성능수준 만족을 위한 가새헝 소성 감쇠기의 설계)

  • 김진구;김유경;최현훈
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.6
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    • pp.47-54
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    • 2001
  • Unbond brace hysteretic dampers are generally used to prevent or decrease structural damage in building structures subjected to strong earthquake by its energy dissipating hysteretic behavior. In the study, a straightforward design procedure for unbond brace hysteretic dampers was developed. The required amount of equivalent damping to satisfy given performance acceptance criteria was obtained conveniently based on the capacity spectrum method without carrying out time-consuming nonlinear dynamic time history analysis. Then the size of the unbond braces is determined from the required equivalent damping. Parametric study has been performed for the design variables such as natural period, yield strength, the stiffness after the first yield stress of the unbond brace. The procedure was applied to 5-story and 10-story steel frames for verification of the proposed method. According to the earthquake time history analysis results, the maximum displacement of the model structure with unbond braces supplied in accordance with the proposed method corresponds well with the given target displacement.

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Hysteretic Behavior Characteristics of SM490-TMC Steel Column (SM490-TMC 강재를 적용한 기둥부재 이력거동의 특성)

  • Chang, Kyong Ho;Jang, Gab Chul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5A
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    • pp.833-840
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    • 2006
  • In design of steel column member using TMCP steels, hysteretic behavior characteristics of steel column must be clarified. To predict hysteretic behavior of steel column using TMCP steels, a cyclic plasticity model is necessary which can consider the mechanical characteristics and stress-strain relationship of TMCP steels. In this paper, a cyclic plasticity model of SM490-TMC was formulated based on monotonic and cyclic loading tests. The formulated cyclic plasticity model was applied to 3-dimensional finite element analysis. Hysteretic behavior characteristics of steel circular column and H-section column using SM490-TMC was presented by carrying out numerical analysis. Also, influence of SM490-TMC on hysteretic behavior of steel column was presented by comparing analysis results both SM490 and SM490-TMC steel column.

Determination of the Strength and Stiffness Degradation Factor for Circular R/C Bridge Piers (원형 철근콘크리트 교각의 강성 및 강도감소지수 결정)

  • 이대형;정영수
    • Journal of the Earthquake Engineering Society of Korea
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    • v.4 no.2
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    • pp.73-82
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    • 2000
  • 본연구의 목적은 반복하중을 받는 철근콘크리트 교량 교각의 비선형 이력거동을 해석적으로 예측하는 것이다 이를 위해서 반복적인 횡하중이 작용하는 경우에 실험결과와 일치하는 교각의 하중-변위 이력곡선을 도출하고자 수정된 trilinar 이력거동모델을 이용하였다 철근과 콘크리트의 비선형 거동특성과 각 하중단계에 따른 교각의 중립축을 구하여 소성힌지부의 모멘트와 변형률을 구하고 반복하중하에서의 강성의 변화를 해석적으로 모형화하기 위하여 각기 다른 강성을 갖는 5가지 지선을 갖춘 형태의 이력거동모델식을 제안하였다 본 연구에서는 실험적으로 구한 하중-변위 이력곡선을 이용하여 축하중비 주철근비 및 구속철근비에 따른 강도감소지수와 강성감소지수의 영향을 회귀분석을 이용하여 일반식으로 제안하였다 새로운 이력거동 해석 모델을 프로그램 SARCF III에 적용함으로써 기존 철근콘크리트 교각에 강도 및 강성감소 현상을 정확하게 예측하였다

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Finite Element Simulation of Hysteretic Behavior of Structural Stainless Steel under Cyclic Loading (반복하중을 받는 스테인리스강의 이력거동 해석모델 개발)

  • Jeon, Jun-Tai
    • Journal of the Society of Disaster Information
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    • v.15 no.2
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    • pp.186-197
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    • 2019
  • Purpose: This study intends to develop a nonlinear cyclic plasticity damage model in the framework of finite element formulation, which is capable of taking large deformation effects into account, in order to accurately predict the hysteretic behavior of stainless steel structures. Method: The new cyclic constitutive equations that utilize the combined isotropic-kinematic hardening rule for plastic deformation is incorporated into the damage mechanic model in conjunction with the large strain formulation. The damage growth law is based on the experimental observations that the evolution of microvoids yields nonlinear damage accumulation with plastic deformation. The damage model parameters and the procedure for their identification are presented. Results and Conclusion: The proposed nonlinear damage model has been verified by simulating uniaxial strain-controlled monotonic and cyclic loading tests, and successfully applied to a thin-walled stainless steel pipe subjected to constant and alternating strain-controlled cyclic loadings.

Experimental Study on the Behavior of Brace with Elasto-Plastic Hysteretic damper (탄소성 이력 댐퍼가 부착된 브레이스의 거동에 관한 실험적 연구)

  • Oh, Sang Hoon;Ryu, Hong Sik;Moon, Tae Sup
    • Journal of Korean Society of Steel Construction
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    • v.17 no.5 s.78
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    • pp.617-625
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    • 2005
  • The brace is often used to resist lateral force such as that exerted by an earthquake. Because of buckling at bifurcation load, the brace shows unstable hysteretic characteristics in the plastic zone. Therefore, in this study, the brace with damper that consists of slit plates were suggested on the purpose of preventing buckling and increasing plastic deformation capacity. The experimental results regarding the brace member were analyzed and the feasibility was also examined.

Verification of Single Hardening Model (단일 경화 모델의 검증)

  • Kim, Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.4
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    • pp.821-825
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    • 2007
  • In this study, the single hardening model with stress history-dependent plastic potential, which has been most recently proposed based on the critical state soil mechanics and needs few model parameters, was verified for the normally, lightly, and heavily over-consolidated clayey specimens. The triaxial compression tests were strictly conducted. The predictions using the single hardening model generally agree with the measurement. The discrepancy exists on its main focusing on the principal stress rotation; however, the plastic work H and the principal stress rotation angle ${\beta}$ are found to be effective indicators of loading history for the plastic potential function of the stress path dependent materials.

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Seismic Energy Response of Steel Moment Resisting Frames with Mass Irregularity (질량비정형을 갖는 강 모멘트 저항 골조의 지진에너지 반응)

  • Choi, Byong-Jeong;Song, In-Hawn
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.213-220
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    • 2003
  • 고층의 강 모멘트저항골조에 대한 지진 반응을 살펴보기 위해서 동적해석을 실시하였다. 구조물은 세가지의 다른 설계절차로 의도적으로 설계하였고 그 세가지의 개념은 강도 지배설계, 강기둥-약보 지배설계, 횡변위 지배설계이다. 그렇게 설계한 구조물이 각각 질량비정형이 존재하도록 하여 힁변위, 소성힌지, 이력에너지 입력 및 요구응력에 대해서 토론하였다. 미래에 설계에의 응용을 위해서 최대 지반가속도로 표현한 두 등급의 지진 하중을 이용해서 이력에너지 입력요구 곡선을 제시하였다.

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