• Title/Summary/Keyword: Inelastic behavior

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Inelastic analysis for the post-collapse behavior of concrete encased steel composite columns under axial compression

  • Ky, V.S.;Tangaramvong, S.;Thepchatri, T.
    • Steel and Composite Structures
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    • v.19 no.5
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    • pp.1237-1258
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    • 2015
  • This paper proposes a simple inelastic analysis approach to efficiently map out the complete nonlinear post-collapse (strain-softening) response and the maximum load capacity of axially loaded concrete encased steel composite columns (stub and slender). The scheme simultaneously incorporates the influences of difficult instabilizing phenomena such as concrete confinement, initial geometric imperfection, geometric nonlinearity, buckling of reinforcement bars and local buckling of structural steel, on the overall behavior of the composite columns. The proposed numerical method adopts fiber element discretization and an iterative M${\ddot{u}}$ller's algorithm with an additional adaptive technique that robustly yields solution convergence. The accuracy of the proposed analysis scheme is validated through comparisons with various available experimental benchmarks. Finally, a parametric study of various key parameters on the overall behaviors of the composite columns is conducted.

Nonlinear Finite Element Analysis of Precast Segmental Prestressed Concrete Bridge Columns (조립식 프리스트레스트 콘크리트 교각의 비선형 유한요소해석)

  • Kim, Tae-Hoon;Jin, Byeong-Moo;Kim, Young-Jin;Shin, Hyun-Mock
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.292-299
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    • 2006
  • The purpose of this study is to investigate the inelastic behavior of precast segmental prestressed concrete bridge columns. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. An unbonded tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. A joint element is newly developed to predict the inelastic behaviors of segmental joints. The proposed numerical method for the inelastic behavior of precast segmental prestressed concrete bridge columns is verified by comparison with reliable experimental results.

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Inelastic Energy Absorption Factor for the Seismic Probabilistic Risk Assessment of NPP Containment Structure (확률론적 지진위험도 분석을 위한 원전 격납건물의 비탄성에너지 흡수계수 평가)

  • 최인길;서정문
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.5
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    • pp.47-56
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    • 2001
  • In order to assure the safety of NPP structures, margin of safety or conservatism is incorporated in each design step. Seismic risk evaluation of NPP structures is performed based on the realistic capacity and response of structure eliminated the safety margin and conservatism. In this study, the comparative study on the various evaluation methods of the inelastic energy absorption capacity was performed. The inelastic energy absorption capacity due to the nonlinear behavior of structures has significant effect on the results of seismic probabilistic risk assessment. And the comparison study of the HCLPF(high confidence of low probability of failure) values according to the inelastic energy absorption factors was performed. As a conclusion, the inelastic energy absorption factor of NPP containment structure is estimated about 1.5~1.75. It is essential to estimate the nonlinear behavior of structure and its ductility factor correctly for the seismic risk assessment.

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Evaluation of Seimic Capacity of Cable-Stayed Bridges Considering Inelastic Behavior of Steel Pylons (강주탑의 비선형거동 특성을 고려한 케이블교량의 지진해석)

  • Bae, Sung-Han;Lee, Kyoung-Chan;Chang, Sung-Pil;Kim, Ick-Hyun
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.277-283
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    • 2005
  • Inelastic model of Second Jindo Bridge is investigated to perform nonlinear dynamic analyses with various earthquake ground motions. The modal analysis is performed to obtain dynamic characteristics of the bridge and verify the model. It proves that the model has an appropriate dynamic characteristic and its natural frequency is relatively low. Four ground motions are chosen for time history dynamic analyses; El Centro, Kobe, Taft, and Mexico earthquake. Each ground motion multiplied by specified factors to investigate damages of the structure. The analyses prove that responses of the bridge depend on the duration time and the frequency characteristics of ground motion, not only peak acceleration. Static push-over analysis of steel pylon shows that the dynamic analysis over-estimates the seismic behavior of steel pylon definitely. Nonlinear spring hinge model is suggest to improve the shortage of the inelastic model could not deliberate local buckling damage. According to the time history analysis of nonlinear spring hinge model, it is proved that the inelastic beam element analysis overestimate the seismic capacity of steel pylon unquestionably with a large amount of errors.

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Simplified beam-column joint model for reinforced concrete moment resisting frames

  • Kanak Parate;Onkar Kumbhar;Ratnesh Kumar
    • Structural Engineering and Mechanics
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    • v.89 no.1
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    • pp.77-91
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    • 2024
  • During strong seismic events, inelastic shear deformation occurs in beam-column joints. To capture inelastic shear deformation, an analytical model for beam-column joint in reinforced concrete (RC) frame structures has been proposed in this study. The proposed model has been developed using a rotational spring and rigid links. The stiffness properties of the rotational spring element have been assigned in terms of a moment rotation curve developed from the shear stress-strain backbone curve. The inelastic rotation behavior of joint has been categorized in three stages viz. cracking, yielding and ultimate. The joint shear stress and strain values at these stages have been estimated using analytical models and experimental database respectively. The stiffness properties of joint rotational spring have been modified by incorporating a geometry factor based on dimensions of adjoining beam and column members. The hysteretic response of the joint rotational spring has been defined by a pivot hysteresis model. The response of the proposed analytical model has been verified initially at the component level and later at the structural level with the two actually tested RC frame structures. The proposed joint model effectively emulates the inelastic behavior precisely with the experimental results at component as well as at structural levels.

Analytical Study on the Inelastic Behavior of Reinforced High-Strength Concrete Bridge Columns (고강도 철근콘크리트 교각의 비탄성거동에 관한 해석적 연구)

  • Shin, Hyun-Mock;Lee, Heon-Min;Sung, Dae-Jung;Kim, Tae-Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.2 s.48
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    • pp.73-81
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    • 2006
  • The purpose of this study is to investigate the inelastic behavior of reinforced high-strength concrete bridge columns. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model ol reinforcing steel. The smeared rack approach is incorporated. The increase of concrete strength due to the lateral confining reinforcement has been also taken into account to model the confined high-strength concrete. The proposed numerical method for the inelastic behavior of reinforced high-strength concrete bridge columns is verified by comparison with reliable experimental results.

Analytical Study on Inelastic Behavior of RC Bridge Columns with Unbonding of Main Reinforcements at Plastic Hinge Region (소성힌지영역에서 비부착 주철근을 갖는 철근콘크리트 교각의 비탄성거동에 관한 해석적 연구)

  • Kim, Tae-Hoon;Shin, Hyun-Mock
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.2 s.42
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    • pp.29-36
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    • 2005
  • The purpose of this study is to investigate the inelastic behavior of reinforced concrete bridge columns with unbonding of main reinforcements at plastic hinge region. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The smeared crack approach is incorporated. The effect of unbonding of main reinforcements at plastic hinge region has been also taken into account to model the concrete and reinforcing steel. The proposed numerical method for the inelastic behavior of reinforced concrete bridge columns with unbonding of main reinforcements at plastic hinge region is verified by comparison with reliable experimental results.

Inelastic Behavior and Ductility Capacity of Reinforced Concrete Frame Subjected In Cyclic Lateral Load (반복 휭하중을 받는 철근콘크리트 골조의 비탄성 거동 및 연성능력)

  • 김태훈;김운학;신현목
    • Journal of the Korea Concrete Institute
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    • v.14 no.4
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    • pp.467-473
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    • 2002
  • The purpose of this study is to investigate the inelastic behavior and ductility capacity of reinforced concrete frame subjected to cyclic lateral load and to provide result for developing improved seismic design criteria. A computer program named RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology) for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The smeared crack approach is incorporated. The strength increase of concrete due to the lateral confining reinforcement has been taken into account to model the confined concrete. In boundary plane at which each member with different thickness is connected local discontinuous deformation due to the abrupt change in their stiffness can be taken into account by introducing interface element. The effect of number of load reversals with the same displacement amplitude has been also taken into account to model the reinforcing steel. The proposed numerical method for the inelastic behavior and ductility capacity of reinforced concrete frame subjected to cyclic lateral load is verified by comparison with reliable experimental results.

Investigation on Inelastic Behavior of Tall Buildings Based on Efficient Analysis Algorithm (효용적인 알고리즘에 의한 초고층건물의 비탄성 해석 연구)

  • Ju, Young Kyu;Hong, Won Kee;Kim, Sang Dae;Park, Chil Lim
    • Journal of Korean Society of Steel Construction
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    • v.10 no.1 s.34
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    • pp.115-123
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    • 1998
  • In design of tall buildings, the flows of stress and ultimate strength of structures cannot be obtained by the elastic analysis alone. The current inelastic analysis are very impractical for practical engineer due to the amount of work involved in engineering calculation. In this paper the PC-based inelastic analysis by the residual strength ratio concepts is introduced. The efficiency of inelastic analysis is evaluated by comparing the results of inelastic analysis with those of elastic analysis for the existing tall buidling located in Seoul. Some modification in terms of lateral resisting structural system is proposed to improve the system ductility.

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Experimental Study on the Inelastic Behavior of Single-layer Latticed Dome with New Connection (새로운 접합상세를 가진 단층 래티스 돔의 비탄성 거동에 관한 실험연구)

  • Kim, Myeong Han;Oh, Myoung Ho;Jung, Seong Yeol;Kim, Sang Dae
    • Journal of Korean Society of Steel Construction
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    • v.21 no.2
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    • pp.145-154
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    • 2009
  • This study discusses the inelastic behavior of single-layer latticed dome, which consists of a tubular truss member and newly proposed joint sections, through a loading test on a scaled-down structure. The loading test was performed under displacement control conditions, using loading transfer system for the same value of point loads on all joints. The maximum applied load was nearly 1.6 times of the design load, and structural failure occurred after exceeding the compressive yielding in some members. Structural displacement was maintained up to the limit of the oil jack. The behavior of the latticed dome from the loading test was analyzed according to the order of loading steps.