• Title, Summary, Keyword: elasto plastic model

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Elasto-plastic Analysis of Circular Cylindrical Shell under Horizontal Load by Rigid-bodies Spring Model

  • Park, Kang-Geun
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.3
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    • pp.87-92
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    • 2006
  • This paper is a study on the experiment and elasto-plastic discrete limit analysis of reinforced concrete circular cylindrical shell by the rigid-bodies spring model. In the rigid bodies-spring model, each collapsed part or piece of structures at the limiting state of loading is assumed to behave like rigid bodies. The present author propose new discrete elements for elasto-plastic analysis of cylindrical shell structures, that is, a rectangular-shaped cylindrical element and a rhombus-shaped cylindrical element for the improvement and expansion of this rigid-bodies spring model. In this study, it is proposed how this rigid element-bodies spring model can be applied to the elasto-plastic discrete limit analysis of cylindrical shell structures. Some numerical results of elasto-plastic discrete limit analysis and experimental results such as the curve of load-displacement and the yielding and fracturing pattern of circular cylindrical shell under horizontal load are shown.

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Finite Element Analysis of Elasto-Plastic Large Deformation considering the Isotropic Damage(the 2nd Report) (등방성손상을 고려한 탄소성 대변형 무제의 유한요소해석(제2보))

  • 이종원
    • Journal of Ocean Engineering and Technology
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    • v.14 no.2
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    • pp.76-83
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    • 2000
  • this paper was concentrated on the finite element formulation to solve boundary value problems by using the isotropic elasto-plastic damage constitutive model proposed previously(Noh, 2000) The plastic damage of ductile materials is generally accompanied by large plasticdeformation and strain. So nonlinearity problems induced by large deformation large rotation and large strain behaviors were dealt with using the nonlinear kinematics of elasto-plastic deformations based on the continuum mechanics. The elasto-plastic damage constitutive model was applied to the nonlinear finite element formulation process of Shin et al(1997) and an improved analysis model considering the all nonlinearities of structural behaviors is proposed. Finally to investigate the applicability and validity of the numerical model some numerial examples were considered.

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Characteristics of Long-Term Settlement in the Soft Ground of Nakdong River by Numerical Analysis (수치해석에 의한 낙동강 하구 연약지반의 장기침하특성)

  • Park, Choon-Sik;Ryu, Mean-Young
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.3
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    • pp.55-67
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    • 2019
  • Deep soft ground in mouth of Nackdong river requires to be analysed with prediction method concerning characteristics of secondary consolidation from the beginning because it causes excessive settlement due to time-dependant secondary consolidation characteristics. This study investigated characteristics of extended settlement by conducting one-dimensional theory, elasto-plastic model and visco-elasto-plastic model as well as analyzing long-term measuring data observed over 2,000 days. According to one-dimensional theory and elasto-plastic model, there is not definite correlation between height of embankment and depth of soft ground while visco-elasto-plastic model showed similar result of settlement to that of long-term measuring data. Consequently it is suggested that applying visco-elasto-plastic model to developing deep underground place as studied area on predicting extended settlement before construction prevents economic loss and delay during process by preparing secondary consolidation characteristics.

Investigation of elasto-plastic seismic response analysis method for complex steel bridges

  • Tang, Zhanzhan;Xie, Xu;Wang, Yan;Wang, Junzhe
    • Earthquakes and Structures
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    • v.7 no.3
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    • pp.333-347
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    • 2014
  • Multi-scale model can take both computational efficiency and accuracy into consideration when it is used to conduct elasto-plastic seismic response analysis for complex steel bridges. This paper proposed a method based on pushover analysis of member sharing the same section pattern to verify the accuracy of multi-scale model. A deck-through type steel arch bridge with a span length of 200m was employed for seismic response analysis using multi-scale model and fiber model respectively, the validity and necessity of elasto-plastic seismic analysis for steel bridge by multi-scale model was then verified. The results show that the convergence of load-displacement curves obtained from pushover analysis for members having the same section pattern can be used as a proof of the accuracy of multi-scale model. It is noted that the computational precision of multi-scale model can be guaranteed when length of shell element segment is 1.40 times longer than the width of section where was in compression status. Fiber model can only be used for the predictions of the global deformations and the approximate positions of plastic areas on steel structures. However, it cannot give exact prediction on the distribution of plastic areas and the degree of the plasticity.

Finite Element Analysis for Plastic Large Deformation and Anisotropic Damage

  • Nho, In-Sik;Yim, Sahng-Jun
    • Journal of Hydrospace Technology
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    • v.1 no.1
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    • pp.111-124
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    • 1995
  • An improved analysis model for material nonlinearity induced by elasto-plastic deformation and damage including a large strain response was proposed. The elasto-plastic-damage constitutive model based on the continuum damage mechanics approach was adopted to overcome limitations of the conventional plastic analysis theory. It can manage the anisotropic tonsorial damage evolved during the time-independent plastic deformation process of materials. Updated Lagrangian finite element formulation for elasto-plastic damage coupling problems including large deformation, large rotation and large strain problems was completed to develop a numerical model which can predict all kinds of structural nonlinearities and damage rationally. Finally a finite element analysis code for two-dimensional plane problems was developed and the applicability and validity of the numerical model was investigated through some numerical examples. Calculations showed reasonable results in both geometrical nonlinear problems due to large deformation and material nonlinearity including the damage effect.

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A STUDY ON ELASTO-PLASTIC ANALYSIS OF SPHERICAL SHELL BY RIGID ELEMENT METHOD(I) - Theoretical Consideration on Elasto-Plastic Analysis of Spherical Shell - (강체요소법에 의한 구형쉘의 탄소성해석에 관한 연구( I ) - 구형쉘의 탄소성 해석에 관한 이론적 고찰 -)

  • 권택진;한상율;서삼열;박강근
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.18-23
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    • 1988
  • This study on the elasto-plastic analysis of spherical shell by rigia element method is classified into two parts : (1) theoretical consideration on elasto-plastic analysis of spherical shell, (2) elastic and elasto-plastic analysis of spherical shell with the open stiff ring. In 1982, Y. Tsuboi proposed the new analytical method which is called the rigid element method, for analyzing the elasto-plastic behavior of wall-type precast concrete structures by applying the concepts of rigid bodies-sprins model (i.e., when structures reach their ultimate state of leading, they may be yield, collapsed ana crushed into pieces, and each part or piece of structures mar move like a rigid body.). In this paper, for improvement and expansion this rigid element method, it is proposed the adaptation equation of rectangular-shaped spherical element and rectangular-shaped spherical bending element developed by present authors, and the analytical procedure for the elastic and the elasto-plastic increment method of structures.

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Finite Element Analysis of Elasto-Plastic Large Deformation considering the Isotropic Damage (the 1st Report) -Development of Elasto-Plastic Damage Constitutive Model- (등방성 손상을 고려한 탄소성 대변형 문제의 유한요소해석(제1보) -탄소성 손상 구성방정식 개발-)

  • 노인식
    • Journal of Ocean Engineering and Technology
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    • v.14 no.2
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    • pp.70-75
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    • 2000
  • In this paper a new constitutive model for ductile materials was proposed. This model can describe the material degradation due to the evolution of isotropic damage during elasto-platic deformation. The plastic flow rule was derived under the framework of thermodynamic approach of continuum damage mechanics(CDM) in which plastic strain hardening parameters and isotropic damage were taken as thermodynamic state variables. And the process to determine material constants for constitutive model using an experimental data was presented.

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Analysis of 2-Dimensional Elasto-Plastic Stress by a Time-Discontinuous Variational Integrator of Hamiltonian (해밀토니안의 시간 불연속 변분적분기를 이용한 2차원 탄소성 응력파 해석)

  • Chol, S.S.;Huh, H.;Park, K.C.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.263-266
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    • 2008
  • This paper is concerned with the analysis of elasto-plastic stress waves in a mode I semi-infinite cracked solid subjected to Heaviside pulse load. This study adopts a time-discontinuous variational integrator based on Hamiltonian in order to reduce the numerical dispersive and dissipative errors. This also utilizes an integration scheme of the constitutive model with 2nd-order accuracy which is formulated on the strain space for a rate and temperature dependent material model. Finite element analyses of elasto-plastic stress waves are carried out in order to compare the accuracy between a conventional Galerkin method and the time- discontinuous variational integrator.

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Iterative global-local approach to consider the local effects in dynamic analysis of beams

  • Erkmen, R. Emre;Afnani, Ashkan
    • Coupled systems mechanics
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    • v.6 no.4
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    • pp.501-522
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    • 2017
  • This paper introduces a numerical procedure to incorporate elasto-plastic local deformation effects in the dynamic analysis of beams. The appealing feature is that simple beam type finite elements can be used for the global model which needs not to be altered by the localized elasto-plastic deformations. An overlapping local sophisticated 2D membrane model replaces the internal forces of the beam elements in the predefined region where the localized deformations take place. An iterative coupling technique is used to perform this replacement. Comparisons with full membrane analysis are provided in order to illustrate the accuracy and efficiency of the method developed herein. In this study, the membrane formulation is able to capture the elasto-plastic material behaviour based on the von Misses yield criterion and the associated flow rule for plane stress. The Newmark time integration method is adopted for the step-by-step dynamic analysis.

A Constitutive Model for Plastic Damage of Ductile Materials

  • Nho, In-Sik;Yim, Sahng-Jun;Shin, Jong-Gye
    • Selected Papers of The Society of Naval Architects of Korea
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    • v.2 no.1
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    • pp.106-128
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    • 1994
  • An elasto-plastic-damage constitutive model for ductile materials is proposed within the framework of a thermodynamic approach of continuum damage mechanics (CDM) in which internal irreversible thermodynamic changes of micro-structure of materials such as plastic deformation and damage evolution are considered as thermodynamic state variables. The new constitutive model can predict not only the elasto-plastic behaviors but also the sequential stiffness degradation process of ductile materials more rationally.

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