• Title/Summary/Keyword: Elasto-plastic buckling

Search Result 68, Processing Time 0.025 seconds

Analysis of Elasto-Plastic Buckling Characteristics of Plates (평면판의 탄소성 좌굴 특성 해석)

  • 김문겸;김소운;황학주
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1990.10a
    • /
    • pp.16-21
    • /
    • 1990
  • Recently, the finite element method has been sucessfully extended to treat the rather couplet phenomena such as nonlinear buckling problems which are of considerable practical interest. In this study, a finite element program to evaluate the elasto-plastic buckling stress is developed. The Stowell's deformation theory for the plastic buckling of flat plates, which is in good agreement with experimental results, is used to evaluate bending stiffness matrix. A bifurcation analysis is performed to compute the elasto-plastic buckling stress. The subspace iteration method is employed to find the eigenvalues. The results are compared with corresponding enact solutions to the governing equations presented by Stowell and also with experimental data due to Pride. The developed program Is applied to obtain elastic and elasto-plastic buckling stresses for various loafing cases. The effect of different plate aspect ratio is also investigated.

  • PDF

The Elasto-Plastic Buckling Analysis of Ball-Jointed Single Layer Latticed Domes considering the Characteristics of a Connector (적합부 특성을 고려한 볼 접합 단층 래터스 돔의 탄소성 좌굴해석)

  • Han, Sang-Eul;Kwon, Hyun-Jae;Kim, Jong-Bum
    • Journal of Korean Association for Spatial Structures
    • /
    • v.3 no.2 s.8
    • /
    • pp.91-99
    • /
    • 2003
  • The purpose of this study is to analyze the characteristics of the connector having an influence on the elasto-plastic buckling load of ball-jointed single layer latticed domes. As an analytic model, domes are composed of tubular member elements, balls and connectors. The joint system of members in single layer latticed domes has influence on the buckling load. Therefore, in this paper, the variation of the elasto-plastic buckling load by effects of the connectors characteristics is analyzed. The structural behavior of the connector is investigated by following points: (1) the length of rigid zone, (2) looseness of screw and (3) the diameter of connector. In addition, the elasto-plastic buckling analysis is carried out through the variation of the connectors section of yielding part, and then the buckling mode of the dome is examined. As a result, it is emphasized that the characteristics of the connector have significant effects on the buckling load of latticed domes.

  • PDF

Non-linear stability analysis of a hybrid barrel vault roof

  • Cai, Jianguo;Zhou, Ya;Xu, Yixiang;Feng, Jian
    • Steel and Composite Structures
    • /
    • v.14 no.6
    • /
    • pp.571-586
    • /
    • 2013
  • This paper focuses on the buckling capacity of a hybrid grid shell. The eigenvalue buckling, geometrical non-linear elastic buckling and elasto-plastic buckling analyses of the hybrid structure were carried out. Then the influences of the shape and scale of imperfections on the elasto-plastic buckling loads were discussed. Also, the effects of different structural parameters, such as the rise-to-span ratio, beam section, area and pre-stress of cables and boundary conditions, on the failure load were investigated. Based on the comparison between elastic and elasto-plastic buckling loads, the effect of material non-linearity on the stability of the hybrid barrel vault is found significant. Furthermore, the stability of a hybrid barrel vault is sensitive to the anti-symmetrical distribution of loads. It is also shown that the structures are highly imperfection sensitive which can greatly reduce their failure loads. The results also show that the support conditions pose significant effect on the elasto-plastic buckling load of a perfect hybrid structure.

Elasto-Plastic Buckling Analysis Based on the Slope-Deflection Method (처짐각법을 이용한 선형부재의 탄소성 좌굴해식)

  • Cheong, Myung-Chae
    • Journal of Korean Association for Spatial Structures
    • /
    • v.6 no.4 s.22
    • /
    • pp.63-72
    • /
    • 2006
  • Fundamental equations of a member to analysis the elasto-plastic buckling analysis based on the deflection method are derived in this paper, and its validity and accuracy are shown by the numerical examples. The model discussing in the present paper has three elasto-plastic springs which are located at the both ends and center of a member and two elastic beam elements between them. The elasto-plastic springs represent the elasto-plastic behavior of the member and elastic beam element represents buckling behavior of the member. Numerical example shows the validity of this formulation.

  • PDF

Buckling behavior of strengthened perforated plates under shear loading

  • Cheng, Bin;Li, Chun
    • Steel and Composite Structures
    • /
    • v.13 no.4
    • /
    • pp.367-382
    • /
    • 2012
  • This paper is dedicated to the buckling behaviors of strengthened perforated plates under edge shear loading, which is a typical load pattern of steel plates in civil engineering, especially in plate and box girders. The square plates considered each has a centric circular hole and is simply supported on four edges in the out-of-plane direction. Three types of strengthening stiffeners named ringed stiffener (RS), flat stiffener (FSA and FSB) and strip stiffener (SSA, SSB and SSC) are mainly discussed. The finite element method (FEM) has been employed to analyse the elastic and elasto-plastic buckling behavior of unstrengthened and strengthened perforated plates. Results show that most of the strengthened perforated plates behave higher buckling strengths than the unstrengthened ones, while the enhancements in elastic buckling stress and elasto-plastic ultimate strength are closely related to stiffener types as well as plate geometric parameters including plate slenderness ratio and hole diameter to plate width ratio. The critical slenderness ratios of shear loaded strengthened perforated plates, which determine the practical buckling pattern (i.e., elastic or elasto-plastic buckling) of the plates, are also studied. Based on the contrastive analyses of strengthening efficiency considering the influence of stiffener consumption, the most efficient cutout-strengthening methods for shear loaded perforated square plates with different slenderness ratios and circular hole diameter to plate width ratios are preliminarily identified.

The Elasto-Plastic Buckling Analysis of Ball-jointed Sing1e Layer Latticed Domes Considering the Connection Characteristics (접합부의 성질을 고려한 볼 접합 단층 래티스 돔의 탄소성 좌굴해석)

  • 한상을;권현재;신용환;배상달;이진섭
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2000.10a
    • /
    • pp.90-100
    • /
    • 2000
  • The present paper investigates the elasto-plastic buckling of ball-jointed single layer latticed domes considering the connection characteristics. The domes are composed of tubular member elements, ball joints and connectors. To judge yielding of the member, the ends and central part of tubular member elements are assumed as five elasto-plastic springs. Elasto-plastic buckling load can be identified the yielding load of estimated member As a numerical analysis technique, loading incremental method based on the Newton-Raphson method is used. The effects of connection characteristics are investigated by the following points; (1) the length of rigid zone, (2) looseness of screw, (3) diameter of connector Finally, it is emphasized that the connection characteristics as well as the material non-linearity have significant effects upon the buckling toad of domes.

  • PDF

A Study on the Estimation of Elasto-Plastic Buckling Loads for Sing1e Layer Latticed Domes by Unit Member Modeling Technique. (단위부재 모델화에 따른 단층 래티스 돔의 탄소성 좌골하중의 산정에 관한 연구)

  • 한상을;이상주;유용주;이경수
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1998.10a
    • /
    • pp.290-297
    • /
    • 1998
  • In this paper, we propose to a method to estimate the elasto-plastic buckling for single layer latticed domes. First, we assume that each member consists of the rigid zone and elastic spring at both end joint, the elastic element and three elasto-plastic spring to judge for yeilding the member. Next, the member which has most influence on buckling for structures is determined by a distributed pattern of the strain energy which is calculated through linear eigenvalue analysis. And then, normalized slenderness ratio of the element is derived considering the axial force at elastic buckling load. Later, we execute elasto-plastic nonlinear analysis that based on loading increasement method and displacement increasement method. From this results, we discusses the effect of the joint rigidity and the half open angle $\theta$$_{0}$ on the buckling strength of single layer lattice domes ; (1) how the joint rigidity contributes to the reduction of buckling loads, (2) how the reduction can be interrelated to compressive strength curves in terms of the generalized slenderness for the member most relevant to the overall buckling of domes.s.

  • PDF

Elasto-plastic Post-buckling Analysis of Spatial Framed Structures using Improved Plastic Hinge Theory (개선된 소성힌지이론을 이용한 공간 뼈대구조물의 탄-소성 후좌굴 해석)

  • Kim, Sung Bo;Ji, Tae Sug;Jung, Kyoung Hwan
    • Journal of Korean Society of Steel Construction
    • /
    • v.18 no.6
    • /
    • pp.687-696
    • /
    • 2006
  • An efficient numerical method is developed to estimate the elasto-plastic post-buckling strength of space-framed structures. The inelastic ultimate strength of beam-columns and frames is evaluated by the parametric study. Applying the improved plastic hinge analysis that evaluate the gradual stiffness decrease effects due to spread of plasticity, elasto-plastic post-buckling behavior of steel frames is investigated considering the various residual stress distributions. Introducing the plastification parameter that represent pread of plasticity in the element and performing parametric study of equivalent element force and member idealization, finite-element solutions for the elasto-plastic analysis of space frames are compared with the results by plastic region analysis, shell elements and experimental results.

Analysis of Eelasto-Plastic Buckling Characteristics of Plates Using Eigenvalue Formulation (고유치문제 형성에 의한 평면판의 탄소성 좌굴 특성 해석)

  • 황학주;김문겸;이승원;김소운
    • Computational Structural Engineering
    • /
    • v.4 no.1
    • /
    • pp.73-82
    • /
    • 1991
  • Recently, the finite element method has been sucessfully extended to treat the rather complex phenomena such as nonlinear buckling problems which are of considerable practical interest. In this study, a finite element program to evaluate the elasto-plastic buckling stress is developed. The Stowell's deformation theory for the plastic buckling of flat plates, which is in good agreement with experimental results, is used to evaluate bending stiffness matrix. A bifurcation analysis is performed to compute the elasto-plastic buckling stress. The subspace iteration method is employed to find the eigenvalues. The results are compared with corresponding exact solutions to the governing equations presented by Stowell and also with experimental data due to Pride. The developed program is applied to obtain elastic and elasto-plastic buckling stresses for various loading cases. The effect of different plate aspect ratio is also investigated.

  • PDF

Semi-rigid Elasto-Plastic Post Buckling Analysis of Space Frame by Using the Explicit Arc-Length Method (명시적 호장법을 이용한 공간프레임의 반강접 탄소성 후좌굴 해석)

  • Lee, Kyoung-Soo;Han, Sang-Eul
    • Journal of Korean Society of Steel Construction
    • /
    • v.23 no.5
    • /
    • pp.535-546
    • /
    • 2011
  • In this paper, semi-rigid elasto-plastic post-buckling analysis of a space frame was performed using various explicit arc-length methods. Various explicit arc-length methodsand a large-deformation and small-strain elasto-plastic 3D space frame element with semi-rigid connections and plastic hinges were developed. This element can be appliedto both explicit and implicit numerical algorithms. In this study, the Dynamic Relaxation method was adopted in the predictor and corrector processesto formulate an explicit arc-length algorithm. The developed "explicit-predictor" or "explicit-corrector" were used in the elasto-plastic post-buckling analysis. The Eulerian equations for a beam-column with finite rotation, which considers the bowing effects, were adopted for the elastic system and extended to theinelastic system with a plastic hinge concept. The derived tangent stiffness matrix was asymmetrical due to the finite rotation. The joint connection elements were introduced for semi-rigidity using a static condensation technique. Semi-rigid elasto-plastic post-buckling analyses were carried out to demonstrate the potential of the developed explicit arc-length method and advanced space frame element in terms of accuracy and efficiency.