• Title/Summary/Keyword: Buckling Stress

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Effects of geometrical initial imperfection in proportioning member sections of single layer reticulated dome (단층 래티스 돔의 단면산정에 있어서의 형상초기불완전의 영향)

  • Kim, Jong-Min;HwangBo, Seok;Han, Sang-Eul;Kwun, Teak-Jin
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.83-88
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    • 2004
  • First author proposed a proportioning method for member sections of a single layer reticulated dome subjected to uniform and non-uniform load without any geometrical initial imperfection, and discussed the validity and effectiveness of the method which was based on linear buckling stress and a knock down factor. However, buckling of a single layer reticulated dome is strongly affected by initial imperfection. It is well known that geometrical initial imperfections reduce the nonlinear buckling capacity of a single layer raticulated dome. Thus, structural engineers may be recommended to reflect the effects of geometrical initial imperfections in proportioning member sections. In this paper, firstly, the presented proportioning method by first author is applied to dome without consideration of any imperfections and the thickness and diameter of each member are determined. Secondly, the load bearing capacities of the proportioned domes are checked with the imperfection, by the inelastic buckling analysis.

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

  • 김문겸;김소운;황학주
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1990.10a
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    • pp.16-21
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    • 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.

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A Study on Buckling Strengths for Steel Compression Members at High Temperatures (고온 강구조 압축재의 좌굴 강도에 관한 연구)

  • Choi, Hyun-Sik
    • Journal of Korean Association for Spatial Structures
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    • v.19 no.2
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    • pp.73-81
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    • 2019
  • The high-temperature properties of mild steels were studied by comparing the test results of Kwon and the yield strength, tangent modulus predicted by the design provisions of ASCE and Eurocode(EC3). The column strengths for steel members at high temperatures were determined by the elastic and inelastic buckling strengths according to elevated temperatures. The material properties at high temperatures should be used in the strength evaluations of high temperature members. The buckling strengths obtained from the AISC, EC3 and approximate formula proposed by Takagi et al. were compared with ones calculated by the material nonlinear analysis using the EC3 material model. The newly simplified formulas for yield stress, tangent modulus, proportional limit and buckling strength which were proposed through a comparative study of the material properties and buckling strengths. The buckling strengths of proposed formulas were approximately equivalent to ones obtained from the formulas of Takagi et al. within 4%. They were corresponded to the lower bound values among the buckling strengths calculated by the design formulas and inelastic buckling analysis.

The Effects of Sheet Strength and Thickness on Bending Behavior of Steel Pipes (소재강도와 두께가 파이프 굽힘변형의 꺽임발생 거동에 미치는 영향)

  • 박기철;이형진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.9
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    • pp.2071-2081
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    • 1995
  • In order to examine the effects of yield stress, tensile strength and thickness on the buckling behavior during bending of pipes, the nonlinear finite element analysis of the 3-point bending tests was carried out using the commercial software (ABAQUS) under the condition of L4(2$^{3}$) performed according to the designed condition. Form the analysis of simulation results, it was found that yield stress and thickness were the major factors on buckling load at pipe bending and tensile strength gave little influence because the plastic strain and plastic zone are small. For the punch displacement to the occurrence of buckling, thickness is a major factor and yield stress and tensile strength are the minor factors.

Inelastic Buckling Behavior of Simply Supported I-Beam under Transverse Loading (횡방향 하중을 받는 I형강 단순보의 비탄성 좌굴거동)

  • Lee, Dong Sik;Oh, Soon Taek
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1 s.68
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    • pp.155-167
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    • 2004
  • In this paper, the inelastic buckling behavior of the beam under uniform bending was investigated using the energy-based method, which can tackle problems in fourth order eigenvalue. The pattern of residual stress was not available to satisfy the I-sections manufactured in Korea. however; therefore, the well-known polynomial and simplified pattern of residual stress was adopted in this study. The inelastic lateral-distortional buckling behavior of the beam with I-sections manufactured in Korea was investigated. The study was then extended to the inelastic lateral-torsional buckling of the beam by minimizing the out-of-plane web distortion. The inelastic lateral-torsional buckling results obtained in this paper were compared with the prediction of allowable bending stress given in the Korean steel designers' manual (1995). Results showed that the importance of inelastic lateral-distortional buckling did not arise for beams under uniform bending. Likewise, the design method in KSDM (1995) was proven to bo too conservative for intermediate and short spans of beams without intermediate bracing.

On the post-buckling behaviour of plates under stress gradient

  • Bedair, Osama K.
    • Structural Engineering and Mechanics
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    • v.4 no.4
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    • pp.397-413
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    • 1996
  • In this paper the elastic post-buckling behaviour of plates under non-uniform compressive edge stress is investigated. The compatibility differential equations is first solved analytically and then an approximate solution of the equilibrium equation is obtained using the Galerkin method. Explicit expressions are derived for the load-deflection, ultimate strength and membrane stress distributions. Analytical effective width formulations, based on the characteristics of the stress field of the buckled plate, are proposed for this general loading condition. The predicted load-deflection expression is compared with independent test results. Results are also presented detailing the load-deflection behaviour and stress distribution for various aspect ratios.

A Study on the Structural Behavior of Welded Box Columns (강제 교각의 거동에 관한 연구)

  • 김인한;손용석;엄진호;송준엽;권영봉
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.10a
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    • pp.87-94
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    • 1999
  • The structural behavior of welded steel box columns subjected to axial compression and combined load of axial and horizontal load is described. The nonlinear stress-strain relation of the material and residual stress resulted from welds were included in the analysis. Inelastic buckling analysis of hollow rectangular sections of various width-thickness and slenderness ratios was carried out using the semi-analytical and spline finite strip method to investigate the local and global bucking stress and mode interaction. The buckling stress was compared with test results and design curves. Post-buckling behavior was traced by the finite element program(ADINA) and compared with experimental results. The comparison showed that the ultimate stress can be used for the design purpose.

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Buckling analysis of functionally graded plates using HSDT in conjunction with the stress function method

  • Bakoura, Ahmed;Bourada, Fouad;Bousahla, Abdelmoumen Anis;Tounsi, Abdeldjebbar;Benrahou, Kouider Halim;Tounsi, Abdelouahed;Al-Zahrani, Mesfer Mohammad;Mahmoud, S.R.
    • Computers and Concrete
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    • v.27 no.1
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    • pp.73-83
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    • 2021
  • In this article, the mechanical buckling analysis of simply-supported functionally graded plates is carried out using a higher shear deformation theory (HSDT) in conjunction with the stress function method. The proposed formulation is variationally consistent, does not use a shear correction factor and gives rise to a variation of transverse shear stress such that the transverse shear stresses vary parabolically through the thickness satisfying the surface conditions without stress of shear. The properties of the plate are supposed to vary across the thickness according to a simple power law variation in terms of volume fraction of the constituents of the material. Numerical results are obtained to study the influences of the power law index and the geometric ratio on the critical buckling load.

Buckling behavior of strengthened perforated plates under shear loading

  • Cheng, Bin;Li, Chun
    • Steel and Composite Structures
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    • v.13 no.4
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    • pp.367-382
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    • 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.

Buckling analysis of steel plates in composite structures with novel shape function

  • Qin, Ying;Luo, Ke-Rong;Yan, Xin
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.405-413
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    • 2020
  • Current study on the buckling analysis of steel plate in composite structures normally focuses on applying finite element method to derive the buckling stress. However, it is time consuming, computationally complicated and tedious for general use in design by civil engineers. Therefore, in this study an analytical study is conducted to predict the buckling behavior of steel plates in composite structures. Hand calculation method was proposed based on energy principle. Novel buckling shapes with biquadratic functions along both loaded and unloaded direction were proposed to satisfy the boundary condition. Explicit solutions for predicting the critical local buckling stress of steel plate is obtained based on the Rayleigh-Ritz approach. The obtained results are compared with both experimental and numerical data. Good agreement has been achieved. Furthermore, the influences of key factors such as aspect ratio, width to thickness ratio, and elastic restraint stiffness on the local buckling performance are comprehensively discussed.