• Title/Summary/Keyword: 좌굴후 거동

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A Study on the Buckling and Postbuckling Behaviors of Laminated Composite Plates and Stiffened Laminated Composite Panels by Finite Element Method (유한요소법을 이용한 복합적층판과 보강된 복합적층 패널의 좌굴 및 좌굴후 거동에 관한 연구)

  • 허성필;양원호;성기득;조명래
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.12 no.4
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    • pp.599-606
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    • 1999
  • 복합 적층 판과 보강 재를 설치한 보강된 복합 적층 패널의 좌굴을 고려한 설계에서, 좌굴이 항상 구조물의 최종 파손을 의미하는 것은 아니므로 이들의 좌굴 및 좌굴 후 거동에 대한 정확한 이해와 연구가 필요하다. 본 연구에서는 유한요소 법을 이용하여 적층 메커니즘과 섬유 배향각, 적층 순서 등이 복합 적층 판과 보강된 복합 적층 패널의 좌굴 및 좌굴 후 거동에 미치는 영향을 체계적으로 해석하였고, 각 변수에 따른 좌굴 및 좌굴 후 거동 특성을 분석하였다.

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A study on the Thermal Buckling and Postbuckling of a Laminated Composite Beam with Embedded SMA Actuators (형상기억합금 선을 삽입한 복합적층 보의 열좌굴 및 좌굴후 거동에 관한 연구)

  • Choi, S.;Lee, J.J.;Lee, D.C.
    • Composites Research
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    • v.12 no.3
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    • pp.55-65
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    • 1999
  • In this paper, the thermal buckling and postbuckling behaviour of composite beam with embedded shape memory alloy (SMA) wires are investigated experimentally and analytically. The results of thermal buckling tests on uniformly heated, clamped, composite beam embedded with SMA wire actuators are presented and discussed in consideration of geometric imperfections, slenderness ratio of beam and embedding position of SMA wire actuators. The shape recovery force can reduce the thermal expansion of composite laminated beam, which result in increment of the critical buckling temperature and reduction of the lateral deflection of postbuckling behaviours. It is presented quantitatively on the temperature-load-deflection behaviour records how the shape recovery force affects the thermal buckling. The cross tangential method is suggested to calculate the critical buckling temperature on the temperature-deflection plot. Based on the experimental analysis, the new formula is also proposed to describe the critical buckling temperature of a laminated composite beam with embedded SMA wire actuators.

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Postbuckling and Vibration Analysis of Cylindrical Composite Panel subject to Thermal Loads (열하중을 받는 복합적층 원통형 패널의 좌굴후 거동 및 진동해석)

  • Oh, Il-Kwon;Lee, In
    • Journal of the Korea Institute of Military Science and Technology
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    • v.2 no.2
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    • pp.148-156
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    • 1999
  • The thermal postbuckling and vibration characteristics of cylindrical composite panel subject to thermal loads are analyzed using finite elements. The von-Karman nonlinear displacement-strain relation based on the layerwise theory is applied to consider large deflections due to thermal loads. Cylindrical arc-length method is used to take into account the snapping phenomena. Thermal snapping and vibration characteristics are investigated for various structural parameters such as thickness ratio, shallowness angle and boundary conditions. The present results show that thermal snapping changes the mode shapes as well as static deformations.

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A Study on Shape Optimization for Buckling and Postbuckling Behavior of Stiffened Laminated Composite Panels (보강된 복합적층 패널의 좌굴 및 좌굴후 거동의 형상 최적설계에 관한 연구)

  • Lee, Gwang-Rok;Jeong, Gi-Hyeon;Heo, Seong-Pil;Yang, Won-Ho;Jo, Myeong-Rae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.1
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    • pp.106-114
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    • 2001
  • In this study, a shape optimization of stiffener was conducted to increase buckling load or failure load in each case with a different design value and a different objective function for stiffened laminated composite panel of I-type under compression loading. Regarding each of buckling load or failure load as objective function, optimum design was carried out. In respect of optimum design, the effects of relative length of web and cab of stiffener on buckling load or failure load of postbuckling were investigated.

Postbuckling and Damage Analysis of Composite Laminated Hollow Cylinder under Lateral Pressure (횡방향 압력을 받는 복합적층 원통실린더의 좌굴후 거동 및 손상해석)

  • Chongdu Cho;Guiping Zhao;HeonJu Kin
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.4
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    • pp.163-172
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    • 2000
  • The postbuckling behavior and progressive damage of composite laminated cylindrical shell under uniform external pressure were investigated by nonlinear finite element method programming. For the finite element analysis, nine-node 3-D degenerated elements were utilized, and arc-length method including line search was adopted for the iteration and load-increment along postbuckling equilibrium path. As results. buckling load, postbucking behavior, and progressive failure f3r various composite laminated cylindrical shells were discussed.

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Postbuckling Behavior of Composite Laminated Cylinder under Lateral Pressure (횡방향 압력을 받는 복합적층 원통실린더의 좌굴후 거동해석)

  • 조종두;김헌주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.843-846
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    • 1994
  • The bucking and postbuckling behavior of composite laminated long cylinders under lateral pressure are investigated by the nonlinear finite element method. A long cylinder of 3-D shell problem is modelled as 2-D plane strain problem for analysis. And for the finite element analysis, eight nodes quadratic element is utilized. Arc-length method is adopted for the iteration and load-increment along postbuckling equilibrium path. The composite laminated cylinders in study are composed of cross-plied uniaxially reinforced shells. As a prsult, buckling load and postbuckling behavior are discussed.

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Analytical Method for Elastoplastic Behavior of Truss element under Cyclic Axial Loading (반복 축 하중을 받는 트러스 요소의 탄소성 좌굴거동 해석기법에 관한 연구)

  • Baek, Ki Youl
    • Journal of Korean Society of Steel Construction
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    • v.20 no.3
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    • pp.377-387
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    • 2008
  • The post-buckling behavior of slender members, such as the chord of truss structures generally implies extreme strength degradation. The buckling strength is usually determined as the performance of the compressed steel members, so it is important to understand the exact buckling behavior of a member in order to design the entire structure. A target analytical model is usually divided by beam or shell element when we simulate the buckling behavior of a compressed steel member such as atruss member. In this case, it is possible to accurately obtain the behavior, but such would be expensive and would require experience inanalysis even in monotonic loading. In this paper, we propose a consistent and convenient method to analyze the post-buckling behavior of elastoplastic compression members. The present methods are formulated to satisfy the second law of thermodynamics. Three numerical examples were tested to determine the validity of the proposed model in cyclic loading with comparable F.E.M results.

Buckling and Postbuckling Behavior of Stiffened Laminated Composite Panels (보강된 복합적층 판넬의 좌굴 및 좌굴후 거동 연구)

  • Lee, In-Cheol;Gyeong, U-Min;Gong, Cheol-Won;Hong, Chang-Seon;Kim, Cheon-Gon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.10
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    • pp.3199-3210
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    • 1996
  • The buckling and postbuckling behaviors were sutdied analytically and experimentally for stiffened laminated composite panels under compression loading. The panels with I-, blade, -and hat-shapeed stiffeners were investigated. In the analysis, the stiffened panels were anlyzed using the nonlinear finite element method combined with an improved arc-length method. The progressive failure analysis was done by adopting the maximum stress criterion and complete unloading failure model. The effects of the fiber angles were investigated on the buckling and postbuckling behaviors. In the experiment, the web and the lower cap of each stiffener were formed by the continuous lay-up of the skin for cocuring the stiffened panels. Therefore, the separation between stiffener and skin was not found in the junction part even after postbuckling ultimate load and the stiffened panels had excellent postbuckling load carrying capacity. A shadow moire thchnique was used to monitor the out-of-plane deformations of the panels. The piezoelectric films were attached to the panels to get the failure characteristics of the panel. The analytical results on the buckling load, postbuckling ultimate load, and failure pattern showed good agreement with the experimental results.

Post-Buckling of Shear Deformable Uniform Columns Under a Combined Load (조합하중을 받는 전단변형 기둥의 좌굴 후 거동 해석)

  • Yoo, Yeong Chan;Shin, Young Jae
    • Journal of Korean Society of Steel Construction
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    • v.15 no.3
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    • pp.313-320
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    • 2003
  • The governing equation of the post-buckling of shear-deformable uniform columns under a combined load consisting of a uniformly distributed axial load and a concentrated load at a free end was derived and the post-buckling analysis was investigated by using differential transformation. The loads were obtained for various end-slopes. The results obtained by the present method agree well with published results. In this paper, the differential transformation method was illustrated through its application to the non-linear differential equation of the post-buckling. It is expected that applications of the method to more challenging problems will are expected follow in future to ensue.