• Title/Summary/Keyword: 좌굴 거동 현상

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A Nonlinear Truss Finite Element Model for Structures with Negative Poisson Effect Accompanied by Tensile Buckling (인장 좌굴 현상을 수반하는 음의 포아송 효과를 가지는 구조물 해석을 위한 비선형 트러스 유한요소 모델)

  • Tae-Wan Kim;Jun-Sik Kim
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.3
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    • pp.193-201
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    • 2023
  • In this study, a nonlinear truss finite element is developed to analyze structures with negative Poisson effect-induced tensile buckling. In general, the well-known buckling phenomenon is a stability problem under a compressive load, whereas tensile buckling occurs because of local compression caused by tension. It is not as well-known as classical buckling because it is a recent study. The mechanism of tensile buckling can be briefly explained from an energy standpoint. The nonlinear truss finite element with a torsional spring is formulated because the finite element has not been reported in the literature yet. The post-buckling analysis is then performed using the generalized displacement control method, which reveals that the torsional spring plays an important role in tensile buckling. Structures that mimic a negative Poisson effect can be constructed using such post-buckling behaviors, and one of the possible applications is a mechanical switch. The results obtained are compared to those of analytical solutions and commercial finite element analysis to assess the validity of the proposed finite element model. The numerical results show that the developed finite element model could be a viable option for the basic design of nonlinear structures with a negative Poisson effect.

Determination of Efficient Shear Stud Spacing in Steel-Concrete Panel(SCP) considering Local Buckling Behavior (국부좌굴 현상을 고려한 강판 콘크리트 패널의 효율적인 스터드 배치 간격 설정)

  • Kim, JoungRae;Lee, WonHo;Kwak, Hyo-Gyoung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.6
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    • pp.479-484
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    • 2017
  • In this paper, finite element analysis of Steel-Concrete panel(SCP) was conducted considering the local buckling behavior and the optimized design of shear studs arrangement was studied by comparing with design guidelines. If the spacing of the studs of SCP is widened, it is easy to be manufactured and the weight fo members become lighter. On the other hand, the steel plate would be vulnerable to the local buckling behavior. Therefore, the guidance and design of SCP limit the maximum spacing of the studs to prevent the development of shear cracks and local buckling, however this is based on the design criteria of the other composite structures. Parameter studies with changes in stud spacing on steel plate and SCP are conducted and the obtained result was compared with values given in design guidelines.

The Dynamic Post-Buckling Analysis of the Non-Conservative System including Damping Effects (감쇠효과(減衰效果)를 고려한 비보존력계(非保存力系)의 동적(動的) 후좌굴(後挫屈) 해석(解析))

  • Kim, Moon Young;Chang, Sung Pil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.3
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    • pp.67-75
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    • 1990
  • A geometrically nonlinear analysis procedure including the damping effects is presented for the investigation of the dynamic post-divergence and post-flutter behavior of a non-conservative system. The dynamic nonlinear analysis of plane frame structure subjected to conservative and non-conservative forces is carried out by solving the equations of motion using Newmark method. Numerical results are presented to demonstrate the effects of the internal and external damping forces in the conservative and non-conservative systems.

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A Study on the Ultimate Strength According to the Boundary Condition of a Ship Plate under Thrust (압축하중을 받는 선체판의 경계조건에 따른 최종강도에 관한 연구)

  • 고재용;박주신;이돈출
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.11a
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    • pp.89-93
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    • 2002
  • One of the primary factors like plate structure in ship is redundancy structure that is comparable with ocean structure and frame structure. The more component material becomes buckling collapsed locally the less structure stiffness becomes accordingly. As a result, by increasing the load distribution of my other subsidiary structure continually component member collapses, therefore the structure could be in danger of collapse. So, in order to interpret this phenomenon precisely, the study on boundary condition of the ship's plate and post-buckling analysis must be considered In this study, the rectangular plate is compressed by the in-plane load Buckling & Ultimate strength characteristics are applied o be the elasto-plasticity large deformation by ansys code with F.E.M method On this basis, elasto-plasticity of the plain plate are investigated. This study proved elasto-plasticity behaviour of the ship's plate in accordance with boundary condition based on the series analysis in case of the compressive load operation

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The Instability Behavior of Shallow Sinusoidal Arches(2) : Classification of Dynamic Buckling under Step Pressure (얕은 정현형 아치의 불안정 거동에 관한 연구(2) : 스텝하중에서의 동적좌굴 특성)

  • 김승덕;박지윤;권택진
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.12 no.3
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    • pp.417-426
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    • 1999
  • The some papers which deal with the dynamic instability for shell-like structures under the step load have been published, but there are few papers which treat the essential phenomenon of the dynamic buckling using the phase plane for investigating occurrence of chaos. In nonlinear dynamics, examining the characteristics of attractor on the phase plane and investigating the dynamic buckling process are very important thing for understanding why unstable phenomena are sensitively originated by various initial conditions. In this study, the direct and the indirect snap-buckling of shallow arches considering geometrical nonlinearity are investigated numerically and compared with the static critical load.

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Analysis for Nonlinear Behavior of Concrete Panel Considering Steel Bar Buckling (철근 좌굴을 고려한 콘크리트 패널의 비선형 거동에 대한 해석)

  • Lee, Sang-Sup;Park, Keum-Sung;Bae, Kyu-Woong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.6
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    • pp.130-137
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    • 2018
  • Many constitutive models for concrete have been developed to predict the nonlinear behavior of concrete members considerably. The constitutive model for reinforcing bar that include the tension stiffening effect due to the bond characteristics between steel bars and concrete is being studied but the bilinear model is generally used. It was found that the buckling of the longitudinal reinforcing bars is controlled the nonlinear behavior of hybrid precast concrete panel, which is being developed for core wall. In this study, the constitutive models that can consider the embedding and buckling effects of reinforcing bar are investigated and a new model combing these constitutive models is proposed. In order to verify the proposed model, the analysis results are compared with experimental results of the concrete wall and hybrid precast concrete panel. The analysis of embedding-effect-only modeling predicted that the deformation increases continually without the decrease in the load carrying capacity. However, the analysis results of proposed model showed good agreement with some experimental results, thus verifying the proposed computational model.

Study on Buckling of Composite Laminated Cylindrical Shells with Transverse Rib (횡리브로 보강된 복합적층 원통형 쉘의 좌굴거동에 관한 연구)

  • Chang, Suk Yoon
    • Journal of Korean Society of Steel Construction
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    • v.16 no.4 s.71
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    • pp.493-500
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    • 2004
  • In this study, the effects of ring stiffeners for buckling of cylindrical shells with composite materials were analyzed. The finite element method was used: 3-D beam elements were used for stiffeners and flat shell elements were used for cylindrical shells and were improved by introducing a substitute shear strain. The ring stiffeners were of the transverse rib type. The buckling behaviors of the cylindrical shells were analyzed based on various parameters, such as locations and sizes of stiffeners, diameter/length ratios and boundary conditions of shells, and fiber-reinforced angles. Effective reinforcement was examined by understanding the exact behaviors for buckling. The results of the analysis may serve as references for designs and future investigations.

안정적 좌굴 모델을 통한 저감쇠 직물 시뮬레이션

  • Choe, Gwang-Jin;Go, Hyeong-Seok
    • Journal of the Korea Computer Graphics Society
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    • v.8 no.1
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    • pp.37-45
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    • 2002
  • We present a cloth simulation technique that is very stable yet also responsive. The stability of the technique allows the use of a large fixed time step when simulating various types of fabrics and character motions. The animations generated using this technique are strikingly realistic. Wrinkles form and disappear in a quite natural way, which is the feature that most distinguishes textile fabrics from other sheet materials. Significant improvements in both the stability and realism were made possible by overcoming the post-buckling instability as well as the numerical instability. The instability caused by buckling arises from a structural instability and therefore cannot be avoided by simply employing an implicit method. Addition of a damping force may help to avoid instabilities; however, it can significantly degrade the realism of the cloth motion. In this paper, a new buckling model based on immediate buckling assumption is proposed. A cloth element is assumed to reach a stable configuration immediately once it begins to buckle. This assumption makes it possible to simulate the fabric buckling stably without introducing any fictitious damping force. Consequently, it produces highly responsive cloth motion as well as improves the stability by modeling the fabric-specific buckling property adequately.

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Dynamic Buckling Characteristics of Arch Structures by Running Response Spectrum (연속 응답 스펙트럼 분석에 의한 아치 구조물의 동적 좌굴 특성)

  • Kim, Seung-Deog;Yun, Tae-Young
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.2 s.12
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    • pp.81-88
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    • 2004
  • The dynamic instability of snapping phenomena has been studied by many researchers. Few papers deal with dynamic buckling under loads with periodic characteristics, and the behavior under periodic excitations is expected to be different from behavior under STEP excitations. We investigate the fundamental mechanisms of the dynamic instability when the sinusoidally shaped arch structures are subjected to sinusoidally distributed excitations with pin-ends. The mechanisms of dynamic indirect snapping of shallow arches are especially investigated under not only STEP function excitations but also under sinusoidal harmonic excitations, applied i the up-and-down direction. The dynamic nonlinear responses are obtained by the numerical integration of the geometrically nonlinear equation of motion. And using this analyze characteristics of the dynamic instability through the running response spectrum by FFT(Fast Fourier Transform).

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Inelastic Behavior and Seismic Retrofit of Inverted V Braced Steel Frames (역V형 철골 가새골조의 비탄성거동 및 내진성능향상 방안에 관한 연구)

  • Kim, Nam Hoon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
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    • v.15 no.5 s.66
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    • pp.571-578
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    • 2003
  • An effective seismic retrofit scheme for inverted V braced (or chevron type) steel frames was proposed by studying the redistribution of forces in the post-buckling range. The steel frames with chevron bracing are highly prone to soft story response once the compression brace buckles under earthquake loading. This paper shows that the seismic performance of such frames could be significantly improved by supplying tie bars to redistribute the inelastic deformation demand over the height of the building. A practical design method of the retrofit tie bars was also proposed by considering the sequence of buckling occurrence.