• Title/Summary/Keyword: finite member element

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Deflection of battened beams with shear and discrete effects

  • Li, Ji-liang;Chen, Jian-kang
    • Structural Engineering and Mechanics
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    • v.59 no.5
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    • pp.921-932
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    • 2016
  • This paper presents a theoretical analysis for determining the transverse deflection of simply supported battened beams subjected to a uniformly distributed transverse quasi-static load. The analysis considers not only the shear effect but also the discrete effect of battens on the transverse deflection of the battened beam. The analytical solution is obtained using the principle of minimum potential energy. Numerical validation of the present analytical solution is accomplished using finite element methods. The present analytical solution shows that the shear effect on the transverse deflection of battened beams increases with the cross-section area of the main member but decreases with the cross-section area of the batten. The longer the battened beam is, or the larger the moment of inertia of the main member is, the smaller the shear effect will be.

A Study for Stress Distribution of the High-voltage Transmission Tower Under Wind Forces (풍하중이 작용하는 고용량 송전철탑의 해석을 통한 응력 분포 고찰)

  • Chang, Jin-Won;Kim, Seung-Jun;Park, Jong-Sub;Kang, Young-Jong
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.75-78
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    • 2007
  • The structural methodology in designing a transmission tower have been performed to assume a simple truss behavior. But there're quite differences between a simple truss behavior and a real one. A suitable explanation for a structural stability can be expressed as a semi-rigid connection instead of the assumed hinged connection. This study proposes an alternative structural analysis modelling strategy for the transmission tower design. Proposed element models are truss element model, beam element model, and combined beam-truss element model. The static finite element analysis shows that there's a moment distribution between a mainpost member and the other bracing member.

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Effects of initial imperfections on nonlinear behaviors of thin-walled members

  • Ohga, M.;Takaue, A.;Shigematsu, T.;Hara, T.
    • Structural Engineering and Mechanics
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    • v.11 no.5
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    • pp.519-534
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    • 2001
  • The effect of the initial imperfections on the nonlinear behaviors and ultimate strength of the thin-walled members subjected to the axial loads, obtained by the finite element stability analysis, are examined. As the initial imperfections, the bucking mode shapes of the members are adopted. The buckling mode shapes of the thin-walled members are obtained by the transfer matrix method. In the finite element stability analysis, isoparametric degenerated shell element is used, and the geometrical and material nonlinearity are considered based on the Green Lagrange strain definition and the Prandtl-Reuss stress-strain relation following the von Mises yield criterion. The U-, box- and I-section members subjected to the axial loads are adopted for numerical examples, and the effects of the initial imperfections on the nonlinear behaviors and ultimate strength of the members are examined.

A Study on FEM of the Bearing Girder in the Large Vessel Engine Structure (선박 엔진 베어링 거더의 유한요소해석에 관한 연구)

  • Park, Young-Joon;Shim, Mun-Bo;Kim, Hyun-Jun;Suh, Myung-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.12
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    • pp.1877-1885
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    • 2004
  • The purpose of this study is to show pressure distribution of the bearing girder in large vessel engine and to consider finite elements analysis using the pressure distribution. Various kinds of the exciting forces act on a bearing girder. And at the same time, it is necessary to consider the contact between a crankshaft and a bearing girder because a bearing girder supports a crankshaft. However it is to need the computer resource with much time if we apply the contact element to a complex solid model and perform a repeated analysis. Thus we have accomplished a contact analysis in the simplistic finite element model of the bearing girder. After that we take a pressure distribution, and apply this to actual finite element model and accomplish finite element analysis. The result of stresses and strains has been produced using superposition method. The concept of superposition method is to find the resultant deflection of several loads acting on a member as the sum of contributions of individual loads. The results were compared with measured results and were verified to be accurate. Resulting analyzed strain favorably coincides with measured strain. The experiment result justifies this paper method.

Experimental and finite element studies of special-shape arch bridge for self-balance

  • Lu, Pengzhen;Zhao, Renda;Zhang, Junping
    • Structural Engineering and Mechanics
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    • v.35 no.1
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    • pp.37-52
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    • 2010
  • Special-shape arch bridge for self-balance (SBSSAB) in Zhongshan City is a kind of new fashioned spatial combined arch bridge composed of inclined steel arch ribs, curved steel box girder and inclined suspenders, and the mechanical behavior of the SBSSAB is particularly complicated. The SBSSAB is aesthetic in appearance, and design of the SBSSAB is artful and particular. In order to roundly investigate the mechanical behavior of the SBSSAB, 3-D finite element models for spatial member and shell were established to analyze the mechanical properties of the SBSSAB using ANSYS. Finite element analyses were conducted under several main loading cases, moreover deformation and strain values for control section of the SBSSAB under several main loading cases were proposed. To ensure the safety and rationality for optimal design of the SBSSAB and also to verify the reliability of its design and calculation theories, the 1/10 scale model tests were carried out. The measured results include the load checking calculation, lane loading and crowd load, and dead load. A good agreement is achieved between the experimental and analytical results. Both experimental and analytical results have shown that the SBSSAB is in the elastic state under the planned test loads, which indicates that the SBSSAB has an adequate load-capacity. The calibrated finite-element model that reflects the as-built conditions can be used as a baseline for health monitoring and future maintenance of the SBSSAB.

An Axially Moving Thermoelastic Beam-plate: Spectral Element Modeling and Analysis (이동하는 열탄성 보-평판의 진동에 대한 스펙트럴요소 해석)

  • Kwon Kyung-Soo;Cho Joo-Yong;Lee U-Sik
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.344-349
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    • 2005
  • The axially moving thin beam-plates exposed to sudden thermal loadings may experience severe vibrations through the thermal shock process. For accurate prediction of the thermal shock-induced vibrations, this paper develops a spectral element model for axially moving thermoelastic beam-plates. The spectral element model which is represented by spectral element matrix is formulated from the frequency-dependent dynamic shape functions which satisfy the governing equations in the frequency-domain. Thus, when compared with the classical finite element model in which simple polynomial functions are used as the shape functions, the spectral element model can provide exact solution by treating a whole uniform structure member as a single finite element, regardless of its length.

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A Study on the Buckling Strength and Effective Length of Tubular Member with Gusset Plate Considering End Restraints (단부구속효과를 고려한 관통 가셋트 부착 강관부재의 좌굴내력 및 유효세장비 산정에 관한 연구)

  • Kim, Woo Bum
    • Journal of Korean Society of Steel Construction
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    • v.15 no.2
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    • pp.159-165
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    • 2003
  • A tubular member with through-gusset plate is often used to transmit axial compression in an electric transmission towers. In current code, the strength of tubular member is evaluated with an effective length factor k=0.9 without considering the deformation of boundary element. A buckling strength of member with end gusset plate is affected by stiffness ratio($\beta$) and the length ratio(G) between main tubular member and end gusset plate. In this study theoretical mechanism based on the elastic buckling behavior was investigated, and finite element analysis was performed to propose a formula for the buckling strength and effective length factor of tubular member in elsatic and inelastic ranges.

Splitting of reinforced concrete panels under concentrated loads

  • Foster, Stephen J.;Rogowsky, David M.
    • Structural Engineering and Mechanics
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    • v.5 no.6
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    • pp.803-815
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    • 1997
  • It is well understood that concentrated forces applied in the plane of a beam or panel (such as a wall or slab) lead to splitting forces developing within a disturbed region forming beyond the bearing zone. In a linearly elastic material the length of the disturbed region is approximately equal to the depth of the member. In concrete structures, however, the length of the disturbed region is a function of the orthotropic properties of the concrete-steel composite. In the detailing of steel reinforcement within the disturbed regions two limit states must be satisfied; strength and serviceability (in this case the serviceability requirement being acceptable crack widths). If the design requires large redistribution of stresses, the member may perform poorly at service and/or overload. In this paper the results of a plane stress finite element investigation of concentrated loads on reinforced concrete panels are presented. Two cases are examined (i) panels loaded concentrically, and (ii) panels loaded eccentrically. The numerical investigation suggests that the bursting force distribution is substantially different from that calculated using elastic design methods currently used in some codes of practice. The optimum solution for a uniformly reinforced bursting region was found to be with the reinforcement distributed from approximately 0.2 times the effective depth of the member ($0.2D_e$) to between $1.2D_e$ and $1.6D_e$. Strut and tie models based on the finite element analyses are proposed herein.

A Study on Nonlinear Behavior of RC Structure using Different Crack Models (균열모델을 사용한 철근콘크리트 구조물의 비선형거동 해석에 관한 연구)

  • Kim, Sung-Chil;Ahn, Young-Ki;Park, Sung-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.4
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    • pp.139-146
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    • 2002
  • A analysis of crack behavior in RC member was performed by nonlinear finite element method. Two crack models were used in F.E.M.(finite element method): one was FCM (the fixed crack model) and the other was RCM (the rotated crack model). Based on parametric study, the ratio of shear steel, strength of concrete, and a/d(shear span/effective depth) were compared with test results of references. According to the test results, when the member behavior was affected by the shear or diagonal tension, RCM was reasonable. However, when the behavior was affected by the flexibility, FCM was more appropriate. In addition, each crack model behavior for the change of shear steel ratio, the increase of strain energy was constant in FCM, but it was different in RCM because of diagonal crack distribution and crack width. Since the strength of concrete is affected not only by shear but also by flexural strength, each crack model behavior yields similar results.

Buckling Behaviors of Single-Layered Lattice Dome under Radial Uniform Loads (등분포 중심축 하중을 받는 단층래티스돔의 좌굴거동)

  • Kim, Choong-Man;Yu, Eun-Jong;Rha, Chang-Soon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.1
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    • pp.53-61
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    • 2015
  • This paper presented the nonlinear behaviors of the single-layered lattice dome, which is widely used for the long-span structure system. The behaviors were analysed through the classical shell buckling theory as the single-layered lattice dome behaves like continum thin shell due to its geometric characteristics, and finite element analysis method using the software program Nastran. Shell buckling theory provides two types of buckling loads, the global- and member buckling, and finite element analysis provides the ultimate load of geometric nonlinear analysis as well as the buckling load of Eigen value solution. Two types of models for the lattice dome were analysed, that is rigid- and pin-jointed structure. Buckling load using the shell buckling theory for each type of lattice dome, governed by the minimum value of global buckling or member buckling load, resulted better estimation than the buckling load with Eigen value analysis. And it is useful to predict the buckling pattern, that is global buckling or member buckling.