• 대한기계학회논문집
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• 제17권7호
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• pp.1761-1771
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• 1993

In this paper, the design of thick laminated composite plate subjected to thermal buckling load under uniform temperature distribution is presented. In the design procedures of composite laminated plates for maximum thermal buckling load. the finite element method based on shear deformed theory is used for the analysis or laminated plates. One-demensional search method is used to find optimal fiber orientation and, in the next step, optimal thickness is investigated. Design variables such as fiber orientation and ply thicknesses coefficient of plates are adopted. The optimal design for the symmetric or antisymmetric laminated plates consisted of 4 layers with maximum thermal buckling load is performed.

• Journal of Welding and Joining
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• 제10권4호
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• pp.250-258
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• 1992

In order to clarify the mechanical behavior of welding crack and to evaluate the mechanical characteristics of welded parts in thick plate, it is very important to accurately predict the welding deformation and residual stress including transient state before welding. In this paper, the theory of a three-dimensional elasto-plastic problem for the analysis of mechanical phenomenon of welding joint on the plate is developed into an efficient and accurate method based on the finite element method, and then several examples are considered by using the proposed model. The results of numerical analyses are discussed in the viewpoint of the mechanical characteristics of the distribution of three-dimensional welding residual stresses, plastic strains and their production mechanism on the thick plate.

• Structural Engineering and Mechanics
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• 제14권5호
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• pp.575-593
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• 2002

Based on the Mindlin plate theory, a refined discrete 15-DOF triangular laminated composite plate finite element RDTMLC with the re-constitution of the shear strain is proposed. For constituting the element displacement function, the exact displacement function of the Timoshenko's laminated composite beam as the displacement on the element boundary is used to derive the element displacements. The proposed element can be used for the analysis of both moderately thick and thin laminated composite plate, and the convergence for the very thin situation can be ensured theoretically. Numerical examples presented show that the present model indeed possesses the properties of higher accuracy for anisotropic laminated composite plates and is free of locking even for extremely thin laminated plates.

• Architectural research
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• 제16권3호
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• pp.121-129
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• 2014

A plate element is developed by using isogeometric approach in order to determine natural frequencies of laminated composite plates. Reissner-Mindlin (RM) assumptions is adopted to consider the shear deformation and rotatory inertia effect. All terms required in isogeometric element formulation are consistently derived by using Non-uniform rational B-spline surface (NURBS) definition. Gauss quadrature rule is used to form the element stiffness matrix and separately Lobatto quadrature rule is used to calculate element mass matrix. The capability of the present plate element is demonstrated by using numerical examples. From numerical tests, the present isogeometric element produces reliable numerical results for both thin and thick plate situations.

• Advances in Computational Design
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• 제3권2호
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• pp.113-132
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• 2018

This paper presents the vibration and harmonic analysis of orthotropic laminated composite plate. The response of plate is determined using Finite Element Method. The eight noded shell 281 elements are used to analyze the orthotropic plates and results are obtained so that the right choice can be made in applications such as aircrafts, rockets, missiles, etc. to reduce the vibration amplitudes. Initially the model response for orthotropic plate and harmonic response for isotropic plate is verified with the available literature. The results are in good agreement with the available literature. Numerical results for the natural frequency and harmonic response amplitude are presented. Effects of boundary conditions, thickness to width ratio and number of layers on natural frequency and harmonic response of the orthographic plates are also investigated. The natural frequency, mode shape and harmonic analysis of laminated composite plate has been determined using finite element package ANSYS.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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• pp.25-32
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• 2004

In this proposed work new finite element model for multi-delaminated plates is proposed. In the current analysis procedures of multi-delaminated plates, plate element based on Mindlin plate theory is used in order to obtain accurate results of out-of-plane displacement of thick plate. And for delaminated region, plate element based on Kirchhoff plate theory is considered. To satisfy the displacement continuity conditions, displacement vector based on Kirchhoff theory is transformed to displacement of transition element. The numerical results show that the effect of delaminations on the modal parameters of delaminated composites plates is dependent not only on the size, the location and the number of the delaminations but also on the mode number and boundary conditions. Kirchhoff based model have higher natural frequency than Mindlin based model and natural frequency of the presented model is closed to Mindlin based model.

• Coupled systems mechanics
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• 제1권2호
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• pp.115-131
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• 2012

Paper presents an improved solution algorithm based on Finite Element Method to analyse piled raft foundation. Piles are modelled as beam elements with soil springs. Finite element analysis of raft is based on the classical theory of thick plates resting on Winkler foundation that accounts for the transverse shear deformation of the plate. Four node, isoparametric rectangular elements with three degrees of freedom per node are considered in the development of finite element formulation. Independent bilinear shape functions are assumed for displacement and rotational degrees of freedom. Effect of raft thickness, soil modulus and load pattern on the response is considered. Significant improvement in the settlements and moments in the raft is observed.

• 한국철도학회논문집
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• 제15권6호
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• pp.588-596
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• 2012

이 논문은 두꺼운 디스크의 면외 고유 진동을 유한 요소법을 사용하여 회전 관성 및 횡 전단 변형의 효과를 포함하면서 단순하고 효율적으로 정밀하게 해석할 수 있는 새로운 준-해석적 환상 민드린 평판 요소를 제시한다. 환상 민드린 평판의 평형 방정식의 정확한 해인 정적 변형 모드를 사용하여 요소의 보간 함수, 강성 및 질량 행렬은 절 직경 수에 대하여 유도되며, 이와 같은 요소는 면외 강체 운동을 정확하게 표현할 수 있고 전단 잠김이 없다. 제시된 요소를 적용하여 동심 링으로 지지되거나 지지되지 않은 균일 디스크 및 다단 디스크의 고유진동수를 해석하고, 그 결과를 선행 연구의 이론적 결과 또는 2차원 쉘 요소를 사용하여 얻어진 유한요소 해석 결과와 비교하여 제시된 요소의 수렴성 및 정확성을 조사하였다.

• Structural Engineering and Mechanics
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• 제41권2호
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• pp.205-229
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• 2012

This paper presents a new nine-node Lagrangian quadrilateral plate bending element (MQP9) using the Integrated Force Method (IFM) for the analysis of thin and moderately thick plate bending problems. Three degrees of freedom: transverse displacement w and two rotations ${\theta}_x$ and ${\theta}_y$ are considered at each node of the element. The Mindlin-Reissner theory has been employed in the formulation which accounts the effect of shear deformation. Many standard plate bending benchmark problems have been analyzed using the new element MQP9 for various grid sizes via Integrated Force Method to estimate defections and bending moments. These results of the new element MQP9 are compared with those of similar displacement-based plate bending elements available in the literature. The results are also compared with exact solutions. It is observed that the presented new element MQP9 is free from shear locking and produced, in general, excellent results in all plate bending benchmark problems considered.

• 대한토목학회논문집
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• 제7권1호
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• pp.65-73
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• 1987

본(本) 연구(硏究)에서는 면내(面內) 고차(高次) 수평변위(水平變位)를 고려(考慮)한 6절점(節點) 21자유도(自由度)를 갖는 판(板) 유한요소(有限要素)를 Galerkin 가중잔차법(加重殘差法)으로 3차원(次元) 연속체(連續體)로부터 유도(誘導)하고 있다. 요소(要素)의 강성행렬(剛性行列)과 질량행렬(質量行列)은 판의(板) 운동방정식(運動方程式)을 이산화(離散化)(discretization)하여 ($3{\times}3$) Gauss 적분점(積分點)을 이용(利用)한 감차(減次) 적분(積分)을 수행(遂行)하여 구하였다. 본(本) 고차(高次) 판(板) 유한요소(有限要素)의 정확도(正確度)와 효율성(効率性)을 고찰(考察)하기 위하여 여러가지 경계조건(境界條件)을 갖는 정사각형(正四角形) 판(板)의 처짐해석(解析)을 수행(遂行)한 결과(結果), 판(板)의 두께에 관계없이 월등(越等)한 정확도(正確度)를 나타내었다.