• Title/Summary/Keyword: 1차전단변형판이론

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A Study on Mechanical Characteristics of Laminated Plates by FEM (유한요소법에 의한 적층판의 역학 특성에 관한 연구)

  • Park, Sung-Jin;Yang, Su-Jeong
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2015.11a
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    • pp.150-151
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    • 2015
  • 본 연구에서는 충격 문제를 거론하며 Mindlin 판 이론을 확장한 1차 전단 변형 이론에 근거하여 충격 하중을 받는 임의의 형상 라미네이트 응답 특성의 해명을 목적으로 아이소파라메트릭요소에 의한 정식화를 시도한다.

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Bending and Dynamic Characteristics of Antisymmetric Laminated Composite Plates considering a Simplified Higher-Order Shear Deformation (역대칭 복합적층판의 단순화된 고차전단변형을 고려한 휨과 동적 특성)

  • Han, Seong Cheon;Yoon, Seok Ho;Chang, Suk Yoon
    • Journal of Korean Society of Steel Construction
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    • v.9 no.4 s.33
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    • pp.601-609
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    • 1997
  • Bending and vibration results for a laminated plate base on a simplified higher-order plate theory with four variables are presented. Assuming a constant in-plane rotation tensor through the thickness in Reddy's higher-order shear deformation theory it is shown that a simpler higher-order theory can be obtained with the reduction of one variable without significant loss in the accuracy. This simple higher-order shear deformation theory is then used for predicting the natural frequencies and deflection of simply-supported laminated composite plates. The results obtained for antisymmetrical laminated composite plates compare favorably with third-order and first-order shear deformation theory. The information presented should be useful to composite-structure designers, to researchers seeking to obtain better correlation between theory and experiment and to numerical analysts in checking out their programs.

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Impact Analysis of Laminated Composite Plate Using Higher-Order Shear Deformation Theory (고차 전단 변형 이론에 의한 적층 복합판의 충격 해석)

  • 김문생;김남식;이현철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.3
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    • pp.735-750
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    • 1991
  • 본 연구에서는 적층 복합판의 충격 해석을 위하여 Reddy의 고차 전단 변형 이 론에 기초를 두고, 정적 압입 실험에 의한 접촉 법칙을 고려한 동적 유한 요소 해석 (dynamic finite element analysis)을 행하여 충격 실험에 의한 결과와 1차 전단변형 이론에 의한 해와 비교 검토하므로서, 그 유용성과 우수성을 입증하고, 적층 복합재의 충격 응력 및 응력파 전파 특성에 대하여 연구하고자 한다.

Nonlinear Random Vibration of Laminated Composite Plates by Comparison of Classical Theory, 1st and 3rd Order Shear Theories (복합적층판의 비선형 불규칙 진동 해석에 관한 고전 이론, 1차 및 3차 전단 이론의 비교 연구)

  • Kang, Joowon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.1
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    • pp.129-138
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    • 2000
  • Composites are finding increasing use in a wide variety of engineering applications due to their outstanding mechanical properties. A number of studies have focused on the development of new materials as well as the response of composite structures to static and dynamic loads by assuming the external driving forces to be deterministic. However, there ate many situations in practice where the exciting forces vary randomly. In this work, the nonlinear response of laminated composite plates excited by stochastic loading is studied by the finite element method. Classical, first-order and third-order shear theories for plates are used in the finite element formulation. Since most composites exhibit significant nonlinearity in the shear stress-strain law, this is included in the present analysis.

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Dynamic Characteristics of Anisotropic Laminated Plates (이방성 복합재료의 동적특성에 관한 연구)

  • Park, Sungjin;Baek, Jooeun
    • Journal of the Society of Disaster Information
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    • v.12 no.1
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    • pp.62-68
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    • 2016
  • In this study, the impact problems are brought up and the formulation by isoparametric element is attempted for the purpose of analyzing the response characteristics of laminated plate receiving impact load based on the first-order shear deformation theory expanded from the Mindlin plate theory. The result of static analysis and dynamic analysis is drawn through the numerical analysis rectangular and circular plates of antisymmetric Angle-Ply laminated plate using the finite element method and the analysis on each displacement is compared.

Bending, Free Vibration and Buckling Analysis of Anisotropic Composite Laminated Plate and Shell Structures (비등방성 복합적층판 및 쉘 구조의 휨, 자유진동 및 좌굴해석)

  • Yoon, Seok Ho
    • Journal of Korean Society of Steel Construction
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    • v.11 no.1 s.38
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    • pp.55-67
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    • 1999
  • The ratios of elastic to shear modulus of the structures as laminated composite plates and shells, are very large. They are much susceptible to effect of shear deformation. In order to obtain the accurate solutions of laminated composite plate and shells, the effects of shear strain should be considered for the analysis and design of them. Especially, the more exact solution can be obtained in applying to higher-order shear deformation theory. Therefore, in this paper, the third-order shear deformation theory is used to present the distributions of bending, the characteristics of natural frequencies and the buckling load according to the effects of ply orientation, number of layers for the laminated composite plates and shells with simply supported boundary conditions.

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Static, Buckling and Free Vibration Analyses of Fibrous Composite Plate using Improved 8-Node Strain-Assumed Finite Formulation by Direct Modification (직접수정된 8절점 가정변형률 유한요소를 이용한 복합적층판의 정적, 좌굴 및 자유진동 해석)

  • Park, Won-Tae;Chun, Kyoung-Sik;Yhim, Sung-Soon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.107-114
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    • 2004
  • In this paper, a simple improved 8-node finite element for the finite element analysis of fibrous composite plates is presented by using the direct modification. We drive explicit expressions of shape functions for the 8-node element with bilinear element geometry, which is modified so that it can represent any quadratic fields in Cartesian coordinates. The refined first-order shear deformation theory is proposed, which results in parabolic through-thickness distribution of the transverse shear strains and stresses from the formulation based on the third-order shear deformation theory. It eliminates the need for shear correction factors in the first-order theory. This finite element is further improved by combined use of assumed strain, modified shape function, and refined first-order theory. To show the effectiveness of our simple modification on the 8-node finite elements, numerical studies are carried out the static, buckling and free vibration analysis of fibrous composite plates.

Vibration Analysis of Stiffened Corrugated Composite Plates (보강된 적층 복합재료 주름판의 진동해석)

  • Park, Kyung-Jo;Kim, Young-Wann
    • Composites Research
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    • v.33 no.6
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    • pp.377-382
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    • 2020
  • The free vibration characteristics of corrugated laminated composite plates with axial stiffeners is investigated using the Rayleigh-Ritz method. The plate is stiffened by beams with open cross-section area. The equivalent homogenization model is used for the corrugated laminated composite plates. This homogenization model is treated a corrugated plate as an orthotropic plate that has different material properties in two perpendicular directions. The motion of equivalent plate is represented on the basis of the first order shear deformation theory (FSDT) to account for the effect of rotary inertia and transverse shear deformation. Stiffeners are considered as discrete elements to predict the local vibration mode to be generated by the presence of stiffeners. To validate the proposed analytical approach, natural frequencies and vibration mode shapes from the analytical method are compared with those from the FEA by ANSYS.

Critical Buckling Temperatures of Anisotropic Laminated Composite Plates considering a Higher-order Shear Deformation (고차전단변형을 고려한 비등방성 적층복합판의 임계좌굴온도)

  • Han, Seong Cheon;Yoon, Seok Ho;Chang, Suk Yoon
    • Journal of Korean Society of Steel Construction
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    • v.10 no.2 s.35
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    • pp.201-209
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    • 1998
  • The presence of elevated temperature can alter significantly the structural response of fibre-reinforced laminated composites. A thermal environment causes degradation in both strength and constitutive properties, particularly in the case of fibre-reinforced polymeric composites. Furthermore, associated thermal expansion, either alone or in combination with mechanically induced deformation, can result in buckling, large deflections, and excessively high stress levels. Consequently, it is often imperative to consider environmental effects in the analysis and design of laminated systems. Exact analytical solutions of higher-order shear deformation theory is developed to study the thermal buckling of cross-ply and antisymmetric angle-ply rectangular plates. The buckling behavior of moderately thick cross-ply and antisymmetric angle-ply laminates that are simply supported and subject to a uniform temperature rise is analyzed. Numerical results are presented for fiber-reinforced laminates and show the effects of ply orientation, number of layers, plate thickness, and aspects ratio on the critical buckling temperature and compared with those obtained using the classical and first-order shear deformation theory.

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Simplified Analytical Model for Flexural Response of Fiber Reinforced Plastic Decks (FRP 바닥판의 휨 해석모델 개발)

  • Kim, Young-Bin;Lee, Jae-Hong
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.3 s.17
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    • pp.65-74
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    • 2005
  • An analytical model was developed to investigate the flexural behavior of a pultruded fiber-reinforced plastic deck of rectangular unit module. The model is based on first-order shea. deformable plate theory (FSDT), and capable of predicting deflection of the deck of arbitrary laminate stacking sequences. To formulate tile problem, two-dimensional plate finite element method is employed. Numerical results are obtained for FRP decks under uniformly-distributed loading, addressing the effects of fiber angle and span-to-height ratio. It is found that the present analytical model is accurate and efficient for solving flexural behavior of FRP decks. Also, as the height of FRP deck plate is higher, the necessity of higher order Shear deformable plate theory(HSDT) is announced, not the FSDT in the plate analysis theory.

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