• Title/Summary/Keyword: Laminated Composite Structures

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Natural Frequency and Mode Characteristics of Composite Pole Structures for Different Layup Sequences (복합소재 기둥 구조의 적층배열 변화에 따른 고유진동 및 모드 특성)

  • Kim, Gyu-Dong;Rus, Guillermo;Lee, Sang-Youl
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.4 no.1
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    • pp.9-14
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    • 2013
  • The dynamic analysis of poles made of advanced composite materials is carried out for different length-thickness ratios and layup sequences. The numerical results using ABAQUS obtained for plates and shells are in good agreement with those reported by other investigators. The new results for laminated composite pole structures in this study mainly show the effect of the interactions between the radius-length ratio and other various parameters. The effect of fiber angles of long composite poles also investigated. Key observation points are discussed and a brief design guideline is given.

Nonlinear vibration analysis of laminated plates resting on nonlinear two-parameters elastic foundations

  • Akgoz, Bekir;Civalek, Omer
    • Steel and Composite Structures
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    • v.11 no.5
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    • pp.403-421
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    • 2011
  • In the present manuscript, geometrically nonlinear free vibration analysis of thin laminated plates resting on non-linear elastic foundations is investigated. Winkler-Pasternak type foundation model is used. Governing equations of motions are obtained using the von Karman type nonlinear theory. The method of discrete singular convolution is used to obtain the discretised equations of motion of plates. The effects of plate geometry, boundary conditions, material properties and foundation parameters on nonlinear vibration behavior of plates are presented.

Optimization of interlaminar strength with uncertainty of material properties (물성치의 불확실성을 고려한 층간강도의 최적화)

  • 조맹효;이승윤
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.70-73
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    • 2001
  • The layup optimization by genetic algorithm (GA) for the interlaminar strength of laminated composites with free edge is presented. For the calculation of interlaminar stresses of composite laminates with free edges, extended Kantorovich method is applied. In the formulation of GA, repair strategy is adopted for the satisfaction of given constraints. In order to consider the bounded uncertainty of material properties, convex modeling is used. Results of GA optimization with scattered properties are compared with those of optimization with nominal properties. The GA combined with convex modeling can work as a practical tool for maximum interlaminar strength design of laminated composite structures, since uncertainties are always encountered in composite materials and the optimal results can be changed.

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Vibration and Stability of Composite Cylindrical Shells Subjected to Electromagnetic and Thermal Fields (자기장 및 열하중을 받는 복합재료 원통셸의 진동 및 안정성해석)

  • Park, Sang-Yun;Kang, Sunghwan;Seo, Jung Seok;Song, Ohseop
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.9
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    • pp.797-805
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    • 2013
  • In this paper vibration and stability analysis of laminated composite shells based on the first order shear deformation theory(FSDT) for two different boundary conditions(clamped-clamped, simply supported) are performed. Structural model of cross-ply symmetric laminated composite cylindrical shells subjected to a combination of magnetic and thermal fields is developed via Hamilton's variational principle. These coupled equations of motion are based on the electromagnetic equations(Faraday, Ampere, Ohm, and Lorenz equations)and thermal equations which are involved in constitutive equations. Extended Galerkin method is adopted to obtain the discretized equations of motion. Variations of dynamic characteristics of composite shells with applied magnetic field, temperature gradient, laminate thickness-ratio and radius ratio for two boundary conditions are investigated and pertinent conclusions are derived.

The Effects of Different Cross Section on Natural Frequency of the Advanced Composite Materials Road Structures (복합신소재 도로구조물의 변환단면이 고유진동수에 미치는 영향)

  • Han, Bong Koo
    • International Journal of Highway Engineering
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    • v.15 no.3
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    • pp.23-29
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    • 2013
  • PURPOSES: This paper aims to give a guideline and the way to apply the advanced composite materials theory to the road structures with different cross sections to the practicing engineers. METHODS: To simple but exact method of calculating natural frequencies corresponding to the modes of vibration of road structures with different cross sections and arbitrary boundary conditions. The effect of the $D_{22}$ stiffness on the natural frequency is rigorously investigated. RESULTS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. CONCLUSIONS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. This method is a simple but exact method of calculating natural frequencies of the road structures with different cross sections. This method is extended to be applied to two dimensional problems including composite laminated road structures.

Buckling behavior of functionally graded porous plates integrated with laminated composite faces sheets

  • Xu, Kuo;Yuan, Yuan;Li, Mingyang
    • Steel and Composite Structures
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    • v.32 no.5
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    • pp.633-642
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    • 2019
  • In this work, lightweight sandwich plates consisting of a functionally graded porous (FGP) core and two laminated composite face sheets resting on elastic foundation have been proposed. Three different profiles are considered for the distributions of porosities along core thickness. The main aim of this paper is the investigation of the buckling behavior of the proposed porous sandwich plates (PSPs) by reporting their critical mechanical loads and their corresponding mode shapes. A finite element method (FEM) based on first order shear deformation theories (FSDT) is developed to discretize governing equations for the buckling behavior of the proposed sandwich plates. The effects of porosity dispersion and volume, the numbers and angles of laminated layers, sandwich plate geometrical dimensions, elastic foundation coefficients, loading and boundary conditions are studied. The results show that the use of FGP core can offer a PSP with half weight core and only 5% reduction in critical buckling loads. Moreover, stacking sequences with only ${\pm}45$ orientation fibers offer the highest values of buckling loads.

Effect of visco-Pasternak foundation on thermo-mechanical bending response of anisotropic thick laminated composite plates

  • Fatima Bounouara;Mohamed Sadoun;Mahmoud Mohamed Selim Saleh;Abdelbaki Chikh;Abdelmoumen Anis Bousahla;Abdelhakim Kaci;Fouad Bourada;Abdeldjebbar Tounsi;Abdelouahed Tounsi
    • Steel and Composite Structures
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    • v.47 no.6
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    • pp.693-707
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    • 2023
  • This article investigates the static thermo-mechanical response of anisotropic thick laminated composite plates on Visco-Pasternak foundations under various thermal load conditions (linear, non-linear, and uniform) along the transverse direction (thickness) of the plate, while keeping the mechanical load constant. The governing equations, which represent the thermo-mechanical behavior of the composite plate, are derived from the principle of virtual displacements. Using Navier's type solution, these equations are solved for the composite plate with simply supported condition. The Visco-Pasternak foundation type is included by considering the impact of the damping on the classical foundation model, which is modeled by Winkler's linear modulus and Pasternak's shear modulus. The excellent accuracy of the present solution is confirmed by comparing the results with those available in the literature. The study investigates the impact of geometric ratios, thermal expansion coefficient ratio, damping coefficient and foundation parameters on the thermo-mechanical flexural response of the composite plate. Overall, this article provides insights into the behavior of composite plates on visco-Pasternak foundations and may be useful for designing and analyzing composite structures in practical applications.

Deflection Analysis of Laminated Composite Cylindrical Shell Structures Based on Micro-Mechanics (마이크로 역학기반 GFRP 원통형 적층 쉘 구조의 변위 해석)

  • Kim, Gyu-Dong;Lee, Sang-Youl
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.4 no.4
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    • pp.15-21
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    • 2013
  • This study carried out finite element deflection analysis of cylindrical shell structures made of composite materials, which is based on the micro-mechanical approach for different fiber-volume fractions. The finite element (FE) models for composite structures using multi-scale approaches described in this paper is attractive not only because it shows excellent accuracy in analysis but also it shows the effect of the material combination. New results reported in this paper are focused on the significant effects of the fiber-volume fraction for various parameters, such as fiber angles, layup sequences, and length-thickness ratios. It may be concluded from this study that the combination effect of fiber and matrix, largely governing the dynamic characteristics of composite shell structures, should not be neglected and thus the optimal combination could be used to design such civil structures for better dynamic performance.

Free Vibration Analysis based on HSDT of Laminated Composite Plate Structures Using Multi-scale Approach (멀티 스케일 접근 방법에 의한 복합소재 적층 판구조의 HSDT 기반 고유진동 해석)

  • Lee, Sang-Youl
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.61-71
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    • 2014
  • This study carried out finite element vibration analysis of composite plate structures for construction using multi-scale approaches, which is based on the higher-order theory. The finite element (FE) models for composite structures using multi-scale approaches described in this paper is attractive not only because it shows excellent accuracy in analysis but also it shows the effect of the material combination. The FE model is used for studying free vibrations of laminated composite plates for various fiber-volume fractions. In particular, new results reported in this paper are focused on the significant effects of the fiber-volume fraction for various parameters, such as fiber angles, layup sequences, and length-thickness ratios. It may be concluded from this study that the combination effect of fiber and matrix, largely governing the dynamic characteristics of composite structures, should not be neglected and thus the optimal combination could be used to design such civil structures for better dynamic performance.

Morphing of Composite Beam actuated by SMA Actuator (형상기억합금 작동기로 작동되는 복합재 보의 형상변형)

  • Kim Sanghaun;Cho Maenghyo
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.04a
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    • pp.123-126
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    • 2004
  • Two-way shape memory effect(TWSME) under residual stresses are considered in the present study. The structure using two-way shape memory effect concept returns to its initial shape by increasing or decreasing temperature under the initially given residual stress. In the present study, we use a thermo-mechanical constitutive equation of SMA and laminated composite beam are considered as simple morphing structural components which are based on large deformable 2D composite beam theory. Numerical results of fully coupled SMA-composite structures are presented.

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