• Advances in Automotive Engineering
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• 제1권1호
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• pp.41-59
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• 2018

In the study, investigation of fiber- reinforced composite materials that can be an alternative to conventional steel was performed by finite element analysis with the help of software. Steel and composite materials have been studied on a four axle truck chassis model. Three-dimensional finite element model was created with software, and then analyzes were performed. The analyses were performed for static and dynamic/fatigue cases. Fatigue cases are formed with the help of design spectra model and fatigue analyses were performed as static analyses with this design spectra. First, analyses were performed for steel and after that optimization analyses were made for the AS4-PEEK carbon fiber composite and Eglass-Epoxy fiber composite materials. Optimization of composite material analyzes include determining the total laminate thickness, thickness of each ply, orientation of each ply and ply stacking sequence. Analyzes were made according to macro mechanical properties of composite, micromechanics case has not been considered. Improvements in weight reduction up to %50 provided at the end of the composite optimization analyzes with satisfying stiffness performance of chassis. Fatigue strength of the composite structure depends on various factors such as, fiber orientation, ply thickness, ply stack sequence, fiber ductility, ductility of the matrix, loading angle. Therefore, the accuracy of theoretical calculations and analyzes should be correlated by testing.

• Structural Engineering and Mechanics
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• 제70권5호
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• pp.535-549
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• 2019

This study aimed to develop a high-order shear deformation theory to predict the free vibration of hybrid cross-ply laminated plates under different boundary conditions. The equations of motion for laminated hybrid rectangular plates are derived and obtained by using Hamilton's principle. The closed-form solutions of anti-symmetric cross-ply and angle-ply laminates are obtained by using Navier's solution. To assess the validity of our method, we used the finite element method. Firstly, the analytical and the numerical implementations were validated for an antisymmetric cross-ply square laminated with available results in the literature. Then, the effects of side-to-thickness ratio, aspect ratio, lamination schemes, and material properties on the fundamental frequencies for different combinations of boundary conditions of hybrid composite plates are investigated. The comparison of the analytical solutions with the corresponding finite element simulations shows the good accuracy of the proposed analytical closed form solution in predicting the fundamental frequencies of hybrid cross-ply laminated plates under different boundary conditions.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.361-368
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• 2001

This paper deals with the buckling load of antisymmetric angle-ply and cross-ply laminated rectangular plates. Buckling analysis is preformed for a simply supported, shear deformable laminated plate subjected to uniaxial compression and biaxial compression combined with uniform lateral pression. The shear deformation theory is considered to figure out a more exact behavior of laminated plates exactly. The purposes of this study are to formulate anisotropic laminated plates with shear deformation and to investigate the buckling load according to the various variables of laminated plates by using the exact solutions for anisotropic laminated plates having simply supported boundary.

• 항공우주시스템공학회지
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• 제1권4호
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• pp.28-36
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• 2007

This paper presents critical buckling loads of laminated composites under cylindrical bending. In-plane displacements are assumed to vary exponentially through plate thickness. The accuracy of this theory is examined for symmetric/antisymmetric cross-ply, angle-ply and unsymmetric laminates under cylindrical bending. Analytical solutions are provided to investigate the effect of transverse shear deformation on critical buckling loads of the laminated plates, and the results are compared with those obtained from the first-order shear deformation plate theory and the classical laminated plate theory.

• 한국강구조학회 논문집
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• 제9권1호통권30호
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• pp.65-79
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• 1997

Composite materials are consist of two or more different materials to produce desirable properties for structural strength. Because of their superiority in strength, corrosion resistance, and weight reduction, they are used extensively as structural members. The objective of this study is to present the effectivness of the laminated composite elements by analyzing in-plane displacement and stress of the anisotropic laminated annular elements. Anisotropic laminated structures are very difficult to analyze and apply, compared with isotropic and orthotropic cases for arbitrary boundaries and fiber angle -ply. Boundary conditions for the examples used in this study consist of two opposite edges clamped and the other two edges free, and finite difference method is used in this study for numerical analysis. From the numerical result, it is found that the program used in this study can be used to obtain the displacement of the straight beams considering it's transverse shear deformation as well as anisotropic laminated elements. Several numerical examples show the advantages of the stiffness increase when the angle-ply composite materials are used. Therefore it gives a guide in deciding how to make use of fiber's angle for the subtended angle, load cases, and boundary conditions.

• Journal of Mechanical Science and Technology
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• 제17권1호
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• pp.48-56
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• 2003

This paper investigates the collapse characteristics of CF/Epoxy composite tubes subjected to axial loads as changing interlaminar number and outer ply orientation angle. The tubes are aften used for automobiles, aerospace vehicles, trains, ships, and elevators. We have performed static and dynamic impact collapse tests by a way of building impact test machine with vertical air compression. It is fanad that CF/Epoxy tube of the 6 interlaminar number (C-type) with 90$^{\circ}$ outer orientation angle and trigger absorbed more energy than the other tubes (A. B and D-types). Also collapse mode depended upon outer orientation angle of CF/Epoxy tubes and loading type as well； typical collapse modes of CF/Epoxy tubes are wedged, splayed and fragmentcl.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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• pp.349-355
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• 2004

The material such as steel or concrete has used to civil structures such as drainage pipes , but many problems such as corrosion in using steel and concrete pipes have happened. So, Necessity of developing new materials with high strength and anti-corrosion has been topic recently. One of this topics is study about ERP pipe. The strength of orthotropic FRP tends to be higher than it of isotropic FRP, the buckling problems can be significant in materials with high strength. thus, the study about bucking of orthotropic FRP-pipe is needed. In this study, buckling analysis of laminated cylindrical composite structures subjected In ply angle change under external uniform pressure was performed.

• 한국재난정보학회 논문집
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• 제12권1호
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• pp.62-68
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• 2016

본 연구에서는 충격 문제를 거론하며 Mindlin 판 이론을 확장한 1차 전단 변형 이론에 근거하여 충격 하중을 받는 적층판의 응답 특성의 해석을 목적으로 아이소파라메트릭요소에 의한 정식화를 시도한다. 유한요소법을 이용하여 역대칭 Angle-Ply 적층판의 사각판과 원형판의 수치해석을 통해 정적해석과 동적해석의 결과를 도출하여 각 변위에 대한 분석결과를 비교한다.

• 한국생산제조학회지
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• 제7권4호
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• pp.89-95
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• 1998

This paper focuses on the effect of structural coupling in the behavior of composite rotor blade. We have searched for bending, extension and shear coupling term with the ply angle of rotor blade and the dynamic behavior of rotor blade for each coupling term. It was found that natural frequency increases as the rotating speed of rotor blade increases. In the couplings with feathering, bending coupling is main parameter, because bending coupling term is larger than shear . Also, the couplings with feathering is less effective in 0$^{\circ}$, 90$^{\circ}$, of ply angle and more variable at blade tip.

• 대한기계학회논문집
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• 제12권4호
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• pp.670-674
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• 1988

본 연구에서는 저자들에 의해 제시된 직교이방성 적층 원통셸의 진동해법을 이용하여, 국내외적으로 많은 분야에서 이용되고 있는 CFRP 적층 원통셸에 대한 진동 해석을 수행하였다. 본 연구에서는 원통셸의 경계조건, 기하학적 매개변수 및 적층 방법에 따른 CFRP원통셸의 진동특성을 고찰하였다.