• Journal of Industrial Technology
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• v.19
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• pp.235-243
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• 1999

Vibration analysis for some of simple supported antisymmetric composite laminated plate loaded uniformly distributed axial force and attached mass was carried out. Because it is complicated to analysis this type of plate by theory of antisymmetric laminate, possibility for application of theory of special orthotropic laminate was studied, and natural frequency of laminated plate attached mass was calculated. Stiffness $B_{16}$, $B_{26}$, $D_{16}$, $D_{26}$ for this type of antisymmetric laminated plate converge on zero as the number of ply increases and it is possible to use classical theory by reason that considered plate has quasi-homogeneity without relevance to variation of angle. Difference between results by theory of antisymmetric and special orthotropic laminate is 0.36~1.96%, therefore it is convenient to analyze this by use of theory of special orthotropic laminate. When composite laminated plate with attached mass is analyzed range that was able to neglect self-weight of plate was proposed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.181-190
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• 2000

Vibration analysis for some of simple supported antisymmetric composite laminated plate loaded uniform axial-loading and attached mass was carried out. Because it is complicated to analyze this type of plate by theory of antisymmetric laminate possibility for application of theory of special orthotropic laminate was studied, and natural frequency of laminated plate attached mass was calculated. Stiffness $B_{16}$, $B_{26}$, $D_{16}$, $D_{26}$ for this type of antisymmetric laminated plate converge on zero as the number of ply increases and it is possible to use classical theory by reason that considered plate has quasi-homogeneity without relevance to variation of angle. Difference between results by theory of antisymmetric and special orthotropic laminate is 0.36~1.96%, therefore it is convenient to analyze this by use of theory of special orthotropic laminate. When composite laminated plate with attached mass is analyzed range that Was able to neglect self-weight of plate was proposed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.69-73
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• 1999

This study discusses a non-contact optical technique, electronic speckle pattern interferometry(ESPI), that is well suited for in-plane and out-of-plane deformation measurement. AS4/PEEK[30/-30/90]s, composite laminate plate was analyzed by ESPI to determine the vibration characteristics with tensile loading and without it. vibration mode shapes are quantitatively compared with the result of numerical analysis. The experimental results agree well with those of numerical analysis. we found that when the composite laminate plate is under the tensile loading, vibration modes can be measured with high accuracy by ESPI.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.170-176
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• 2006

Multi-layered laminate made of ceramic/composite have been developed to prevent penetration by high velocity impact. In this study, three-layered plates consisted of 1) cover layer (glass fiber reinforced polymer), 2) $Al_{2}O_{3}$, ceramic plate, and 3) backing plate (glass fiber reinforced polymer) were fabricated with various conditions and tested for their ballistic protection characteristic. The ceramic composite laminates, with thin backing plate, were completely penetrated by armor piercing projectile. The plate with inserted rubber between ceramic and backing plate showed excellent ballistic protection, though completely penetrated by the second shoot.

• Composites Research
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• v.20 no.5
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• pp.1-6
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• 2007

This study was performed to make a comparison on low-velocity impact behavior between graphite/epoxy composite laminate and steel plate. In order to validate the proposed scheme fur the impact behavior of the plate, the Karas's impact model was used. The impact models for this comparative study are the graphite/epoxy composite plate having $[0/90/45/-45/-45/45/90/0]_{8S}$ laminate sequence and the steel plate with a steel ball impactor. The low-velocity impact behaviors for two types of plates were comparatively investigated and performed by considering different impactor velocities and weights respectively. In this investigation, it was found that the composite laminate has impact energy absorption effect due to more flexible behavior than the steel plate, and also it has better characteristics on impact damage and weight.

• Smart Structures and Systems
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• v.5 no.5
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• pp.531-546
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• 2009

In the present analysis, the spline finite strip with higher-order shear deformation is formulated for the static analysis of piezoelectric composite plates. The proposed method incorporates Reddy's third-order shear deformation theory, Touratier's "Sine" model, Afaq's exponential model, Cho's higher-order zigzag laminate theory, as well as the classic plate theory and the first-order plate theory. Thus, the analysis can be conducted based on any of the above-mentioned theories. The selection of a specific method is done by simply changing a few terms in a 2 by 2 square matrix and the results, obtained according to different plate theories, can be compared to each other. Numerical examples are presented for piezoelectric composite plates subjected to mechanical loading. The results based on different shear deformation theories are compared with the three-dimensional solutions. The behaviours of piezoelectric composite plates with different length-to-thickness ratios, fibre orientations, and boundary conditions are also investigated in these examples.

• Smart Structures and Systems
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• v.15 no.5
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• pp.1177-1202
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• 2015

The present paper is concerned with the optimal control and/or design of symmetric and antisymmetric composite laminate with two piezoelectric layers bonded to the opposite surfaces of the laminate, and placed symmetrically with respect to the middle plane. For the optimal control problem, Liapunov-Bellman theory is used to minimize the dynamic response of the laminate. The dynamic response of the laminate comprises a weight sum of the control objective (the total vibrational energy) and a penalty functional including the control force. Simultaneously with the active control, thicknesses and the orientation angles of layers are taken as design variables to achieve optimum design. The formulation is based on various plate theories for various boundary conditions. Explicit solutions for the control function and controlled deflections are obtained in forms of double series. Numerical results are given to demonstrate the effectiveness of the proposed control and design mechanism, and to investigate the effects of various laminate parameters on the control and design process.

• Structural Engineering and Mechanics
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• v.73 no.6
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• pp.631-640
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• 2020

Using backup plate is one of the most commonly used methods to decrease drilling-induced delamination of composite laminates. It has been shown that, the size of the delamination zone is related to the vertical element of cutting force named as thrust force. Also, direct control of thrust force is not a routine task, because, it depends on both drilling parameters and mechanical properties of the composite laminate. In this research, critical feed rate and thrust force are predicted analytically for delamination initiation in drilling of composite laminates with backup plate. Three common theories, linear elastic fracture mechanics, classical laminated plate and mechanics of oblique cutting, are used to model the problem. Based on the proposed analytical model, the effect of drill radius, chisel edge size, and backup plate size on the critical thrust force and feed rate are investigated. Experimental tests were carried out to prove analytical model.

• Steel and Composite Structures
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• v.3 no.3
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• pp.213-229
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• 2003

A high precision shear deformable triangular element has been proposed for free vibration analysis of composite trapezoidal plates. The element has twelve nodes at the three sides and four nodes inside the element. Initially the element has fifty-five degrees of freedom, which has been reduced to forty-eight by eliminating the degrees of freedom of the internal nodes through static condensation. Plates having different side ratios (b/a), boundary conditions, thickness ratios (h/a=0.01, 0.1 and 0.2), number of layers and fibre angle orientations have been analyzed by the proposed shear locking free element. Trapezoidal laminate with concentrated mass at the centre has also been analyzed. An efficient mass lumping scheme has been recommended, where the effect of rotary inertia has been included. For validation of the present element and formulation few results of isotropic trapezoidal plate and square composite laminate have been compared with those obtained from open literatures. The numerical results for composite trapezoidal laminate have been given as new results.

• Journal of Korean Society of Steel Construction
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• v.13 no.1
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• pp.41-52
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• 2001

In this paper the analysis of laminate composite folded plates with arbitrary angle connection like box girder is studied by finite strip method Total stiffness of laminated plate is obtained by integration of the stiffness in each layer or lamina through laminate thickness and total stiffness in each layer or lamina through laminate thickness and total tiffness matrix is obtained by substitutionto equilibrium equation derived from the minimum total potential energy theorem. The assumed displacement functions for a finite strip method in plate or box girder analysis are combinations of one-way polynomial functions in the transverse direction and harmonic functions in the span-wise direction. Finite strip method with the merits of the simplification in modeling and the reduction of analytical time is accurate in the analysis of laminate composite folded plates shaped like box firders.