• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.691-700
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• 2000

A powerful analytical procedure and strain energy analysis to investigate the free vibration of antisymmetric angle-ply laminated plates, having one pair of opposite edges simply supported, are develped on the basis of the Yang, Norris and Stavsky (YSN) theory. The equation of motion of the plate are solved by the use of collocation method. A range of results are presented for plates to show the effects of modulus ratio and number of layers on natural frequency. In addition, an analysis of the strain energy distributions is used as an aid for the better understanding of the vibration characteristics of the plates.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.188-189
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• 2016

본 논문은 초기하중을 하중을 받는 역대칭 angle-ply 와 cross-ply 적층판의 좌굴 및 진동특성을 무재하시의 고유진동수를 이용하여 산정하는 간편법을 제시하였다. 마주보는 두변이 단순 지지된 역대칭 적층판의 운동방정식은 전단변형과 회전강성효과를 고려한 YSN 이론으로 유도하였으며 이를 선점법을 이용하여 해석하였다. 초기응력을 받는 적층판의 무차원화 고유진동수, 임계좌굴계수 및 동적 주 불안정영역 문제들을 무재하시의 무차원화 고유진동수로서 각각의 특성을 정립시켰다. 본 연구에서 제안한 진동특성에 관한 간편산정식의 정당성과 사용성을 입증하기 위하여 수치예들로서 검토하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.28-40
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• 1991

Affine transformation was used to analyze the bending, buckling and vibration behaviors of a thick antisymmetric angle-ply rectangular simply supported laminate. Introducing the generalized parameters, the comprehensive solutions are found. The generalized parameters are a generalized rigidity ratio ( $D^*1), a generalized Poisson's ratio (.epsilon.) and a principal rigidity ratio (.alpha.). Hence, the transverse deflection decreases, the uniaxial buckling load and the fundamental frequency increase with increasing $D^*1 and decreasing .alpha., but the effect of .epsilon. is negligible. With decreasing the thickness ratio, the results by the classical plate theory are more erroneous. The transverse deflection is minimum, the uniaxial buckling load and the fundamental frequency are maximum if the fiber angle is 45.deg., and number of plies is more than 4. The time and efforts can be saved to understand the behaviors of composite laminates because these results can be applied to another composite material easily.sily.

• 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.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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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 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.

• Journal of Korean Society of Steel Construction
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• v.12 no.3 s.46
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• pp.291-302
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• 2000

In recent years the development of high modulus, high strength and low density boron and graphite fibers bonded together has brought renewed interestes in structural elements. When a plate with arbitrarily oriented layers and clamped boundary conditions is subjected to uniform loading, it is difficult to analyze and apply, compared with isotropic and orthotropic cases. Therefore the numerical methods, such as finite difference method or finite element method, should be emloyed to analyse such problems. In this study the finite difference technique is used to formulate the bending analysis of symmetric composite laminated skew plates. When this technique is used to solve the problem, it is desirable to reduce the order of the derivatives in order to minimize the number of the pivotal points involved in each equation. The 4th order partial differential equations of laminated skew plates are converted to an equivalent three of 2nd order partial differential equations with three dependant variables.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.4
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• pp.37-44
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• 1991

A powerful analytical procedure and strain energy analysis to investigate the free vibration of antisymmetric cross-ply laminated plates, having one pair of opposite edges simply supported, are develped on the basis of the Yang, Norris abd Stavsky (YSN) theory. The equation of motion of the plate are solved by the use of collation method. A range of results are presented for plates to show the effects of modulus ratio and number of layers on natural frequency. In addition, an analysis of the strain energy distributions is used as an aid for the better understanding of the vibration characteristics of the plates.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.150-159
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• 2014

A simplified method for the calculation of buckling and vibrational characteristics of initially stressed rectangular plate and antisymmetric angle-ply laminated plates is presented in this paper using the natural frequencies under unloading state. The equation of motion of rectangular plate with two opposite edges simply supported is investigated on the basis of Rayleigh-Ritz method and Mindlin plate theory with effect of the curvature term. The relationships of the non-dimensional natural frequencies with initial stresses the coeffcients of critical buckling and the boundaries of the dynamic principal instability region can be characterized by the non-dimensional natureal frequencies under unloading state. Numerical examples are presented to verify the simplified equations and to illustrate potential applications of the analysis.

• Journal of Korean Society of Steel Construction
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• v.15 no.2
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• pp.97-107
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• 2003

To obtain a more accurate response from larninated composite structures, the effect of transverse shear deformation, transverse normal strain/stress, and nonlinear variation of in-plane displacements vis-$\\grave{a}$-vis the thickness coordinate should be considered in the analysis. The improved higher-order theory was used to determine the critical buckling load and natural frequencies of laminated composite structures. Solutions of simply supported laminated composite plates and sandwiches were obtained in closed form using Navier's technique, with the results compared with calculated results using the first order and other higher-order theories. Numerical results were presented for fiber-reinforced laminates, which show the effects of ply orientation, number of layers, side-toithickness ratio, and aspects ratio.