Parametric instability of laminated composite plates with transverse shear deformation

1990 ◽  
Vol 26 (7) ◽  
pp. 801-811 ◽  
Author(s):  
J. Moorthy ◽  
J.N. Reddy ◽  
R.H. Plaut
Author(s):  
Aniket Chanda ◽  
Utkarsh Chandel ◽  
Rosalin Sahoo ◽  
Neeraj Grover

In the present study, the electro-mechanical responses of smart laminated composite plates with piezoelectric materials are derived using a two-dimensional (2 D) displacement-based non-polynomial higher-order shear deformation theory. The kinematics of the mathematical model incorporates the deformation of laminates which account for the effects of transverse shear deformation and a non-linear variation of the in-plane displacements using inverse sine hyperbolic function of the thickness coordinate. The equilibrium equations are obtained using the minimization of energy principle known as the principle of minimum potential energy (PMPE) which is also based on a variational approach and the solutions are obtained using Navier’s solution technique for diaphragm supported smart laminated composite plates. The responses obtained in the form of deflection and stresses are compared with three dimensional (3 D) solutions and also with different polynomial and non-polynomial based higher-order theories in the literature. The transverse shear stresses are obtained using 3 D equilibrium equations of elasticity to enhance the accuracy of the present results. Various examples are numerically solved to establish the efficiency of the present model.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Atteshamuddin Shamshuddin Sayyad ◽  
Bharati Machhindra Shinde ◽  
Yuwaraj Marotrao Ghugal

AbstractThis study presents the thermoelastic analysis of laminated composite plates subjected to sinusoidal thermal load linearly varying across the thickness. Analytical solutions for thermal displacements and stresses are investigated by using a unified plate theory which includes different functions in terms of thickness coordinate to represent the effect of shear deformation. The theory presented is variationally consistent, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. Governing equations of equilibrium and associated boundary conditions of the theory are obtained using the principle of virtual work. The Navier solution for simply supported laminated composite plates has been developed. Numerical results are presented to demonstrate the thermal response of the laminated composite plates.


Author(s):  
Sarada P Parida ◽  
Pankaj C Jena

The strength of the conventional composite plates can be enhanced by the use of additional fillers. These composite plates are often subjected to dynamic loading conditions which necessitate the study of their static and dynamic behavior. In this study, laminated composite plates (LCP) are fabricated by open layup process with epoxy as a base resin, E-glass fiber as reinforcement, and fillers: flyash and graphene. The fillers are included in order to improve the mechanical properties of the composite. The filler content in the composite is limited to 5% of the total volume. The weight percentage of fiber combined with fillers, treated as reinforcing constituents is limited to 60%. Graphene and flyash are added in different proportions to develop different kinds of LCPs. The free and forced vibrations of LCPs (using simple support end conditions) are measured by an indigenously developed low-cost vibration testing module. The experimental results have been used to validate the results obtained from the mathematical modeling by using fifth-order shear deformation theory and finite element approaches. Additionally, the effect of existing discontinuity in the LCP is studied. Circular holes of different dimensions at different locations are simulated in the numerical model and the consequences on modal frequencies are analyzed.


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