Free vibration of composite laminated plates subjected to hygrothermal loads

Abstract

Laminated composite plates are very important engineering structure with wide application in aerospace, automobile, and nuclear industry due to their high specific strength and specific modulus. In recent years, these materials have been used extensively in aircraft. In such cases certain portions of the aircraft structure may be subjected to experience thermal and moisture environment. It is therefore necessary to predict the free vibration response of the composite plate when subjected to thermal and moisture environment. The free vibration behaviour of laminated composite plates is considerably more complicated than that of isotropic ones due to the anisotropy of the individual lamina. The effect of temperature and moisture on the free vibration of Carbon Fibre Reinforced Polymer (CFRP) plates has been investigated. First-order shear deformation theory was applied in Finite Element Method (FEM) to investigate free vibration analysis of fully clamped laminated plate. FEM results of simply supported composite plates were compared with analytical results to validate the FEM analysis. Composite plates of [02, 902], [0, 90]4, [±452], [±45]4, [0, 90]2s, [±45]2s, [0, ±45, 90]s layup were investigated. The parametric study showed that the single cross ply [02, 902] and double angle ply [±452] laminates showed greatest variations in fundamental frequencies with temperature and moisture. Only slight variations are predicted for the multi-ply laminates of [0, 90]4, [±45]4, [0, 90]2s, [±45]2s, [0, ±45, 90]s.