FREE-VIBRATION OF LAMINATED COMPOSITE PLATES - A SIMPLE FINITE-ELEMENT BASED ON HIGHER-ORDER THEORY

A four-noded rectangular element with seven degrees of freedom at each node is developed for the vibration analysis of laminated composite plate structures having a constant thickness of any individual layer. The displacement model is so chosen that it can explain adequately the parabolic distribution of transverse shear stresses and the non-linearity of in-plane displacements across the thickness. The mass matrix is derived in a consistent manner. Rectangular plates of antisymmetric angle-ply laminates whose material properties are typical of highly anisotropic composite materials are considered. Two sets of material properties are used to show the parametric effects of plate aspect ratio, length-to-thickness ratio, number of layers and lamination angle. Results are compared with existing analytical and numerical solutions. The present element formulation confirms its applicability for a wide variety of laminated plates.