A higher-order theory for free vibration of unsymmetrically laminated composite and sandwich plates-finite element evaluations

Abstract

This paper presents a refined higher-order theory for free vibration analysis of unsymmetrically laminated multilayered plates. The theory accounts for parabolic distribution of the transverse shear strains through the thickness of the plate and rotary inertia effects. A simple C⁰ finite element formulation is presented and the nine-noded Lagrangian element is chosen with seven degrees of freedom per node. Numerical results are presented showing the parametric effects of aspect ratio, length/thickness ratio, number of layers, and lamination angle. The present theory predicts the frequencies more accurately when compared with first-order and classical plate theories.