Nonlinear response of composite plates using the finite element modal reduction method

This paper presents a time-domain modal formulation using the finite element method for large-amplitude vibrations of generally laminated thin composite rectangular plates. By using the modal reduction method, the system equations of motion in physical coordinates are transformed into the linear modal coordinates. The sizes of the system matrices are reduced drastically; and the procedure for obtaining the modal equations of the general Duffing-type is simple when compared with the classical continuum Galerkin's approach. The modal participation, which is defined as the contribution of the mode to the plate deflection, is quantified.