FINITE-ELEMENT ANALYSIS OF DYNAMIC BEHAVIOR OF VISCOELASTIC MATERIALSUSING FFT

A new kind of finite element method is presented for analyzing dynamic behavior of viscoelastic materials. Tn this method, the finite elemen t formulation can be accomplished in a simple form based on the corres pondence principle between elasticity and viscoelasticity. Namely, the finite element equations for a viscoelastic problem are found by appl ying the Laplace transform to those for the corresponding elastic prob lem and then replacing elastic constants by viscoelastic functions. La place transforms of the nodal displacements can be obtained by solving the matrix equation represented in the Laplace domain (complex s doma in). Laplace inverse transformation is subsequently performed with the FFT (fast Fourier transform) algorithm to obtain solutions in the tim e domain. The present method is successfully applied to analyze some t ypical problems, and the numerical results show the adequacy of the me thod.