Time-Domain BEM Analysis for Three-dimensional Elastodynamic Problems with Initial Conditions

In this paper, a time-domain boundary element method formulation for the analysis of three-dimensional elastodynamic problems with arbitrary, non-null initial conditions is presented. The formulation is based on the convolution quadrature method, by which the numerical stability is improved significantly. In order to take into account the non-null initial conditions in this formulation, a general method is developed to replace the initial conditions by equivalent pseudo-forces based on the pseudo-force method. The original governing equation is transformed into a new one subjected to null initial conditions. In the numerical examples, longitudinal vibrations of a free beam and a cantilevered beam are considered as the illustrative problems to evaluate the new formulation. Results are shown to be in good agreement with the analytical solutions or the finite element method solutions.