The theta scheme for time-domain BEM/FEM coupling applied to the 2-D scaler wave equation

There exist quite a number of published papers showing that BEM/FEM couplin g in time domain is a robust procedure leading to great computer time savin gs for infinite domain analyses. However, in many cases, the procedures pre sented so far have considered only constant time interpolation for BEM trac tions, otherwise one may have (mainly in bounded domains) strong oscillatio ns which invalidate the results. In this paper, such a limitation is overco me by employing the linear theta method which consists, basically, of compu ting the response at the time t(n+1) from the response previously computed at the time t(n+theta) theta greater than or equal to 1.0. This procedure i s implicitly incorporated into the BEM algorithm in the coupled BEM/FEM pro cess presented here, i.e. the response is calculated directly at time t(n+1 ). Proceeding this way, it becomes possible to adopt the Newmark scheme in the FEM algorithm. Two examples are presented in order to validate the form ulation. Copyright (C) 2000 John Wiley & Sons, Ltd.