Elastodynamic direct boundary element methods with enhanced numerical stability properties

Evidence of numerical instabilities in two-dimensional time domain direct boundary element methods is presented. The e!ects of numerical versus analytical integration of spatial integrals on stability are shown, and two new time-stepping algorithms are introduced and compared to existing formulations. The so-called new &direct half-stepʹ scheme and the &epsilonʹ scheme are shown to improve the numerical stability of direct boundary element methods