A Faster Galerkin Boundary Integral Algorithm

The symmetry present in Green's functions is exploited to signi®cantly reduce the matrix assembly time for a Galerkin boundary integral analysis. A relatively simple modi®cation of the standard Galerkin implementation for computing the non-singular integrals yields a 20±30 per cent decrease in computation time. This faster Galerkin method is developed for both singular and hypersingular equations, and applied to symmetric-Galerkin implementations in two dimensions for the Laplace equation and for orthotropic elasticity. In three dimensions, the modi®ed algorithm has been implemented for the singular equation for the Laplace and elastodynamics equations. Comparison timing results for standard and modi®ed algorithms are presented. # 1998 John Wiley & Sons, Ltd.