In this paper a direct boundary element hypersingular formulation for three-dimensional potential problems is presented. It is shown that the integrals which arise in this formulation are Cauchy principal value integrals, i.e., divergent terms of the finite part integrals cancel one another. Since in the present formulation the collocation points are placed within boundary elements, free terms are computed by simple expressions. The resulting integrals are one-dimensional and regular, therefore can be evaluated by Gaussian quadrature. For the numerical implementation, both linear and quadratic isoparametric triangular and quadrangular elements were used. Numerical results are presented to show the efficacy of the proposed hypersingular formulation.
Boundary element method; hypersingular formulation; cauchy principal value; finite part integral
