A GENERAL ALGORITHM FOR CALCULATING NEARLY SINGULAR INTEGRALS OVER HIGH-ORDER ELEMENTS IN 3D BEM

This work presents a general methodology to compute nearly singular integrals arising in 3D BEM using the eight-node second-order quadrilateral and six-node second-order triangular surface elements. The proposed method constructs a new distance function. The exponential transformation, which was proposed by present authors and is accurate and easy to implement according to extensive applications of 2D BEM, will be extended to 3D BEM to remove the near singularities of integrands. Several numerical examples are given to verify the high efficiency and the stability of the proposed scheme.