A NUMERICAL QUADRATURE FOR NEARLY SINGULAR BOUNDARY-ELEMENT INTEGRALS

Nearly singular integrals arise in the boundary element method when an alyzing thin structures and gaps and when calculating the field very n ear the boundary. Hayami proposed the PART method for the accurate and efficient calculation of such nearly singular integrals over general curved surface elements. In this paper, a new radial variable transfor mation for the method, which reduces the number of integration points for flux integrals, is proposed with theoretical error analysis using complex function theory. Also, an implementation technique of the meth od is proposed, which considerably reduces the number of integration p oints.