THIN BRIDGES IN ISOTROPIC ELECTROSTATICS

Fast hierarchical methods for potential field evaluations have in rece nt years found interesting applications in computational physics and e ngineering. For example, these methods have been used in combination w ith integral equation methods for solving the electrostatic and elasto static equations for materials with inclusions. A lingering obstacle o n the way to constructing a general purpose algorithm for inclusion pr oblems is the treatment of inclusion interfaces that lie very close to each other. The difficulty is to assess the need for resolution and t o evaluate layer potentials close to their sources in a fast and accur ate fashion. This paper presents an automated algorithm for such an as sessment and evaluation. The robustness and speed of the algorithm is demonstrated through a series of examples involving thin bridges, coat ings, narrow necks, corners, cusps, and random mixtures. (C) 1996 Acad emic Press, Inc.