Elimination of rigid body modes from discretized boundary integral equation

Free rigid body modes in Neumann problems are typically eliminated by suitably restraining the body. An alternative approach, here called "regularization", involves first computing the singular stiffness matrix and then suitably modifying it using ideas from linear algebra. This idea has been suggested by V~rchery (1990) for symmetric matrices. This paper is concerned with regularization of nonsymmetric stiffness matrices that arise from the boundary element method (BEM) for linear elasticity. Existence and uniqueness issues, as well as properties of the displacement field, for elasticity problems with tractions prescribed at every point on the boundary, are discussed in this paper. (9 1998 Elsevier Science Ltd. All rights reserved.