ANALYSIS OF SEMICOERCIVE CONTACT PROBLEMS USING SYMMETRICAL BEM AND AUGMENTED LAGRANGIANS

We present a parallel algorithm for identification of the contact inte rface and evaluation of contact stresses of systems of elastic bodies in contact that may comprise bodies which admit some rigid body motion . The algorithm is based on the discrete reciprocal formulation obtain ed by the symmetric boundary element method. The solution of the resul ting problem is reduced to the solution of a sequence of strictly conv ex quadratic programming problems with simple bounds by a variant of t he augmented Lagrangian method. The algorithm in the inner loop uses p rojections and adaptive precision control for the solution of auxiliar y problems so that it can efficiently identify the contact interface. Both theoretical results and numerical experiments indicate that there are problems which may be solved efficiently by the algorithm present ed. Since the coupling procedure is iterative, the algorithm may proce ss most information concerning each body locally so that it is suitabl e for parallel implementation. (C) 1997 Elsevier Science Ltd.