BOUNDARY-ELEMENT ANALYSIS OF 2-DIMENSIONAL ELASTOPLASTIC CONTACT PROBLEMS

A general boundary element formulation for contact problems, capable o f dealing with local elastoplastic effects and friction, is presented. Both conforming and nonconforming problems may be analysed. The conta ct problem is solved by means of a direct constraint technique, in whi ch compatibility and equilibrium conditions are directly enforced in t he general system of equations. The contact areas are modelled with li near interpolation functions, and quadratic interpolation functions ar e used everywhere else. Elastoplasticity is solved by a BEM initial st rain approach. The Von Mises yield criterion with its associated flow rule is adopted. Both perfectly plastic and work hardening materials a re studied in the proposed formulation. An incremental loading techniq ue is proposed, which allows accurate development of the loading histo ry of the problem. The non-linear nature of these problems demands the use of an iterative procedure, to determine the correct frictional co nditions at every node of the contact area and the value of the plasti c strains at selected points where local yielding may have occurred. S everal numerical examples are presented to demonstrate the efficiency of the proposed formulation. (C) 1998 Published by Elsevier Science Lt d. All rights reserved.