INTERPRETATION OF THE PROBLEMS FOUND IN APPLYING CONTACT CONDITIONS IN NODE-TO-POINT SCHEMES WITH BOUNDARY-ELEMENT NON-CONFORMING DISCRETIZATIONS

Several procedures for considering contact problems between deformable bodies using boundary elements with non-conforming discretizations ar e discussed in this paper. All the procedures considered (both those f ormerly proposed and a new one presented here) are based on an approac h of strong imposition of the contact conditions, relating values of d isplacements and tractions of points and nodes of both bodies to force equilibrium and compatibility equations. All the procedures lead to s imilar results when the same general rule is followed in all cases: th e body whose nodes control the displacements of the contact zone is di scretized with more refined meshes. There are, nevertheless, cases, no t previously referenced in the literature, where these procedures prod uce wrong definition of the subzones of adhesion and sliding, as well as some jumps in the stresses. These problems, whose appearance is sho wn to be due to the intrinsic nature of the node-to-points contact sch emes, are discussed and recommendations are given to avoid them. Three classical examples belonging to the conforming, receding and advancin g contact problems are studied, considering the presence and absence o f friction. (C) 1998 Published by Elsevier Science Ltd. All rights res erved.