BOUNDARY-ELEMENT MODELING OF COATED MATERIALS IN STATIC AND SLIDING BALL-FLAT ELASTIC CONTACT

Boundary element modelling of elastic ball-flat contact is presented. The loading of a homogeneous medium is considered and the validity of the half space assumption is shown to depend on the relative dimension s of the specimen; i.e. the ratio of the real dimensions over the cont act radius. The subsurface stress field in a coating-substrate composi te is analysed. It is influenced by the ratio of Young's moduli of the materials. As to the impact of relative specimen dimensions, the key parameter is the relative coating thickness. All the general tendencie s of the subsurface stress held modifications are identical to those o f plane strain (cylinder-flat) contact geometry. Friction is shown to mainly affect stresses in the coating close to the contact surface. (C ) 1998 Elsevier Science S.A.