ON STRESS SINGULARITIES INDUCED BY THE DISCRETIZATION IN CURVED RECEDING CONTACT SURFACES: A BEM ANALYSIS

This paper is concerned with the e¤ects of the piecewise approximation of the geometry of contacting solids, in which a discontinuity of the normal outward boundary vector is, in general, implied. This discontinuity is shown to be of particular relevance when contact takes place on a curved surface, and sliding occurs. Only load-independent receding contact problems are considered. The behaviour of a sliding contact zone having a corner inside is investigated Þrst, by means of a particular problem. Then, it is shown that using curved elements, a meshing reÞnement process can reduce the e¤ects of unreal corners, whereas discretizations based on ßat elements may produce unacceptable results regardless of the performed meshing reÞnement. Chances to overcome this drawback are recognized for some special ßat boundary elements, but others are to be discarded for these kinds of problems. A parameter to quantify the error due to unreal stress concentrations is proposed. Two-dimensional examples discretized using boundary elements are presented for illustration purposes