An evolutionary shape optimization procedure for contact problems in mechanical designs

The finite element method (FEM) has been extensively applied to explore contact stress distributions in multi-body mechanical systems. Uneven contact stresses are often one of the main concerns of mechanical design engineers. By adopting the evolutionary structural optimization (ESO) concept, this paper presents a non-gradient procedure for gradual shape redesign of prescribed contact interfaces. In this method, interfacial gaps are considered as design variables and contact stress deviations over design interfaces are set as the objective function. To deal with multiple contact region problems, two different design objectives, namely an individual criteria and a unified criteria, are formulated respectively. Several practical examples show that this method is effective for design problems consisting of single- or multiple-contact regions in mechanical systems, in which a uniform contact stress pattern is the desired optimality criterion.