Elastic Contact Analysis of Shot-Peened Rough Surfaces

Abstract

Shot peening can effectively improve the mechanical performance of metal components, and thus has been widely employed in the engineering field. During the processing, the surface roughness of treated components will be completely changed, which could strongly affect their tribological behavior. However, few of the existing contact models are directed toward the rough surfaces generated by shot peening. In this study, the normal contact response between a shot-peened surface and a rigid plane is investigated based on the finite element method and the recently developed incremental contact model. The elastic contacts of the rough surfaces experimentally measured on three different shot-peened specimens are considered. Contrary to the conventional rough contact models, it is found that the dependence of the external load on the real contact area for the shot-peened surfaces is not at all linear, even for light loads. The slope of the area–load curve significantly varies at two transition points, which are intrinsically linked to the special structure of shot-peened surfaces.