Research on Elastic-Plastic Contact Behavior of Hemisphere Flattened by a Rigid Flat.

The contact behavior of a hemisphere pressed by a rigid plane is of great significance to the study of friction, wear, and conduction between two rough surfaces. A flattening contact behavior of an elastic-perfectly plastic hemisphere pressed by a rigid flat is researched by using the finite element method in this paper. This behavior, influenced by different elastic moduli, Poisson's ratios, and yield strengths, is compared and analyzed in a large range of interference values, which have not been considered by previous models. The boundaries of purely elastic, elastic-plastic, and fully plastic deformation regions are given according to the interference, maximum mean contact pressure, Poisson's ratio, and elastic modulus to yield strength ratio. Then, a new elastic-plastic constitutive model is proposed to predict the contact area and load in the elastic-plastic range. Compared with previous models and experiments, the rationality of the present model is verified. The study can be applied directly to the contact between a single sphere and a plane. In addition, the sphere contact can also be used to simulate the contact of single asperity on rough surfaces, so the present proposed model can be used to further study the contact characteristics of rough surfaces.