Finite element analysis of contact deformation regimes of an elastic-power plastic hardening sinusoidal asperity

A series of finite element simulations of frictionless contact deformation between an elastic-power plastic sinusoidal asperity and a rigid flat are carried out to explore the influence of the ratio of yield stress to elastic modulus on the evolution of contact deformation regime. The deformation behavior comprises five regimes with four transitional states corresponding to four critical events determined by curve-fitting of simulation results. The transitional boundaries between neighboring deformation regimes are: (1) initiation of plastic deformation; (2) plastic deformation just reaches the top surface; (3) the whole contact surface just experiences plastic deformation; (4) the attainment of maximum mean contact pressure. It is found the mean contact pressures at transitional events are closely associated with yield stress and characteristic stress, which can be used as normalization parameters.