Finite Element Analysis on the Influence of Material Mechanical Properties in Local Contact Conditions

Previous results, obtained using the load-scanning technique, indicate that the amount of plastic deformation of the contact surface contributes to a change in the global friction coefficient. This technique allows describing the friction from a local analysis method, since the normal and tangential contact forces to the sliding direction can be measured simultaneously, independently and precisely. It also allows maintaining a constant contact surface geometry [1]. In this paper the load-scanning results are analysed using the finite element method (FEM), which allows a local analysis to advance their understanding. The numerical study is performed applying the Amontons-Coulomb friction model in the simulation of local contact conditions, in order to determine the normal load value that dictates the transition between elastic and elastoplastic contact. The numerical model considers the contact between a rigid sphere and a deformable body. The study focuses on the influence of elastoplastic mechanical properties of the deformable body, namely, the hardening coefficient and the Poisson ratio, in the normal load corresponding to the onset of plastic strain.