An Analysis of Elasto-Plastic Sliding Spherical Asperity Interaction

This work seeks to characterize the component of friction which arises from energy being dissipated via elasto-plastic deformation during sliding contact (as apposed to adhesive mechanisms). The sliding interaction between spheres is analyzed using two approaches (a semi-analytical and finite element simulation). These analyses are used to formulate empirical equations which describe the average tangential and normal forces resulting from the sliding interaction. A parametric study of the properties of typical metals is then used to help verify the effectiveness of the empirical equations. The study shows that the effective friction coefficient between spherical asperities increases with the elastic modulus, decreases with yield strength, and increases with the interference between the contacts (dependant on the normal load).