Frictional Energy Dissipation in a Contact of Elastic BodiesSubjected to Superimposed Normal and Tangential Oscillations

Frictional damping in elastic contact of a parabolic indenter subjected to a combination of oscillations in normal and tangential directions is numerically simulated. The dissipated energy first increases linearly with coefficient of friction, then decreases linearly, and finally reaches a constant value. These three regions correspond to the states of complete slip, partial slip and complete stick. All three asymptotical dependencies can be described analytically. The dissipated energy in a dimensionless form is function of the ratio of normal oscillation amplitude and mean indentation depth, the ratio of change in contact area and sticking area, and phase shift between normal and tangential oscillation. Master curves are suggested.