LAUSR

In the paper, we consider the tangential contact of single microasperities of the interacting surfaces the mechanical characteristics of which are close to the characteristics of typical rail steels. Using computer simulation by the method of discrete elements, we study the influence of the parameters of adhesive interaction of both external and internal surfaces on the regime of wear of asperities. It has been established that with increasing adhesion work, the wear regime changes from slipping (low wear) to grinding or brittle fracture of asperities (high wear), and this change is of threshold nature. An empirical sigmoid dependence of the location of the boundary between the two wear regimes (namely, the threshold value of the adhesive stress) on the value of the material hardening coefficient has been established. It is shown that the logistic nature of this dependence is due to the competition of two mechanisms of elastic strain energy dissipation, which determine the wear regime. These are plastic deformation and adhesion of the contacting surfaces. Special discussion is devoted to the influence of the scale factor on the threshold values of the mechanical characteristics of the material which provide the change of the wear regime.