Numerical modelling of crack path in the lubricated rolling–sliding contact problems

A two-dimensional computational model for simulation of contact fatigue of lubricated rolling–sliding contact problems is presented. In the model it is assumed that the initial crack of length 0.02 mm is initiated at the surface due to previous mechanical or heat treatment of the material as well as a consequence of running process in an early stage of exploitation. The discretised model with the initial crack is then subjected to the normal contact pressure and tangential loading due to friction between the contacting surfaces. The model also considers the moving contact of the contacting surfaces and fluid trapped in the crack. The crack propagation path is predicted with the MTS and modified MTS criterion, which takes into account the influence of the stress intensity factor KI and KII, T-stress, stress on the crack surface caused by lubricant pressure inside the crack and critical distance ahead the crack tip. The numerical results correspond well with available experimental data.