EHL under cyclic squeeze motion

A time-dependent EHL problem of a ball impacting a plate by a cyclic approach–separation motion has been solved. Previous experimental findings by some of the authors have been numerically confirmed, i.e., the nearly constant central film thickness during the load-sustaining stage, and the linear relationship between this constant film thickness and the frequency in a log–log scale. The numerical results show a constriction in the trace of central film thickness versus time. Similar to the experiments, numerical results give a dimple film shape, which is caused by the high pressure induced within the contact region. However, the present Newtonian model overestimates the central film thickness and the squeezing contact forces. The influences of the frequency, the static contact load, the amplitude and the pressure–viscosity coefficient on the film thickness and the film pressure have also been investigated.