EVALUATION OF THE REAL CONTACT AREAS, PRESSURE DISTRIBUTIONS AND CONTACT TEMPERATURES DURING SLIDING CONTACT BETWEEN REAL METAL-SURFACES

A three-dimensional elastic contact algorithm has been developed to an alyse the normal contact problems of bodies having rough surfaces. The algorithm can evaluate the real contact areas and contact pressure di stributions using measured surface roughness data. Following an approx imate elastic-plastic contact solution the analysis produces more real istic elastic and plastic contact areas; in addition results of contac t pressure distributions can be predicted according to a given maximum plastic limit pressure. The technique can simulate (in an approximate way) the elastic-plastic sliding contact behaviour in the vicinity of asperities or concentrated contact areas by ignoring the effect of th e tangential forces on the vertical displacement.Assuming a certain sl iding speed and a particular coefficient of friction the local tempera ture distribution due to the heat generation over the real contact are as can also be calculated for 'slow sliding' problems. The results sho w the moving real contact areas and the contact temperature fields for an electric spark mechanical steel surface moving over a planed bronz e surface. Changes of the rigid body displacement, as well as the aver age and maximum pressures are also presented during sliding. The micro -contact or asperity contact behaviour for bodies having large nominal contact area and the macro-contact behaviour for bodies being in 'con centrated contact' are also compared, In the latter case an ideal smoo th steel ball was slid over the previously mentioned bronze surface.