EFFECT OF SURFACE TEXTURE ON CONTACT CONDITIONS AND TRIBOLOGICAL BEHAVIOR OF SIMULATED WHEEL-RAIL PAIRS IN A TWIN-DISC MACHINE

To understand the tribological behaviour of rolling-sliding pairs with textured surfaces, two-dimensional Hertz equations for the contact patch and stress distribution of two cylinders in contact were modified to account for the introduction of deterministic patterns. The theoretical framework developed was applied to study the effect of surface texture on the tribological response of a wheel-rail pair tested in a twin-disc machine. It was found that the contact semi-width increased in the textured discs, which led to a reduction in the apparent contact pressure and subsequent effects on the stick/slip ratio for each percentage of slip. The study shows that it is possible to reach a constant friction condition at lower slip percentages in textured surfaces. This could be a benefit in addressing problems associated with friction management. That is, to design the texture for contacts where it is difficult to control friction and also to be able to reduce contact pressures.