Effect of thermo-elastic deformation on lubricated point contacts

In lubricated contacts, viscous shearing of lubricant and frictional heating inevitably result in thermo-elastic deformation of contacting surfaces, which will change the distribution of contact pressure, and hence affect the behaviour of the contact. This study presents a thermo-mechanical model for lubricated point-contacts problem. The model takes into account the interactions between pressure and temperature, and asperity distortion due to thermal and elastic deformations. A unified Reynolds equation system is used to obtain the pressure distribution, and an FFT-based algorithm is applied to speed up the calculation of temperature rise and surface deformations caused by the normal pressure and surface temperature rise. The results show that interfacial frictional heating results in thermo-elastic deformation comparable with elastic deformation. As a result, the gap between mating surfaces will be decreased, and the pressure near the centre of contact will be elevated, especially for rough surface and high speed.