Rheology Solutions revealed the abstract of a numerical study of temperature and shear flow in a transiently loaded lubricant film. The numerical study was undertaken to provide an understanding of the influence of thermal conditions on friction build-up for a paraffinic mineral oil (PAM). Matlab 6.5 was used to perform computations for two lubricated infinite and rigid plates in relative motion, subjected to a transient load pulse. Two different rheological models, one nonlinear viscous and one nonlinear viscoelastic (Ree-Eyring), were used.
From the friction coefficients calculated it is concluded that viscosity effects do not account for the phenomenon of decreasing friction coefficient with increasing maximum pressure of the loading pulse. It appears that an explanation for this phenomenon must be sought in the friction properties of the interface of the ruptured solidified lubricant. It is also concluded that the thermal properties of the lubricated medium present in the contact affect friction and the formation of shear bands.