Simplified analysis of non-Newtonian effects in a circular elastohydrodynamic contact and comparison with experiment

摘要

The paper describes a simplified non-Newtonian numerical model of an elastohydrodynamic point contact. It is based on the control volume flow continuity technique described by Holt et al. (9). Observation of the shear stress values produced in the solutions to the problem obtained by Holt has led to the consideration of a simplifying approximation in the non-Newtonian formulation for calculation of flow rates in which the resultant shear stress is approximated by the shear stress in the predominant direction of sliding. This assumption gives easily calculated expressions for the flow rates. The simplification leads to direct evaluations of the surface shear stress components without recourse to an iterative solution of simultaneous transcendentalequations. Results of the simplified model are found to agree with the more exact treatment of Holt et al. under realistic operating conditions. A thermal treatment of the oil film for sliding contacts is also included. Experimental measurements of filmthickness in contacts with varying degrees of sliding have been carried out which show good agreement with the simplified theory.