Finite-element analysis of layered rolling contacts

Abstract

A fundamental, two-dimensional finite-element analysis (FEA) of coated surfaces in rolling contact is presented with detailed listing of all modelling steps. A large number of basic results from a parametric study has been derived, focusing on the stress analysis and the effect of coatings on the life expectancy of coated surfaces, without actually getting into the ambiguities of fatigue life evaluation. Parameters included in the study are the metallic coating thickness (from zero to 50 μm) and elastic modulus (from 180 to 240 GPa), the Coulomb friction coefficient (0, 0.05, and 0.10) and the endurance limit of the coated substrate. A generalization involves the application of traction to simulate driving or driven wheels. The effect of that traction on the stress results is thoroughly examined. The set of results, summarized in a figure with nine diagrams, assists the quick selection of the optimum parameter values for maximizing coating performance and minimizing the risk of contact fatigue within the design limits used in the study. The model is realistic in that it does not use idealized load distributions in the rolling contact but actual geometrical solids in contact under normal operating conditions, letting the FEA software resolve the loads and stresses, which are subsequently validated.