A QUANTITATIVE INVESTIGATION OF DISPLACEMENT ACCOMMODATION IN 3RD-BODY CONTACT
Résumé
Recently, the `'velocity accommodation'' concept was introduced in tribology. In third-body contacts, velocity accommodation can occur in five sites and according to four modes, giving rise to 20 possible combinations, i.e. 20 velocity accommodation mechanisms. The present paper addresses the role of third and first bodies in elastic and/or plastic deformations in velocity accommodation. For this, a simplified model is first proposed to represent third-body contacts separated by wear debris or solid lubricants. Then, by using the finite element method, the relative movement between first bodies in contact under different types of loading is simulated and the deformation of the model as well as the stress and strain field in the third body is determined numerically. Results quantify the role of the third and first bodies in either elastic or plastic deformation. When only relative tangential displacement is imposed, a simple analytical formula based upon a model of two compliances in series is suggested in order to estimate the displacement accommodation of third and first bodies.