A novel formulation for radial fretting wear: Application to false brinelling in thrust bearings

Abstract

Radial fretting is defined as the damage caused by the relative motion of a ball under a variable normal load. The conducted experimental tests proved the existence of this damage even in contacting bodies with similar materials and elastic properties; however, the reviewed analytical methods do not predict damage under these conditions, and the numerical methods are time-consuming, especially when the investigation requires the analysis of several loading cases or during large number of cycles. The main objective of this work was to develop a fast analytical method to analyse radial fretting wear. For this purpose, a novel formulation for contact displacements under a normal variable load was built and merged to different contact mechanic formulas. For validation purposes, false brinelling in thrust bearings was used as a representative industrial example. The results were compared with a FEM model showing a relative difference under 9% and a massive reduction of the calculation time of more than 30 000 times, moreover experimental tests were carried out, showing a good agreement between the density of friction energy and the obtained fretting damage what endorse the use of this formulation for the analysis of a large number of cycles and loading cases.