Analysis of a shrink-fit failure on a gear hub/shaft assembly

The paper presents results and conclusions arising from an investigation into a shrink-fit failure on a gear hub/shaft assembly. The work formed one element of a full failure investigation and set out specifically to determine whether or not fretting or micro-slipping was the cause of failure. The basic rationale of the study was to start with assumed operating conditions and progressively refine the model in order to accurately take account of the true operating conditions. This approach permitted conclusions to be drawn after every simulation concerning the propensity to slip along the gear hub/shaft interface. Two modelling techniques were used in parallel: a novel analytical approach and a finite element study. Results from the two approaches were consistent and in relatively good agreement. The principal conclusion made was that the observed slip and subsequent fretting damage could only have occurred as a result of another, principal, failure mechanism which was responsible for increasing the internal diameter of the gear hub.