Finite element modelling and experimental validation of bolt loosening due to thread wear under transverse cyclic loading

Abstract

A finite element model, considered for the wear profile evolution of a threaded surface, is proposed to simulate the self-loosening of bolted joints under transverse loading. The method for wear profile simulation is based on an energy-based approach. To verify this finite element model, interrupted bolt loosening tests were carried out. The finite element model successfully simulated the phenomenon in which fretting wear causes a gradual reduction in clamping force by changing the distribution and magnitude of contact stress between the threads. The predicted results agreed with the experimental results with respect to the evolutionary trend of the wear profile and clamping force. It can be seen from the finite element analysis that the fretting wear causes a change in the distribution and magnitude of contact stress, and an increment in the sliding distance along the radial direction on the thread surface, which can further change the distribution of the wear depth. Because the accumulation of wear debris is not considered in the finite element model, the predicted wear depth and reduction of clamping force is larger than that obtained from the experimental results.