Influence of Ratcheting on Self-Loosening of Bolted Joints

Considering the ratcheting behavior, the early stage of bolt tension losses was studied numerically, and effects of some factors, load direction, pre-tightenforce, side load amplitude and friction factor, which may affect the progress were analyzed. Simulation results show that the bolt tension declines greatly after the first load circle, and in the following load circles, its further loss is caused by ratcheting behavior of the first thread root. In all factors studied in this paper, load amplitude impacts the progress most significantly.