A Mathematical Model to Simulate Self-loosening Behavior of Bolted Joints Due to Thread Wear under Transverse Loading

To improve the understanding of the loosening behavior caused by thread wear, a mathematical model of bolted joint with consideration of thread wear was proposed. The method for wear simulation is based on Archard wear equation. The mathematical model simulated the phenomenon where thread wear leads to a gradual reduction in the clamping force by using numerical iterative calculation. The evolutionary trend of the thread wear and clamping force is consistent with the previous test results. The predicted results show that the wear on the thread surface causes a change in the distribution and magnitude of the loads carried by each engaged thread. The thread loads initially tend to be equal, and then all gradually decreases. Besides, the bolt with a higher wear coefficient can obtain a greater ability to resist the self-loosening caused by thread wear, but retightening the bolt and the nut seems not to be a very effective method to resist the loosening caused by thread wear.