Effect of wear between contact surfaces on self-loosening behaviour of bolted joint under low frequency torsional excitation

Abstract

A theoretical analysis method is proposed for bolted joint under low frequency torsional excitation, based on which the changes of bolt axial force can be divided into three scenarios, continuous rapid drop, remaining unchanged and fluctuating. The structural hysteresis loops of the three scenarios are slightly different in shape. The stress distribution on contact surfaces is not uniform, which affects the corresponding equivalent friction diameters. Finite element analysis is carried out to calculate the equivalent friction diameters of interfaces. Furthermore, wear-induced loosening is investigated numerically based on Archard’s theory with MATLAB. Numerical analysis shows that interface wear causes bolt self-loosening, and wear depth values between threads are different, which causes decreased axial force and load redistribution between threads.