Fretting wear of bolted joint interfaces

Under vibration loading, fretting wear between bolted joint interfaces may change the dynamic characteristics of structures. Even the reliability of long-lasting assembly structures could be affected. This paper focuses on an experimental study on the fretting wear behavior of bolted joint interfaces under tangential loading. A recently developed fretting test apparatus was used to measure the hysteresis loops and the bolt preload at different fretting wear cycles. Changes of tangential contact stiffness and friction coefficient were estimated from the measured hysteresis loops. Experimental results showed a large change in bolt preload, contact stiffness, and friction coefficient due to fretting wear. The effect of surface roughness on fretting wear behavior of bolted joint interfaces was discussed. A modified Iwan model, comprehensive of wear effects, was proposed to simulate the hysteresis loops. Comparison between simulations and experimental results was performed to validate the proposed method. Results achieved in this research can provide the basis for the dynamic analysis of long-lasting joint structures in which wear plays a fundamental role in modifying the contact parameters.