Bolted joint clamping force variation due to axial vibration

Recent experiments and analyses have revealed that threaded fasteners subjected to axial vibration can experience either loosening or tightening. In this paper, the authors examine the variation of clamping force in a single-bolt assembly model due to axial vibration. Specifically, the effect of vibration level and initial pre-load on clamping force is studied. It is found that the clamping force can remain steady, decrease, or increase when the assembly is subjected to axial vibration. However, changes in clamping force are generally transient and a steady value is reached over time. (C) 1998 Academic Press Limited.