Mechanisms and prevention of vibration loosening in bolted joints

Loosening of bolted joints under a vibratory environment has been an ongoing problem associated with many engineering applications. Total loss of the fastener or subsequent fatigue failure due to loss of bolt pre-tension are the predominant failure models of vibration loosening. The present paper analyses two possible mechanisms of vibration loosening and identifies critical parameters in preventing loosening. The mathematical models developed shed light on the effect of various bolted-joint related parameters on vibration loosening and joint integrity. It also develops simple rules of thumb for the prevention of vibration loosening. Finally, based on the results of the above mathematical model the paper discusses the available locking devices and their correct usage and limitations.