The Influence of Tightening Conditions on the Fatigue Strength of Bolted Joints under Transverse Vibration

In this study, influence of grip length and engaging thread length for a bolted joint on fatigue characteristics under transverse vibration has been investigated. The relationship between the apparent fatigue limit and the real fatigue limit has been experimentally revealed. In the experiments, the apparent fatigue limit and the real fatigue limit were investigated for three separate tightening conditions of a bolted joint combined with various grip lengths and engaged thread lengths. And fatigue characteristics of a bolt/nut assembly also were investigated. The results showed that the relationship between the apparent fatigue limit and the real fatigue limit depends on the bending moment at the root of the first thread.