Fatigue Strength Analysis for Bolts and Nuts Which Have Slightly Different Pitches Considering Clearance

The fatigue strength of bolt and nut is experimentally investigated for three types of different pitch difference. The effect of fitting clearance on the strength of bolt is discussed as well as the effect of pitch difference. The conclusions are summarized as follow : (l)By introducing the pitch difference, the mean stress and stress amplitude can be reduced at the first root of bolt thread. (2)The fracture pos北ion of bolt thread is changed depending on the pitch difference. (3)The clearance affects the stress distribution along threads more significantly when the pitch difference is larger