Analysis of Fretting Fatigue Crack Initiation Location in Press-fitted Shaft

Abstract

In order to investigate the fretting fatigue crack initiation of the press-fitted shaft,the rotary bending fretting fatigue tests are conducted by the press-fitted shaft consisted of locking assembly,pad and the shaft specimen.The crack initiation locations of the specimens under different applying nominal bending stress are observed.It is found that the crack initiation locations are at the internal area of the contact pair,which is deeper than the location of the open region.According to the experiment condition,the elastic finite element analysis is conducted by ANSYS and the crack initiation locations are predicted by Ruiz method.The predicted results by Ruiz method are compared with the experimental results.It shows that the prediction error dramatically increases with the increase of nominal bending stress.It is found that the opened region at the rim of the contact pair has large effect on the accuracy of the prediction by Ruiz method.So it is necessary to consider the effect of open region when predicting the fretting fatigue crack initiation location of press-fitted shaft by Ruiz method,especially when the ratio of the nominal bending stress and the contact press is large.