Effect of Attachment Lug′s Bevel Angle on Fatigue Crack Growth Rate

The stress intensity factors (SIFs) on crack tips of four typical attachment lugs under longitudinal load were solved by using the finite element method (FEM), cosine-distributed load that accord with the load transfer of pin was set as the boundary condition. The effect of the bevel angle on stress intensity factor (SIF) at different stages of crack growth was analyzed. The corresponding fatigue test of 30CrMnSiA lugs with the same size as the FEM models was carried out. The results show that the SIF of beveled lug were obviously less than straight lug under the conditions of the same crack length and the load, the crack growth rate of beveled lug with 15° was obviously less than that of the straight lug, and increasing bevel angle had not obviously increase the crack growth resistance. The test result get a satisfactory accordance with the finite element analysis result.