Research on Type Ⅱ Fatigue Crack Propagation Threshold of Wheel Steel

Ⅱ fatigue crack growth test of wheel steel was carried out with lifting load method. A finite element model was established with ANSYS software to calculate the stress intensity factor of crack tip under type Ⅱ loading, and the effect of loading force ratio R on the type Ⅱ fatigue crack propagation threshold (ΔK_Ⅱth) of wheel rim was studied. The results show that ΔK_Ⅱth decreases slightly with the increasing of loading force ratios R, under the condition of the same R, ΔK_Ⅱth and propagation threshold of type I fatigue crack ΔK_Ith are basically equal.