Abstract: Bending test is the most important performance test of automotive wheel. At present, the fatigue life prediction still based on nominal stress approach or local stress-strain approach. The effect of microstructure and casting defects has not been considered in presently used approaches, there is a considerable difference between prediction results and real practice when these approaches are used to predict the high-cycle fatigue life of the aluminum alloy automotive wheels under low stress level. A fatigue life prediction model concerning secondary dendrite arm spacing and casting defect is built based on small fatigue crack propagation theory. Casting simulation and finite element analysis are integrated into fatigue analysis. An integrated platform to predict wheel mechanical performance that includes casting process, related casting defect and downstream manufacturing process is constructed primarily. The bending fatigue life of a certain type of wheel is predicted by using this model, and the experiment validates that the result is more accurate than Simth-Waston-Topper method.

Key words: Aluminum alloy automotive wheel, Casting simulation, Fatigue analysis, Finite element analysis