Research on Fatigue Life of the Automobile Differential Case

Basing on the fatigue breaking of the differential case of the drive axle with the material of nodular graphite cast iron, the fatigue analysis is made. According to the criterion of `Q/T 543-1999 Drive Axle Bench Test Standard´, with the fatigue software FEMFAT 4.7D, the research on the cumulative damage and endurance limit safety factors in differential case is studied in terms of the Miner modified fatigue theory. The reason of the failure of the differential case can be sure that the stress concentration is at the region of the differential shaft hole in the differential case, and the safety factors are beyond the safe yield limit of the material QT450-10. Same is the comparison of the experimental results to simulation results on the failure sample, which is sure that the fatigue analysis method is reasonable and effective. It is helpful to optimize the structure parameter in the differential case design through the optimization algorithm for the drive axle in the automobile.