Loaded contact fatigue-oriented carburizing surface optimization model of spiral bevel gears

Abstract

In order to improve geometric accuracy and loaded contact fatigue life on tooth surface carburizing, an innovative optimization model is established for spiral bevel gears. First, finite element method (FEM)-based tooth surface carburizing simulation is performed. Where, the output carbon content and hardness gradient are used to determine the S-N curve of the given material 20MnCr5 steel. The output residual stress is integrated into the bending stress solution. The output carburizing surface deformation is introduced into the composite surface geometric accuracy. Second, loaded contact fatigue assessment is performed by FEM-based loaded contact stress and S-N curve. Where, loaded contact stress considering residual stress is determined by simulated loaded tooth contact analysis (SLTCA). Third, loaded contact fatigue life-oriented carburizing surface optimization model is established. In this modeling, the composite surface geometric error including carburizing deformation, loaded contact deformation and the prescribed ease-off is used to reflect manufacturing geometric accuracy. Moreover, the limit fatigue life at dangerous point is used a standard to determine the target surface. A sensitivity analysis strategy-based optimization strategy is developed. The proposed method can effectively improve the process parameter modification strategy by considering the collaborative optimization on geometric accuracy and loaded contact fatigue life. Moreover, it also can provide new technical for the current co-design and manufacture of spiral bevel gears.