Carburizing effect-inspired bending fatigue forecasting model for spiral bevel gears

•Finite element method (FEM) based tooth flank carburizing simulation.•Carburizing effect considering the residual stress and root hardness gradient.•Multiaxial fatigue damage model for bending fatigue assessment.•Carburizing effect-inspired root bending fatigue life forecasting model. Collaborative optimization considering complex meshing interface physical performance evolution is always an important challenge for designer in recent field of spiral bevel gears. Where, an innovative root bending fatigue life forecasting model is established by considering the root flank carburizing effect for spiral bevel gears. First, root flank carburizing simulation is performed to output carburizing effect evaluations, namely the root flank hardness gradient at different carburizing layers and residual stress distribution. Then, carburizing effect-inspired root bending fatigue life forecasting model was established. Where, finite element method (FEM) based bending stress considering residual stress is determined, and root flank hardness gradient is used to compute S-N curve. Considering tooth flank carburizing effect, root bending fatigue life forecasting is performed by correlating with multiaxial fatigue criterion. Finally, the proposed forecasting model is exercised with an instance aerospace spiral bevel gears to verify the impact of key machine settings on the result root bending fatigue life. [Display omitted]