Strategy for Accounting Residual Stresses Heterogeneity on the Stress Modelling Oriented to Tooth Root Bending Fatigue

Resumo

Copyright © (2025) by American Gear Manufacturers Association. All rights reserved.Energy transition has driven the search for torque efficient drivetrains, resulting in the downsizing of components. In this context, residual stress is a key factor for achieving higher power densities, due to its influence on fatigue resistance. Due to its complex nature, however, including heterogeneity along the component surface, this knowledge is not properly incorporated into gear rating standards, hindering it to be widely accepted as a design tool for downsizing. Therefore, the objective of this study is to develop a strategy to account for the residual stress heterogeneity influence on the fatigue life estimation at the gear tooth root. The assessment started with a review of the Dang Van and Fatemi-Socie fatigue models regarding their consideration of the residual stress influence. Further on, the Finite Element Method was used to simulate the shot peening process at the gear's tooth root, oriented to identify the residual stress heterogeneity induced at the surface. The selected fatigue models were then used to combine the simulated residual stress profiles with the bending stresses at the tooth, allowing to estimate the influence in fatigue life. Distinct combinations of residual stress states and actuating stresses were achieved, as a consequence of the variation of the residual stresses in the tooth root, revealing a variation in the failure tendency along the tooth.