残余应力对齿轮弯曲疲劳的量化影响研究

随着风电、高铁、掘进等高端装备对齿轮功率密度、服役寿命等要求的提高，齿轮的弯曲疲劳问题日益显著。为提升齿轮弯曲疲劳性能，通过渗碳热处理、喷丸强化等工艺为齿轮引入较高的残余压应力已逐渐成为工业界的标配。为揭示残余应力对齿轮弯曲疲劳性能的量化影响，在最大主应变寿命预测准则中引入残余应力影响项，通过弯曲疲劳试验确定最优残余应力影响系数，进而采用新的试验数据验证模型的准确性。基于工程应用出发，引入修正应力的概念统一不同残余应力状态下的齿轮弯曲应力-寿命(S-N)曲线，研究结果显示，最大主应变准则中，残余应力影响系数取值为0.15时，可实现较高的寿命预测精度，而修正的S-N曲线中，最佳残余应力影响系数为0.25。研究成果可用于工程实际中齿轮弯曲疲劳快速评估。

Quantitative Effect of Residual Stress on Gear Bending Fatigue

The gears bending fatigue problem has become increasingly prominent due to the increasing requirement of gear power density and service life for sophisticated equipment such as wind turbines, high-speed rails, shield tunneling et al. In order to improve the bending fatigue performance of gears, carburizing heat treatment, shot peening and other processes have become commonly used methods to introduce high compressive residual stress (RS) on gear. The RS influence coefficient is introduced into the maximum principal strain life prediction criterion to quantitatively reveal the influence of RS on gear bending fatigue performance. The optimal RS influence coefficient is determined through bending fatigue test, and then verified by the new test data. Based on engineering applications, the concept of modified stress is introduced to unify gear bending stress-life (S-N) curves under different residual stress states. The research results show that the optimal RS influence coefficient in the maximum principal stress criterion is 0.15. The best RS influence coefficient in the revised and unify S-N curve is found as 0.25. The research results can be used for rapid assessment of gear bending fatigue in engineering practice.