齿面形貌-润滑-残余应力耦合的齿轮传动接触机理与疲劳寿命研究

The tendency towards higher speeds and heavier loads requires the improvement of power density of gear drives. Traditional gear contact strength design method is based upon the Hertzian theory, which is not able to explain the effects of surface lubrication conditions and the elastic-plastic behaviours. Hence early tooth surface failures occur in engineering practice frequently which affect the reliabilities of gear devices. Accurate descriptions on the surface tribological states and the accumulation of the plasticity strains form the foundation for the prediction of the contact fatigue damage. The project aims to use the theories in contacts, lubrication, test technologies, gear meshing, and continuous damage to study the gear contact fatigue mechanism. A gear contact fatigue method, which combines the effects of the surface roughness, lubrication and the residual stress, is proposed. The effective numerical algorithm based upon the generalized Reynolds equation and the semi-analytical method is developed for the calculation of the evolutions of the tooth surface roughness, the lubrication state and the plasticity strain during gear meshing. The chracteristics of the coupling phenomenon between the tooth surface roughness, the residual stress, and the plasticity strain will be shown based on the numerical model. Considering the fatigue damage accumulation due to the time-varying multiaxial stress state and the plasticity strain increment, the effects of the gradient distributions of the yield strength and the residual stress along the tooth surface depth, and of the surface roughness-lubrication state on the stress-strain fields, the pressure, the film thickness, as well as the contact fatigue life are to be determined. The mechanical performances of the gears are to be tested while tests are to be conducted which will be used to verify the therotical results. The projects aims to clarify the mechanism of the gear contact fatigue behaviour, which will support future anti-fatigue gear design and manufacture in modern engineering practice.

机械装备朝高速重载的发展趋势对齿轮功率密度要求不断提高，基于赫兹理论的传统齿轮接触强度设计方法无法揭示齿轮界面润滑接触状态和塑性应变对疲劳损伤的影响，导致工程实际中经常发生早期齿面失效，严重影响装备可靠性。项目针对齿轮接触疲劳失效机理不清楚导致过早齿面失效的问题，采用接触力学、润滑理论、现代测试技术、齿轮啮合理论、连续损伤力学多学科交叉方法，考虑齿面微观形貌-润滑界面状态和塑性应变累积因素，建立齿面形貌-润滑-残余应力作用下的齿轮接触疲劳分析模型，研究服役过程中齿面形貌、残余应力、塑性应变的关联特征，实现基于时变多轴应力状态和塑性应变增量的疲劳寿命预估，阐明残余应力分布特征以及齿面形貌-润滑界面状态对应力-应变场等润滑接触性能和接触疲劳寿命的影响规律，结合试验测试验证，揭示齿轮接触疲劳失效机理，为现代齿轮抗疲劳设计提供支撑。

面向机械装备高速重载发展趋势对齿轮功率密度提升和抗疲劳设计的需求，针对齿轮接触疲劳失效机理不清楚导致过早齿面失效的问题，突破传统赫兹接触理论的局限，采用接触力学、啮合理论、损伤力学、试验测试等多学科交叉方法，建立了齿面形貌-残余应力耦合作用下的齿轮接触疲劳分析模型，辨识了服役过程中齿面形貌、残余应力、塑性应变的耦合关联特征，实现齿轮接触疲劳寿命预估，阐明了残余应力、齿面形貌特征对应力-应变场等润滑接触性能和接触疲劳寿命的影响规律，开展了齿轮接触疲劳试验验证，为现代齿轮抗疲劳设计提供支撑。