飞行汽车齿轮传动系统动态可靠性分析

Dynamic Reliability Analysis of Flying Car Gear Transmission System

飞行汽车作为面向未来城市空中交通的新型交通工具,具有智能、高效和便捷的特点。齿轮传动作为飞行汽车动力传输的关键部件,其安全性与可靠性已成为制约飞行汽车发展的难题。但目前针对飞行汽车齿轮传动系统的可靠性分析方法缺失,现有齿轮传动设计方法未能考虑强度退化与失效相关性对系统可靠性的影响,存在潜在失效风险。因此,基于应力-强度干涉理论,建立了考虑强度退化与失效相关性的某飞行汽车齿轮传动系统动态可靠性分析模型;根据飞行任务剖面图建立载荷谱,并获得了齿轮接触与弯曲应力,通过Goodman准则将齿轮脉动循环应力历程等效为对称循环应力,以匹配基于S-N曲线的疲劳损伤计算;基于非线性疲劳累积损伤理论,建立了齿轮强度退化模型,并通过Copula函数描述了传动系统中的失效耦合相关性;结合应力-强度干涉理论,阐述了飞行汽车齿轮传动系统可靠性演化规律,为飞行汽车齿轮传动系统动态设计与可靠性优化奠定了基础。

As a new type of transportation for future urban air transportation,flying cars are intelligent,efficient and convenient.As a key component of the power transmission of a flying car,the safety and reliability of gear transmission has become a difficult problem restricting the development of flying cars.However,the current reliability analysis method for the gear transmission system of flying cars is lacking.The existing design method fails to consider the influence of the strength degradation and failure correlation on the reliability of the transmission system which has a potential failure risk.Therefore,a dynamic reliability analysis model of a flying car gear transmission system considering the correlation between strength degradation and failure is established based on the theory of stress-strength interference.According to the flight mission profile,the load spectrum is established and the gear contact and bending stress are obtained.The complex stress history is equivalent to symmetric cyclic stress by Goodman criterion,which matched the fatigue damage calculation based on S-N curve.A gear strength degradation model is established based on the theory of non-linear fatigue cumulative damage,and the Copula function is used to describe the failure coupling correlation in the transmission system.Combined with the stress-strength interference theory,the reliability evolution law of the flying car gear transmission system is expounded,which lays a foundation for the dynamic design and reliability optimization of the gear transmission system of flying car.