考虑参数不确定性的疲劳断轴可靠性分析方法

主轴是综合传动装置中的核心元件,其可靠性直接影响综合传动装置的正常运行。针对综合传动装置主轴的疲劳失效模式,在有限元仿真的基础上考虑参数不确定性进行可靠性分析。针对疲劳断裂的主轴建立模型进行瞬态动力学仿真,获取承载工况下最大剪切应力。在此基础上考虑参数分散性对主轴强度与所受应力的影响,进行不确定性分析,并基于广义应力-强度干涉理论,运用蒙特卡洛抽样方法进行可靠度计算。在实际使用中,特殊任务下多次发生未预料的断轴故障,主轴的实际使用寿命远低于设计寿命,以该特殊任务为例进行主轴的可靠性分析。研究结果表明：针对疲劳断轴故障,采用考虑不确定性的可靠性分析方法可行。通过案例分析得到了主轴特殊工况下的疲劳寿命。

Reliability Analysis Method of Fatigue Broken Spindle Considering Parameter Uncertainty

The spindle is the core component of the integrated transmission device,and its reliability directly affects the normal operation of the integrated transmission device.Aiming at the fatigue failure mode of the integrated transmission spindle,the reliability analysis was carried out considering the parameter uncertainty based on the finite element simulation.A model of the fatigue fracture spindle was established for transient dynamic simulation,and the maximum shear stress under load condition was obtained.On this basis,the influence of the parameters dispersion on the strength and stress of the spindle was analyzed,and the reliability was calculated by Monte Carlo sampling method based on the generalized stress-strength interference theory.In practice,unexpected broken shaft failures occur many times under special tasks,and the actual service life of the spindle is far lower than the design life.Taking this special task as an example,the reliability analysis of the spindle was carried out.The results show that the reliability analysis method considering uncertainty is feasible for fatigue broken shaft failure.The fatigue life of spindle under special working conditions is obtained through case analysis.