多种失效模式履带车辆扭力轴可靠性稳健设计

履带车辆扭力轴通常存在多种失效模式,因此对其进行灵敏度设计分析时需要充分考虑不同失效模式的影响。提出一种多失效模式机械零件可靠性灵敏度分析的数值方法,运用随机摄动理论和四阶矩技术,求得各个失效模式状态函数的前四阶矩和可靠性指标,有效解决了结构随机变量参数分布未知时,不同失效模式下构件可靠度的计算问题。根据机械零件发生一种失效模式即整体失效的具体特点,研究含相关性的不同失效模式机械零件的可靠度计算方法。结合灵敏度分析的梯度算法,推导出关于随机变量均值和方差的灵敏度计算公式,进而根据灵敏度的分析结果,提出多种失效模式下多目标优化的可靠性稳健设计模型。数值算例表明,本文方法可以高效迅速地估计多失效模式下机械构件的可靠性灵敏度。最后还对其进行了可靠性稳健优化设计研究。 

Reliability robust design of tracked vehicle torque axis with multiple failure modes

Several potential failure modes may occur when tracked vehicle torque axis fail, and therefore it is necessary to take each failure mode into account as reliability sensitivity estimation is performed. A reliability sensitivity analysis method for mechanical components with multiple failure modes is proposed. Concerning the unknown distributions of random variables, the random perturbation technique and the fourth moments method are employed to respectively calculate the first four moments and the reliability index of each performance function of the failure mode. According to the characteristic that the overall fails when a failure mode occurs in mechanical parts, the mechanical parts reliability calculation method with correlation between different failure modes is determined. The calculating formulas of reliability sensitivity with respect to the mean and variance of random variables are derived with the gradient method. According to the result of reliability sensitivity analysis, we put forward the model multi-objective optimization design of mechanical parts with multiple failure modes. The numerical example illustrates that the proposed method could quickly and effectively estimate the reliability sensitivity of the mechanical components with multiple failure modes, and could optimize the mechanical robust design.