双筒式液压减振器阻尼力退化建模与可靠性评估

Study on the Reliability Test and Degradation Modelling of Double-tube Hydraulic Damping Force

针对双筒式液压减振器的性能退化和寿命评估问题,根据阻尼力的产生机理,分析内泄、阻尼阀片卡滞或力学性能退化、油液黏度退化三种典型故障模式下减振器的阻尼力变化机理,在此基础上建立其相应的复原力和压缩力计算模型,通过仿真对比不同退化情况下的示功图和速度特性图,得到了复原力和压缩力的退化规律。提出基于双动耐久试验台和性能试验台的减振器退化试验方案,经试验获得了减振器复原力和压缩力的退化数据;利用Linear模型和最小二乘法获得了退化模型参数的估计值,根据失效阀值确定了减振器的伪失效寿命数据;结合先验信息,采用虚拟增广样本及Bootstrap方法,对极小样本的伪失效寿命数据进行了样本增广,得到了该型减振器的寿命均值。

Aiming at the performance degradation and life evaluation of double-tube hydraulic damper, according to the mechanism of damping force, the changing mechanism of damping force characteristics is analyzed with three typical failure modes which including inside leaking, damping valve binding and performance degradation and the oil viscosity degradation, and based on this, its rebound and compression force model is established. By simulating the indicator diagram and velocity-force diagram are compared to that in different degradation, and the relevant degradation feature is gained. The experiment schedule of damper degradation based on the double-action endurance test rig and performance test rig is presented, and the degradation data of damper quality, rebound force and compression force are obtained by test. Utilizing the linear model and least square method, the estimated parameters of degradation are got, and the damper' pseudo failure life data are determined according to the failure threshold. Combining with the prior information, the minimum sample pseudo failure life data of sample is augmented and corrected by using a virtual augmented samples and the Bootstrap method.