多故障模式高长寿命产品相关性失效的综合可靠性评估

Comprehensive Reliability Assessment of Long-life Products with Correlated Multiple Failure Modes

为解决高长寿命产品多故障模式相关性失效下的实时可靠性综合预估问题,基于产品的性能退化数据,运用确定性趋势组合时序模型,提炼既定故障模式退化量分布发展的特征信息,依条件期望原理差分方程方法,给出动态退化量分布特征参数、多退化量之间相关程度参数的估计方法。根据退化量间的正相关结构,建立多故障模式相关性失效的Copula综合可靠性模型,并拓展至退化量-随机失效阈值相关性干涉的普适性模型。Copula相关性模型的研究结果表明,产品的可靠度既依赖于其强度衰减的时序特征,也随故障模式相关程度参数动态连续变化。算例验证了该类模型的可行性和有效性。

To solve the problem of updated comprehensive reliability prediction involving correlated multiple failure modes for the long-life products. The statistical analysis of performance degradation data is studied for the high-reliability and long-life products. Deterministic time series combined models are used to extract the characteristic information of the distribution of degradation variables, and according to the differential equation method, the suited methods are given to estimate the dynamic characteristic parameters of the distribution of degradation variables, also the scalar parameter of correlation among in multiple degradation variables. Based on the positive correlation among in degradation characteristic variables, it builds the suitable copulas reliability model to calculate the comprehensive reliability of products which have dependent multiple failure modes, and promote it to the general model involving correlative interference between random failure threshold and degradation characteristic variables. The Copula theoretical models show that the reliability value of products both rely on the time series characteristics of their strength, but also change in a special interval dynamically with the scalar parameter of correlation among in multiple degradation variables. Finally, an example is given to demonstrate the feasibility and effectiveness of the model.