双指标阶段性退化建模及可靠性分析

高可靠长寿命产品常需同时满足多种功能, 退化机理复杂, 其性能退化过程中多指标、多阶段的问题日益凸显。为此, 考虑退化过程的阶段性特征及不同阶段指标间耦合性规律, 基于Copula函数和Wiener过程建立了双指标阶段性退化模型及可靠性分析方法。同时, 针对产品退化过程中两指标变点不在同一位置的一般性情况, 提出了一种考虑双指标变点的模型参数整体估计方法。最后, 通过舱门锁实例的对比分析, 对所提方法的适用性和有效性进行了验证。结果表明, 同传统双指标模型相比, 所提方法能更为准确地描述退化过程的相关性与阶段性规律, 得到的可靠性评估结果更合理有效。

Bivariate and two-stage degradation modeling and reliability analysis

High reliability and long life products often need to meet multiple functions at the same time, and the degradation mechanism is complex. The problem of multi-index and multi-stage in the process of performance degradation is becoming more and more prominent. Therefore, considering the stage characteristics of degradation process and the coupling law between indexes in different stages, a two index stage degradation model and reliability analysis method are established based on Copula function and Wiener process. At the same time, aiming at the general situation that the change points of two indexes are not in the same position in the process of product degradation, a global estimation method of model parameters considering two index change points is proposed. Finally, the applicability and effectiveness of the proposed method are verified by the comparative analysis of an example of cabin door lock. The results show that the proposed simultaneous interpreting method can more accurately describe the correlation and stage rules of degradation process compared with the traditional dual index model, and the reliability evaluation results obtained are more reasonable and effective.