基于随机过程和竞争失效理论的可靠性建模方法

发布时间：2018-06-12 05:03

本文选题：可靠性 + 竞争失效　；参考：《兰州理工大学》2017年硕士论文

【摘要】：在工程领域当中,随着运行时间的增加,由于机械产品自身性能的衰退和环境冲击作用,会使产品发生失效。在此失效过程中,产品既有可能由于自身的性能衰退造成退化失效,也可能由于环境冲击造成突发失效,产品的失效是由于最先出现的模式引起的。考虑到在运行过程当中,产品的退化是一个连续的过程,使用随机过程对产品的退化过程进行描述,可以更好地对产品进行可靠性评估。本文主要讨论退化过程和冲击过程同时存在的产品的可靠性,基于随机过程和竞争失效理论的描述,建立产品可靠度模型。首先,综述可靠性与竞争失效的相关背景,介绍可靠性建模的相关理论和特点。给出退化模型的基本概念和可靠性建模过程的分析步骤。对存在冲击过程的产品进行介绍,对现有的冲击模型进行描述。其次,在产品的运行使用过程中,冲击不仅会使产品的失效阈值降低,而且会使产品的退化速率加快。基于相关假设以及竞争失效的相关理论,建立了产品在极端冲击模型下的可靠度模型,该模型认为产品的失效阈值为某一固定阈值。采用微机电系统的相关理论数据对模型进行验证,最终验证了模型的合理性。最后,进一步考虑在产品使用过程中,冲击不仅会影响产品的整体失效过程,还会对其自身性能退化量产生一定影响,并且在失效过程中,产品的失效阈值为某一随机值。根据这一条件,考虑冲击对退化的影响以及失效阈值的随机性,建立产品的竞争失效可靠性模型。使用极大似然估计对相关参数进行估计,对所建立模型取不同参数,计算可靠度。
[Abstract]:In the engineering field, with the increase of running time, the mechanical products will fail due to the degradation of their own performance and the impact of environment. In the process of failure, the product may either degenerate due to its own performance decline or cause sudden failure due to environmental impact. The failure of the product is caused by the first mode. Considering that the degradation of the product is a continuous process in the running process, the stochastic process can be used to describe the degradation process of the product, which can better evaluate the reliability of the product. This paper mainly discusses the reliability of the products which exist simultaneously in the degradation process and the impact process. Based on the description of the stochastic process and the competitive failure theory, the reliability model of the product is established. Firstly, the related background of reliability and competitive failure is summarized, and the related theories and characteristics of reliability modeling are introduced. The basic concepts of the degenerate model and the analytical steps of the reliability modeling process are given. The products with impact process are introduced and the existing impact models are described. Secondly, the impact will not only reduce the failure threshold of the product, but also accelerate the degradation rate of the product. Based on the relevant hypothesis and the theory of competition failure, the reliability model of the product under extreme impact model is established. The model considers that the failure threshold of the product is a fixed threshold. Finally, the rationality of the model is verified by using the relevant theoretical data of MEMS. Finally, in the process of product use, the impact will not only affect the overall failure process of the product, but also have a certain impact on its own performance degradation, and in the process of failure, the failure threshold of the product is a random value. According to this condition, considering the impact on degradation and the randomness of failure threshold, the model of competitive failure reliability of products is established. The maximum likelihood estimation is used to estimate the related parameters, and different parameters are taken to calculate the reliability of the established model.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB114.3

【参考文献】