Reliability analysis of failure threshold value with uncertain Liu process1

Abstract

A system undergoes a failure process in which the internal degradation and external loads are independent and compete with each other. In the reliability model of competitive failure, the threshold of failure is often a dynamic process that changes with time. Based on this, this paper constructs a model in which the failure threshold is an uncertain Liu process and applies it to the competitive failure reliability process, where soft and hard failure thresholds are modeled by different Liu processes. In the absence of a large amount of failure data, uncertainty theory is used as a tool to analyze the belief reliability and mean time to failure of the system. Taking gas-insulated substation (GIS) as an example, the effect of parameters on belief reliability is analyzed, and the reliability under Liu process threshold and constants threshold is compared, which shows the validity of the prosed model.

Reliability assessment models for competing failure processes with two types of correlative thresholds

“…Xie et al 26 considered that shocks affect both hard and soft failure thresholds and accelerate the degradation rate during the failure process. Chun et al 27 considered the uncertainty of hard and soft failure thresholds and used the Liu process to describe the dynamic change of failure thresholds. These studies considered the variation of hard and soft failure thresholds to make the reliability assessment more realistic.…”