Reliability evaluation of coil spring for fuse with multiple performance parameters

As a common energy storage component in fuse, spring is an important part which affects the reliability of fuse. The failure of fuse will cause serious hidden danger. In order to accurately predict the change of reliability of the spring for fuse during storage, a multivariate normal reliability evaluation method based on modified Arrhenius model was proposed. Taking the stress loss rate and permanent deformation rate as performance parameters, the constant stress accelerated test was designed to obtain the degradation data of spring at 120 ℃, 130 ℃, 150 ℃ and 160 ℃. Anderson darling statistics were used to verify that the optimal distribution of degradation was normal distribution. According to the modified Arrhenius model, the degradation trajectory curve of spring at storage temperature was obtained. Based on multivariate normal distribution, the storage reliability model of spring was established, and the change characteristics of spring reliability during storage were analyzed. Compared with other reliability models, the prediction results of this model are more accurate, which provides a theoretical basis for the condition-based maintenance of fuse.