Reliability Modeling for Multi-correlation Degradation Considering Random Variable Failure Threshold
Since the failure of mechanical components was affected by the coupling effects of mul-tiple degradation processes and external shocks and other factors,the current studies mostly consid-ered a single factor and thought that the failure threshold was a fixed value,ignoring the facts that the equipment might reduce the shock resistance due to the degradation.Therefore,the influences of shocks on the degradation processes and the random uncertainty of the degradation processes on the shock failure threshold,as well as the correlation among different degradation processes were consid-ered.A multi-correlation degradation reliability model was proposed considering a random variable threshold.In addition,the Copula function was used to describe the correlation among different degra-dation processes,and the parameter estimation method of the correlation model was given.According to the measured wheel wear data of a certain electric multiple unit(EMU),the accuracy of the model was verified by the Monte Carlo method.The influences of the correlation in the degradation processes on the reliability were discussed,and the sensitivity analysis of the random variable failure threshold was carried out to further illustrate the practicability of the proposed model.
reliabilitymultiple-correlation degradationrandom variable failure thresholdwheel weardegradation-threshold-shock model