Storage Life Evalution of Optocoupler under Competitive Failure Condition

Abstract

Purpose:

For assessing the storage life of the terminal-guided projectile optocoupler, the reliability of two-factor independent competition failure based on Wiener process-based degradation failure and Weibull-based sudden failure is carried out.

Methods：In the aspect of degradation failure modeling, the linear Wiener process is improved. The drift coefficient is randomized by establishing the random variable Arrhenius equation. The problem of transforming nonlinear data into linear data is solved by using the time-scale transformation formula, and parameter estimates were solved by the two-step maximum likelihood estimation method. The Weibull distribution is studied for sudden failure modeling. Assuming m<10 and t0.9>10, the “data island” method is proposed. The obtained convergence solution was evaluated by the maximum likelihood estimation, and then the initial values of three parameters are determined.

Results:Its t0.9 is about 25.46 to 27.5 years in the case of degradation failure only and 17.1 years in the case of sudden failure only.

Conclusion:The long-term storage of the optocoupler is estimated to be about 17 years under 0.9 reliability conditions due to the combination of degradation failure and burst failure.