Storage life and reliability evaluation of accelerometer by step stress accelerated degradation testing

The method of step-stress accelerated degradation testing(SSADT) is utilized to evaluate the storage reliability and life of accelerometer. First, based on failure mode effect and criticality analysis(FMECA) as well as fault tree analysis(FTA), it is determined that temperature stress is its sensitive stress, and Arrhenius model is taken as its accelerated model. Then, an appropriate liner model was built with the test data. Combined with the threshold of failure, the storage life of each sample can be calculated. The hypothesis test show that the storage life complies with Weibull distribution pattern. The distribution parameters of the accelerometer under normal temperature are obtained with the accelerated model. The reliability of the accelerometer is 0.988 when it has stored for 140 160 h (16 a).