Lifetime assessment method based on step-stress accelerated lifetime test

For the old product with the field using period, the single-stress & timing-conversion step-stress accelerated life test (SSALT) is carried out to derive the product's lifetime by using the field using data and accelerated life data. The product's lifetime is assumed to obeying to Weibull distribution with double parameters. Considering the stress difference between the field and laboratory, the lifetime distribution model based on correction factors is built. The SSALT data modeling analysis is carried out to build the cumulative distribution function under each stress. Data iteration algorithm is applied to obtain the estimates of unknown the model parameters. An example by Monte Carlo simulation test is analyzed to verify the accuracy and validity.

I. Introduction

With the development of reliability technology, the product's quality and reliability have rapid increased, which meet the demand of high reliable and long lifetime product in the field of aviation & space, electric engineering and so on. In order to assess the product's lifetime quickly and precisely, accelerated life test (ALT) technology is applied to reach the reliability test target under the premise of the limited test time and funds [1].