An Evaluation Method of Step-Down Stress Accelerated Life Test Based on Amsaa Model

Life evaluation method of complex systems is facing main difficulties including selection of multiple failure modes or competition failure mode, and expensive test equipment and high testing costs currently. To solve this problem, a multiple step down stresses accelerated life test evaluation method is put forward based on the reliability growth model of complex systems. We reduce the comprehensive stress to an equivalent single stress by properly designing the comprehensive stress profile. We further use the similarity between the growth test and step-down stress accelerated life test to evaluate the reliability of the step-down stress accelerated life test using the Amsaa model. The Amsaa model overcomes the difficulties of choosing from multiple the accelerated models of step-down stress. Finally, the simulation results verify the feasibility of the method.