基于加速因子不变原则的加速退化试验优化设计

Accelerated degradation test has been extensively applied to reliability assessment for degrading-failure products. To improve the efficiency-cost ratio, the optimal design theory and method of accelerated degradation test becomes a research hot. In order to promote the development of relative theory and method, the optimal design of accelerated degradation test based on acceleration factor constant principle, in which Wiener degradation model and step-temperature accelerated degradation test are considered, is proposed. Whether the parameters of Wiener degradation model are dependent on accelerated stress or not is derived according to the acceleration factor constant principle. Thus the accelerated degradation model is objectively constructed and the expression of acceleration factor is got. Furthermore, in order to ensure that the failure mechanism under accelerated stresses is probably consistent with that under the normal use stresses, the asymptotic variance of acceleration factor, which is selected to be the objective function of optimization, is then derived to set up a mathematical model of test plan. A combined algorithm consisting of 3 sequent steps is developed to resolve the mathematical model, and the algorithm is actualized by programs to improve the solving efficient. Through a case application of optimal design for the accelerated degradation test of a certain type electrical connector, the effectiveness and feasibility of the proposed method is validated.