Accelerated Tests of Wiper Motor Retainers Using CAE Durability and Reliability Techniques

An accelerated test procedure has been developed at Visteon to reduce the component durability test time, while meeting the reliability requirements. The method and procedure are presented in this paper with application examples to wiper motor bearing retainers. The new test speed, load level, and test duration of the accelerated test are derived by employing the CAE durability and reliability techniques. The accelerated test speed is determined based on the dynamic characteristics of the test specimen-fixture-machine system, using the CAE finite element analysis method. The increased test load level is obtained based on CAE dynamic stress simulation, material fatigue model, and durability damage equivalence. The reduced test duration (or number of test cycles) is determined based on CAE equivalent fatigue damage technique and modified from the reliability requirement parameters, such as reliability target, confidence level, and sample size. From a project example it is shown that the durability test time of a wiper motor retainer is reduced by more than 18 times while maintaining the required reliability target.