Fatigue analysis of a plastic component in the window regulator system via considering the variation of fatigue characteristics

The variation of fatigue characteristics in a plastic component was examined during the durability test. To assure the safety of the window regulator system for an automobile, it is necessary to perform strength and fatigue analysis of the carrier plate including engineering plastics such as polyacetal. In this study, strain-controlled fatigue tests were conducted under constant 50% humidity and room temperature condition by a universal testing machine at strain ratio, R = 0. This paper is aimed to provide two major goals. New assessment of probabilistic strain-life curves developed by considering the variation of fatigue characteristics in engineering plastics. To investigate the validity of the suggested assessment, the fatigue life of the carrier plate is estimated with fatigue analysis. Moreover, the predicted fatigue life is verified with the durability test based on the real window regulator system. Selected case study shows that the result of fatigue test fits into the estimated range of fatigue life using probabilistic strain-life curves.