Development of a Program-Loading Spectrum for the Accelerated Durability Test of Lower Control Arm

摘要

This study aims to develop a program-loading spectrum for the accelerated durability test of automotive components, with the lower control arm of a suspension as an example. Spectrum development is divided into three parts, namely, load spectrum acquisition, spectrum preprocessing, and program-loading spectrum development. Based on the strengthening property of structural low-amplitude loads under constant and random loadings, a program-loading spectrum-development method considering the strengthening effect of low-amplitude loads (SLAL) below the fatigue limit is proposed. Meanwhile, an equivalent strengthening methodology is considered during spectrum development. The number of loading cycles is decreased, and the bench test time is notably reduced by adjusting strengthening loads to the most effective level. The bench test proved that the influence of SLAL during spectrum development can simulate actual load conditions more effectively and precisely. Thus, this method can accurately predict fatigue failure from the durability test and can efficiently reduce durability test time.