Random fatigue life prediction of automobile lower arm via modified Corten–Dolan model

• Published in: Fatigue & fracture of engineering materials & structures Vol. 45; no. 12; pp. 3500 - 3513
• Main Authors: Yang, Xizhou, Liu, Xintian, Wang, Yuhan
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.12.2022
• Subjects: Cumulative damage; Damage assessment; Fatigue failure; Fatigue life; fatigue life prediction; Histograms; Life prediction; load spectrum; lower arm; Measuring instruments; modified Corten–Dolan model; Prediction models; Signal processing; Stress ratio
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1111/ffe.13824

The fatigue life for the rear suspension lower arm of the passenger car is investigated. The road load signals collected by the sextant force measuring instrument are processed. And the frequency histogram of it is plotted and its distribution characteristics are analyzed. The load signal is extrapolated to a cumulative frequency of 106 using the parametric method, and the one‐dimensional load spectrum of the lower arm is compiled. Based on the nonlinear fatigue cumulative damage theory, Corten–Dolan model is modified by introducing the kth power of the stress ratio between two adjacent levels. The improved fatigue life prediction model is established and the validity of the model was determined by experimental data. And the improved Corten–Dolan and the linear cumulative damage model are used to predict the life of the lower arm under one‐dimensional load spectrum respectively. Highlights The load signals are analyzed and the one‐dimensional load spectrum is compiled. Corten–Dolan is modified by the kth power of the stress ratio between two adjacent levels. The modified model is verified with experimental data. The fatigue life of the lower arm is predicted via the modified model.