An improved fatigue accumulation damage model based on load interaction and strength degradation. (March 2022)

• Record Type: Journal Article
• Authors: Zhao, Gongwei; Liu, Yating; Ye, Nanhai
• Is Part Of: International journal of fatigue. Volume 156(2022)
• Publication Date: 2022-03
• Subjects: Damage accumulation -- Life prediction -- Damage equivalence -- Load histories -- Residual strength; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2021.106636
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: In consideration of the effect of load interaction on cumulative damage, the Manson-Halford model is modified by introducing stress ratio. Accounting for the properties of strength degradation, a new logarithmic residual strength model is proposed. Based on the equivalent criterion of strength degradation, the residual strength model under variable amplitude loading is deduced. Considering that the damage will become more obvious with the decrease of the strength of parts, the fatigue damage model is improved by strength degradation coefficient. Abstract: This paper presents an improved accumulation damage model which is closer to the actual conditions based on the Manson-Halford (M-H) model. The model considers both the effect of load interaction and the phenomenon of strength degradation of materials induced by loading history. In addition, a new logarithmic residual strength model is proposed and its accuracy is verified by two sets of strength degradation experimental data. Finally, five sets of experimental data under two-level and multi-level loadings are compared with the prediction results. It is shown that the improved model has better applicability and higher accuracy.