A fatigue driving energy approach to high-cycle fatigue life estimation under variable amplitude loading

• Published in: Fatigue & fracture of engineering materials & structures 2016-02, Vol.39 (2), p.180-193
• Main Authors: Peng, Z., Huang, H-Z., Zhu, S-P., Gao, H., Lv, Z.
• Format: Article
• Language: English
• Subjects: Deviation; Fatigue (materials); Fatigue failure; Fracture toughness; High cycle fatigue; life estimation; Load; Materials fatigue; Mathematical models; Miners; non-linear damage model; strain energy density; Stress-strain curves; Variable amplitude loading
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1111/ffe.12347

In this paper, a concept of fatigue driving energy is formulated to describe the process of fatigue failure. The parameter is taken as a combination of the fatigue driving stress and strain energy density. By assessing the change of this parameter, a new non‐linear damage model is proposed for residual life estimation within high‐cycle fatigue regime under variable amplitude loading. In order to consider the effects of loading histories on damage accumulation under such condition, the load interaction effects are incorporated into the new model, and a modified version is thus developed. Life predictions by these two models and Miner rule are compared using experimental data from literature. The results show that the proposed model gives lower deviations than the Miner rule, while the modified model shows better prediction performances than the others. Moreover, the proposed model and its modifications are ease of implementation with the use of S–N curve.