Experimental study of the strengthening effect: A novel fatigue life prediction method for variable amplitude loads.
- Resource Type
- Article
- Authors
- Jiang, Renjie; Yang, Xiaoguang; Shi, Duoqi; Cheng, Muwei; Sun, Yantao
- Source
- Fatigue & Fracture of Engineering Materials & Structures. Nov2023, Vol. 46 Issue 11, p4254-4268. 15p.
- Subject
- *HIGH cycle fatigue
*DAMAGE models
*FATIGUE life
*FATIGUE cracks
*FORECASTING
*POWDER metallurgy
*HIGH temperatures
- Language
- ISSN
- 8756-758X
The strengthening effect of low‐amplitude loading at elevated temperatures was investigated experimentally. A powder metallurgy nickel‐based superalloy FGH96 was preloaded with different cycle numbers and stress levels, and the residual fatigue life was tested under subsequent high‐amplitude loads. The results show that when the number of preloading cycles is in a specific range, the residual fatigue life is higher than that of the virgin specimen under the same load. A novel damage accumulation model was proposed to incorporate the strengthening effect into the life prediction framework. The proposed model was validated using experimental results for various materials in the literature. The mechanism of the strengthening effect of FGH96 was discussed based on electron backscatter diffraction (EBSD) analysis. Highlights: The strengthening effect was found in FGH96 under low‐high sequence loading.The effect of pre‐applied load on the strengthening effect was investigated.A new fatigue damage model considering the strengthening effect was proposed.The microscopic mechanism of the strengthening effect was discussed [ABSTRACT FROM AUTHOR]