A study of ultra-low cycle fatigue failure based on a fracture strain energy model. (May 2021)

• Record Type: Journal Article
• Authors: Wang, Tao; Wen, Jian-Feng; Liao, Peng-Peng; Zhang, Xian-Cheng; Kim, Yun-Jae; Tu, Shan-Tung
• Is Part Of: International journal of fatigue. Volume 146(2021)
• Publication Date: 2021-05
• Subjects: Ultra-low cycle fatigue (ULCF) -- Fracture strain energy -- Ductile fracture -- Finite Element Analysis -- Seismic load; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2021.106149
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: Extensive ULCF test data are provided for a C-Mn-Si steel. An energy-based model is proposed to predict the ULCF failure. The model considers the effect of both cyclic loading and stress triaxiality. The model can well correlate the ULCF life to within a scatter band of 1.5. Abstract: Ductile failure under ultra-low cycle fatigue (ULCF) loading is often the limit service state of a nuclear structure. In the paper, ULCF tests for a C-Mn-Si steel are carried out. It is observed that the fracture displacement decreases as the number of fatigue cycles increases. An energy-based model, which considers the effects of both stress triaxiality and cyclic loading on the critical fracture strain energy, is proposed. Coupled with the new model, finite element analyses of the round notched specimens can predict the equivalent plastic strain and the number of fatigue cycles to fracture within a scatter band of 1.5.