Experimental-numerical study of laser-shock-peening-induced retardation of fatigue crack propagation in Ti-17 titanium alloy

• Published in: International journal of fatigue Vol. 145; p. 106081
• Main Authors: Sun, Rujian, Keller, Sören, Zhu, Ying, Guo, Wei, Kashaev, Nikolai, Klusemann, Benjamin
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2021; Elsevier BV
• Subjects: Crack closure; Crack propagation; Fatigue crack propagation; Fatigue failure; Fatigue life; Laser shock peening; Laser shock processing; Life prediction; Materials fatigue; Numerical simulation; Peening; Residual stress; Stress intensity factor; Stress propagation; Ti-17 titanium alloy; Titanium alloys; Titanium base alloys; Numerical simulation; Laser shock peening; Stress intensity factor; Ti-17 titanium alloy; Fatigue crack propagation; Residual stress
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2020.106081

[Display omitted] •An experimental-numerical combined study of LSP for titanium alloy is presented.•LSP-induced residual stresses retard the FCP significantly in the titanium alloy.•A multi-step simulation strategy is applied for the prediction of the FCP.•Crack closure during the propagation accounts for the retardation of the fatigue crack.•The influence of peening patch positon and residual stress magnitude on FCP is investigated. Residual stresses induced by laser shock peening in Ti-17 titanium specimens were experimentally and numerically investigated to identify the mechanisms and generation conditions of the retardation of fatigue crack propagation (FCP). The retardation was experimentally observed with fatigue life prolonged by 150%. A multi-step simulation strategy for fatigue life prediction is applied, which successfully predicts the experimentally observed FCP behavior. The fractographic observations and numerical simulation indicate that crack closure, as opposed to other microstructural influences, is the dominant effect on retardation. The studies of multi-FCP aspects show that significant retardation occurs in specimens at high values of residual stresses, small peening gap distances, and lower externally applied loads.