A fatigue damage-cumulative model in peridynamics

• Published in: Chinese journal of aeronautics Vol. 34; no. 2; pp. 329 - 342
• Main Authors: LIU, Binchao, BAO, Rui, SUI, Fucheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2021; Institute of Solid Mechanics,School of Aeronautic Science and Engineeing,Beihang University,Beijing 100083,China%Shenyang Aircraft Design and Research Institute,Shenyang 110801,China
• Subjects: Fatigue crack growth rate; Fatigue damage; Fatigue element model; Fatigue lifetime; Multiple site damage; Peridynamics; Fatigue lifetime; Peridynamics; Multiple site damage; Fatigue crack growth rate; Fatigue damage; Fatigue element model
• ISSN: 1000-9361
• DOI: 10.1016/j.cja.2020.09.046

While the present structural integrity evaluation method is based on the philosophy of assumed similitude, Fatigue and Damage Tolerance (F&DT) evaluations for next generation of air-vehicles require high-fidelity physical models within cyberspace. To serve the needs of F&DT evaluation in digital twin paradigm, a fatigue damage-cumulative model within peridynamic framework is proposed in this paper. Based on the concept of fatigue element block and damage accumulation law in form of Coffin-Manson relationship, the proposed model applies to both fatigue crack initiation and fatigue crack growth; fatigue crack growth rates under constant-amplitude and simple variable-amplitude block loading cases can be well predicted for three common structural materials without inputs of Paris law parameters. Additionally, the proposed model can also be easily extended to a probabilistic version; for verification, multiple-site-damage problems are simulated and the statistic nature of fatigue process in experiments can be well captured. In the end, main features of the proposed model are summarized, and distinctions from the other models are discussed. There may be a potential for the peridynamic damage-cumulative model proposed in this work to numerically predict fatigue problems in digital twin paradigm for future generations of aerospace vehicles.