A fatigue damage-cumulative model in peridynamics

• 来源期刊: 中国航空学报（英文版）
• 年，卷（期）: 2021,（2）
• 页码范围: 329-342
• 页数: 14页
• 语种: 英文

摘要

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 eval-uation 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 statis-tic nature of fatigue process in experiments can be well captured. In the end, main features of the pro-posed 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.