关键词: 飞机结构, 广布裂纹, 有限元方法, 裂纹扩展, 损伤累积, 疲劳寿命

Abstract: For three-dimensional widespread cracks caused by corrosion, fatigue, and other potential damages on the surface of an aircraft, the interaction which exists in adjacent cracks accelerates the damage of the structure under fatigue loading. In order to find a solution to the fatigue life of threedimensional widespread cracks, a rectangular plate of finite thickness with two semielliptical surface cracks of different geometric dimensions in close vicinity is used as a model, and the parametric finite element method is used to compute stress intensity factors, crack extension directions, and crackgrowth increments. The stress intensity factor history is set up using the crackgrowth increment and stress intensity factors, and the fatigue life of the structure under fatigue loading is estimated through cyclebycycle damage accumulation. The result provides a theoretical reference for fatigue life prediction of an aircraft structure with three-dimensional widespread cracks in complicated environments.

Key words: aircraft structure, widespread cracks, finite element method, crack propagation, damage accumulation, fatigue life