关键词: 飞机结构, 表面裂纹, 广布损伤, 有限元方法, 应力强度因子

Abstract:

Three dimensional widespread cracks exist on the surface of aircraft caused by corrosion, fatigue, and other potential damage mechanisms, and the interaction in adjacent cracks accelerate the damage of structures under fatigue loading. In order to quantitatively describe the rules affecting adjacent cracks, a rectangular plate of finite thickness under remote tensile load with two semielliptical surface cracks of different geometric dimensions in close vicinity is used as a model, and a parametric finite element method along with the 1/4 point displacement method and circulatary iterative algorithm are used to calculate the stress intensity factors and stress changing pictures of these two cracks in coplanar, center overlapped parallel and inclined parallel situations. The results may provide a theoretical reference to determine the residual strength and fatigue life for aircraft structures with three dimensional widespread cracks.

Key words: aircraft , structure,  , surface , crack,  , widespread , damage,  , finite , element , method,  , stress , intensity , factor