Fatigue Crack Growth Rule of Corroded Stringer Structure with Fastening Holes

Based on the three-dimensional crack propagation theory of fracture mechanics and finite element simulation method of FRANC3D software, the three-dimensional crack propagation rule of corroded stringer structure with fastener holes under fatigue action was studied. The results showed that the error between the stress intensify factor (SIF) and the theoretical solution of finite element simulation was within 5%, and the error of the crack propagation life was within 10%, which verified the effectiveness of the simulation model. Type I cracks were most likely to cause brittle fractures in stringer structure. As the initial crack size increased, SIF and crack growth rate also increasd. In the early stage of crack propagation, small crack mainly propagated along the thickness direction. After penetration, the cracks propagated rapidly, mainly by long crack.