Fatigue shape analysis for corner cracks at fastener holes

• Published in: Engineering fracture mechanics Vol. 59; no. 1; pp. 73 - 87
• Main Authors: Lin, X.B., Smith, R.A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1998
• Subjects: corner cracks; fastener hole; fatigue growth simulation; stress intensity factor; three-dimensional finite element analysis; three-dimensional finite element analysis; fastener hole; corner cracks; stress intensity factor; fatigue growth simulation
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/S0013-7944(97)00085-4

Fatigue crack shape is simulated in this paper by a step-by-step finite element technique for corner cracks emanating from fastener holes in plates under cyclic tension loading. The numerical technique calculates the local growth increments at a set of points defining a crack front by employing a Paris type fatigue growth law, and permits the growth to be automatically advanced on a step-by-step basis. Hence, it can directly predict the shape development of propagating cracks. The fatigue shape analysis is concentrated on the growth simulation for several assumed initially quarter-elliptical corner cracks at three fastener holes of different hole radius. An initially irregular corner crack is also modelled to examine its shape development characteristic. The crack shape deviation from the widely-assumed quarter ellipse is numerically investigated by both the proposed relative residual and standard deviation criteria. The aspect ratio changes during crack growth are obtained and compared with limited experimental data found in the literature. Moreover, the influence of the power contained in the Paris law on the aspect ratio variation is studied.