Stress Intensity Factor Calibration for Corner Flaws at an Open Hole.

摘要

The fatigue crack growth test was used to investigate corner flaws at holes in polymethylmethacrylate plates loaded in uniform, cyclic tension. Using baseline data and Paris' relationship, a calibration of stress intensity factor for the constant thickness, constant hole diameter specimens was made. Nondimensional stress intensity factors were plotted for crack shape values, ratios of crack length at the hole to crack length at the surface, of 1.2 to 1.6. In general, this study demonstrated lower stress intensity at the hole and higher stress intensity at the surface for larger crack sizes when compared to other researchers. It was concluded that fatigue crack growth rate testing with PMMA is a useful method of obtaining stress intensity factor calibrations for complex, three-dimensional problems where no exact solutions exist.