Interpolation Between Calculated Stress Intensity Factors of Semi and Quarter Elliptical Cracks

摘要

Accuracy of interpolation of calculated stress intensity factors for semi-elliptical surface cracks and for quarter elliptical corner cracks at open holes and pin loaded holes was studied. Depth to thickness ratio (a/t) aspect ratio of ellipse (a/c) and hole radius to thickness ratio were interpolated. For surface cracks the best interpolation results are obtained with F3 values. For corner cracks F2 values are better. The first interpolation step should be made between results for different a/c-values but the same a/t, to get the required c/t (crack length), instead of interpolating to the required a/c (crack shape). In the first interpolation step a linear interpolation with a/c as a variable gives the best results. In the second step a linear interpolation with a/t as a variable gives the best results for surface cracks, for corner cracks square root of a/t is better. Accuracy is within 2%.