Mode I Crack Surface Displacements and Stress Intensity Factors for a Round Compact Specimen Subject to a Couple and Force

Abstract

Mode I displacement coefficients along the crack surface and stress intensity coefficients are presented for a radially cracked round compact specimen, treated as a plane elastostatic problem, subjected to two types of loading; a uniform tensile stress and a nominal bending stress distribution across the net section. By superposition the resultant displacement coefficient or the corresponding stress intensity coefficient can be obtained for any practical load location. Load line displacements and stress intensity coefficients are presented for A/D ratios ranging from 0.40 to 0.95, where A is the crack length measured from the crack mouth to the crack tip and D is the specimen diameter. Through a linear extrapolation procedure, crack mouth displacements are also obtained. Experimental evidence and comparisons with other investigators shows that the results of this study are valid over the range of A/D ratios analyzed for a practical pin loaded round compact specimen.