4. RESULTS AND DISCUSSION 4.1 Deterministic analysis The crack profiles were digitised and analysed using the line spring technique of Rice and Levy [10] as implemented in ABAQUS [11] to determine the local stress intensity factor and T-stress. Defects were re-characterised following BS 7910 [12], with a bounding semi-elliptical defect. Results for the re-entrant and re-characterised geometries are presented in Figure 4. Figure 4(a) shows the crack profiles. The normalised stress intensity factors are given in Figure 4(b), and the T-stress normalised with the outer fibre stress is shown in Figure 4(c). Compressive T-stresses and amplified stress intensity factors develop in re-entrant sectors. Limit loads were determined numerically as 208 kN at –196 oC for the defect with the pronounced re-entrant sector and 225 kN for re-characterised defects and 197 kN and 108 kN for the two defects tested at –100 oC.
RkJQdWJsaXNoZXIy MjM0NDE=