3.3.3. Strain-based CTOD estimation formula for A-867744 biaxial loading cases
The values of B0B0, β1β1 and β2β2 in Eq. (7) – for biaxial loading cases.p (mm)c/aB0B0β1β1β2β2311.09671.57020.764933.85161.62540.829756.95181.72200.8787510.85961.26240.757932.51511.27230.793553.75691.40360.7846710.55710.85940.752832.19941.18410.770753.00271.28240.7510Full-size tableTable optionsView in workspaceDownload as CSV
Fig. 12. The CTOD values obtained from Eq. (7) and the FE results under the biaxial loading: (a) p = 3 mm, (b) p = 5 mm and (c) p = 7 mm.Figure optionsDownload full-size imageDownload as PowerPoint slide
4. A comparison of fracture assessment between BS7910: 2005 and the current results
Few literatures provide guidelines to perform the fracture assessment of the pipeline girth welds subjected to large plastic strains, such as DNV-RP-F108 & DNV-OS-F101. However, blending was observed that DNV documents mainly recommend the use of BS7910: 2005 assessment procedure with limited modifications for offshore pipelines. In both DNV documents and BS7910: 2005, the reference stress approach is employed to make the assessment on the fracture toughness of the flawed pipelines. Here BS7910: 2005 is adopted to illustrate the reference stress method for fracture assessment, and then the required CTOD toughness values are compared with the current results.