In recent years increased attention has been given to the transferability of standardized fracture test data to thin-walled pressurized equipment. For smaller diameter piping, for example, standard test specimens loaded in “hoop” tension are not possible due to pipe curvature and thinner wall thickness (often less than 1/3 inch). Further, it is not clear that standardized fracture specimens produce transferrable results to the seam weld fracture problem due to low plastic constraint, which is exacerbated in thin wall pipe. Single-edge notched tension (SENT) specimens were fabricated by extracting a segment pipe wall and finishing to a parallel piped incorporating nearly all the wall thickness. These segments were electron beam welded to low carbon steel grip ends to produce only localized heat affected zone without affecting the test section. The result is a nearly ideal pin-loaded SENT specimen for radial fracture testing. This geometry was evaluated with 2D and 3D nonlinear finite element analysis in Abaqus, and plastic constraint matching was evaluated compared to a thin-walled pipe under internal pressure with a radially growing crack. A nearly ideal plastic constraint match between the pin-loaded SENT and radial seam weld crack was confirmed up to about 500 psi-in, which is substantially beyond a typical JIc in the X52 steel used in the analysis. Thus, pinned SENT testing is recommended for evaluation of radial fracture in thin-walled piping.

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