In-plane and out-of-plane constraint characterization of different constraint parameters for semi-elliptical surface cracks in pipes

The two‐parameter fracture criterion based on the J‐A concept

“…[23][24][25][26][27] The J-T zu -A T concept connects the advantages of the J-T zu and J-A 2 solutions; the J-T zu-A T solution is developed for the 3D crack-tip constraint theory. 28 To characterize two types of constraints, the following parameters of the plastic deformation behavior of the material near the crack tip can be also introduced in the model, 16,[29][30][31] the crack tip opening displacement, [32][33][34] the critical crack tip opening angle, 35 and the plastic work-based parameter. 36 At the same time, a discussion of the limitations of the plane strain two-parameter fracture mechanics approaches is cited in this paper so that readers can understand the reason why so many approaches were proposed.…”

Validation and application of a two‐parameter J‐Ad approach for fracture behaviour prediction

“…The two-parameter approach can be used for fracture analysis of any specimens and structures. 8,20,24,26,39,40 In this work, to validate the J-A d two-parameter approach, extensive experimental fracture toughness data of SEN(B) specimens having various sizes (different inplane and out-of-plane constraints) measured by Neimitz and Galkiewicz 35 were used. The experimental materials are 40H steel with two different heat treatments, namely, material A and material B.…”

“…24,26 The material toughness locus based on A d can also be easily obtained using the fracture toughness data of several specimens with various constraints. It should be noted that all constraint parameters (like Q, h, A 2 , T z , and A d 7,8,20,24,40 ) generally need to be determined by FE analysis. In the three-parameter J-Q-T z approach, the calculation of the two constraint parameters Q and T z needs the help of FE analysis.…”