A ductile failure model applied to the determination of the fracture toughness of welded joints. Numerical simulation and experimental validation

Local fracture resistance behavior of interface regions in a dissimilar metal welded joint

“…The material with smaller f 0 value usually has higher ductile fracture resistance [32]. Although the GTN model parameters for simulating the ductile crack initiation and propagation of a material may not be unique [33], a set of parameters can be found by adjusting the different parameters in a calibration procedure of fitting the numerical J-resistance curve with experimental one [12,22,31,34]. And this set of parameters can be used to predict ductile fracture of specimens with different geometries [12,20,22,31,34].…”

“…The modified model in Eq. (2) is referred as GTN model, which has been implemented in ABAQUS code and widely used to predict and simulate ductile crack growth and fracture resistance behavior of different specimens, material interfaces and welded joints [10,[20][21][22][23][24][25]. In this study, GTN damage model was used in the FEM simulations to obtain the crack growth resistance curves and ductile fracture toughness of the two interface regions in the Alloy52M DMWJ with different initial crack locations.…”

“…(6) for each loading point i are those of the material where the crack is located in. In addition, the crack growth length was corrected for including the blunting effect [22]:…”

“…For simulating this process, the damage mechanics model, such as the Gurson-Tvergaard-Needleman (GTN) model [17][18][19] was developed. This model has been widely used in simulating the ductile crack growth and fracture resistance behavior for different specimens [20], material interfaces [20,21] and similar metal welded joints [22][23][24][25][26]. The fracture resistance curves of a DMWJ also have been simulated using the GTN model by authors [10].…”

Failure resistance of drilling rig casing pipes with an axial crack

“…Such an approach, i.e. setting the value of f 0 as equal to the volume fraction of non-metallic inclusions in steel, was applied previously in [36][37][38][39][40].…”