A loss of constraint assessment using σ*-V* approach to describe the effect of crack depth on reference transition temperature T0

The assessment of fracture behaviour of ferritic/ferritic martensitic steels in Ductile to Brittle Transition (DBT) region iscrucial for shallower cracks. In this work the fracture behavior of In-RAFM steels isinvestigated with systematically varying a/W using Master Curve approach. This a/W effect is investigated using σ*-V* approach by calculating the active volume at simulated crack front. It is observed that the fitting parameter of σ*-V* approach is in direct correlation with changing constraint parameter ΔTstress. The constraint effect with varying crack depth is also captured by a novel constraint parameter referred as Weibull triaxiality.