Simulation of critical J-integral in functionally graded steels components weakened by U and blunt V-shape notches under Charpy test

In the present study, the failure resistance of the dual-layer austenitic–martensitic functionally graded steel components weakened by blunt U and V-shape notches has been modeled by finite element method. The mentioned materials contain graded austenitic region were produced through electro slag remelting process by setting the plain carbon and austenitic stainless steel with appropriate arrangements as initial electrode. The failure resistance of functionally graded materials (FGMs) specimens has been obtained experimentally in the form of crack divider configuration for the following values of the notch opening angle: 0 < 2α < 90° by analysis load–displacement curves acquired from Charpy tests instrumented with Hopkinson pressure bar. Cubic elements were joined together to build the standard Charpy specimen in finite element software ABAQUS environment. The data used for each cubic element in finite element modeling was the corresponding stress–strain curve obtained considering predicted load–displacement curve of that layer under Charpy test loading. After applying the impact loading, a sound compatibility between experimental results and those obtained from simulation was observed.