Modification of VCCT method with implementation of GTN model for the determination of J-integral

The use of miniaturized specimen test methods is a promising way to overcome the limited materials problem of RPV monitoring programs. The use of small specimens allows the evaluation of fracture toughness from other specimen materials used. In particular, the small size compact tensile specimen (0.16 CT, 4 mm thickness) is promising for fracture toughness determination as it can be produced from the already tested standard size Charpy specimen. The aim of this paper is to demonstrate the feasibility of fracture toughness testing using small sized specimens. For this local approach modeling method was applied. The necessary damage parameters were determined with the help of artificial neural networks, which parameters later were implemented into the modified virtual crack closure technique. The novelty of the research is that the improved simulation method can be used to determine the fracture toughness of the material with good accuracy even for small specimens.