New approach to failure onset analysis of Trip steel

چکیده مقاله

Various criteria, as such Gurson-Tvergaard-Needleman (GTN), have been presented to anticipate the ductile fracture onset of metals during forming processes by FE analyses. According to GTN criterion, voids nucleate and coalesce during forming and they inform crack when void volume fraction in a local position of substance gets a critical value. In the current research, the fracture onset of TRIP700 steel during forming process by cross die and Nakazima tests was analyzed experimentally and numerically. GTN model was applied as damage criterion and height at which fracture initiated during the studied tests was predicted. To get the proper values of GTN model parameters, response surface methodology (RSM) was applied for simulation of tensile test. Strength and ductility values during tensile test were applied as response, while GTN model parameters were the input variables. The results showed that TRIP700 steel behavior during the cross die and Nakazima tests could be predicted fairly, if GTN model parameters were identified properly. RSM can be applied confidently for identification.