Evaluation of Ductile Fracture Behavior Using GTN Model

Abstract

Ductile fracture behavior using GTN (Gurson-Tvergaard-Needleman) model in commercial FEA code was evaluated. The material properties of the GTN model for Type 304 SS were experimentally identified. Smooth-bar and notched-bar specimens were subjected to monotonic loading by tensile test, and load-displacement curves were measured. Then, the tensile test was simulated. Material properties of the GTN model were calculated from measured and simulated load-displacement curves with inverse analysis based on Bayes’ theorem. Simulated load-displacement curves using the GTN model of different curvature notched-specimens agreed well with the measured results. To verify the evaluation of ductile fracture behavior using the GTN model, flat-plate specimen with a single surface flaw and specimen with multiple through flaws were subjected to monotonic loading. Ductile fracture of the flat-plate specimen was simulated by FEA using the GTN model using the calculated material properties. The simulated load was less than the measured load at the same displacement. The analysis using the GTN model can estimate the load on the safe side and the GTN model can conservatively simulate ductile fracture behavior.