Numerical Analysis of the Damage Evolution of DP600 Steel Using Gurson–Tvergaard–Needleman Model

Abstract

This research models the ductile fracture in DP600 steel sheets by using Gurson–Tvergaard–Needleman (GTN) damage model with experimentally obtained parameters. Uniaxial tensile tests are carried out to determine the deformation behavior of the material and obtain GTN model parameters. Further, SEM investigations on the fractured surface of the material display a dimpled surface, which indicates ductile fracture. Also, density measurements are carried out to define the critical and final volume fractions. A finite element model (FEM) of the tensile testing is developed. Then, the experimental parameters of the GTN model are verified by comparing load–displacement curves and porosity values for different zones. The results put forth that the experimental parameters can be used to model the deformation behavior of the DP 600 steel. Further, the growth of total void volume fraction increases exponentially, attributed to the increasing value of stress triaxiality. Also, the shift in the void volume fraction after the critical void volume fraction is explained with the void coalescence. Finally, the thickness of the sheet has a power‐law relationship and the porosity level of the material can be predicted for a known thickness value.