Grain modeling and finite element simulation of damage evolution for AA5182-O aluminum alloy sheet

Abstract

The evolution of crystal damage in rolled AA5182-O aluminum alloy sheet was studied by experiment and finite element simulation in this paper. Grain size characteristic on rolling anisotropy was determined by electron backscatter diffraction (EBSD) test and section line method, and the average grain size of R00°and R90° with the rolling direction was achieved. An improved grain modeling method was proposed by adjusting base rectangle and regularity coefficient based on Voronoi method. It established six finite element models of uniaxial tension grains, which considers anisotropic grain size and regularity coefficient. The Gurson–Tvergaard–Needleman (GTN) model was applied to analyze damage evolution of elements in grains, and whose damage parameters were achieved by the tensile test and the response surface method. The mechanical properties of grain boundaries were characterized by cohesive zone model. The Abaqus software was adopted to conduct the uniaxial tension finite element analysis to investigate influence of anisotropic grain size, number, and regularity coefficient on plasticity damage evolution of this material. The results show that when regularity coefficient of is 0.01 and 007, the fracture elongation of 54 grains model which is considering grain sizes of R00° and R90° is the closest to experimental results.