Study on ductile fracture of aluminum alloys. (Observation of the fracture process by FRASTA and FEM simulation)

The microscopic process of ductile fracture in the process zone is studied in this paper. First, the FRASTA (fracture surface topographic analysis) technique is used, and the ductile fracture processes of two kinds of aluminum alloys, 7075-T6 and 2017-T4, are observed. The nucleation, growth and coalescence of voids are observed in detail. The finite element analyses based on Gurson's model are then carried out. The element vanishing technique is used with the finite deformation theory. Using the void volume percent as the fracture criterion, the nucleation and growth of voids and coalescence with the crack are simulated. It is shown that these phenomena occur in the process zone, and the numerical results agree qualitatively with the experimental ones.