Influence of plastic anisotropy and stress state on damage evolution and fracture behavior of aluminum 1100

In this paper, the damage growth and fracture locus of specimens with plane anisotropy at different triaxiality are investigated. Damage evolution along the deformation is achieved using the loading-unloading technique in tensile test. In this technique, the degradation in elastic modulus is referred to the damage parameter. Changing the geometry of fracture zone in the simple tension specimen gives different stress triaxiality. For this purpose, three different geometries, dog-bone, notched and in-plane shear specimens, from aluminum 1100 were fabricated. All samples are tested along rolling, diagonal and transverse directions in order to investigate the anisotropy behavior. The fracture strain of all specimens is measured experimentally using Microstructural Image Processing (MIP). For validating the experimental results, a combined experimental-numerical simulation is performed. In this regard, the all tests are simulated in ABAQUS/Explicit via VUSDFLD and VUHARD codes. In the simulation, a nonlinear law models the damage. In this regard, the anisotropic behavior of material is described by Hill's 1948 yield criterion and Johnson-Cook fracture model which characterizes the dependency of fracture strain on the stress triaxiality. The simulation results are in good agreement with experimental data in force, damage and fracture strain locus. The maximum and minimum errors for fracture strain are found as 17.8% and 1.5%, respectively. It is found that the anisotropy has no important effect on the fracture strain as well as damage evolution for aluminum 1100. On the contrary, the stress triaxiality has significant effect rather than anisotropy on the fracture strain and damage growth.

Automated summary

This study investigates the damage growth and fracture locus of specimens with plane anisotropy under different triaxiality. Damage evolution during deformation is achieved using the loading-unloading technique in tensile test. Different stress triaxiality is achieved by changing the geometry of the fracture zone in the simple tension specimen. Three different geometries of aluminum 1100 specimens, including dog-bone, notched, and in-plane shear specimens, were fabricated. The anisotropy behavior was investigated by testing all samples along rolling, diagonal, and transverse directions. The experimental results were validated using a combined experimental-numerical simulation in ABAQUS/Explicit. It was found that anisotropy has no significant effect on fracture strain and damage evolution for aluminum 1100, while stress triaxiality has a significant effect.