Modeling shear-controlled fracture in AL2024-T351 at high strain rates

In Al2024-T351 and other materials, the fracture strain strongly depends on the stress state. This feature becomes relevant in predicting material resistance and fracture behavior in ballistic impact. In this work, fracture strain at low and high-strain rates, under prescribed stress triaxiality and third invariant-related parameter conditions, was measured. To this purpose, specifically designed specimen geometries, such as tensile notched tubular, compact forced simple-shear, and shear-compression plate, were used. The experimental results were used to identify the Plasticity Damage Self Consistent (PDSC) model's parameters. A constitutive model, which accounts for viscous drag and dynamic strain aging (DSA) phenomena, has been used in the framework of the Kroon-Faleskog plasticity. For model validation purposes, the occurrence of fracture in Taylor rod impact tests at different velocities was predicted computationally and compared with experimental results.