Two-Scale Modelling of Effects of Microstructure and Thermomechanical Properties on Dynamic Performance of an Aluminium Alloy

Influences of microstructure and properties of an aluminium alloy on resistance to dynamic perforation are predicted using a decoupled multiscale modelling approach. At the scale of individual grains, a crystal plasticity model is developed accounting for finite elastic and plastic deformations, thermal softening and energy storage mechanisms linked to microscopic residual stress fields induced by line defects and second-phase particles. An averaging scheme is invoked to compute macroscopic stress-deformation responses corresponding to various microstructures. The results of the averaging process motivate choices of parameters entering a macroscopic plasticity model, with different parameter sets corresponding to different microstructures. This macroscopic model, with various parameter sets, is in turn used to simulate impact and perforation of a thin plate of the aluminium alloy by a cylindrical projectile. The results provide quantitative assessments of possible benefits of texturing, insertion of strengthening and energy storage mechanisms and enhancement of ductility on performance of the alloy.