Title: Two-scale modelling of effects of microstructure and thermomechanical properties on dynamic performance of an aluminium alloy

Authors: J.D. Clayton

Addresses: Impact Physics, RDRL-WMP-B, US Army Research Laboratory, Aberdeen Proving Ground, MD 21005-5066, USA

Abstract: 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.

Keywords: crystal plasticity; aluminium alloys; multi-scale modelling; ballistics; microstructure; thermomechanical properties; dynamic perforation; elastic deformation; plastic deformation; thermal softening ; energy storage; residual stress; line defects; second-phase particles; cylindrical projectiles; texturing; ductility; alloy performance.

DOI: 10.1504/IJMSI.2010.035202

International Journal of Materials and Structural Integrity, 2010 Vol.4 No.2/3/4, pp.116 - 140

Published online: 14 Sep 2010 *

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