Events Calendar

Title: A Continuum Mesoscale Perspective of the Dynamic Response of Metals & Explosives

Presented by: Darby Luscher

Los Alamos National Laboratory

Abstract: The dynamic thermomechanical responses of polycrystalline materials under shock loading are often dominated by the interactions of defects and interfaces. Polymer-bonded explosives can be initiated under weak shock impacts that would be insufficient to drive a reaction if the material response were homogeneous. Within metals, a prescribed deformation associated with a shock wave may be accommodated by crystallographic slip, void nucleation and growth, and fracture; the competition amongst these processes is often influenced by the behavior of grain boundaries. Direct numerical simulation at the mesoscale offers insight into these physical processes that can be invaluable to the development of macroscale constitutive theories. However, this approach requires that the mesoscale models adequately represent the nonlinear thermomechanical response of individual crystals and their interfaces. Here, we highlight a mesoscale modeling approach and then discuss progress towards improving the underlying theory and models for each constituent based on experimental observation.