Density Functional Theory as a Finite Element Constitutive Model

Matt Fago, California Institute of Technology

We present a method that utilizes ab initio material properties computed in real-time during a finite element solid mechanics simulation. The material behavior is modeled, under the Cauchy-Born assumption, as individual non-interacting unit-cells at each mesh integration point. Density Functional Theory is used to compute stresses and energies, with the global solution fields obtained by energy minimization.

This approach allows for the prediction of phase changes (with basis optimization), simulation under large ranges of stresses (including very high pressures), and the study of alloy composition, and models all material behaviors allowed by the chosen unit cell including plastic slip.

We will present the method, implementation details, and preliminary results.

Abstract Author(s): M Fago and R Hayes