Advancing Material Modeling in Hydrocodes Beyond Equations of State

TL;DR

This paper introduces a multiscale simulation framework that integrates molecular dynamics with finite element methods, bypassing traditional equations of state to incorporate detailed microscale physics in hydrodynamic modeling.

Contribution

It presents a novel coupling approach using lifting and restriction operators for continuum-atomistic simulations, validated against experiments and conventional EOS models.

Findings

Validated against experimental data and EOS models.

Achieves 99% weak scaling efficiency in simulations.

Demonstrates feasibility of atomistic EOS evaluation as an alternative.

Abstract

We present a multiscale simulation framework that couples the Finite Element Method with molecular dynamics. Bypassing traditional equations of state (EOS) by using in-line atomistic simulations, the method offers the advantage of incorporating detailed microscale physics not easily represented with coarse-grained models. Coupling consistency with the continuum code is ensured through the use of lifting and restriction operators, in line with heterogeneous multiscale methods. The concurrent continuum-atomistic framework is validated through comparison with experimental results and conventional EOS models, and demonstrated in a shock-driven hydrodynamic flow simulation under extreme conditions. We further evaluate the framework's usability by comparing it to state-of-the-art EOS models of deuterium. A computational performance study reveals that the atomistic EOS evaluation is a feasible alternative to conventional approaches, and demonstrates a weak scaling of 99% efficiency. These results highlight the framework's potential for large-scale multiscale modeling across a broad range of materials and conditions.