Homogenization of discrete diffusion models by asymptotic expansion

Homogenization of discrete diffusion models by asymptotic expansion

WoS Article

Diffusion behaviors of heterogeneous materials are of paramount importance in many engineering problems. Numerical models that take into account the internal structure of such materials are robust but computationally very expensive. This burden can be partially decreased by using discrete models, however even then the practical application is limited to relatively small material volumes. This paper formulates a homogenization scheme for discrete diffusion models. Asymptotic expansion homogenization is applied to distinguish between (i) the continuous macroscale description approximated by the standard finite element method and (ii) the fully resolved discrete mesoscale description in a local representative volume element (RVE) of material. Both transient and steady-state variants with nonlinear constitutive relations are discussed. In all the cases, the resulting discrete RVE problem becomes a simple linear steady-state problem that can be easily pre-computed. The scale separation provides a significant reduction of computational time allowing the solution of practical problems with a~negligible error introduced mainly by the finite element discretization at the macroscale.

Diffusion behaviors of heterogeneous materials are of paramount importance in many engineering problems. Numerical models that take into account the internal structure of such materials are robust but computationally very expensive. This burden can be partially decreased by using discrete models, however even then the practical application is limited to relatively small material volumes. This paper formulates a homogenization scheme for discrete diffusion models. Asymptotic expansion homogenization is applied to distinguish between (i) the continuous macroscale description approximated by the standard finite element method and (ii) the fully resolved discrete mesoscale description in a local representative volume element (RVE) of material. Both transient and steady-state variants with nonlinear constitutive relations are discussed. In all the cases, the resulting discrete RVE problem becomes a simple linear steady-state problem that can be easily pre-computed. The scale separation provides a significant reduction of computational time allowing the solution of practical problems with a~negligible error introduced mainly by the finite element discretization at the macroscale.

homogenization; mass transport; diffusion; discrete model; concrete; Poisson's equation; quasi-brittle material

homogenization; mass transport; diffusion; discrete model; concrete; Poisson's equation; quasi-brittle material

ELIÁŠ, J.; YIN, H.; CUSATIS, G.

2023

01.11.2022

Wiley

0363-9061

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS

46

16

United Kingdom of Great Britain and Northern Ireland

3052

3073

21

https://onlinelibrary.wiley.com/doi/full/10.1002/nag.3441