Homogenization of discrete diffusion models by asymptotic expansion
نویسندگان
چکیده
Diffusion behaviors of heterogeneous materials are paramount importance in many engineering problems. Numerical models that take into account the internal structure such robust but computationally very expensive. This burden can be partially decreased by using discrete models, however even then practical application is limited to relatively small material volumes. paper formulates a homogenization scheme for diffusion models. Asymptotic expansion applied distinguish between (i) continuous macroscale description approximated standard finite element method and (ii) fully resolved mesoscale local representative volume (RVE) material. Both transient steady-state variants with nonlinear constitutive relations discussed. In all cases, resulting RVE problem becomes simple linear easily pre-computed. The scale separation provides significant reduction computational time allowing solution problems negligible error introduced mainly discretization at macroscale.
منابع مشابه
Asymptotic Expansion Homogenization of Discrete Fine-scale Models with Rotational Degrees of Freedom for the Simulation of Quasi-brittle Materials
Discrete fine-scale models, in the form of either particle or lattice models, have been formulated successfully to simulate the behavior of quasi-brittle materials whose mechanical behavior is inherently connected to fracture processes occurring in the internal heterogeneous structure. These models tend to be intensive from the computational point of view as they adopt an “a priori” discretizat...
متن کاملSimultaneous diffusion and homogenization asymptotic for the linear Boltzmann equation
This article is on the simultaneous diffusion approximation and homogenization of the linear Boltzmann equation when both the mean free path ε and the heterogeneity length scale η vanish. No periodicity assumption is made on the scattering coefficient of the background material. There is an assumption made on the heterogeneity length scale η that it scales as ε for β ∈ (0,∞). In one space dimen...
متن کاملEffective diffusion tensor computed by homogenization
Introduction Diffusion MRI can give useful information on cellular structure and structural change (for a review see [1]). We show that the effective diffusion tensor obtained by mathematical homogenization theory (see e.g. [2,3]) is a good approximation to the long time apparent diffusion tensor under realistic DMR scanning conditions for both isotropic and anisotropic diffusion and general ge...
متن کاملAn Asymptotic Expansion for the Discrete Harmonic Potential
We give two algorithms that allow to get arbitrary precision asymptotics for the harmonic potential of a random walk.
متن کاملAsymptotic expansion for the models of nonlinear dispersive, dissipative equations
Considered herein are the family of nonlinear equations with both dispersive and dissipative homogeneous terms appended. Solutions of these equations that start with finite energia decay to zero as time goes to infinity. We present an asymptotic form which renders explicit the influence of the dissipative, dispersive and nonlinear effect in this decay. We obtain the second term in the asymptoti...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Journal for Numerical and Analytical Methods in Geomechanics
سال: 2022
ISSN: ['1096-9853', '0363-9061']
DOI: https://doi.org/10.1002/nag.3441