An efficient strategy for large scale 3D simulation of heterogeneous materials to predict effective thermal conductivity

Xiaodong Liu,Julien Réthoré,Marie-Christine Baietto,Philippe Sainsot,Antonius Adrianus Lubrecht

doi:10.1016/j.commatsci.2019.05.004

Abstract

The behavior of heterogeneous materials (e.g. composite, polycrystalline) is one of the most challenging subjects for researchers. Imaging techniques based on X-ray tomography permit one to obtain the inner structure of these materials. To account for such detailed information and understand the material behavior, the use of tomographic images as an input for numerical simulations is becoming more and more common. The main difficulty is the computational cost, mesh generation in the context of finite element simulations and the large discontinuities of the material properties, which can lead to divergence. The subject of this paper is to resolve these problems and understand the behavior of a material with high heterogeneity. The application of a MultiGrid method coupled with homogenization technique is proposed. The MultiGrid method is a well known method to increase convergence speed. The homogenization technique is applied to compute the coarse grid operators of the MultiGrid process. The combination of the two methods can efficiently deal with large property variations. Hybrid MPI/OpenMP parallel computing is used to save computational time. The influence of material heterogeneity is analyzed as well as the ratio of material properties for the thermal conduction. The effective thermal conductivity of material is illustrated.

Highlights

The use of composite materials in many industrial fields has become more and more wide spread during the last decade
The goal of this paper is to show that one can employ numerical simulations directly on tomographic images
The strategy to use the MG method coupled with a homogenization technique, permits one to deal with this kind of problems

Summary

Introduction

The use of composite materials in many industrial fields has become more and more wide spread during the last decade. It is well known that many composite materials exhibit an excellent mechanical behavior. Due to the complex structures and variable components of composite materials, it is not simple to understand their properties, which limits the application of these materials. Traditional experiments permit to globally characterize some of their properties. It can just reduce this problem but not solve it fully. The characterization of the thermal properties of a composite material is an example

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