Numerical Investigation on Mechanical Behaviour of Closed-cell Aluminium Foams Using a Representative Volume Element Method

Chengjun Liu,Chunhui Yang,Y.X Zhang,R.K Agarwal,H Abd Rahman

doi:10.1051/matecconf/20166503003

Abstract

In this study, a representative volume element (RVE) method is developed to capture the mechanical behaviour of aluminum foams under compressive loadings. Octadecahedrons are selected for forming cells of a microstructured RVE model to simulate mechanical behaviour of the aluminium foams under quasi-static compressive loadings. A convergence test is conducted to determine an appropriate mesh density. The stress-strain relationship obtained from the numerical simulations is compared to that from experimental study and agreements between these results demonstrate the efficiency of the proposed RVE model. Thereafter failure modes during a compressive loading process of the aluminum foams are also identified and discussed using this RVE model.

Highlights

Closed-cell aluminium foams are very competitive materials for applications in engineering structures where weight and impact resistance are the main concerns, due to their superior mechanical characteristics such as light weight and energy absorption
As for validation and verification, the stress-strain relations extracted from the representative volume element (RVE) model were compared to that from a compression test of equal-porosity Alporas® foams
A RVE model based on repeated octadecahedrons has been developed in this study to model the mechanical behaviour of closed-cell aluminum foams numerically

Summary

Introduction

Closed-cell aluminium foams are very competitive materials for applications in engineering structures where weight and impact resistance are the main concerns, due to their superior mechanical characteristics such as light weight and energy absorption. It is difficult to achieve such a systematic algorithm across both length and time scales To simplify this complex problem with ignoring the influence from time scale, a systematic framework on multiscale analysis and digital material representation of heterogeneous material [4], which are multiphase and microstructured, has been developed and ustilised to fabricate and evaluate their overall material properties, i.e., porous materials and particle-reinforced composites. It is based on micromechanics and theory of localisation and homogenisation. A Representative Volume Element (RVE) method is proposed to model the closed-cell aluminium foams focusing on their mechanical behaviour under compressive loading. This microstructured RVE model is employed to model Alporas® foams with a porosity of 0.915 under quasistatic compressive loading with a loading rate of 2 mm/min

RVE model of Closed-Cell Foams

FEA of the RVE model

Results and discussion

Concluding Remarks