Finite element simulation of the plastic collapse of closed-cell aluminum foams with X-ray computed tomography

Abstract

The detailed deformation and plastic collapse mechanisms of closed-cell Al foams under uniaxial compressive loading, which govern the energy absorption capacity of the foam material, are analyzed with the method of finite elements and experimental measurements. A three-dimensional (3D) finite element (FE) model for a real closed-cell Al foam specimen fabricated via the direct foaming route is constructed by employing the micro-focus X-ray CT system, the 3D reconstruction program, the 3D scanned data processing software, and the commercially available mesh generation program. Finite element analysis is subsequently carried Out using the constructed FE model to explore the deformation and collapse mechanisms of the foam specimen, and the numerical predictions are compared with the experimentally measured results. From this research, it is found that all increase in the 0.2% offset yield stress considerably increases the magnitude of the plateau stress, whereas a decrease in the power-law hardening exponent not only increases the magnitude of the plateau stress but also modifies the shape of the plateau stage. Also, it is found that an increase in the 0.2% offset yield stress with a decrease in the power-law hardening exponent dramatically increases the magnitude of the plateau stress. (C) 2010 Elsevier Ltd. All rights reserved.