An Improved Model for FE Modeling and Simulation of Closed Cell Al-Alloy Foams

الملخص EN

Cell wall material properties of Al-alloy foams have been derived by a combination of nanoindentation experiment and numerical simulation.

Using the derived material properties in FE (finite element) modeling of foams, the existing constitutive models of closed-cell Al-alloy foams have been evaluated against experimental results.

An improved representative model has been proposed for FE analysis of closed-cell Al-alloy foams.

The improved model consists of a combination of spherical and cruciform-shaped cells similar to those of Meguid et al.'s cruciform-hemisphere model (Finite Elem.

Anal.

Design: 2002, 38, 631).

However, the spherical cells, which are smaller in size, are made of thicker cell walls in the new improved model compared to the cruciform-shaped cells, based on observation of the underlying Al-alloy foams.

The compressive mechanical properties of Al-3wt.%Si-2wt.%Cu-2wt.%Mg alloy foams of relative density 12%–20% have been obtained by simulation using the improved representative model.

While the traditional foam models overpredict the foam strength, the new weaker-cruciform-stronger-hemisphere model is found to predict the foam properties with much better accuracy.

It is found that the proposed new model is capable of producing all three different types of deformation pattern of closed-cell metal foams, namely, uniform deformation, layerwise deformation, and the progressive deformation from the locations of lowest densities and highest impurities to those of higher densities and lower impurities.