Behaviour of aluminium foam under uniaxial compression

The deformation behaviour of different types of closed cell aluminium foam (Alulight, Alporas) was studied. Compression tests indicate that inhomogeneities in the density distribution might be the key factor in determining the mechanical behaviour of foams. Strengthening and softening of the foam can be related to the formation of deformation bands. Depending on the composition and the microstructure of the cell wall material, cells undergo either ductile or brittle collapse. A three dimensional finite element analysis, which has the capability to simulate the initial deformation of foam samples, is presented. Continuum mechanics methods are used to describe the behaviour of foam. Each foam sample is divided into subregions, according to their density distribution. Scaling laws are used to simulate the mechanical properties of the subregions. Experimental data are compared with results of the presented model. Very good agreement between experiments and modelling was found for the rather inhomogeneous Alulight material.