Modeling strain localization bands in metal foams

Experimental evidence has documented that during compression of metal foams, deformation is governed by the development of horizontal strain localization bands. Higher-order theories, such as the micromorphic continuum and gradient plasticity have been successfully employed to model experimental data. In the present study after comparing the aforementioned theoretical approaches, an analytical model, using gradient plasticity, is developed that can predict the strain distribution within the foam localization bands. Furthermore, in order to obtain a better understanding of the foam mechanics a numerical approach using cellular automata is used to predict the damage evolution and the stress-strain response during compression; the resulting stress-strain graphs are in very good agreement with experimental data.