Compression Behaviour of Finite Dimensional Cellular Metals by Generalization of Cell Buckling Effects

Metal foams are materials of recent developments and applications that show interesting combinations of physical and mechanical properties. Foams are commonly used as of passive safety components due to their high capacity of energy absorption under impact conditions. In this work the foam is represented as a cellular material with a regular structure and specimens of a cellular metal are used to study the foam behaviour. Considering that compression is the dominant loading in impact situations, the deformation behaviour of finite dimensional cellular metal specimens under compression is investigated. The specimen deformation configuration is determined by means of fundamental buckling effects on cells walls evaluated from simple representative volume elements. Damage effects under a finite strain context are included together with self-contact considerations. The overall behaviour of a finite specimen is derived from an analytical and numerical framework based on the boundary conditions present on the foam. The main advantage of this method is the capability of determine the full behaviour of a complex foam configuration with only simple case analyses, with low computational cost.