Computational modelling of irregular open‐cell foam behaviour under impact loading

Cellular structures represent an important class of engineering materials. Typical representative of such structures are metallic foams, which are being increasingly used in many advanced engineering applications due to their low specific weight, appropriate mechanical properties and excellent energy absorption capacity. For optimal design of cellular structures it is necessary to develop proper computational models for use in computational simulations of their behaviour under impact loading. The paper studies the effects of open‐cell metallic foam irregularity on deformation behaviour and impact energy absorption during impact loading by means of parametric computational simulations, using the lattice‐type modelling of open‐cell material structure. The 3D Voronoi technique is used for the reproduction of real, irregular open‐cell structure of metallic foams. The method uses as a reference a regular mesh structure and utilises an irregularity parameter to reproduce the irregularity of real open‐cell structure. A smoothing technique is introduced to assure proper stability and accuracy of explicit dynamic simulations using the produced lattice models. The effects of the smoothing technique were determined by comparative simulations of smoothed and unsmoothed lattices subjected to dynamic loading.