Regular and irregular highly porous open cell structures with a relative density of 12.5% are investigated by the Finite Element Method. The three-dimensional models are based on beam elements and account for the material distribution and the constrained deformation in the vertices [
Six generic cell structures with regular arrangements of struts (Simple Cubic, Body Centered Cubic, Reinforced Body Centered Cubic, Gibson Ashby, Kelvin, and Weaire Phelan) are modeled by a unit cell approach for predicting the entire tensors of elasticity. Out of the six the two cell architectures with the highest and the lowest elastic anisotropy are selected for further nonlinear studies.
Cuboidal and cylindrical samples consisting of a given number of base cells and different cell orientations are generated. Irregular modifications thereof are created by randomly shifting the position of the vertices within a spherical domain. Defects are introduced by randomly removing base cells.
The nonlinear overall mechanical behavior is predicted for uniaxial compression in different directions under consideration of an elastic-plastic strut material and large deformations. Also localization of the deformation is considered [
]. The mechanical performance of the structures with different defects and different magnitudes of perturbations is compared in terms of the absorbable energy, the maximum bearable load, and deformation localization.
The computational predictions are compared to results from experiments. The latter are performed on samples with corresponding architecture, fabricated by rapid prototyping [