Investigation of mechanical behavior of Aluminum foam under uniaxial tests using Voronoi tessellation method

Aluminum foams are among the materials that have many applications in the construction of various building elements, including sandwich panels. This category of materials has unique features due to low density, the presence of small holes, sound insulation, thermal insulation, and corrosion resistance. In this paper, the Voronoi tessellation method is proposed to simulate the porous configuration of aluminum foams, which has the high capability to generate the porous structure with different densities. It is demonstrated that the Voronoi tessellation method can generate porous structures with different densities, hole sizes and wall thicknesses stably. Moreover, the Voronoi tessellation method has a high speed and can be used to construct different sizes of aluminum foams. Comparison of the configurations obtained from the Voronoi tessellation method and experimental tests demonstrates the capability and competence of this method in generating the porous structure of the aluminum foam. In order to numerically investigate the mechanical behavior, the uniaxial tension test is applied to the aluminum nanofoams through the molecular dynamics (MD) method. The MD analysis is performed in the LAMMPS open-access software using the embedded-atom model (EAM) interatomic potential. The periodic boundary condition is imposed in all the boundaries of the atomistic model to satisfy the essential condition of the representative volume element (RVE) based on the homogenization theory. After minimization and relaxation of RVE, the uniaxial tension test is applied in an increment manner to reduce the strain rate effect. The evolution of the stress-strain curve along with the stress contours are presented for the aluminum nanofoam during the uniaxial tension test. Young’s modulus of nanofoam obtained by numerical analysis is compared to that of experimental data to confirm the accuracy of the computational modeling. Moreover, the results emphasize the high dependence of the mechanical behavior of aluminum nanofoams on the density and porosity.