Stress-strain states and energy absorption in open-cell aluminium foams under hypervelocity impact

Open-cell aluminium (Al) foam is widely used in the field of hypervelocity impact (HVI) energy absorption, especially in space science, but the mechanical properties have been less studied. In this case, HVI numerical simulations are conducted on it to predict the mechanical properties and energy absorption performance. Firstly, an open-cell Al foam model based on the Voronoi tessellation is established for HVI simulation tests using a rigid plate inside a closed pipe with a velocity range of 2 km/s to 6 km/s. The wavefront during the impact process is referred to as a “crushing shock”, and the position of the wavefront is defined by the FER (Finite Element Reconstruction). By extracting wave velocity versus particle velocity, the Hugoniot is obtained for different ligament and pore radius foam materials which is linear. Combined with the classical equations for shock waves, the stress, strain, as well as energy dissipated per unit volume of the foam material are predicted. Results show that all numerical results are in general agreement with the theoretical predictions, which verifies the high accuracy of using the method to predict the shock-wave mechanical and energy absorption properties of foam materials.