Mechanical properties and energy absorbing capabilities of Z-pinned aluminum foam sandwich

Aluminum foam sandwich (AFS) structures are suitable for impact protection in lightweight structural components due to their specific energy absorption capability under compression. However, tailoring the deformation patterns of the foam cells is a difficult task due to the randomness of their internal architecture. The objective of this study is to analyze the effect of embedding aluminum pins into an AFS panel (Z-pinning) to better control its deformation pattern and improve its energy absorption capability. This study considers a closed-cell AFS panel and analyzes the effect of multi-pin layout parallel to the direction of the uniaxial compressive loading. The results of the experimental tests on the reference (without Z-pinning) AFS are utilized to develop numerical models for the reference and Z-pinned AFS structures. Physical experiments and numerical simulations are carried out to demonstrate the advantages of Z-pinning with aluminum pins. The results exhibit a significant increase in elastic modulus, plateau stress and energy absorption capability of the Z-pinned samples. Also, the effect of the pin size and Z-pinning layout on the mechanical performance of the Z-pinned AFS is also investigated using numerical simulations.