Introducing auxetic behavior to syntactic foamsNovak, Nejc (Avtor) Kolar, Miha (Avtor) Movahedi, Nima (Avtor) Vesenjak, Matej (Avtor) Ren, Zoran (Avtor) Fiedler, Thomas (Avtor) auxetic cellular structuresyntactic foamsexperimental testsmechanical propertiesPoisson’s ratioThis paper proposes an innovative multi-material approach for introducing auxetic behaviour to syntactic foams (SFs). By carefully designing the size, shape, and orientation of the SFs, auxetic deformation behaviour was induced. Re-entrant hexagon-shaped SF elements were fabricated using expanded perlite (EP) particles and a plaster of Paris slurry first. Then, an auxetic pattern of these SF elements was arranged within a stainless-steel casting box. The empty spaces between the SF elements were filled with molten aluminium alloy (A356) using the counter-gravity infiltration casting technique. The cast auxetic composite had a bulk density of 1.52 g/cm3. The cast composite was then compressed under quasi-static loading to characterise its deformation behaviour and to determine the mechanical properties, especially the Poisson’s ratio. The cast composite deformation was auxetic with a Poisson’s ratio of −1.04. Finite Element (FE) simulations were conducted to understand the deformation mechanism better and provide means for further optimisation of the geometry.MDPI20202024-03-28 10:44:18Članek v reviji87763sl© 2024 by the authors