Enhanced compressive mechanical properties of aluminum based auxetic lattice structures filled with polymers

Auxetic lattice structures are prospective candidates in many engineering applications because of their unique negative Poisson's ratio effect as well as excellent mechanical properties. An aluminum based auxetic lattice structure reinforced by polymer fillers was fabricated through pressure infiltration technology, and the compressive mechanical properties of the resultant auxetic composites were then investigated through experimental tests combined with finite element analyses in the present study. The results show that the composites exhibit higher elastic modulus, compressive strength and energy absorption capacity compared with original aluminum based auxetic lattice structures. This enhancement is ascribed to intensified interaction between the struts and the polymer filler resulted from the special deformation mode of auxetic lattice structures. Furthermore, the deformation mechanism mode of the auxetic structures and corresponding auxetic composites were also discussed. It is therefore suggested that there will be pronounced enhancement in auxetic lattice structures if the negative Poisson's ratio effect is restrained.