Positive, zero and negative Poisson’s ratio non-stochastic metallic cellular solids: dependence between static and dynamic mechanical properties

Abstract

Cellular solids are attractive materials due to their high specific static and dynamic mechanical properties. Even though these mechanical domains are interdependent, they are generally studied separately. This study uses a combination of additive manufacturing and vacuum assisted investment casting to manufacture low specific density (0.042 to 0.098) non-stochastic metallic cellular solids. An in-situ unitary cell geometric control is used to produce samples with positive, zero and negative Poisson’s ratios. The different values of this elastic constant allow the analysis of the distinct deformation in auxetic and non-auxetic behaviors. Deformation models are used to describe the static and dynamic behavior of the referred samples. It is shown that auxetic samples display higher values of apparent modulus and plastic collapse stress due to their densification effect. In terms of dynamic properties, samples with slightly negative and zero rib angles show higher values of damping. This is attributed to the more favorable flexure component of deformation and variations in material volume that influence the hysteretic damping. Overall, it is suggested that the most beneficial combination of specific density, static and dynamic mechanical properties is observed in samples with a rib angle of -10° and a Poisson’s ratio of -0.34.