Metamaterial Predicted by Granular Micromechanics

Granular micromechanics approach (GMA) provides a predictive theory for granular material behavior by connecting the grain-scale interactions to continuum models. GMA provides the micro-macro linkages necessary for designing the physical (meta)material system.  For example, grain-pair interactions that include coupling between normal and tangential deformations lead to emergence of non-standard chiral behavor of 1D bar and negative Poisson’s effect in 2D plates as depicted in the graphics.  We have designed such a grain-pair connection for physical realization and quantified with FE model.  The verification of the prediction is then performed using a physical model obtained by 3D printing