Professor Nidhi Pashine Talk on Granular Metamaterials

Join Professor Nidhi Pashine for her talk on granular metamaterials in Physics 202!

Jammed packings of granular materials display complex mechanical response that is qualitatively different from continuum solids. The elastic behavior of jammed packings depends on, among other factors, the interparticle interactions present in the packing. By modifying how particles interact with each other, we can tune the properties of a packing. In this talk, she will present “tessellated” granular metamaterials where both G as well as the ratio of shear to bulk modulus (G/B) decrease with increasing pressure, even in the large system limit. This is unlike the behavior of bulk granular packings, where the ensemble-averaged shear modulus increases as a power law in pressure. Tessellated granular metamaterials are made from flexible tessellations that are connected to each other, each containing a small number of solid particles. For under-constrained tessellations, the dominant contributions to G and B are the particle–particle and particle–cell interactions. Tessellating a system prevents particles in one cell of the tessellation from interacting with particles in other cells, resulting in unexpected behavior. Towards the end of her talk, she will discuss some future directions with experimental granular systems where they plan to use the ideas of physical learning to create trainable packings.