Dispersão de energia em um cristal granular hexagonal decorado

Abstract

The decorated hexagonal granular crystal consists of main spherical grains arranged in a two-dimensional hexagonal array, with small spherical grains filling the interstitial spaces. These additional grains barely touch the main grains, increasing the number of contacts per grain. Additionally, all grains are initially at rest, with null velocities. For comparation, we used results from a similiar arrangement without decoration (i.e., without interstitial grains). We investigated the mechanical responses of both granular arrangements to the punctual incidence of an external grain. Our analysis focused on how the mechanical energy is dispersed and mitigated after a single initial impact. The proposed model confirmed the significant role of interstitial grains in the granular crystal. The decorated arrangement demonstrated accelerated behavior of the energy wavefront, both in its mitigation and propagation. In our analysis of energy scattering orientations, we found that the decorated arrangement exhibits greater energy mitigation and reorientation of return energy compared to the undecorated arrangement. Thus, the addition of interstitial grains promoves a greater return of mechanical energy to the external medium of origin. We conclude that with proper decoration, a granular crystal could act as a barrier against strong impacts.