Passive Elastic Structures Interacting with Grains in Motion

Recent publications have shown how non-linear interactions between elastic structures and granular media lead to unique behaviors (complex bending transition, non-symmetric buckling, etc..) that can be described by characteristic elastogranular lengths. Studies have been focused on passive granular media activated by an elastic structure or passive elastic structures interacting with grains in motion.
In this talk, we will describe how the Brownian motion of grains affects the relaxation and the equilibrium shape of a thin elastic structure (a beam or a ring). Once the grains are set in motion, the bending energy of the elastic structure exponentially decay toward a minimum of energy. The characteristic relaxation time is controlled by the beam thickness and the grains packing fraction and kinetic energy. In the case of a ring, the equilibrium shape of the elastic structure is also controlled by these parameters. The present experiment opens new ways to study experimentally the equilibrium shape of membranes has a function of their environment.