Wave Propagation in Granular media composed of Visco-elastic Beads - Internship Research (Master)

The aim of this study is to develop a theoretical model and an experimental setup to study the collision between spherical particles in soft viscoelastic chains. The hydrogel beads (made of polyacylamide) used are "highly" elastic and have a thin layer of liquid on their surfaces. The interaction of two viscoelastic spheres has already been studied, however very few studies are performed on an entire chain. The experimental setup used in our case is the Newton’s Cradle, one is made with metallic beads and the second with hydrogel beads.. The experimental results allow us to fit the unknown parameters of the hydrogel beads such as the Young’s modulus and the viscous coefficient for the simulation. In the experimental viscoelastic Newton’s cradle, simulations and experiments are in good agreement with the fitted values of the physical parameters of the viscoelastic beads. Therefore we can conclude that the fit done in our approximation is well justified. The total time of impact and the solitary wave velocity are calculated. [PDF]

This project was made in collaboration with the Acoustics laboratory of Le Mans University (L.A.U.M., France) and the Polytechnical University of Valencia (U.P.V., Spain).