Ultrasonic characterization of unconsolidated granular media undergoing compaction

In this work we present a method using ultrasonic waves to probe accurately the elasticity of a 3-D granular packing, where other existing methods fail (optical for instance). In order to reach a large number of different mechanical states of the disordered granular structure, we use the well-known compaction process. The objective is to understand the influence of parameters like compacity on the linear and nonlinear elastic properties of non cohesive granular media.