Nonlinear wave dynamics of a disperse granular layer stimulated by an inwards moving piston

Three-dimensional simulations of wave propagation in a granular medium layer containing particles with polydisperse size distribution are performed using the discrete element method (DEM). The wave is generated by a piston subjected to an impulse load. It is shown that in the free surface layer, rotation wave structures are formed. Their location, time of occurrence and duration are determi-ned using correlation analysis. These wave structures are revealed when the friction between the grains (particles) is incorporated and, moreover, the gravitation (cid:28)eld resulting in the non-uniform distribution of the inter-particle force (cid:28)eld is taken into account. The absence of the rotation wave formation is also shown when the inhomogeneity caused by the gravitational (cid:28)eld is destroyed by vertical loading.