Abstract
In granular layers, an impulsive force is transmitted into the layer through the contact points between particles. This fact reflects to the bulk properties of granular layer itself. In other words, the intrinsic properties of particles and the configurations between the granules (these properties are identified with the word ‘local’) are all intimate connections with the overall dynamic status (non-local property) of granular layers.
Experimental results are easy to understand that the granular layer becomes ‘structural’ in some cases and in other cases it behaves as ‘the motion of the ensemble of particles’ (collective motion). In most cases granular layer has above two properties at the same time.
From the several experiments, it is also recognized that the structural property, collective motion of the particles, shock isolating ability and propagation velocity (non-local property) are all classified well with the shape factor of the constituent particle (local property).
