Clustering in Granular Medium in Biaxial Compression

The experimental and theoretical studies show that plane deformation of granular medium induces formation of clusters with sizes of the order of 10–15 diameters of particles. The process of biaxial compression is examined. It is found that deformation has four basic modes conformable with different shapes of clusters. The modes feature a very complex alternation behavior. The process of deformation possesses memory with the Hurst exponent of 0.84. The limit loads in different modes can differ by 2 or 3 times. In problems on deformation of granular media, the calculation of mechanical condition of domains less than 80–100 diameters of particles in size should use not the continuum models but the discrete element method.