Force chains in sheared granular media of irregular particles

We study topological and dynamical properties in sheared granular media particularly when avalanches occur, i.e. at the abrupt increase of the total kinetic energy durin g the shear process. Our model considers irregular polygonal particles compressed between two moving plates. At the occurrence of an avalanche, we monitor the time evolution of the underlying contact force network. When all contact forces are considered, topological and dynamical quantities vary as a reaction to the avalanche, while the decomposition of the contact force network into strong and weak contacts uncovers a topology that is strongly correlated with the occurrence of avalanches.