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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 65: Granular Matter / Contact Dynamics (joint session DY/CPP)
CPP 65.4: Talk
Thursday, March 15, 2018, 10:45–11:00, BH-N 333
Structural Evolution of Planar Granular Media — •Clara Wanjura1, Takashi Matsushima2, Othmar Marti1, and Rafi Blumenfeld3,4,5 — 1Ulm University, Germany — 2University of Tsukuba, Japan — 3Inst. of Physics, Chinese Academy of Sciences, China — 4Imperial College London, UK — 5Cambridge University, UK
Granular materials are ubiquitous in nature, but continuum models of their macroscale behaviour and properties have proved to be difficult. Particle-scale properties and the structure affect strongly the large-scale behaviour.
Here we study a key characteristic of the structure in two dimensions: the cell-order distribution (COD). We first describe the evolution of the COD by a set of master equations and establish their validity by comparison to simulation data. The structure and the COD evolve mainly by contact making and breaking events. Of these, we identify and quantify 'non-clapping' events as the most relevant to the COD evolution and distinguish these from the less relevant 'clapping' events, which only add noise to the dynamics. The role of the cell order transition rates and their behaviour in the master equations are studied in detail analytically and numerically.
This formalism can be extended to the study of other structural characteristics.