Particle alignment and clustering in sheared granular materials composed of platy particles Mauricio Boton, Nicolas Estrada, Emilien Azéma and Farhang Radjaï Eur. Phys. J. E, 37 11 (2014) 116 Published online: 24 November 2014 DOI: 10.1140/epje/i2014-14116-0