Numerical study of the force network ensemble

The force network ensemble of Snoeijer et al. (Force network ensemble: a new approach to static granular matter, Phys. Rev. Lett. 92 (2004), 054302) is a convenient model to study networks of contact forces that are typically present in granular matter. Recently, we have shown that it is possible to extremely accurately determine the probability distribution of contact forces in the framework of this ensemble (van Eerd et al., Tail of the contact force distribution in static granular materials, Phys. Rev. E 75 (2007), 060302(R); Tighe et al., Entropy maximisation in the force network ensemble for granular solids, Phys. Rev. Lett. 100 (2008), 238001). In this work, we review several important details of these computations. In particular, we study in detail the angle-resolved contact force distribution, finite-size effects, the maximum allowed shear stress and the effect of walls. In addition, we investigate how well the force network ensemble resembles systems with 'real' interactions.