The flow of granular material, like sand, presents many intriguing effects in particular when it is shaken, poured or sheared. Here, the granular medium is modelled by a packing of elastic spheres and simulated via molecular dynamics. Dissipation of energy and shear friction at collisions are...

The propagation of a crack in an isotropic elastic medium is treated as a moving boundary problem. Linear stability analysis shows that for the stretched membrane with a central, initially circular hole all modes are stable. On the other hand all modes are unstable for a two-dimensional...

We describe the contact network of granular packings by a frustrated lattice gas that contains steric frustration as esential ingredient. Two transitions are identified, a spin glass transition at the onset of Reynolds dilatancy and at lower densities a percolation transition. We describe the...

We present various lattice Boltzmann models which reproduce the effects of rough walls, shear thinning and granular flow. We examine the boundary layers generated by the roughness of the walls. Shear thinning produces plug flow with a sharp density contrast at the boundaries. Density waves are...

We investigate cellular automata in four and five dimensions for which Chaté and Manneville recently have found nontrivial collective behaviour. More precisely, though being fully deterministic, the average magnetization seems to be periodic respectively quasiperiodic, with superimposed noise...

We introduce the concept of damage spreading in the context of Monte Carlo dynamics. This provides us with an efficient method to calculate correlation functions and generates the clusters of the fluctuations in magnetization. These clusters have at Tc the fractal dimension d-β/ν. In general,...

A simple model for gelation of monomers in a solution under shear has been studied at different concentrations in two dimensions. Different properties of the clusters like the length R and width W of the clusters, and the angle θ formed with the negative x-direction are determined as a function...

Clusters of infected individuals are defined on data from health laboratories, but this quantity has not been defined and characterized by epidemy models on statistical physics. For a system of mobile agents we simulate a model of infection without immunization and show that all the moments of...

We study a decomposition process where all nodes with a targeted degree are removed from the network. Each removal step results in changes in the degrees of the remaining nodes, and other nodes may attain the targeted degree. The processes continue iteratively until no more nodes with the...

We present a simple model for the friction of two solid bodies moving against each other. In a self-consistent way we can obtain the dependence of the macroscopic friction force as a function of the driving velocity, the normal force and the ruggedness of the surfaces in contact. Our results are...