PFC2D (Particle Flow Code in Two Dimensions) is a code for modelling assemblies of circular particles in two dimensions. The particles may represent individual grains in a material such as sand or they may be bonded together to represent a solid material such as concrete or rock. "Fracturing" is modelled when bonds break under load.
The particles are assumed to be rigid in general, but they deform locally at contact points (i.e. contacts are "soft"). There is no limit to allowed displacement, rotation, sliding and separation. Any properties or parameter (even particle radius) may be changed at any time in a simulation. Applications of the code include fundamental research in granular materials, flow of particles in silos and chutes, studies of microcracking in solid bodies, and collapse of slopes, foundations and tunnels.
An important feature of PFC is its adaptability; the built-in programming language, FISH, allows users to customise almost any aspect of the model, such as particle distributions, loading conditions, material behaviour and output quantities.