The calculation of contact forces between particles using spring and damping models

Discrete element simulations can be used to model the behaviour of both fluids and contacting particles in a very flexible manner. These simulations have wide applications in both mining and mineral processing. They require the calculation of forces between the discrete elements used in the simulation typically by assuming spring, dashpot and slider components at the contact points. The accuracy of the simulations depends on the assumptions made in the calculation of interelement forces. The different methods that can be used to calculate the forces have been examined and unrealistic behaviour found for most of methods commonly used. The non-linear force formula of Tsuji et al., Powder Technol., 71 (1992) 239, with the particles separating when the force returns to zero rather than when the distance between the centres exceeds the sum of the radii is found to give realistic results.