Simulating Granular Material using Nonsmooth Time-Stepping and a Matrix-Free Interior Point Method

For the product design of earth-moving machinery, a simulation framework for the soil-tool interaction is an appreciated tool. When modelling soil using nonsmooth time stepping methods, a large complementarity problem must be solved per time step. As a consequence, the method is stable for large time steps and potentially fast. Yet when it comes to the prediction of draft forces, state-of-the-art solvers for the complementarity problems fail to deliver the necessary accuracy. This doctoral thesis introduces a specialized Interior Point Method to overcome this issue. In addition, a detailed derivation of the nonsmooth equations of motion is presented.