An implicit time-stepping scheme and an improved contact model for ice-structure interaction simulations

This paper presents a novel time-stepping scheme for the modelling of discrete ice-structure interaction. The scheme extends the non-smooth discrete element modelling (NDEM) technique to enable compliant continuous and discontinuous contacts. This increases the accuracy and expands the applicability range of the NDEM technique related to ice-structure interaction problems. We derive the parameters representing the compliant behaviour of contacts. The accuracy of the presented scheme for discontinuous contacts is compared to an existing, simpler scheme that limits the contact force based on a maximum force assumption. The comparison shows that the derived scheme results in more accurate contact forces, for the same time step size, as previously applied NDEM schemes in ice-structure interaction. An example simulation is compared against ice tank tests of a 4-legged, vertical-walled structure moving through a broken ice field.