Full-Scale FEM Simulations of Single Ice Floe Impacts on a Non Ice-Strengthened Ship Structure Using the MCNS Model

Abstract In this study ice floe impacts on a non-ice strengthened ship structure are investigated using the finite element method (FEM) with the Mohr-Coulomb Nodal Split (MCNS) as ice material model. With this analysis, we address three questions: How does the shape of the ice affect the impact? Is the location where the impact occurs significant? How does the direction of impact influence the loads experienced by the ship? The ice shapes used for this study are modeled based on previous experimental analyses and include round (dome), flat-parallel (truncated cone), and sharp (cone) geometries. Impact locations considered are the plate field, bulkhead, and longitudinal stiffener, with impact directions of 0° (glancing impact), 30°, 60°, and 90° (perpendicular impact). The study compares load magnitude, plastic deformation, and strain energies across these scenarios to pinpoint significant influencing factors. Findings are validated against existing experimental and literature data, highlighting the critical impact parameters and identifying the worst-case scenario. The study indicates that all three parameters significantly affect the impact. Round and flat-parallel ice shapes result in higher loads compared to the sharp shape. The greatest deformations occur in the plate field and in the bulkhead impact locations. Additionally, the loads increase as the impact becomes more perpendicular.