Open water ice-structure interactions

Prevailing environmental forces such as winds, waves, and currents, combined with the open water environment, make it possible for large ice floes or icebergs to acquire relatively high velocities (6 to 12 knots). Consequently, high local forces can be generated during collisions with offshore structures. The magnitudes of the forces developed depend primarily on the geometrical, kinematical, and mechanical properties of the approaching ice feature. This paper presents a systematic approach to the analysis of the open water, high speed ice-structure interactions. A numerical model is provided for the evaluation of the interaction forces and displacements. The initial analysis procedure presented considers only single degree of freedom motions. Necessary expansions for the evaluation of two and three motion degrees of freedom are subsequently discussed. Finally, a single degree of freedom example is presented and pertinent design recommendations are derived.