Abstract | Numerical simulations of a collision between the CCGS Terry Fox icebreaker and a bergy bit (1911 t glacial ice mass) have been conducted using LS-DynaTM software, which incorporates a full Navier-Stokes solver for the fluid component. First results compared favorably with actual data acquired during field tests in June, 2001. The simulations were run on a Beowulf cluster consisting of 15 high-performance CPU's. The modeled volume, including the vessel, water and bergy bit, was meshed using AnsysTM software and contained approximately one million elements. A prior set of non-impact simulations of a model tanker transiting in proximity to model bergy bits showed that at least this number of elements was required. In the results presented here the vessel was traveling at 5 m/s and the impact occurred on the port side of the hull, in the region where the instruments were located during the field tests. A hard crushable foam material model was used for the bergy bit in order to model previously observed ice behavior where the ice contact interface consists of a relatively intact hard zone of ice surrounded by softer pulverized ice. The simulation produced reasonable values for the load, pressure and impact duration values obtained in the field. |
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