Ocean Systems Engineering Volume 6, Number 4, December 2016 , pages 345-362 DOI: https://doi.org/10.12989/ose.2016.6.4.345 |
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Numerical simulation of dynamic Interactions of an arctic spar with drifting level ice |
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H.K. Jang, H.Y. Kang and M.H. Kim
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Abstract | ||
This study aims to develop the numerical method to estimate level ice impact load and investigate the dynamic interaction between an arctic Spar with sloped surface and drifting level ice. When the level ice approaches the downward sloped structure, the interaction can be decomposed into three sequential phases: the breaking phase, when ice contacts the structure and is bent by bending moment; the rotating phase, when the broken ice is submerged and rotated underneath the structure; and the sliding phase, when the submerged broken ice becomes parallel to the sloping surface causing buoyancy-induced fictional forces. In each phase, the analytical formulas are constructed to account for the relevant physics and the results are compared to other existing methods or standards. The time-dependent ice load is coupled with hull-riser-mooring coupled dynamic analysis program. Then, the fully coupled program is applied to a moored arctic Spar with sloped surface with drifting level ice. The occurrence of dynamic resonance between ice load and spar motion causing large mooring tension is demonstrated. | ||
Key Words | ||
ice interaction; arctic spar; level ice; sloped surface; coupled dynamics; bending failure; breaking phase; rotating phase; sliding phase; ice-induced resonance; time domain analysis; platform motions; mooring forces | ||
Address | ||
H.K. Jang, H.Y. Kang and M.H. Kim: Department of Ocean Engineering, Texas A&M University, College Station, TX 77843, USA | ||