• Journal of the Society of Naval Architects of Korea
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• v.55 no.1
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• pp.22-27
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• 2018

Ships strengthened for navigation in ice encounter level ice, ice ridge and broken ice fields. Thus, the ship resistance in ice is a very critical concern to the designers of ice-going vessels. The objective of this study is to understand the physical aspects of ship performance in ice and to investigate the characteristics of the ship resistance in broken ice channels. In particular, this study identifies the ship resistance in ice associated with the broken ice channel width and the size of broken ice pieces. Model testings of towed-resistance condition in broken ice channels with three ship speeds were conducted in KRISO ice model basin. The influence of the ship resistance characteristics in broken ice channels for channel width and size of broken ice pieces was analyzed.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.6
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• pp.75-83
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• 2004

Ice rubble pieces broken by the bow impact load and side hull of an icebreaking vessel usually pass along the ship's bottom hull and may hit the propeller/rudder or other stern structures causing serious damage to ship's hull . Therefore it is important to estimate the size of broken ice pieces during the icebreaking process. The dynamic interaction process of icebreaker with infinite ice sheet is simplified as a wedge type beam of finite length supported by elastic foundation. The wedge type ice beam is leaded with vertical impact forces due to the inclined bow stem of icebreaking vessels. The numerical model provides locations of maximum dynamic bending moment where extreme tensile stress arises and also possible fracture occurs. The model can predict a failure length of broken ice sheet given design parameters. The results are compared to Nevel(1961)'s analytical solution for static load and observed pattern of ice sheet failure onboard an icebreaker. Also by comparing computed failure length with the characteristic length, the meaning of ice rubble sizes is discussed.