| Summary: | This thesis analyses the loads that occurred during an ice ridge ramming experiment with the icebreaker Oden. Sea ice ridges are formed due to breaking and deformation of the ice cover. Wind, current, thermal expansion and Coriolis forces induce compression and shear forces onto level ice which can break the ice into rubble. The blocks of ice rubble are pushed together, forming a wall of broken ice in hydrostatic equilibrium. This wall of broken ice forced up by pressure is defined as an ice ridge. In general ice ridges are long, nonsymmetrical, curvilinear features with a wide variability of sizes and shapes. In Arctic regions, sea ice ridges are often used to calculate the design load in the absence of icebergs. Ice ridges also play a major role in icebreaker efficiency, since an icebreaker might need several ‘rams’ to break through an ice ridge. Ice ridge actions on icebreakers are not completely understood. Complex ice behavior under rapidly applied stress, and the complex geometries of the bodies in contact makes it a challenging research topic. The dynamic behavior of the vessel during the ramming can be used to make an estimate of the ice loads that occurred. This thesis analyses the ice load that occurred during a ridge ramming experiment that was performed with icebreaker Oden during the ODEN AT research cruise project in 2013. To advance our understanding in the global ice ridge ramming loads, twomodels were developed: 1) a simulationmodel using the Specific Energy Absorption (SEA) of mechanical crushing of ice to calculate the global ice loads, 2) a load identification model using full-scale data to determine the global ice loads. The simulation model was developed to enhance the understanding of relevant physical phenomena and parameters. During this process, specific energy principles of crushing of ice were identified as a promising although relatively unknown method for impact dynamics into ice. The Specific Energy Absorption (SEA) of mechanical crushing of ice is defined as the energy per unit ...
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