Analysis Of Ship Maneuvering Performances And Ice Loads On Ship Hull With Discrete Element Model In Broken-ice Field

Recent years, with the preliminary navigations of Arctic Passage and the development of oil/gas exploitations in cold regions, the research of ice load on ship hull is required for engineering. Therefore the interaction between ice floe and ship hull is a key problem to the operative and safety aspects of ship navigations in ice-covered region.The interaction between the sea ice and ship hull is a complicated dynamic process. It depends on the ice parameters, such as ice type, strength, velocity, etc, and also the ship navigation and structure parameters, such as hull outline, size, stiffness, etc. In broken ice field, the influence of ice shape, thickness, floes size and concentration should be considerated. The local impact force to ships and the global resistance are two important factors in the ship design and proper maneuvering. The local pressure is the key factor of safety performance, and the damage to the ship structure is the important research content in the ship design and safe navigation. For the local pressure, through the model tests in ice pool and size effect which survey and statistical analysis sea ice pressure, the high pressure zone characteristic in extrusion between sea ice and ship hull have been researched. Ship performance also affects the global ice forces. Moored ship in drifting ice, running ship in static ice field, the straight running, zigzag running and turning of ship etc, with varying the ship maneuver the overall resistance is different.For this purpose, this artical is aimed at the dynamic characteristic of ice floe induced by ship hull, construct the ice floes modelled with discrete elements model (DEM), and then examine the reasonability of model and the accurateness of calculate parameter through the model tests. Similarly the ship hull is constructed with triangle elements. The viscoelastic contact model of the coupling relationship between ice floe and ship hull is established, by which the impact ice load on ship structure is determined. In this project the influences of ice conditions are investigated:consider the ice factor as ice thicknesses, ice floe sizes, concentrations, strength and velocity, etc:ship structure parameters as shape, size and stiffness, etc; ship navigations as the straight running under different ship speed. The global ice load on ships is determined by using DEM under different ice conditions motioned above. Through researching the interaction between ice floe and ship hull with DEM. the major influence factor of the ice load on ships are analyzed, which can be helpful in the navigation security in ice-covered fields and the ship Anti-Ice Structure design.