Research On Ice Load Of Ships Sailing In Broken Ice

As the area of the Arctic ice sheet shrinks year by year,the possibility of full opening of the Arctic route has greatly increased,and the issue of navigation of polar ships has received extensive attention.Compared with specific mission vessels such as icebreakers and scientific research vessels,commercial vessels such as ice-enhanced transport vessels have a greater impact on global resource supply,economic growth,and transportation.In order to ensure the safety of the ice transport in the ice area,how to accurately and quickly predict the ice load and maneuverability of the ships needs to be solved.To this end,this paper studies the ice resistance and handling performance of ships sailing in the ice broken area.Firstly,the forces and moments of the ship in the ice broken area are analyzed.Based on the MMG's separated modeling theory,a three-degree-of-freedom mathematical model of the ship's motion in the plane is established,and the ship's rotary motion is simulated.Then,in order to study the relationship between the ice load and the speed of the ship and the concentration of the pack ice in the direct navigation state,the LS-DYNA finite element software is used to simulate the movement process of the ship in the ice broken area,and the ship and the pack ice contact characteristics and movement status.The ice load data was studied and the variation law between ice resistance and ship speed and broken ice concentration was obtained.The mathematical expression method is used to obtain the functional expression between ship ice resistance and speed and concentration.Combined with the mathematical model of ship motion,the safe speed range of the ship during direct flight in the ice broken area is analyzed and analyzed.The ship's safe navigation provides a data reference.Finally,the characteristics of the broken ice load are analyzed and found to have similar characteristics to the fluid resistance.Based on the research ideas of fluid resistance and the PMM experimental research method,the two specific ship motion forms of the ship's pure sway motion and pure yaw motion were numerically simulated,and the lateral force and the first shaking moment were obtained.Through the simulation results,the expressions of the sway forces and the yaw moments of the ship are obtained,which lays a foundation for the subsequent study of maneuverability problems such as ship's rotary motion.