Research On Ice Resistance And Ice-induced Vibration Response On Local Structure Of Polar Transport Ship

As the ice in the arctic has melted in recent years,the thickness of the ice has shrunk dramatically,allowing many ordinary ships to cut through the ice without the help of icebreakers,saving much time and money.These ships that are going to be responsible for ocean transportation in the future,we call them polar transports.However,what cannot be ignored is that,carrier structure strength may not as strong as the icebreaker.Therefore,the ice-induced response on polar transpors will be more intense.This will have a great impact on the quality of life,working environment and health of crew.Marine equipment will also produce a certain amount of damage.Therefore,this paper will carry out more in-depth research and discussion on a series of problems such as ice resistance,ice-induced vibration on hull structure and anti-vibration structure.Analyzed and discussed the variation of hull ice resistance and ice-induced vibration response under different working conditions.Then,a variety of anti-vibration schemes are proposed and compared with eachother.It has certain reference value to the route selection and anti-vibration structure design of polar transport ship.The main research contents of this paper are as follows:(1)Analyze the basic theory of Lagrange multiphase fluid and hull vibration.Expounde the application of Lagrange multiphase flow theory in CFD software STAR-CCM+,the basic theory of constructing discrete element.Then,introduce the theory of hull vibration and the application of finite element method in hull vibration calculation.(2)Study the ice resistance of ship hull based on discrete element method.The CFD software STAR-CCM+ was used to establish the discrete element ice breaking model,simulate the situation of the ship passing through the crushed ice area,calculate the ice resistance,and analyze its characteristics.At the same time,the variation law of ice resistance under different sailing speeds,ice thickness,ice body diameter and ice density are considered.Then,the finite element method was used to calculate the ice resistance,and the results were compared with those calculated by the discrete element method to verify the feasibility of the discrete element sea ice model.It is also verified that the finite element method is reasonable to apply the excitation force of ice body,which lays a foundation for the research of the later ice-induced hull structure vibration.(3)Study on ice-induced vibration response of local structures of polar transport ships.The nonlinear finite element software LS-DYNA was used to establish the finite element model of the ice body and hull,and used the additional mass method to simulate the ice-breaking process of polar transport ship in the ice crushing and ice leveling areas,obtain the ice-induced vibration response of the local structure of the ship.Then discuss the acceleration of local structure vibration under different working conditions,and analyze the reasons,which provides an effective method for prediction of ice-induced vibration response on polar transport ships.(4)Study on structure of polar transport ship against ice induced vibration.In order to solve the problem of ice-induced vibration caused by polar transport ships,a variety of antivibration schemes are proposed.Firstly,changed the thickness of bone and size plate.Then,use four new sandwich structures of type I,type V,type X and four-side honeycomb type in ship to strengthen the hull.Calculate the vibration response of strengthened structure and compared with the data before.Finally,discuss the advantages and disadvantages of the six vibration mitigation measures,so as to provide the corresponding anti-ice shock vibration enhancement scheme for the transport ships sailing in the polar region.