Simulation Of Crashicebreaking And Research On Collision Effects

The Arctic region has rich resources and high value in scientific research.With global warming,the Arctic ice and snow area is decreasing,and the development of Arctic waterways has become a hot issue.Opening the waterways needs icebreakers.However,the research on icebreakers is not enough,and there is no unified standard for the design of icebreakers.Therefore,studying the icebreaking process is very important to ensure the structural safety of the icebreaker.Crash-icebreaking is an important technical means for icebreakers to cope with severe ice conditions and complete their tasks.How to accurately and efficiently simulate the collision of ship ice is one of the focuses and difficulties of the icebreaker structure design.Aiming at the above problems,research on the crash-icebreaking process has been carried out with taking a 10000 DWT PC3 icebreaker as an example in this thesis.The main contents include:1.The research status and methods of ship-ice collision are summarized.The characteristics and spatial distribution of Arctic sea ice are introduced.A new material model was adopted according to the physical property of ice,which was used to simulate the ‘ice impact to rigid wall’.Compared to the recommended pressure-area curve given by International Standardization Committee(ISO),correctness of the ice material model for ship-ice collision simulation was validated.2.The structural response of an icebreaker in crash-icebreaking was simulated based on the explicit dynamic finite element software ANSYS/LS-DYNA.Deformations of stern components and regulations of energy absorption at different impact velocities and ice thickness were analyzed and compared.3.Simulate the repeated crash-icebreaking process of the icebreaker,and study the following scenes: ram to the same thick ice twice after reversing,ram to different ice twice,ram to ice three times in different velocity configuration,repeated(more than three)ram to ice.The ice forces,damage and energy absorption laws of the bow structure were summarized.4.Bow structure of different design based on CCS rules were used to study the regulations of deformation and energy absorption in crashicebreaking.Influence of different parameters of side girder and frame on the ice-collision response of the ship were summarized,which can promote the design of icebreakers.