Numerical Simulation On Ship Collision With Level Ice Using LS-DYNA

In recent years,the global average temperature has risen year by year under the influenceof the greenhouse effect.This change has accelerated the speed of ice melting in parts of the Arctic,and this phenomenon has made the development of the exploitation of the Arctic and shipping traffic a hot topic nowadays..Therefore,it is of great significance to develop a ship suitable for navigation in ice areas.However,due to the harsh environment of the Arctic waters,there are many potential safety hazards in the shipping and development of the polar region,among which sea ice is the most important threat to the safe navigation of ships in ice areas.Therefore,it is extremely important to conduct research on the response of ships to ice collisions.The study of the collision problem is very complicated.The numerical simulation method has been widely used as the main research method for the ship collision problem at this stage.In this paper,the software LS-Dyna is used to numerically simulate the ship-ice collision problem by nonlinear explicit finite element method.The characteristics of the collision force of the hull are analyzed,the energy change of the structure is analyzed,and the structural response is performed.Calculated,the stress distribution and deformation damage of the ship structure and the ice layer were obtained,and the deformation damage of the hull structure was analyzed in detail.The influence of ice thickness and impact velocity on collision problems was systematically studied.The main contents are as follows:1.The research background and research significance of the ship-ice collision problem are described.The current research results at home and abroad are briefly described,and the research contents and methods of this paper are briefly described.2.The basic principles of nonlinear finite element are briefly described.The origin and development of the finite element method are introduced.The dynamic equations of the nonlinear finite element control equation and the display finite element method are introduced.The control of the time step is described and the contact-collision calculation problem is introduced.3.The basic parameters and failure criteria of the hull material and ice material model adopted in this paper are introduced,and the accuracy of the selected ice material is determined by comparing with the characteristics of the ice material specified in the International Standardization Committee.Simulate the size of the grid.The FEA software ANSYS 17.0 was used to establish the ship-ice collision model and determine the contacttype of the collision system and the application of the attached water quality.The LS-Dyna software was used to simulate the collision process several times and the ice was discussed.The effect of the total size of the layer model and the size of the near area on the accuracy of the calculation results determines the best ice model.4.Based on the numerical simulation of the collision model and parameters established in Chapter 3,the stress distribution and deformation damage of the external and internal structures of the stern and the damage of the ice model during the collision between the ship and the ice were obtained.The collision force and the energy absorption of different structures during the collision are obtained.By separately changing the thickness of the ice layer and the speed of the ship,the above response was compared and analyzed under the influence of different ice thickness and ship speed.