Simulation Study On Crashworthiness Of Ship Side Structure In Polar Region

The Arctic region has abundant and untapped natural gas,oil and fishery resources,which has set off a global concern and development boom.As the global climate changes,the ice content in the polar region is greatly reduced.The routes in the Arctic seas are gradually expanding,making the demand for polar navigation vessels increasing.However,ships sailing in the polar region will have a certain chance of colliding with the ice body.In the event of a collision accident,the catastrophic consequences such as damage to the hull structure and oil and gas leakage may occur.Based on the above background,this paper studies the process of collision between ship and ice sailing in polar region by finite element simulation technology,and analyses the anti-collision performance of main components of side structure.On the one hand,it can evaluate and forecast the damage of ship structure;on the other hand,it can provide guidance for the anti-collision design of ship structure sailing in ice region.The main research contents are as follows:(1)The introduction about ship-ice collision mechanism and its corresponding non-linear characteristics,and the motion control equation and explicit solution algorithm of ship-ice collision,and the finite element analysis method.(2)The finite element model of ship and cubic ice was established by using the finite element software,the definitions of mesh division,element type,and collision contact in the finite element modeling process are described in detail;the appropriate material model and failure criterion were selected as the material parameters of the ice body;Ice strengthening to side structure of the tanker based on the IACS ice class specification.(3)Numerical simulation of the ship-ice collision process under the premise that the ship and ice have a certain speed of motion.Seven kinds of ship-ice collision conditions were designed to study the structural response of different collision speed,outer plate thickness and side impact position.The damage and deformation of ship and ice body under different conditions were compared and analyzed,and the distributions of structural stress and strain with time were given to study the crashworthiness of structures.(4)During the ship-ice collision,the ship and the ice body will absorb part of the energy and transform into the deformation energy of the side members and the ice body.Under different collision conditions,analysing energy absorption of ice bodies and side structure such as outer plates,longitudinal bones and strong frames can not only quantitatively explain the crashworthiness of the structure in resisting the action of ice body,but also play a reference role in strengthening the structure of ice area.(5)Designing the ?-type and ?-type metal sandwich panels and using them in the ship side structure.Comparing and analyzing the structural dynamic response of the conventional ice zone reinforcement side,?-type,?-type sandwich panel side with ice body collision.The results show the sandwich panel structure can significantly improve the crashworthiness of the ship side;in addition,for the good crashworthiness of the ? sandwich panel,further analysis of the collision performance under different sandwich panel thickness and different sandwich layer thickness to determine a reasonable structural size.