Numerical Study Of The Impact Resistance For Ship Structures In Near-Field Underwater Explosion

In modern maritime warfare,the rapid development of weapon guidance technology and the continuous power of destruction are becoming more and more powerful.As a main combat platform,the research on the anti-explosive arid anti-shock performance of ships is increasingly concerned by various countries.The manufacturing technology of ship structure is complicated.If its structural strength can not meet the requirements of vitality,it will not only affect the performance of combat performance,but also bring huge economic losses.Among the various underwater explosion loads encountered by ships,the research on the damage of near-field underwater explosion ship structures needs to be further strengthened.This article builds on the basis of summarizing the research status of underwater explosion loads and structural damage at home and abroad.The cabin model of a certain ship has studied the propagation characteristics of the near-field underwater explosion load and the impact resistance of the ship structure through numerical simulation.Main contributions lie in the following three aspects:Firstly,in order to accurately simulate the underwater explosion environment,a water-air-explosive underwater explosion simulation model is proposed based on the ALE method.By comparing the numerical calculation with the empirical formula,the appropriate grid sizes of explosive in different working conditions are determined,thus ensuring the accuracy of numerical simulation.Besides,the propagation characteristics of shock wave load in near-surface underwater explosion is compared and analyzed with that of free field underwater explosion shock wave.And subsequent numerical simulations are conducted on the phenomenon of water surface water mounds during the near-free-surface underwater explosion.Secondly,on the basis of accurate numerical simulation for the underwater explosion environment,a three-cabin model of a ship is established,considering the influencing factors such as fluid-solid coupling.Based on the ALE method,LS-DYNA is used to analyze the explosives located on the side and bottom of the cabin.The deformation characteristics of the main structure of the ship,the response characteristics of speed and acceleration,and the energy absorption characteristics of each component are obtained when the explosive is located on the side and bottom of the ship.Summarize the change trend of the near-field underwater explosion load to the ship's shock response when the different explosion distance and azimuth change,obtain the influence law,and provide a new idea for the ship structure to improve the impact resistance.Finally,according to the response characteristics of the ship cabin section under different working conditions,in order to improve the impact resistance of the structure under underwater explosion load,on the basis of the energy absorption theory,combined with the excellent energy absorption characteristics of the sandwich panel,the ship is added The rib structure,the traditional V-shaped sandwich plate,and the improved V-shaped sandwich plate are used to analyze the dynamic response of the near-field underwater explosion,from the perspective of the interaction between the structure and the fluid,the deformation of the structure,and the energy absorption characteristics.It is found that the improved sandwich panel can not only ensure a certain lateral strength,but also increase the fold line design and improve the energy absorption capacity of the sandwich panel.This combination design can provide a certain reference for the design of the ship structure.