Research On Damage Of Composite Minesweeper Under Underwater Explosion

Minesweeper boats have played an extremely important role in the exploration of unknown sea areas or in the demining of dangerous mines.They may be affected by active demining or passive explosion of mines.Most modern newly built minesweepers are built with new composite materials,and the hull structure is also different from the ships made of traditional steel.Due to the frequent impact of mid-to-near field underwater explosions,the impact damage research of composite material minesweeper is urgently needed.The shock wave of high temperature and high pressure generated by the underwater explosion acts on the hull,which not only causes a large deformation of the hull structure,but also has a large impact on the internal personnel and equipment.Research on the composite material sandwich panel and the hull are damaged by the explosion shock,which can be designed The impact-resistant structure provides relevant data support.In this paper,the impact of the underwater explosion shock wave on the composite sandwich panel is studied through numerical simulation calculations,the impact of the detonation at different positions on the hull structure is analyzed,and the response of the local composite cabin under underwater explosion is studied.Based on the structure,several impact-resistant structures were improved and designed.(1)For underwater explosions,the shock wave pressure decay process is first analyzed,and then the law of impact deformation of a fixed-supported steel plate under different explosive initiation conditions is studied.The results show that the stress is reflected to the edge of the fixed support,and the stress is strengthened again when it is propagated to the center,which causes large deformation of the plate.(2)The composite material board is composed of multiple layers,and each layer can be designed at different angles.The pavement design at different angles will affect the overall panel impact deformation.The mid-point displacement changes of the front and back explosion surfaces and the overall energy absorption of the sandwich panel under impact are analyzed,which provides relevant data support for the design of anti-impact structures.(3)The underwater explosion module in the ABAQUS program was used to analyze the impact of different explosion angles on the hull model.The propagation method of impact force in the hull is analyzed,and the amount of deformation of the hull section are compared.The results show that the explosion on the side will also have a greater impact on the hull.(4)A part of the hull compartment with composite sandwich panels as the outer shell was established,and the stress distribution of the bottom plate and each deck under the shock wave,the acceleration of the bottom plate and each deck,and the damage of the composite material of the section were analyzed.The results show that the maximum stress occurs at the connection between the second deck and the outer shell of the hull.At the same time,due to the energy absorption of the composite sandwich panel,the acceleration of the three decks is significantly reduced compared to the bottom of the ship.There is no ring breakage in the cabin,but under the effect of explosion load,the tensile stress of the whole cabin model is greater than the compressive stress.(5)Based on the research results of the underwater explosion shock wave on the composite material sandwich panel,the whole ship model and the local cabin section,this paper has improved the design of the anti-shock structure.Based on the traditional structure,by replacing the surface composite materials used and designing the internal and external reinforcement ribs,different improved sandwich structures are proposed,and the impact resistance of the improved structures is discussed.The conclusion shows that the carbon fiber sandwich panel has better Impact resistance.