Research On The Damage Effect Of Two Typical Structures Under The Shock Wave Of Underwater Explosion

With the development of weapons in the water,the underwater explosion load and its damage characteristics to the ship structure have become the frontiers and hotspots of international research.In recent years,underwater weapons such as torpedoes have become the main threat of ship submarines,and they have attracted more and more attention from researchers at home and abroad.The use of underwater explosion shock waves to kill torpedoes has gradually become a defense method adopted by more countries.In order to maximize the power of the underwater warhead and improve the damage effectiveness of underwater weapons,it is a very important research topic to study the structure of the underwater explosion load power field and its damage law to typical targets.The underwater explosion load is mainly composed of explosion shock waves and air bubbles.The explosion shock wave is mainly caused by damage to the local vulnerable structure of the target,and the bubble pulsation is aimed at the overall damage.The solid-supported multi-layer sheet structure is similar to the ship’s side structure,and is also used as a protective structure in civil facilities such as offshore platforms.Its equivalent strength is basically the same as that of the torpedo head self-guide system;the warhead shielding charge structure is the core component of the underwater weapon’s killing is also the main structure for the underwater explosion hard kill.These structures are mainly subjected to explosion shock waves in water and do not involve bubble loads.In this paper,theoretical research、numerical simulation and experimental methods are used to explore the damage behavior of the solid supported multi-layer chip structure under the underwater explosion shock wave.Based on the energy method,the plastic response model of a typical multi-layered sheet structure under the underwater explosion shock wave is established,and the damage of the fixed-layer multi-layer chip structure under different working conditions was simulated.At last,the underwater explosion damage test was carried out.The damage parameters of the underwater explosion shock wave and the damage of the multi-layer chip group structure were tested.From the research results,the theoretical model can predict the damage and damage of the multilayered sheet structure,including the number of plastic deformation layers,the number of shear failure layers and the maximum damage depth.According to the degree of damage,the layer will produce three kinds of damage modes:plastic deformation,tensile tear failure and shear fracture failure.For the 2024T351 aluminum alloy sheet structure,when the impact factor reaches 0.17,the 6-layer solid support layer can be completely destroyed.Based on the combination of theory and numerical simulation,the impact initiation of the shielding charge under the action of underwater explosion shock wave is studied.Theoretically,the calculation method of the impact pressure of the underwater explosion shock wave on the shielding charge is established,and the explosive detonation criterion is combined to determine the critical distance of the explosive impact detonation.The AUTODYN simulation software was used to simulate the process of underwater explosion shock wave impact detonation shielding charge.The parameter of the critical theoretical detonation criterion p~nτ=K was obtained by least squares method.n=1.37,K=2.33×10~7(International System of Units).The comprehensive research results,the theoretical calculation and numerical simulation error does not exceed 6.75%,which is in good agreement,indicating that the theoretical calculation method is effective;when the TNT dose is 6.6kg and the baffle thickness is 10mm,the critical initiation distance is 1.6m.