Study On The Damage Performance Of Double-layer Stiffened Cylindrical Shells Under The Explosive Loading Of The Shaped Charge

As an important direction for the development of torpedo warheads,the charge warheads have been widely used in anti-submarine weapons in recent years.The underwater explosive load of a concentrated energy explosive mainly includes metal jets,shock waves,fragments,bubble pulsations and bubble jets,etc.,which can cause destructive blows to surface ships and underwater combat platforms.Therefore,the characteristics of underwater explosive load and its characteristics are of great significance to the damage law of the structure.Based on AUTODYN software CEL algorithm and LS-DYNA software ALE algorithm,the damage characteristics of double-layered stiffened cylindrical shells under the action of explosive charges of energy-gathering explosives were studied.The mechanism of energy-gathering explosives was revealed,and the effects of metal jet loads were investigated Factors,taking into account the hydrostatic pressure,further study the damage law of the structure under different loads,and put forward an design scheme for the protection of the pressure shell structure under fragment load,which is an important supplement for the design of the submarine structureFirst of all,based on the research status of concentrated charge explosives and the underwater damage characteristics of the charged warhead,the research focus and research methods of this paper are proposed.According to the relevant theories of AUTODYN software CEL algorithm and LS-DYNA software ALE algorithm,the value of the research method is analyzed.The solution was compared with empirical formulas and related experimental results,which effectively verified the accuracy of the research method in this paper.Secondly,in order to explore the influencing factors of metal jet load,based on the two-dimensional axisymmetric algorithm of AUTODYN software,and taking the metal jet velocity and target plate opening size as reference quantities,the shape of the hood and the initiation method on the metal jet load were studied in order.The effect of metal jet load penetration at different water depths under hydrostatic pressure was investigated using a single-layer target plate structure.Thirdly,in order to evaluate the damage performance of the double-layer stiffened cylindrical shell under the explosive load of the concentrated charge,a full-scale structure finite element model was established,and the perforation result of the double-shell structure with the metal jet was used as the initial application of shock wave and bubble load.Conditions,and based on the LS-DYNA software ALE algorithm,the damage of the structure to shock waves and bubble loads at different water depths and angles of attack was investigated.Finally,for the anti-penetration performance of the double shell structure under fragment load,the correctness of the two-dimensional axisymmetric Lagrangian algorithm of AUTODYN software was first verified by numerical simulation.Based on the structural characteristics of the sandwich target,the isoplanar was studied in turn.Anti-penetration performance of three types of target structures:rubber sandwich,polyurea sandwich and steel plate under different densities,with different sandwich thicknesses and different impact velocities.The non-pressure-resistant shell structure was designed based on the calculation resultsThe results show that the arc-shaped cone-shaped hood structure has the best penetration performance in water,and the larger the explosion area,the higher the penetration speed of the metal jet;the double-shell structure has a non-pressure-resistant shell structure under shallow water conditions.Instability occurs,and the pressure shell structure has better stability.Fragment load is the main cause of damage to the pressure shell structure.In deep water,the pressure shell structure is increased due to the increase of hydrostatic pressure and bubble pulsation load.After the secondary pulsation of the bubble,the stability is lost,and the overall structure is severely damaged under subsequent loads.The anti-penetration of the polyurea sandwich target plate is better than the traditional rubber sandwich target plate and homogeneous steel target plate at the same surface density.Through the design of the pressure shell structure,the anti-penetration performance of the new structure is improved compared to the conventional structure.Among them,the anti-penetration performance is improved by more than 15%when the penetration speed is greater than 600 m/s.