Numerical Simulation Study On Impact Effect Of New Energetic Projectiles For Anti-torpedo

The development and application of torpedo weapons has promoted the increasingly innovative anti-torpedo technology,especially the rapid development of underwater highspeed projectiles.The application of energetic reactive materials to underwater highspeed projectiles promotes the practical study of new energetic projectiles for combating torpedoes.Based on the theoretical analysis of the water intrusion and penetration impact characteristics of the truncated cone projectiles,the ANSYS/LS-DYNA finite element software was used to develop the impact effect of new energetic projectiles injecting water and penetrating the torpedo equivalent model in water-air medium,which provided an important basis for the formulation of experimental schemes and the research on the damage effect of new energetic projectiles against torpedoes.The main work and conclusions of this paper were as follows:1.The momentum conservation method and the surface integral method were used to calculate the water slamming pressure of the truncated conical projectiles,and the acceleration variation law of the projectiles into the water was obtained.The general calculation formula of the projectile penetration overload was briefly introduced.A penetrating resistance model on the basis of the composite resistance function model was established,and the propagation law of stress wave in the projectiles was discussed.The typical abroad torpedo MK54 was selected and its equivalent model under the aggressive destruction mode was established.2.The structure of new energetic projectiles and the performance of energetic reactive materials were introduced,and a finite element model for the impact of new energetic projectiles into the water was established.On the basis of the verification of the rationality of the water inlet algorithm and relevant parameters,the impact acceleration characteristics and the variation of stress and strain of the projectiles into the water were studied.The results show that: the larger the inlet-water velocity and the falling angle,the greater the acceleration peak of the projectiles.The closer the installation position of the energetic reactive materials is to the head of the projectiles,the larger the pressure peak and the worse the stability.When entering the water at the speed of no more than 1000m/s,the projectiles are not easily impacted.3.The size of the equivalent targets was determined according to the torpedo equivalent model,and the finite element model of the new energetic projectiles penetrating the targets in the water-air medium was established.On the basis of verifying the rationality of the penetration contact algorithm and its parameters,the impact characteristics of the projectiles into the equivalent targets,such as the interaction between the projectiles and the target plates,the projectile acceleration,and the stress and deformation of the projectiles were studied.The results show that: with the increase of the initial velocity of the projectiles and the thickness of the target plates,the acceleration peak of the projectiles and the pressure peak of the energetic reactive materials increase gradually.The larger the incident angle of the projectiles and the moving speed of the target plates,the more obvious the deflection and deformation of the projectiles and the greater the pressure peak of the energetic reactive materials in the case of penetrating the targets.When penetrating the target plates at a speed of greater than 300 m/s,the impact initiation of the projectiles occurs.