| The protection capability of modern submarines has been greatly improved.Thus,traditional weapons are difficult to give a fatalattack in the water.The use of shaped charge warhead can increase the damage power of the torpedo in the water.Therefore,the research on the forming process ofEFP in the water and thedamage effect of the target is great significance to promote the development of ammunition technology.Firstly,the research status of related content is introduced.Then,under the condition of hydrostatic pressure,followed by a lot of numerical simulation calculations on the process of forming the EFP in the water and the damage effect on the target using LS-DYNA under consideration of hydrostatic pressure.The law of the process of forming the EFP in the water and its damage to the double hull submarine.Finally,in order to improve the damage power of EFP to the double-hull submarine in the water,a combined liner was designed according to the obtained law,and its structure was optimized by orthogonal design method.Using the range analysis,the primary and secondary order of the structural parameters of the combined liner on the damage effect of the double hull submarine was obtained,and the best optimized combination of the structural parameters was obtained.The following conclusions have been determined through research:（1）The difference between process of forming the EFP in water and air is large.When EFP in the water,the head speed is lower than that in the air.With the EFP penetrates the water medium,the head speed will rapidly decay.With the penetration of the water medium,its shape will change and the outer material will be gradually peeled off by the water medium,and the energy is consumed a lot.（2）The greater the thickness of the liner,the greater the mass and volume of the EFP it forms,the smaller the head velocity and its attenuation rate;the greater the radius of curvature,the smaller ratio of length to diameter of the EFP formed,the smaller the head velocity and the attenuation rate.（3）When the EFP penetrates the double hull submarine underwater,it will first generate an initial shock wave in the water,and the shock wave will propagate around in the form of a spherical pressure wave in the water medium.The shock wave will cause a pressure effect on the hull before the EFP penetrates the submarine hull to deform it,and then the EFP continues to move to the end face of the hull to penetrate the hull.The final damage to the hull is caused by the EFP and the water medium.（4）The thickness and radius of curvature of the liner have a great influence on the damage effect of the EFP penetrating the double hull submarine in the water.Under other conditions unchanged,the thickness of liner is proportional to the perforation size of the pressure hull of the double hull submarine,and the radius of curvature of liner should not be too large,otherwise ratio of length to diameter of the EFP is too small to penetrate the pressure hull.（5）The designed torpedo warhead with a combined liner can form two kinds of damage elements,the front-stage JET and the rear-stage EFP.During underwater movement,the front-stage jet speed is faster,and it will penetrate the water medium.Form a cavity to open up channels for subsequent EFP and reduce EFP losses P in the water.Greatly improve the damage of EFP in the water to the double hull submarine.（6）The primary and secondary order of the structural parameters of the combined liner cover on the damage effect is d>R>δ2>δ1>2α,and the best optimized combination of the structural parameters is δ1=3mm,d=25mm,2α=70°,R=110mm,δ2=6mm. |
