Penetration Research Of Shaped Charge Into Typical Soil/Concrete Target

In order to reduce failure and damage of defence works under projectiles penetration, most defence works are covered by soil in modern battlefield. Shallow and deep command posts are going into the deep ground meters or even tens, and the protective capability of the underground command protection work is good. Now the most kinds of warhead can not meet the requirement of penetrated the defence works. The shaped charge warhead can be used in nearly almost kind of weapon transporters, such as missile, torpedo, and so on. The penetrator formed by shaped charge have many advantages, such as high energy density, penetration ability, and so on. Thus, the shaped charge has been widely used in the weapon to penetrate the defence works.That was studied axial penetration and radial crater growth caused by shaped charge jet penetration in soil and concreted in this paper. The process of the stress wave transmitting and damping in the soil/concrete target was discussed when shaped charge jet penetration into soil/concrete target. And the influence of stress wave on the jet penetration was investigated. Numerical simulation was used to calculate the process of detonation propagation and liner collapse. The distribution of jet velocity and jet diameter along the length of the shaped charge jet and the fracture time constant was obtained by combining numerical simulation. X-ray experiments, and theoretical analysis. Moreover, the laws of target resistance and stress wave propagation and attenuation in soil and concrete were obtained by combining theoretical and experimental research. The hole profiles for soil, concrete, and soil/concrete target of jet penetration were described using the input parameters above.Following aspects are included in this paper:1. Supersonic penetration of shaped charge jet into soil and concrete target.Given the low density and low sound velocity of soil and concrete, the effect of stationary shocks and compression cannot be neglected during the penetration process of shaped charge jets into concrete. This paper postulates that a stationary shock that results in the material characteristic alterations affecting the process of penetration and crater growth across the wave front is generated when the penetration velocity is greater than the sound velocity of concrete. A supersonic penetration model of shaped charge jet penetration and radial crater growth is presented by analyzing the influence of stationary shock and compression.2. Radial crater growth for jacketed jet penetration into soil and concrete target. The current study designs a shaped charge structure that could form a jacketed jet to enhance the cavity diameter created by a shaped charge jet into concrete. Moreover, three types of penetration modes during the process of jacketed jet penetration into concrete, including homogeneous jet penetration,"bi-erosion," and "co-erosion" are discussed. A two-step mechanism of cavity growth that contains the trajectory of flowing jet erosion products and the radial momentum of the target is used to describe the penetration modes. The final diameter of the jacketed jet penetration is greater than the core penetration caused by the larger cavity diameter in the first stage.3. The engineering model of shaped charge jet penetration into soil/concrete target.According to the thickness of the soil and the penetration state in soil and concrete, the process of jet penetration into soil/concrete target was divided into three cases. First, supersonic penetration occurs both in soil and concrete when jet reaches soil/concrete interface. Second, supersonic penetration occurs in soil and subsonic penetration occurs in concrete when jet reaches soil/concrete interface. Third, subsonic penetration occurs both in soil and concrete when jet reaches soil/concrete interface. Considering stress wave propagation and influence on jet penetration, this paper analysised the process of jet penetration into soil/concrete target for three cases above. The penetration depth of the jet into soil/concrete target is lower than that of a jet into a concrete target when the thickness of soil is2or3times the charge diameter.Moreover, penetration performance of jet into forward section was studied in this paper. A new type liner was designed for reducing interference during jet penetration forward section and penetration ability increased. This article analyzed equivalent method and homogeneous target which is equivalent to the forward section, and equivalent thickness of homogeneous target was calculated.