Study On The Damage Mechanism Of Light Armor Target With Multiple Core Nested PELE

Based on a PELE warhead with multi-layer core structure,this paper mainly studies its mechanism of action and the factors and rules affecting penetration when it damages light armored targets,and optimizes the warhead.Firstly,the penetration process of PELE projectile with multi-layer core nested structure into metal thin target is analyzed based on the theory of plane one-dimensional shock wave;the calculation formulas of the front and rear velocity of shock wave at different times in different structural media are derived;in combination with the law of energy conservation,the theoretical calculation model of the axial residual velocity of PELE penetration process with multi-layer core nested structure and the projectile after penetration are established.The theoretical calculation model of radial velocity of fractured fragments is validated by numerical simulation and literature test results.Then the penetration process of PELE with different composite core is analyzed.PELE with nickel alloy/nylon and nickel alloy/Al₂O₃ ceramics has better damage effect.On this basis,the numerical calculation is carried out by changing the density,sound velocity,Poisson ratio and elastic modulus of the two core materials.The results are analyzed and the rules that different material parameters affect the penetration of projectiles are obtained.Among them,density and sound velocity affect the axial residual velocity and radial velocity of the fragment,while Poisson ratio and elastic modulus only affect the radial velocity of the fragment;two parameters,i.e.acoustic impedance ratio and Poisson ratio,are selected to study the change of the velocity of the projectile,and the sound impedance matching and Poisson ratio matching of the composite core are determined to obtain the better range of values of the composite core respectively.Finally,under the conditions of high speed and low speed,the shell and composite core are numerically simulated under different aspect ratios and inner diameter ratios.The results show that the ratio of inner diameter to outer diameter of the projectile has obvious influence on the axial residual velocity of the projectile and the radial velocity of the fragments.When the ratio of inner diameter to outer diameter of the composite core is0.8,the maximum axial residual velocity can be obtained.If the ratio of inner diameter to outer diameter of composite core obtains better radial velocity of fragments,the ratio of shell to core length should be above 0.75 at low speed and 0.70 at high speed.Finally,the process of the optimized projectile penetrating the ceramic/rubber composite target is simulated numerically,and the effects and speed changes of PELE penetrating the composite target at different initial speeds are analyzed,and the composite projectile core suitable for high and low speeds is determined.