Study And Design Of A Medium Caliber Shell

Experimental,theoretical and numerical studies about shaped charge have been done in order to study effects of the structural parameters of ammunition to the jet formation,jet penetration,and fragmentation formation in this work.The main contents of this paper are presented as follows:(1)Numerical simulation and theoretical analysis of shaped charge jet formationThe shaped charge jet formation depends on many parameters like High Explosive(HE),liner material,thickness,etc.In this dissertation,shaped charge is designed with different apex angles(36°,42°,48°,56°)and two thicknesses 1.2mm and 2 mm for the purpose to know the effect of the liner design on the jet formation.The main work can be divided into two parts:a numerical simulation carried out in AUTODYN(?)software and an analytical calculation applying Birkhoff's theory.The results given by simulation and analytical calculations show that shaped charge model designed with liner apex angle 36° and thickness 1.2mm can achieve the best jet formation parameters.(2)Numerical simulation and theoretical analysis of shaped charge jet penetrationFive typical shaped charges with different structural parameters of apex angles and thickness are selected for simulation.The jet penetration to steel target are simulated by using AUTODYN(?)to study the penetration performance of different shaped charge structures.The decrease of jet velocity and kinetic energy are obtained through simulations.Meanwhile,an analytical model using Birkhoff's theory is established to calculate the penetration depth.The penetration depth obtained from numerical simulation and analytical calculation generally shows a good agreement.(3)Experimental study on shaped charge jet penetrating steel targetsExperimental study of shaped charge with liner apex angle 42° and liner thickness 1.2 mm penetrating steel targets is performed and penetration depth is obtained.Good agreement observed between experimental results and simulation results where it shown an error of 15.97%with the analytical results.(4)Numerical simulation of the formation of natural fragments and pre-formed fragments3D simulation of natural fragments and pre-formed fragments with different hardness of shell(HRC 20,32,36)are carried out in AUTODYN(?).The variation of mass,velocity and quantity of fragments during formation is presented and discussed.The simulation results show that the pre-formed fragments with internal grooves has a better performance in fragmentation which is in accordance with the theory.