Study On The Relationship Between The Energy Density Of Explosive And The Fragmentation Characteristics Of Alloy Steel Cylinders

High Explosive Projectile destroy target by high-velocity fragment,and the charge is a direct source of fragmentation projectile initial velocity obtained.Projectile`s overkill is affected by internal charge,also affected by the dynamic performance of shell material.So,it is need to find a match of properties between charge and shell material to obtain the best killing efficiency.This paper adopts explosion experiment of the shell with charge inside,numerical simulation and theoretical analysis,to study the dynamic fragmentation of shell under internal different energy density explosive loading.The main research results are as follows:Fragmentation of shell expansion under different energy density explosive loading is studied.it show that,when 2 generation of explosive detonation loading,the 3 mm thick 401 steel shell,with low strength and better dynamic plastic material,can get the most fragment and maximum effective fragment number;When adopting 3 generation of explosive load,this shell material cannot match the internal explosive to get the best fragmentation effect.Under this condition,to choose 4 mm hickness of high strength and low dynamic plastic material of low temperature tempering 401 steel as shell material,can get the best shell fragment number and the best fragment distribution.Under the internal different energy density explosive loading,a series of shells fragmentation experiments were carried out to study on the morphology and fracture mode of the fragments.The experiment results show that improve the density of explosive energy,reduce the wall thickness,reduction of material dynamic plasticity and increase the yield strength of appropriate,all can make fragment fracture mode by the tensile failure to shear fracture development,and to increase the number of the shell fragments.Fragmentation of shell expansion under different energy density explosive loading is studied,and the initial velocity of fragments were tested.the results show that,the shell material and loading characteristics on the same circumstances,increase the shell wall thickness can make the fragment velocity is reduced.the influence of the yield strength of shell material for fragment initial speed is limited by the explosive load characteristics.Using “SPH algorithm” and “principal stress stochastic failure model” based on the numerical simulation software Autodyn,can well simulate the expansion and fragmentation process of cylinder shell internal explosive loading.The distribution and initial speed of fragments which obtained by fitting the numerical simulation data was consistent with the experimental results.This method provides effective reference approach method for the selection of shell material.