Research On Fragments After EFP Penetrates Through The Target Plate

The Behind Armor Debris of Explosively Formed Projectile(EFP)has good target post effect,which makes the study of Behind Armor Debris of EFP has important practical value.The research on the post target effect of the Behind Armor Debris will provide a reference for the designing of the shaped charge warhead and the new armor.The research on the Behind Armor Debris of EFP mainly includes the study of the formation mechanism of fragments and the distribution characteristics of fragments in this paper.Based on the combination of theoretical analysis,numerical simulation and experimental research,the formation mechanism,mass distribution of Behind Armor Debris,spatial distribution of Behind Armor Debris and velocity distribution of Behind Armor Debris are studied.(1)The mechanical model of the EFP vertical penetration the target with finite thickness has been drawn with the help of wave mechanics and basic assumptions.As such,the process and rule of the spallation of the target plate have obtained from that model,thus its formula has been derived.The result shows as following.At velocity of 1800m/s,the target thickness increase from 35mm to 60mm.At that time,the thickness of falcate-spallation zone at the back of the target is expanding,while its length is shortening.For the same thickness at 40mm,the velocity will increase from 1600m/s to 1900m/s with ever-shorting thickness of falcate-spallation zone at the back of the target and ever-expanding length of falcate-spallation zone.Experimental dynamic tests were carried out by using EFP pennetration into the RHA(Rolled Homogeneous Armor)target with 40mm in thickness.From the results,experiment result and theoretical calculation are in good agreement with the theoretical prediction.(2)The process of EFP penetrating target to form a Behind Armor Debris under different conditions is studied by numerical simulation.The distribution of the mass,the distribution of the space and distribution of the velocity are analyzed for the Behind Armor Debris of EFP.The influence of the EFP velocity,the thickness of the target and the inclination angle of the target on the Behind Armor Debris are discussed.(3)Experimental dynamic tests were carried out by using EFP penetration into the RHA target with 40mm in thickness.From the results,experiment results are in good agreement with the theoretical prediction.The recovery test and dispersion test of Behind Armor Debris are carried out.From the results,the experimental results,theoretical calculation results are in good agreement with the simulation results,which verifies the credibility of numerical simulation of Behind Armor Debris.