Study On The Characteristics Of High-speed Elliptical Cross Section Projectile Penetrating Into Concrete

Hypersonic cruise missiles and hypersonic aerocraft are hot topics in missile and aircraft research both at home and abroad,in view of the non-circular cross section shape of the warhead in this type of warhead,the penetration characteristics of non-circular cross section warheads need to be studied.In this paper,elliptical cross section shaped projectile is selected as the object of study,by means of numerical simulation,theoretical derivation and experimental verification,the characteristics of high speed elliptical projectile at different ratios of length to short axis penetrating concrete were studied.The main work is as follows:(1)First of all,the influence of the cross-section shape on the stress on the surface during projectile penetration is studied.Using numerical simulation method,the elliptical cross-section projectile with constant cross-sectional area,constant length and constant mass of circular cross-section projectiles and different ratios of length to short axis is penetrating semi-infinite concrete.The influence of cross section shape on the stress distribution on the surface of projectile is analyzed,and the functional relationship between normal stress and normal velocity and cross section shape of elliptical cross section projectile is obtained,which provides theoretical support for further research.(2)Based on the relationship between the normal stress and the normal velocity on the elliptical cross section projectile head surface,through the surface integral of the projectile to obtain the analytic expression of the penetration resistance,Newton's law of motion was used to calculate the penetrating acceleration,velocity,displacement and other physical quantities to construct the analysis model of the penetration resistance equation and penetration depth.(3)A finite element method of a circular cross section and two types of elliptical cross-section projectiles in the experiment was established.The numerical simulation of the projectile penetrating into the concrete at high speed was carried out.The acceleration,velocity and displacement data of each projectile were obtained,and the results were compared with the theoretical analysis,verifying the accuracy of acceleration,velocity and displacement function in the theoretical analysis.(4)Carrying out elliptical cross-section projectile at 700m/s-1200m/s speed range is penetrating semi-infinite concrete test.Observe the target response,projectile response,the ballistic trajectory after the high-speed penetration of the projectile,record the crater depth of the target,the diameter of the crater,the penetration depth and other data,the relationship between the experimental data and the elliptical cross section shape is analyzed.The results of the test are compared with the theoretical calculation results to verify the rationality and accuracy of the theoretical model.