Study On The Law Of Fragment Striking Special Metal Plate

Killing warhead is one of the main types of conventional warhead.Generally,high-speed fragments are generated by explosion.The high-speed impact,ignition and detonation of fragments on the target are used to damage the target.The research on the penetration ability of fragments to the target is of great significance to the power design of warhead.In this paper,the law of fragment striking special metal plate is studied.The main research contents are as follows:(1)The relevant theories and empirical formulas of fragment armor penetration were summarized,and the penetration test of 30 Cr Mn Si A fragment into 921 A target was carried out.Relying on AUTODYN numerical simulation software,the fragment penetration physical model,constitutive model and reasonable selection of parameters are established,and compared with the test results,including penetration state,residual velocity,perforation diameter and bulge height.It is concluded that the error of each index is Within 10%,the correctness of the numerical simulation is verified,which lays a foundation for the follow-up research work.(2)Based on the established numerical simulation model,the numerical simulation experiments of a series of geometric fragments penetrating the aforementioned target were carried out,the clear physical images of the incident process were obtained,and the influence law of projectile shape on the terminal trajectory was revealed: it was observed that the fragment penetration process can be divided into pit opening,stable penetration and impact There are three stages of armor piercing;Under the conditions of impact velocity of 900 to1300 m / s,target thickness of 8mm and fragment mass of 9.5g,the ultimate penetration velocity of spherical fragment is the smallest,cubic fragment is the second,and cylindrical fragment is the largest.(3)Based on the established numerical simulation model,the numerical simulation test of the cylindrical fragment penetrating the target at a series of incidence angles is carried out,and the influence law of the incidence angle on the end trajectory was revealed: when the fragment penetrates the target at different angles,the penetration state is different.When the incidence angle increases When the incident angle is 15o,the limit penetration velocity is 776m/s,which is 8.2% higher than that of normal penetration;When the incident angle is 30o,the limit penetration velocity is between 1000m/s and 1050m/s,an increase of 39.5%-46.4% compared with normal penetration.When the incident angle increases again,there are fewer working conditions that can completely penetrate the target.When the incident angle is greater than 45o,fragments jump.(4)Based on the established numerical simulation model and referring to the parameters of 93 tungsten alloy,active material and LY12 aluminum material in the literature,the numerical simulation tests of cylindrical fragments penetrating 8mm and 6mm 921 A steel targets and LY12 aluminum targets were carried out,and the influence law of fragment materials on the terminal trajectory was revealed: in the fragment volume phase In the same case,the penetration ability of tungsten alloy fragments is the strongest,and the mass loss is the smallest in the penetration process.The penetration ability of 30 Cr Mn Si A fragments is second to that of tungsten alloy fragments,and the penetration ability of active material fragments is the weakest,but deflagration reaction will occur during penetration.