Research On Related Technologies Of Artillery-launched Submunition Warhead

In order to provide foundation for the design of warhead of ?39.2 mm submunitions,the influence of different ways of initiation,offset initiation,rotational speed and multilayer cavity liner on warhead performance of submunitions is studied using ANSYS/LS-DYNA,then the simulation results are compared with experiments.The influence of shape,quantity and material of prefabricated fragments on after-effect of warhead is studied using ANSYS/LS-DYNA.The influence of cone angle and thickness of cavity liner on penetration depth of ?64 mm shaped charge under different stand-off distance is studied using AUTODYN.The influence of groove shape,groove width,groove depth and number of radial grooves on mass distribution and velocity of fragments is studied using AUTODYN.Simulation results show that the penetration depth caused by surface initiation is greater than point initiation.Penetration depth increases as surface initiation diameter increases.The angle that jet deflects from its axis increases with the increase of offset initiation distance.The angle that jet deviates from its axis is 5.3° and jet penetration depth decreases by 25.2 % when offset initiation distance is 4 mm.The axial velocity of jet when arriving target does not change much when rotational speed is less than 7000 r/min.The axial velocity of jet head decreases by 1.49% when rotational speed is 20000 r/min.Expanding drilling is easier when slug is surrounded by outer cavity liner in jet formation process,penetration is mainly done by internal cavity liner.The penetration depth of single layer powder metallurgy cavity liner is greater than that of single layer compact copper.The penetration effect of four kinds of double layer cavity liner are all better than that of single cavity liner when inner cavity liner's material is the same to single cavity liner's and double layer cavity liner's thickness is the same to single cavity liner's.Simulation results show that the velocity of prefabricated fragments increases when using high strength case.The experimental result of after-effect of ?50 mm shaped charge shows that the number of holes caused by tungsten alloy cylinder and steel ball fragments on target are larger when cone angle of cavity liner is 125°,the distribution area of holes are large and small respectively,those holes mostly are made by jet,the number of fragments that successfully penetrates target is small.The residual specific kinetic energy of 16 ?1.2 mm steel balls or major axis 2.0 mm,minor axis 1.2 mm ellipsoids is high when target is completely penetrated.The mixed fragments of 16 ?1.2 mm steel ball and major axis 2.4 mm,minor axis 1.2 mm ellipsoid can spread out effectively when target is completely penetrated.The number of fragments that successfully penetrates target is decreased when steel ball's diameter is greater than 1.2 mm or ellipsoid's major axis is greater than 2.4 mm,minor axis is 1.2 mm.The more fragments,the easier blocking happens in the process of follow-through.The number of fragments penetrating target is increased when velocity gradient exists among fragments.Simulation results show that the penetration depth of jet is 168 mm and 214 mm when stand-off distance is 50 mm and 150 mm,the error is-1.2% and 1.9% compared to experimental results.The velocity of jet head and slug decreases and increases respectively rapidly as the stand-off distance increases,and becomes stable when stand-off distance is greater than 200 mm.The influence of cavity liner's thickness on jet length is obvious when stand-off distance is greater than 100 mm,the thicker the cavity liner,the longer the jet.In order to increase stand-off distance insensitivity of armor penetration depth of shaped charge,the thickness of cavity liner should be large when cone angle of cavity liner is small and fixed.The thickness of cavity liner should be small when cone angle of cavity liner is large and fixed.Simulation results show that the precontrol is effective using rectangle-shaped groove.The number of fragments weighing 0.1 g~0.3 g decreases and 0.3 g~0.5 g increases with the decrease of groove width,the precontrol maximizes when using 0.6 mm wide groove.The number of fragments weighing 0.1 g~0.3 g increases and 0.3 g~0.4 g decreases with the decrease of groove depth,the precontrol is less effective and effective respectively with 0.4 mm and 0.8 mm or 1.0 mm deep groove.The total number of fragments increases first,then decreases and then increases as the number of radial groove increases.The precontrol is less effective and more effective respectively when the number of radial grooves is less than 15 and greater than 20.