EXPANSION AND FRACTURE OF FRAGMENTING WARHEAD SHELLS OF VARIOUS MATERIALS UNDER A CL-20 EXPLOSIVE CHARGE

摘要

To study the effect of the warhead material characteristics upon warheadexpansion and fracture and upon the formation of fragments under ahigh-power explosive charge, four different warhead materials;30CrMnSiNi2A steel, 40CrMnSiB steel, 50SiMnVB steel and 82 steel; areexamined. This paper builds a analytical modeling to theoretically analyzethe expansion and fracture processes for the different material warheads. Inaddition, the AUTODYN-3D finite element software is used to numericallysimulate the expansion and fracture processes of the four materials, andhigh-speed photography technology and a tinfoil target velocity test systemare used to verify the simulation results. It is found that, for the “Φ62mm”aperture warhead under the explosive CL-20 charge, the expansion andfracture processes of the four materials all require Φ60 μs, and the shellexpansion velocity in the whole process can be divided into three stagescalled libration, acceleration and stabilized. The initial velocities of thefragments along the warhead axis for the different warhead materials areconsistent with each other, though the expansion velocity and the maximuminitial velocity of the fragments are largest for the 30CrMnSiNi2A steelwarhead. It is found that the warhead expansion velocity and the initialvelocity of the fragments decrease gradually as the ultimate tensile strengthof the warhead material decreases and as its dynamic fracture toughnessincreases. This study introduces the coefficient of radial warhead expansionand acquires the function for the distance of the radial warhead expansionover time, which is influenced by the warhead material characteristics. Theresults of this study will provide a reference for fragmenting warhead shellmaterial selection and design.