Numerical Simulation on the Dynamic Damage of PBX Charges Filled in Projectiles During Penetrating Thin Concrete Targets

This paper is devoted to the building of a viscoelastic model based on actual damage mechanisms for explosive charges filled in projectiles during penetrating concrete targets. The characteristic damage modes present in polymer bonded explosive(PBX)s include intragranular voids, crystal fractures, and interfacial debonding. Quasi-static uniaxial compression tests and split-Hopkinson pressure bar tests were modelled to study mechanical responses and damage evolutions of PBXs at different loading conditions, and the dynamic finite element algorithm was applied to estimate the mechanical responses of PBXs under low intensity stimulus. Analyzing the damage and pressure distributions and the variations of different damages, the position of PBXs that is ready to be ignited, we find that the initial loading of the explosive charge head is suffered from the greater compressive stress. When the stress wave is propagated to the tail, reflected tensile waves are produced. Furthermore, the pressure increases rapidly to 0.25 GPa, leading to the more serious damages on the head and the tail, attributed to the inertia of the projectile body and the collision between the charge tail and the inner surface of the shell. It suggests that the head and the tail could be two key protection areas.