Numerical Simulation Of Fuel Tank Response To Projectile Impact

Since the fuel tanks of tactical aircraft have the largest exposure area of all of the vulnerable component, engineering estimates of fuel tank response to penetrating ballistic projectiles are required in order to design more survivable tanks. The finite element calculations have been made by using MSC.Dytran package to simulate the dynamic response and failure of fuel tank wall subjected to projectiles penetration and fuel pressure wave loading.There are two situations for the calculation, one of which is an empty cuboid tank, and another is the same tank containing water where the water is used instead of the fuel and occupies 80% of the tank capacity. Eulerian elements are used to model contained water and Lagrangian element to the projectile and the tank walls. The fuel tank is made of 2024-T351 aluminum alloy. The structural deformation is geometrically nonlinear and the integration in terms of time is explicit. The constitutive relation of the tank material is described by the Johnson-Cook model and the kinematic-hardening rule. The effect of the contacting-collision, the nonlinear geometry and fluid-structure interaction are calculated.The calculating results indicate that the tanks deform differently for the two situations and when the bullet penetrates the water-filled tank, the hydrodynamic pressure waves introduce extra loading to the tank walls and may cause catastrophic failure to the fuel tank. The higher velocity, the severer the more failure may be made.The columniform projectiles can cause more failure than the half-dome head projectiles.