Resistance of composite materials and tank structures to the impact and hydraulic ram pressure generated by a ballistic projectile

Abstract
The purpose of the presented work was to investigate the vulnerability of carbon fibers aircraft composite tank structures to ballistic impacts during take-off or landing (tank full of fuel). Indeed, under certain circumstances, a penetrating projectile can generate a catastrophic ruin scenario inside the tank due to “hydraulic ram” effects. The ONERA experimental contribution in the Research field concerns the implementation of a vertical ballistic shots facility, of caliber 7.62, and the testing of different types of material samples and dummy caissons. The presented test rig was specifically designed and developed for this kind of experiments. The aim of the firing and other dynamic tests is also to supply the necessary input data for numerical simulations and to gather as many results as possible that are of interest for the validation of various FE models. The numerical FE modeling of the passage through a tank by a ballistic projectile depends on the development of stable numerical methods able to efficiently solve so-called “multi-physics” problems (with notably the coupling due to fluid/structure interactions), with “fast dynamics”-type loading (high speeds, large strains).