High-velocity impact resistance of doubly curved sandwich panels with re-entrant honeycomb and foam core

This work describes the high-velocity impact behavior of doubly curved sandwich panels. The panels are manufactured using carbon/fiber epoxy composite face sheets, polyurethane foam core and 3D-printed PLA plastic cellular auxetic (re-entrant) honeycombs. High-velocity tests carried out by a single-stage air gas gun test machine. A spherical steel projectile with radius 5 mm is impacted to center specimens speed 100 m/s. experimental data used validate explicit finite element models structures. An analytical model also developed for ballistic limit flat panels, results compared those obtained from numerical ones. Parametric analyses high-speed then considering various radii curvature show that energy absorption increased as decreased both re-entrant core. In addition, configuration provides key role in resistance Re-entrant an increase specific (SEA) types.