High velocity impact behavior of composite sandwich panels with self-healing capabilities

In this study, the high velocity impact behavior of a dual-plate multifunctional panel composed by a carbon fiber reinforced plastics (CFRP) laminate and an ionomer thermoplastic resin plate is investigated experimentally. A unique characteristic of this panel is the ability to auto-repair holes generated by impacts, which is possible due to the ionomer layer. This panel is also a structural element since it includes a CFRP laminate layer. In the experimental campaign spherical aluminum projectiles with a diameter ranging from 2.3 to 4.5 mm were impacted against the multifunctional panel at impact velocities ranging from ~2.0 to ~2.5 km/s and all impacts were normal to the target. Impacts occurring on the CFRP and ionomer side were investigated. The impact response of the panels discussed in this work concerns the following characteristics: debris cloud shape, damage on the witness plate, momentum transferred to the witness plate and self-healing. It was observed that when the ionomer was located on the back side of the panel it hindered the debris cloud expansion. This configuration also resulted in lower momentum transfer to the witness plate. The layers disposition had a minor effect on fragment velocity at the debris cloud tip for impact energies above ~200 J. Complete self-healing of the hole occurred in all impact cases up to the projectile diameter of 3.5 mm.