Repeated healing of low velocity impact induced damage in orthogrid-stiffened sandwich panel

Herein, we present a new sandwich panel composed of a carbon fiber grid-stiffened shape memory vitrimer (SMV) core. The sandwich panels were fabricated via a pin-guided dry-weaving technology, and their impact responses were evaluated via low-velocity impact testing. The main failure mode observed after the first round of impact was the transverse cracking of the SMV matrix in the sandwich core. The healing efficiency according to the crack initiation energy (CIE) was found to be 76.5% after the first healing cycle. Even after the second healing cycle, the healing efficiency was greater than 72%. From the low-velocity impact tests, reinforcing the pure SMV core with a grid-skeleton enhanced the impact resistance significantly, that is, the crack initiation energy and peak load were increased by 64.0% and 169.0%, respectively. The results also show that smaller bay area leads to higher impact resistance. With the repeated crack healing, increased impact tolerance, and shape memory effect, it is expected that the sandwich panels will have a good possibility for usage in aerospace and automotive applications.

Automated summary

Here, a new sandwich panel was developed using a carbon fiber grid-stiffened shape memory vitrimer (SMV) core. The panels were manufactured using dry-weaving technology and evaluated for their impact response using low-velocity impact testing. The main failure mode observed was transverse cracking of the SMV matrix in the core. The panels showed strong impact resistance and a good possibility for use in aerospace and automotive applications.