Multi-failure Analyses of Carbon-fiber-reinforced Miura-ori Core Sandwich Panels Subjected to In-plane Compressive Load

Sandwich structures with Miura-ori core are supposed to be a promising substitution to traditional sandwich structures with honeycomb core in the aerospace industry. To reveal the failure mechanism of carbon-fiber-reinforced Miura-ori core sandwich panels subjected to in-plane compressive load, a multi-failure theory considering five potential failure modes, including bending and shear global buckling, face local buckling, face debonding and face crushing, is proposed. The critical failure loads of specific geometrical configurations are predicted and failure mechanism map is deduced to figure out the optimizing route for lightweight design. Three groups of the specimens with different face sheet thickness are designed and fabricated by adopting a hot-press molding and twice curing technique. Two typical failure modes including face local buckling and face debonding are revealed by the in-plane compressive tests, and the analytical results are in a reasonable agreement with the tested. Compared to corrugated core sandwich panels with the same dimension, Miura-ori core sandwich panels possess a higher anti-local-buckling capacity thanks to the stronger constraint of Miura-ori core to the face sheet. It is expected that this work can provide a significant guideline for the practical application and design of such kind of sandwich structures.