Quasi-static mechanical properties of composite foldcores based on the BCH patterns

Abstract

Foldcore sandwich structures have aroused considerable research interests in the field of aerospace engineering in recent years. While the Miura-based foldcores have been studied extensively, those based on folding patterns with kirigami features are relatively rare. In this paper, we focus on the mechanical properties of composite foldcores made of woven Kevlar fiber reinforced plastics (KFRP) with the kirigami-inspired folding pattern, known as the BCH pattern. The finite element (FE) modeling procedure is developed for foldcores made of woven KFRP and is validated with fabricated woven KFRP foldcore specimens subjected to compression tests. A parametric numerical study on the mechanical properties of woven KFRP foldcores with various BCH patterns subjected to quasi-static out-of-plane compression and shearing is conducted. Moreover, the BCH-based woven KFRP foldcores are compared with the Miura and curved-creased woven KFRP foldcores, the Nomex honeycomb cores with different cell sizes and the BCH-based foldcores made of Nomex paper and aluminum. The results indicate that the selected BCH-based models exhibit superior specific peak stress and stiffness under compression and shearing along the shear direction 2, and the BCH model made of woven KFRP possesses higher specific peak stress and energy absorption than the same BCH models made of Nomex paper and aluminum, providing the potential of practical application.