Design and preparation of a low density, high strength honeycomb structure with short‐cut carbon fiber and the performance analysis

Abstract

To meet the urgent demands of aerospace vehicle upgrades and replacements, which require honeycomb structures with higher specific strength and environmental adaptability, the development of lightweight and high‐strength short‐cut carbon fiber reinforced polymer (S‐CFRP) honeycombs is an effective approach. First, this study designed a hot pressing process, which was utilized for the fabrication of both short‐cut CF paper and S‐CFRP honeycomb. Second, a finite element model was established to predict the mechanical performance of the S‐CFRP honeycomb. Finally, mechanical experiments were conducted on the S‐CFRP honeycomb and the failure factors were analyzed. The S‐CFRP honeycomb features cell edges as low as 2.75 mm in length, with a density reduced to 47.6 kg/m3, achieving the coexistence of small cell edge length and low density in the honeycomb structure. Compared with the aramid honeycomb of 48.06 kg/m3 from Hexcel Corporation, the compressive strength of the S‐CFRP honeycomb was increased by 21%, and the shear strengths in the L and W directions were improved by 42% and 59%, respectively. This study provides a fabrication method and simulation model for low‐cost, lightweight, high‐strength S‐CFRP honeycombs, which has significant engineering value for enhancing the weight reduction efficiency and the mechanical performance of aircraft structures.Highlights A low‐cost, high‐strength short‐cut CF paper has been prepared. An S‐CFRP honeycomb, lightweight and with small cells, has been made. The strength of S‐CFRP honeycombs exceeds that of aramid ones. The failure factors of the S‐CFRP honeycomb were analyzed. Performed accurate mechanical simulation analysis on S‐CFRP honeycomb.