Mechanical performance of polycarbonate honeycomb cored kevlar composites sandwich structures with silica aerogel fillers

Abstract Lightweight and high-strength sandwich composites are essential for advanced structural applications; nevertheless, conventional designs often face limitations in mechanical performance. This study investigates the fabrication and evaluation of Kevlar fabric-reinforced sandwich composites including a polycarbonate honeycomb core, including both silica aerogel-filled and non-filled versions. Kevlar fabric composites were produced using compression moulding using Epoxy LY556 and Hardener HY915, while the polycarbonate honeycomb cores were created via Fused Deposition Modelling (FDM) additive manufacturing. The Kevlar skins and honeycomb core were adhered using Sikaflex 227 polyurethane sealant to form the final sandwich structure. A thorough characterization was performed using Field Emission Scanning Electron Microscopy (FESEM) analysis, along with mechanical testing that included compression, flexural, impact, and hardness evaluations. The results demonstrated that including silica aerogel fillers significantly enhanced mechanical performance, with notable improvements in impact strength, compressive strength, flexural strength, and surface hardness compared to the unfilled composite. The use of silica aerogel fillers improved the toughness, decreased the weight, and raised the mechanical strength of the sandwich composite, highlighting its appropriateness for high-performance structural and impact-resistant applications.