Novel Impact‐Resistant Honeycomb Sandwich Structures With Heterogeneous Multilayer Panels

ABSTRACT To overcome the issue of brittle fracture in the composite panels of traditional honeycomb sandwich structures, which results in inadequate overall impact resistance, a novel heterogeneous multilayer panel was designed and prepared. The panel comprises three aluminum foil layers interleaved with carbon fiber prepreg tapes, a design that leverages interlaminar property differences to enhance impact resistance. By establishing a theoretical model, this study analyzed the influence of various materials on the interlaminar relative slippage. The results indicate that the aluminum‐prepreg heterogeneous multilayer panel exhibits the most significant interlaminar relative slip under loading, demonstrating superior crack deflection capability at the interlaminar regions. Based on this, a heterogeneous multilayer panel configuration was designed with the specific capability to guide crack deflection. Three‐point bending tests confirm this design effectively promotes interlaminar crack deflection, significantly extending the crack path and delaying damage evolution. Drop‐weight impact tests further validate that, by leveraging crack deflection effects, the heterogeneous multilayer panels substantially improve the impact resistance of sandwich structures. Compared to traditional composite sandwich structures, the new design achieves nearly 20% higher average contact forces and approximately 10% lower maximum displacements. This research provides novel insights into enhancing the impact resistance of carbon fiber honeycomb sandwich structures.