This paper presents an experimental investigation of the multi-scale toughening mechanisms for improving the interlaminar fracture toughness, low-velocity impact damage resistance and compression-after-impact (CAI) strength of continuous carbon fibre-epoxy composite laminates using carbon nano- and micro-fillers spanning the nanometer to millimeter length scales. The fillers used in the epoxy matrix of the composite laminates were carbon nanofibres (CNFs) and short carbon fibres (SCFs). When used together, these two fillers yielded a less-than-additive improvement to the mode I fracture toughness. However, they created a synergistic (i.e. greater-than-additive) increase to the steady-state mode II toughness, compared to when the fillers were applied separately. Hybridising the CNFs with the SCFs also improved the impact damage resistance (up to 24%) and CAI strength (up to 29%) of the laminate at various impact energies. The key toughening mechanisms imparted by the CNFs and SCFs, when used separately or in combination, were identified through analyses and scanning electron microscopy.

本文介绍了多尺度增韧机制的实验研究，以提高使用碳纳米和微米碳纤维连续碳纤维-环氧复合材料层压板的层间断裂韧性、低速冲击损伤抗力和冲击后压缩 (CAI) 强度。 -跨越纳米到毫米长度尺度的填料。在复合层压板的环氧树脂基体中使用的填料是碳纳米纤维 (CNF) 和短碳纤维 (SCF)。当一起使用时，这两种填料对 I 型断裂韧度的改进不足。然而，与单独使用填料时相比，它们对稳态模式 II 的韧性产生了协同（即大于加成）增​​加。CNF 与 SCF 的混合还提高了层压板在各种冲击能量下的抗冲击损伤性（高达 24%）和 CAI 强度（高达 29%）。通过分析和扫描电子显微镜确定了 CNF 和 SCF 在单独或组合使用时赋予的关键增韧机制。