Thin-ply carbon fiber laminates have exhibited superior mechanical properties, including higher initiation and ultimate strength, when compared to standard thickness plies and enable greater flexibility in laminate design. However, the increased ply count in thin-ply laminates also increases the number of ply-ply interfaces, thereby increasing the number of relatively weak and delamination-prone interlaminar regions. In this study, we report the first experimental realization of aligned carbon nanotube interlaminar reinforcement of thin-ply unidirectional prepreg-based carbon fiber laminates, in a hierarchical architecture termed ‘nanostitching’. We synthesize a baseline effective standard thickness laminate using multiple thin-plies of the same orientation to create a ply block, and we find an ∼15% improvement in the interlaminar shear strength via short beam shear (SBS) testing for thin-ply nanostitched samples when compared to the baseline. This demonstrates a synergetic strength effect of nanostitching (∼5% increase) and thin-ply lamination (∼10% increase). Synchrotron-based computed tomography of post mortem SBS specimens suggests a different damage trajectory and mode of damage accumulation in nanostitched thin-ply laminates, notably the complete suppression of delaminations in the nanostitched region. Finite element predictions of damage progression highlight the complementary nature of positive thin-ply and nanostitching effects that are consistent with an ∼15% improvement in Modes I and II interlaminar fracture toughness due to the aligned carbon nanotubes at the thin-ply interfaces.

与标准厚度的层板相比，薄层碳纤维层板展现出卓越的机械性能，包括更高的起始强度和极限强度，并使层压板设计具有更大的灵活性。但是，薄层状层压板中层数的增加也增加了层板界面的数量，从而增加了相对较弱且易于分层的层间区域的数量。在这项研究中，我们报告了在单层预浸料基碳纤维层压板中定向碳纳米管层间增强的第一个实验实现，这种分层结构称为“纳米缝制”。我们使用相同方向的多个细折叠线来合成基线有效的标准厚度层压板，以创建层板块，与基线相比，通过薄层纳米缝合样品的短束剪切（SBS）测试，我们发现层间剪切强度提高了约15％。这证明了纳米缝合（增加约5％）和薄层状层压（增加约10％）的协同强度效果。基于同步加速器的计算机断层扫描验尸后的SBS样品表明，纳米缝合的薄层板中的损伤轨迹和损伤积累方式不同，尤其是纳米缝合区域中的分层完全得到抑制。损伤进展的有限元预测突出了正薄层和纳米缝合效应的互补性质，这与由于薄层界面处对齐的碳纳米管而导致的I型和II型层间断裂韧性提高了约15％是一致的。