A technique based on the electrical resistance change of a network of carbon nanotubes within a polymer composite was implemented to assess damage caused by low-velocity impact in multiscale hierarchical composites. The influence of the electrode configuration in 100 mm x 100 mm x 1.7 mm plates is addressed. Three electrode configurations are evaluated, namely, a grid on the impacted surface, a grid on the opposite (non-impacted) surface, and through the thickness of the plate. Upon impact, matrix cracking, delamination, and fiber rupture cause disruption and redistribution of the electrical network of carbon nanotubes, whose electrical resistance changes can be correlated with such damage. It is found that the non-impacted surface exhibits a higher fractional change of electrical resistance and hence higher sensitivity to damage. The results obtained using the electrical technique showed a good correlation with damage detected by independent measurements by digital holographic interferometry and ultrasonic inspections.

中文翻译：

---

电极配置对自感分层复合材料冲击损伤评估的影响

实施了一种基于聚合物复合材料内碳纳米管网络电阻变化的技术，以评估多尺度分层复合材料中低速冲击造成的损坏。解决了 100 mm x 100 mm x 1.7 mm 板中电极配置的影响。评估了三种电极配置，即受冲击表面上的网格、相反（未受冲击）表面上的网格以及穿过板的厚度。在撞击时，基体开裂、分层和纤维断裂会导致碳纳米管电气网络的破坏和重新分布，其电阻变化可能与这种损坏相关。发现未受冲击的表面表现出更高的电阻变化分数，因此对损坏的敏感性更高。