The addition of Multi-wall carbon nanotubes (MWCNTs) or functionalized-graphene nanoplatelets (f-GNPs) into the epoxy resin create an electrical conductive networks which can be employed for structural health monitoring (SHM) in sensitive adhesive joints. The opening fracture mode (Mode I) loading condition, as one of the important fracture modes in adhesive joints was precisely evaluated in this study. The study aims to investigate the crack extension in the adhesive joint (Fracture mechanics) under mode I loading by both smart adhesives and proper measurement technique. In order to provide high sensing capability in the adhesive joint, several aluminum to aluminum adhesive joints were prepared by dispersion of 2.5 wt% MWCNTs or 12 wt% f-GNPs into the epoxy adhesive, respectively. Considering the electrical impedance changes simultaneously with the mechanical response of the adhesive joints, novel outcomes were obtained. Almost linear trend has been observed in the impedance curve for the strain value of 0.57. During crack growth, the conductive network in epoxy matrix near the crack tip would be break and thus the electrical impedance would be increased. In addition, the electrical impedance curve has exhibited several sharp increases, which are attributed to the rapid crack growth.

在环氧树脂中添加多壁碳纳米管（MWCNT）或功能化石墨烯纳米片（f-GNP）可创建导电网络，可用于敏感粘合剂接头中的结构健康监测（SHM）。在这项研究中，精确评估了开口断裂模式（模式I）的加载条件，该条件是胶接接头中的重要断裂模式之一。该研究旨在通过智能粘合剂和适当的测量技术研究在模式I载荷下粘合剂接头（断裂力学）中的裂纹扩展。为了在粘合剂接头中提供高感测能力，通过将2.5 wt％的MWCNT或12 wt％的f-GNP分别分散到环氧粘合剂中来制备几种铝对铝的粘合剂接头。考虑到电阻抗的变化与粘合接头的机械响应同时发生，获得了新的成果。对于0.57的应变值，在阻抗曲线中观察到了几乎线性的趋势。在裂纹扩展过程中，靠近裂纹尖端的环氧树脂基体中的导电网络将被破坏，因此电阻抗将增加。另外，电阻抗曲线表现出若干急剧的增加，这归因于裂纹的快速增长。