ABSTRACT

Structural Health Monitoring (SHM) systems are commonly integrated in bonded joints for different applications in order to detect and predict potential fatigue and damages caused by internal and external agents they are subjected to during their operation life. However, each of the current SHM systems presents some drawbacks, as the reduction of structural properties or the difficulty in its implementation. This work deals with the use of a Carbon Nanotube film (Bukypaper) as a sensor in double cantilever beam (DCB) bonded joint specimens for crack growth monitoring purposes. Buckypaper (BP) sheets were manufactured and integrated in adhesive film layers and its integration quality was studied by Scanning Electron Microscopy (SEM). The effect of the integration of different thickness BPs in the mechanical performance of the bonded joints was also assessed performing DCB fracture tests. Also, electro-mechanical tests were conducted using the BP as the sensor, monitoring the output in the electrical resistance during the crack propagation. It was observed the capability of BP to detect and locate the damage during the test with a linear dependence between the electrical resistance measured in the BP and the deduced crack growth, proving the potential of the BP to monitor self-sensing bonded joints.

摘要

结构健康监测 (SHM) 系统通常集成在用于不同应用的粘合接头中，以检测和预测在其使用寿命期间由内部和外部因素造成的潜在疲劳和损坏。然而，当前的每个 SHM 系统都存在一些缺点，如结构特性的降低或实施困难。这项工作涉及使用碳纳米管薄膜 (Bukypaper) 作为双悬臂梁 (DCB) 粘合接头试样中的传感器，用于裂纹扩展监测。制造巴克纸 (BP) 片材并将其集成在粘合剂膜层中，并通过扫描电子显微镜 (SEM) 研究其集成质量。在进行 DCB 断裂试验时，还评估了不同厚度 BP 对粘合接头机械性能的影响。此外，使用 BP 作为传感器进行机电测试，监测裂纹扩展过程中的电阻输出。观察到 BP 在测试过程中检测和定位损伤的能力，在 BP 中测量的电阻与推断的裂纹扩展之间存在线性相关性，证明了 BP 监测自感应粘合接头的潜力。