A biomimetic structural health monitoring approach using carbon nanotubes

A self-sensing nanocomposite material has been developed to track the presence of damage in complex composite structures. Multiwalled carbon nanotubes are integrated with polymer matrix to develop a novel bonding material with sensing capabilities. The changes of the piezoresistance in the presence of damage are used to monitor the condition of bonded joints, where the usual bonding material is replaced by the self-sensing nanocomposite. The feasibility of this concept is investigated through experiments conducted on singlelap joints subject to monotonic tensile loading conditions. The results show that the self-sensing nanocomposite is sensitive to crack propagation within the matrix material. An acoustic emission-based sensing technique has been used to validate these results and shows good correlation with damage growth. A digital image correlation system is used to measure the shear strain field in the joint area.