Monitoring the integrity of adhesive joints during fatigue loading using carbon nanotubes

Sensing capabilities of carbon nanotube networks inside epoxy matrix have attracted the attention of many researchers in recent years. Since, there is a lack of literature in investigating the fatigue behavior of adhesive joints, this study evaluates the capability of carbon nanotube networks, formed inside the adhesive, to monitor the integrity of adhesively bonded aluminum joints, which are subjected to fatigue loading. The conductive network inside the adhesive is sensitive to crack initiation, propagation and delamination, therefore, in situ measurement of the bond resistance is capable of monitoring the integrity of the joints subjected to fatigue. Aluminum single lap joints are fabricated, using carbon nanotube reinforced epoxy adhesive, and the electrical resistance perturbation of the joints is monitored during fatigue loading.