On-line tensile damage monitoring of WGF/epoxy T-joint by the embedded MWCNT@WGF sensor

Abstract The electric resistance based-sensor made by woven glass fiber coated with multi-walled carbon nanotube (MWCNT@WGF) was adopted to monitor the mechanical behavior of composite T-joint under tensile loading. The sensor was embedded into the WGF/epoxy composite T-joint, and its resistance along two tunnels was recorded. Bolt fasten and fiber winding fasten were designed to fasten the T-joint after embedding MWCNT@WGF sensor. Finite element (FE) models of the T-joint were built to understand the relationship between the damage process and the in-situ monitoring signal. Results show that damage of T-joint under tensile loading could be monitored by the MWCNT@WGF sensor well. After fastened by the two approaches, the enhanced tensile strength together with the in-situ monitoring ability can be obtained simultaneously. Relationship between the in-situ monitoring resistance and stress distribution of T-joints was built with the assistance of FE simulation results.