The health monitoring of GFRP laminates in a salt spray environment <i>via</i> CNTs film sensor

To date, the lightweight glass fiber reinforced plastic (GFRP) components have been widely used, however, the real‐time damage detection of service behavior of GFRP components is still a major challenge, especially facing long-term seawater aging effects. Herein, the effect of seawater aging on the mechanical properties of GFRP has been explored by establishing a microscopic analysis and three-point bending experiment. Results revealed that the flexural strength of GFRP significantly decreased by 13.1% under a 60-day salt spray aging test. The continuous deterioration of the interfacial properties of GFRP due to water intrusion was confirmed and analyzed. Simultaneously, the evolution of the salt spray aging effect on laminates was revealed by using carbon nanotubes (CNTs) film sensors in a salt spray environment. The dynamic stability and durability of the in situ monitoring capabilities of nanosensor were examined facing the monotone and cyclic flexural loadings in a salt spray environment. The monitoring signal responses indicated that the CNTs film sensor showing good electrical/mechanical sensing characteristics with excellent repeatability, rapid response, and recovery capability, is suitable for in situ damage monitoring and early warning of GFRP components, which provides constructive suggestions for practical salt spray environment application.