Fatigue damage monitoring of repaired composite wind turbine blades using high-stability buckypaper sensors

Abstract

The fatigue load has become an increasingly prominent problem affecting the damage tolerance and service life of wind turbine blades. The damage monitoring of repaired blades is a challenging task. The purpose of this study was to use buckypaper (BP) sensors to monitor the structural health of the repaired composite specimens in fatigue environments. First, the quasi-static tensile failure test and the graded loading and unloading experiment verified the feasibility of using BP sensors to monitor the specimens. Then, the BP sensors were used to systematically monitor the axial fatigue of the repaired and reinforced composite specimens. The cumulative damage caused by fatigue was visualised through the ΔR/R0 response change in the BP sensors. The analysis results of the sensors were compared with the actual damage of the specimens, and a non-destructive inspection chart was used for auxiliary verification, further verifying the feasibility of using the BP sensor to monitor damage on wind turbine blades. The method of monitoring the repaired composite structure damage using BP sensors can be used to study the damage behaviour of the repaired wind turbine blade under fatigue.