FIBER BRAGG GRATING SENSORS FOR FATIGUE MONITORING OF COMPOSITE WIND BLADES

摘要

Fiber Bragg grating sensor can be used to monitor the mechanical behavior of compositernwind blade. The internal strain of composite wind blade during a constant and variable stressrnamplitude fatigue testing process was monitored with fiber Bragg gratings sensors. FBGrnsensors as a fatigue indicator can reveal Young's modulus decrease of the specimen, which isrna direct index of damage. FBG sensors can not only be embedded in composite blades torndetect fatigue damage, but also have excellent durability compared with other sensors such asrnelectric strain gauges. After 1 million cycles, the FBG sensors can still keep good sensibility.rnFBGs as a fatigue indicator are a novel sensor to monitor, evaluate and give crash alert for thernhealth state of composite wind blades during their whole service life.