STRUCTURAL HEALTH MONITORING OF WIND TURBINE BLADES UTILIZING GUIDED WAVES

Wind turbine blades (WTBs), as crucial components of wind turbine generators, are susceptible to structural damage due to severe weather conditions during operation periods. This paper proposes an active structural health monitoring (SHM) system, leveraging guided waves for the WTBs diagnosis. It comprises electro-magnetic actuators, piezoelectric sensing units, and data acquisition and signal processing modules. An algorithm incorporating spectral wave energy and cross-correlation is developed for precise damage detection. To validate the system and algorithm, a simplified SHM system is implemented on a laboratory-scale WTB prototype. Artificial damage simulated by the bonded mass block can be accurately detected and located. For the subsequent phase, a full-scale test is conducted on a XX-192 WTB (anonymity of XX for confidential purpose), exceeding 90 meters in length and fixed on a foundation tower as a cantilever beam under fatigue tests. The practical durability and stability of the system is demonstrated, subjected to over 500,000 flapping and edging cyclic loadings. The system precisely detects the artificial delamination in the fashion of a bonded composite sample on the WTB, achieving the detection of a small delamination area of 80 mm* 30 mm. The paper culminates in summary, concluding remarks, and suggestions for future work.