Session: 17-01-01: Research Posters

Paper Number: 145387

145387 - Structural Health Monitoring of Wind Turbine Blades Utilizing Guided Waves 

Wind power, as a renewable clean energy, has enacted an imperative role in the global effort of mitigating carbon emission, reducing reliance on fossil fuel resources, and diversifying energy portfolios. In recognition of its paramount significance, enormous wind turbine generators (WTGs) have been deployed on a large scale across diverse terrains and geographical regions, spanning ocean, dessert, and mountainous landscapes. The extreme weather conditions, such as gales, freezing conditions, lightning strikes, and sandstorms, pose formidable safety hazards to WTG components, particularly wind turbine blades (WTBs), thereby necessitating Structural Health Monitoring (SHM) strategies for early-stage damage detection. Existing methodologies, predominantly utilizing strain gauges, accelerometers, and thermal cameras, are limited to identifying only conspicuous damage types and structural vibration anomalies, typically occurring at the terminal stage of WTB operational lifespan, thus impeding timely maintenance interventions. Furthermore, scant research attention has been directed towards experimental validation on full-scale WTBs over a long duration. Hence, a robust methodology for detecting early-stage damage and its practical demonstration is required.

This paper proposes an active SHM technique leveraging guided waves for the diagnosis of incipient damage in WTBs. The SHM system comprises of electro-magnetic actuators, piezoelectric active wafer sensors (PWAS), and modules for data acquisition and signal processing. A comprehensive algorithm incorporating time-of-flight analysis, wave energy assessment, cross-correlation index, and empirical modal decomposition (EMD) is established and employed to facilitate precise damage detection. To validate the feasibility of the proposed SHM system and algorithm, a simplified SHM system was implemented on a laboratory-scale WTB prototype measuring 3 meters in length. For the subsequent phase, a full-scale test was conducted on a XX-192 WTB (anonymity of XX due to confidential issue), which was over 90 meter long and suspended on a test tower akin to a cantilever beam under the fatigue test. The practical durability and stability of the actuators and sensors was demonstrated during over 500,000 cycles of flapping and edging loadings. The system managed to detect the artificial delamination prefabricated in a composite sample affixed to the WTB, with the detection resolution of 80 mm. Regarding the ultimate phase, further fatigue tests were carried out on a XX-217 WTB lasting for 8 months. Improvements on actuators, sensors, algorithm, and automatic operation were accomplished, facilitating the periodic evaluation and maintenance. The systematic research underpins the potential for the large-scale deployment and commercialization of the WTB SHM system. The paper culminates in summary, concluding remarks, and suggestions for future work.

Presenting Author: Runye Lu Shanghai Jiao Tong University

Presenting Author Biography: A PhD candidate whose research interest concentrates on structural health monitoring leveraging high frequency resonances and ultrasonics

Authors:

Runye Lu Shanghai Jiao Tong University
Yanfeng Shen Shanghai Jiao Tong University