Session: 01-05-01: Congress-Wide Symposium on NDE & SHM: Computational Nondestructive Evaluation and Structural Health Monitoring

Paper Number: 146115

146115 - Non-Destructive Structural Health Monitoring of Wind Turbine Blade Using Laser Doppler Vibrometer 

Amidst the escalating global concerns of energy scarcity and environmental degradation, adopting renewable energy resources has witnessed a substantial upsurge. Wind energy, in particular, has emerged as a remarkable and viable alternative to traditional fossil fuel-based and nuclear power generation. Wind turbine blades (WTBs), the cornerstone of wind turbine systems, are pivotal in this transition. However, the pressing energy needs have propelled the industry to construct wind turbines with taller towers, larger-sized generators, and transformers, thereby augmenting the power generation capacity. While these advancements have increased efficiency, these colossal structures are prone to damage induced by solid wind, sea waves, and harsh environmental conditions. Such damages can hamper the power generators' efficiency, shorten the wind turbines' lifespan, escalate safety risks, and inflate maintenance costs. They can even trigger catastrophic events like blade fracture and tower collapse in extreme cases. Detecting these damages, which can be initially minuscule and invisible, poses a significant challenge. Our research, therefore, is dedicated to devising a practical approach to monitor the WTB's structure using non-destructive testing (NDT). Through a fusion of numerical simulation and experimental techniques, our study aims to detect structural cracks in WTBs, especially subsurface ones. The numerical simulation leverages COMSOL Multiphysics to assess the wind turbine blade vibrations induced by a 200 kHz short pulse generated by a piezoelectric transducer made from PZT-5H. The experiment employs a laser Doppler vibrometer (LDV) to measure the velocity variations over time at multiple points around the crack on a composite wind turbine blade surface. To decipher the crack's response to the short pulses, we employ advanced signal processing techniques such as the Hilbert-Huang Transformation (HHT) to identify the intrinsic mode functions (IMFs), which indicate structural anomalies. Further analysis, including Fast Fourier Transformation (FFT) and Hilbert spectrum, bolsters our ability to assess the extent of damage to our composite-based model.    

Our findings provide a robust foundation for the non-destructive inspection of WTBs using LDVs. By overcoming the accessibility challenges posed by traditional manual inspections, LDVs can offer a more efficient and rapid assessment of WTBs' structural health. However, challenges may persist in implementing our methodology in real-world scenarios. Nonetheless, this study showcases a viable path towards enhancing the reliability and survivability of wind turbines globally, underscoring the relevance and impact of our research in the renewable energy industry.

Keywords: Non-destructive testing; Glass fiber-reinforced polymer; Elastic time-harmonic wave equations; Laser Doppler vibrometers; Hilbert-Huang transformation; Fast Fourier transformation

Presenting Author: Farhood Aghdasi Rowan University

Presenting Author Biography: My name is Farhood Aghdasi, and I am affiliated with Rowan University, Department of Mechanical Engineering, located in Glassboro, New Jersey. My research interests include structural health monitoring, advanced materials for noise and vibration control, surface acoustic waves (SAW), as well as metamaterials and metasurfaces.

Authors:

Farhood Aghdasi Rowan University
Ali Zabihi Rowan University
Nand Singh Rowan University
Ratneshwar Jha Florida Institute of Technology
Chen Shen Rowan University