Session: 01-08-01: Nondestructive Evaluation and Structural Health Monitoring, 01-11-01: Wind Energy

Paper Number: 137896

137896 - Defect Parameters Effects on Ultrasonic Guided Waves Scattering by Hybrid Global-Local Method for Damage Characterization 

Aerospace structures are exposed to a variety of damage sources throughout their operational lifetime. Manufacturing processes inevitably induce inherent defects; unexpected and/or repeated loads, impact events and aging cause new or further grow such defects into damage, affecting structural integrity and residual strength. If left undetected or improperly assessed, this scenario can threaten passenger safety and cause major costs.

Non-destructive evaluation (NDE) and Structural Health Monitoring (SHM) of composite aerospace structures become crucial to this end. Among the different techniques available, Ultrasonic Guided Waves (UGWs) have been widely adopted particularly for these large complex structures, preserving great sensitivity while providing large monitoring and deep penetration capabilities. Their use, though, is hindered by their dispersive and multi-mode behavior, which makes UGWs propagation and scattering very complex.  

Modeling UGWs can highly aid understanding their interaction with defects to provide valuable insights in both guiding the inspection procedure and correctly interpreting the inspection data.

In this work, the Global-Local approach is used to study the influence of different defect types in composite plates on ultrasonic guided waves scattering. The efficient framework of this hybrid computational tool enables the computation of accurate scattering spectra in composite structures in a parametric manner in the presence of defects, over a broad frequency range and for different incident modes.

These results would have been very challenging to obtain using regular computational approaches and find direct applicability in the selection of sensitive defect specific frequency-mode combination for inspections. They also serve as valuable data for training models on defect type and characteristics, and mode interaction to perform inversions for defect characterization and monitoring.

Presenting Author: Margherita Capriotti San Diego State University

Presenting Author Biography: Dr. Capriotti is currently an Assistant Professor in the Department of Aerospace Engineering at San Diego State University, focusing on Non-Destructive Evaluation (NDE) and wave propagation.
She received her Ph.D. in Structural Engineering from University of California San Diego in 2019, pursuing research in the Experimental Mechanics & NDE Lab. She previously graduated with her B.S. and M.S. in Mechanical Engineering at the University of Parma (Italy). She has been a postdoctoral Research Fellow at Mayo Clinic in the Department of Radiology, within the Ultrasound Research Lab.
Her research aims at developing noninvasive techniques for defect detection and characterization, material characterization and structural assessment of composite aerospace structures, using ultrasonic guided waves and heat diffusion. She is also interested in noninvasive techniques for biomedical applications, specifically shear wave elastography. She is currently setting up her NDE Research Clinic at SDSU.