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Title: Characterization of Anisotropic Guided Wave Propagation and Scattering for Robust In Situ Ultrasonic Imaging of Damage
Committee:
Dr. Jennifer Michaels, ECE, Chair , Advisor
Dr. Thomas Michaels, Co-Advisor (deceased)
Dr. Bonnie Ferri, ECE
Dr. Waymond Scott, ECE
Dr. Ying Zhang, ECE
Dr. Massimo Ruzzene, AE
Abstract:
The objective of this research is to present a methodology for characterizing material wave propagation and scattering from damage in anisotropic composite materials which can then be used to improve in situ sparse array imaging performance. Composite materials used for aerospace applications are highly susceptible to impacts, which can result in barely visible delaminations. Reliable and fast detection of such damage through structural health monitoring is needed to prevent structural failures. The primary novelty of this work is the methodology developed to estimate 2-D scattering matrices for anisotropic composite panels where scattering from both artificial and real impact damage are evaluated and compared. It is shown that incorporating these scattering estimates into in situ imaging improves performance by enhancing damage detection and reducing image noise. Additional work was also performed for characterizing anisotropic wave propagation in the time-domain. This allows for characterization of a wave packet of interest instead of a single wave frequency and the results from this characterization process are utilized in estimating damage scattering in the same anisotropic composites.
