Master of Science

thesisCarbon fiber-reinforced composite materials have been increasingly used in aerospace and aeronautics industries due to their superior strength over metals, low fatigue life, high corrosion resistance, and temperature resistance. Since most damage, such as delaminations, manifest inside the composite material, we often cannot detect damage through visual inspection. As a replacement for visual inspection, ultrasonic guided waves have been widely researched to remotely detect, locate, and characterize damage in structures due to their unique capability to travel long distances and inspect inaccessible locations for damage. Yet the anisotropic nature of composites makes it difficult to identify the velocity characteristics of the guided waves and utilize them for damage localization. To address this challenge, we use sparse wavenumber analysis to determine anisotropic multimodal and dispersive frequency-wavenumber characteristics of guided waves. We then use these multimodal and dispersive properties to predict how guided waves propagate in the anisotropic plate through sparse wavenumber synthesis. Finally, these predictions, which form a wave propagation model for the composite, are integrated with matched field processing, a model-based localization framework, to locate damage on the composite