Theses and Dissertations
ORCID
https://orcid.org/0000-0002-6293-1041
Advisor
Sullivan, Rani
Committee Member
Tian, Zhenhua
Committee Member
Huberty, Wayne
Committee Member
Sun, Chuangchuang
Date of Degree
12-12-2025
Original embargo terms
Embargo 2 years
Document Type
Dissertation - Open Access
Major
Engineering (Aerospace Engineering)
Degree Name
Doctor of Philosophy (Ph.D.)
College
James Worth Bagley College of Engineering
Department
Department of Aerospace Engineering
Abstract
Advanced materials, including composites, additively manufactured alloys, high-temperature ceramics, and biomaterials, are increasingly used to build complex structures and components. Ensuring reliable damage detection, material characterization, and life-cycle assessment for these parts requires nondestructive techniques that are rapid, quantitative, and adaptable to widely varying geometries and internal architecture. This dissertation develops an integrated acoustic wave methodology that unifies guided wave and bulk shear wave sensing, full-field time-space wavefield analysis, and optimization-based inversion to provide both structural health monitoring (SHM) and nondestructive evaluation (NDE) in a single framework. A minimal‑contact piezoelectric transducer - laser Doppler vibrometer (PZT–LDV) platform couples a bonded piezoelectric transducer with scanning laser Doppler vibrometry to acquire high‑resolution wavefields without extensive transducer arrays or couplants. Complementary analytical, semi-analytical, and finite-element models provide dispersion baselines and sensitivity maps for viscoelastic polymers, additively manufactured composites and metals, and ceramic tubes. The earlier chapters concentrate on methodology. Multi‑dimensional frequency‑wavenumber analysis, directional wavefield slicing, and short‑space Fourier transforms are combined with an Adam‑enhanced dispersion‑curve regression algorithm to extract elastic modulus, Poisson’s ratio, and viscoelastic properties from broadband, multimodal wave data. Additional procedures, such as wavefield decomposition, mode‑selective filtering, and direction/space-frequency-wavenumber mapping, visualize wave propagation and interaction phenomena and provide quantitative local characterization of mechanical properties over large scanning areas with high efficiency. The later chapters demonstrate the methodology in four representative applications: (i) viscoelastic property mapping in a gelatin phantom through shear wave dispersion, (ii) directional mechanical properties characterization of a large format additive manufactured (LFAM) thermoset composite plate, (iii) detection of texture‑induced anisotropy in laser powder‑bed fused (LPBF) 316L stainless steel, and (iv) non‑contact evaluation of elastic constants and potential defects in sintered silicon‑carbide nuclear fuel‑cladding tubes. This dissertation advances the state of the art in structural health monitoring and nondestructive evaluation by delivering a universal high-resolution wave-sensing system, providing robust multi-domain analysis tools for dispersive multimodal wavefields, and unifying material-property inversion with defect visualization. The resulting workflow enables rapid, non‑contact inspection and real‑time material metrology across polymers, composites, metals, and ceramics, establishing a foundation for smart manufacturing and autonomous structural health management.
Sponsorship (Optional)
Federal Aviation Administration, Department of Energy, National Science Foundation, and National Aeronautics and Space Administration
Recommended Citation
Cai, Bowen, "Acoustic dispersion analysis for mechanical property characterization of advanced materials" (2025). Theses and Dissertations. 6751.
https://scholarsjunction.msstate.edu/td/6751
