Date of Award

5-2026

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Electrical Engineering

Committee Chair/Advisor

Hai Xiao

Committee Member

Lianfeng Zhao

Committee Member

Tao Wei

Abstract

This thesis investigates laser-induced acoustic signal generation, resonance characterization, and optical sensing in metallic plates as a foundational study for damage-sensitive inspection. Rather than presenting a complete defect-detection system, the work focuses on how measurable acoustic responses can be generated, amplified, and interpreted in a controlled laboratory setting. Experiments showed that pulsed-laser excitation can produce strong and repeatable acoustic responses in metallic structures. Repetition-rate sweeping identified narrow resonant responses, including a cantilever resonance at 57.862 kHz and a maximum circular-disk response at an FFT frequency of 48.8 kHz with a laser repetition rate of about 49.1 kHz. High-Q resonances exceeding 100 mV, and in one case 200 mV, were also observed. At the same time, the measured spectra were strongly affected by geometry, boundary conditions, and resonator–substrate coupling, which limits the direct use of resonance peaks as robust damage indicators. Optical sensing experiments further showed that stable interferometric responses can be obtained, and that layered-plate measurements are sensitive to coupling conditions and internal reflections. Overall, this thesis establishes a signal-centered experimental framework for metallic plates. The results show that resonance is an effective mechanism for amplifying weak laser-induced acoustic signals, while optical interferometric sensing is feasible but remains exploratory.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.