Defect Growth Detection Potential Using Guided Waves
Open Access
- Author:
- Waller, Matthew David
- Graduate Program:
- Engineering Mechanics
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- July 11, 2016
- Committee Members:
- Joseph Lawrence Rose, Thesis Advisor/Co-Advisor
Clifford Jesse Lissenden III, Committee Member
Bernhard R Tittmann, Committee Member - Keywords:
- SHM
NDT
NDE
structural health monitoring
guided waves
ultrasonics
crack detection - Abstract:
- Modern society relies on vast networks of infrastructure such as bridges, pipelines, railroads, and electric generating stations to name a few. Keeping infrastructure operating reliably and safely requires inspection and maintenance. In the United States, inspection and maintenance is especially important for aging infrastructure which is often kept in service beyond its intended lifespan. Inspection is carried out via a range of nondestructive evaluation (NDE) techniques depending on the application. Ultrasonic guided wave testing is a popular NDE technique because of its versatility and ability to quickly inspect large structures and to detect hidden defects. However, ultrasonic guided wave propagation is complex and requires an understanding of wave mechanics for effective inspection. In this thesis, different guided wave modes and frequencies are tested for tracking simulated crack growth in a steel pipe, based on the hypothesis that the effectiveness of the mode and frequency combinations will differ based on the wave structure. Along the way, many concepts relevant to NDE and ultrasonic guided waves such as maintenance philosophies, defect growth and fracture mechanics, guided wave excitation, dispersion principles, source influence, wave structure, noise, and variability in results are discussed.