Lamb wave evaluation of concrete plates
Author
Summary, in English
A new technique based on 2D arrays is also presented. In an example, the technique is used to map (image) the variation of phase velocity for the A0 Lamb mode in the lateral plane of the plate; that is, the technique is in this case used to assess the material and plate thickness homogeneity. Compared to ultrasonic reflection imaging methods, no limitation to a specific set of operating frequencies (transducers) exists since the 2D array technique is based on a full wave field dataset with wide frequency bandwidth. Variation of material properties transversally through the thickness may also exist. For improved understanding about zero-group velocity (ZGV) modes under this type of material condition, two cases with continuously varying acoustic bulk wave velocities are investigated. Results show that a zero-group velocity mode exists with the similar robustness and detectability for both cases: non-destructive applications based on zero-group velocity modes are possible also for these two material variation cases.
Department/s
Publishing year
2017-09-01
Language
English
Full text
- Available as PDF - 15 MB
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Document type
Dissertation
Publisher
Department of Biomedical Engineering, Lund university
Topic
- Engineering and Technology
Keywords
- Lamb waves
- guided waves
- impact-echo
- concrete
- non-destructive evaluation
Status
Published
Project
- Non-destructive evaluation of thick concrete structures using seismic methods
Supervisor
ISBN/ISSN/Other
- ISBN: 978-91-7753-380-1
- ISBN: 978-91-7753-379-5
Defence date
28 September 2017
Defence time
10:00
Defence place
Lecture hall E:B, building E, Ole Römers väg 3, Faculty of Engineering LTH, Lund University, Lund
Opponent
- Odile Abraham (Doktor)