Development of Non-contact Laser Ultrasonic System for Nondestructive Evaluation

Mirsadeghi, Seyed Mehdi

Development of Non-contact Laser Ultrasonic System for Nondestructive Evaluation

dc.contributor.advisor	Hugo, Ronald J.
dc.contributor.advisor	Park, Simon S.
dc.contributor.author	Mirsadeghi, Seyed Mehdi
dc.contributor.committeemember	Kim, Seonghwan
dc.contributor.committeemember	Sun, Qiao
dc.contributor.committeemember	Murari, Kartikeya
dc.date	2018-06
dc.date.accessioned	2018-05-01T18:46:48Z
dc.date.available	2018-05-01T18:46:48Z
dc.date.issued	2018-04-26
dc.description.abstract	The development of cracks and corrosion in pipelines could pose a potential hazard to the community and the pipeline industry. Particularly for buried or insulated pipelines, corrosion and other types of defects may remain invisible unless the pipe is physically excavated or the insulation layers are removed. In this regard, advanced guided wave techniques are rapidly growing due to the advantages that they offer over traditional direct assessment inspection methods. To overcome the challenges associated with the use of conventional ultrasonic techniques, a non-contact laser-based non-destructive evaluation system is proposed in this research work. Compared to conventional ultrasonic transducers, a laser-based technique remains functional at elevated temperatures and can result in high-resolution damage visualization. Using the laser Doppler vibrometer as the ultrasonic detection subsystem, and the pulsed Nd:YAG laser for the ultrasonic generation, a complete non-contact ultrasonic system was implemented. The pulsed laser heats the surface of the specimen, and as a result, thermal and ultrasonic waves are generated in the structure. A reliable numerical model was created using the finite element analysis. The numerical results were validated with experiments in the time and frequency domains. The application of a Nd:YAG laser for ultrasonic wave generation was limited due to a lack of repeatability in the signals and low signal-to-noise ratio and potential damages to the surface. Instead, a piezoelectric transducer in combination with the laser Doppler vibrometer was used to enhance defect identification in aluminum plates. The results show that the proposed method can successfully identify the location and the approximate shape of hidden defects.	en_US
dc.identifier.citation	Mirsadeghi, S. M. (2018). Development of Non-contact Laser Ultrasonic System for Nondestructive Evaluation (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/31867	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/31867
dc.identifier.uri	http://hdl.handle.net/1880/106581
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.faculty	Schulich School of Engineering
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Laser Ultrasonics
dc.subject	Lamb Waves
dc.subject	Defect Identification
dc.subject	Guided Waves
dc.subject	Finite Element Analysis
dc.subject	Nondestructive Evaluation
dc.subject.classification	Applied Mechanics	en_US
dc.subject.classification	Engineering	en_US
dc.subject.classification	Engineering--Mechanical	en_US
dc.title	Development of Non-contact Laser Ultrasonic System for Nondestructive Evaluation
dc.type	master thesis
thesis.degree.discipline	Mechanical and Manufacturing Engineering
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.item.requestcopy	true