A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Laser-based non-destructive detection of inner flaws in concrete with the use of Lamb waves
A laser system for remote non-destructive inspection of concrete structures has been developed. The system is intended for the location of inner flaws in concrete structures, mainly in concrete transportation tunnels. The technique is based on the initiation and detection of Lamb waves and ultrasonic vibration in concrete with the use of a laser photorefractive interferometer. Vibration in concrete is initiated by laser impact provided by a pulsed Nd:YAG laser operating at wavelength of 1064 nm. A CW Nd:YAG laser radiation of 532 nm wavelength is used for detection. The laser interferometer uses principles of dynamic holography via two-wave mixing in photorefractive crystal and homodyne detection. A photorefractive crystal - Bismuth Silicon Oxide (BSO) - is used as a nonlinear medium for the recording of the dynamic hologram. Concrete samples used in the laboratory experiments reproduce real concrete material used in transportation tunnels. Various types of inner defects like voids, cracks and honeycombs have been tested. Lamb waves initiated by laser impact are detected by the interferometer. Analysis of Lamb wave spectra provides information of defect location. Accuracy of location is about 2 cm. A mobile model of the system has been assembled and demonstrated in field conditions.
Laser-based non-destructive detection of inner flaws in concrete with the use of Lamb waves
A laser system for remote non-destructive inspection of concrete structures has been developed. The system is intended for the location of inner flaws in concrete structures, mainly in concrete transportation tunnels. The technique is based on the initiation and detection of Lamb waves and ultrasonic vibration in concrete with the use of a laser photorefractive interferometer. Vibration in concrete is initiated by laser impact provided by a pulsed Nd:YAG laser operating at wavelength of 1064 nm. A CW Nd:YAG laser radiation of 532 nm wavelength is used for detection. The laser interferometer uses principles of dynamic holography via two-wave mixing in photorefractive crystal and homodyne detection. A photorefractive crystal - Bismuth Silicon Oxide (BSO) - is used as a nonlinear medium for the recording of the dynamic hologram. Concrete samples used in the laboratory experiments reproduce real concrete material used in transportation tunnels. Various types of inner defects like voids, cracks and honeycombs have been tested. Lamb waves initiated by laser impact are detected by the interferometer. Analysis of Lamb wave spectra provides information of defect location. Accuracy of location is about 2 cm. A mobile model of the system has been assembled and demonstrated in field conditions.
Laser-based non-destructive detection of inner flaws in concrete with the use of Lamb waves
Laser basierter zerstörungsfreier Nachweis innerer Fehler in Beton mittels Lamb-Wellen
Kotyaev, O. (author) / Shimada, Y. (author) / Hashimoto, K. (author)
2006
11 Seiten, 18 Bilder, 1 Tabelle, 6 Quellen
Conference paper
Storage medium
English
Internal discontinuity detection in concrete by Lamb waves
| Tema Archive | 2001
DETECTION AND SIZING OF PLANAR FLAWS FROM INNER SURFACES USING ID CREEPING WAVES
| British Library Online Contents | 2004
Detection of internal defects in concrete panels by Lamb waves
| Tema Archive | 2000
Composite-concrete interface characterization by Lamb waves
| Tema Archive | 1999
Lamb waves for the non-destructive inspection of monolithic and sandwich composite beams
| British Library Online Contents | 2005