Laser generated ultrasound: efficiency and damage thresholds in carbon fibre reinforced composites

C. Edwards, T. Stratoudaki, S. Dixon, S. Palmer

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Laser techniques are beginning to be used for non-contact ultrasonic inspection of carbon fibre reinforced composites in industry. The ultrasound is normally generated with a high-power pulsed laser and is detected with a laser interferometer. Other non-contact detection methods can also be used, such as simpler laser beam deflection techniques and air coupled transducers. The authors compare the generation efficiency and damage thresholds of a fundamental Nd:YAG laser (1.06μm), and a TEA CO2 laser (10.6μm) which is normally preferred for carbon-fibre reinforced composites. A Nd:YAG laser with an optical parametric oscillator (OPO) tunable up to 4μm is also examined. The laser energy is absorbed within the optical absorption depth; the temperature rise is affected by the wavelength and laser pulse duration. It is essential to remain in the thermoelastic regime in order not to damage the material. A modified Michelson interferometer is used to detect the absolute displacement of the ultrasound. Optical beam deflection techniques and air-coupled transducers are also evaluated as detectors.

LanguageEnglish
Pages139-142
Number of pages4
JournalIEE Proceedings Science Measurement and Technology
Volume148
Issue number4
DOIs
Publication statusPublished - 30 Jul 2001
Externally publishedYes

Fingerprint

Carbon fibers
Ultrasonics
Lasers
Composite materials
Transducers
Optical parametric oscillators
Michelson interferometers
High power lasers
Air
Pulsed lasers
Interferometers
Light absorption
Laser beams
Laser pulses
Inspection
Detectors
Wavelength
Industry
Temperature

Keywords

  • noncontact ultrasonic inspection
  • carbon fiber reinforced composites
  • high-power pulsed laser
  • laser interferometer
  • damage thresholds
  • generation efficency
  • optical parametric oscillator (OPO)

Cite this

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Laser generated ultrasound : efficiency and damage thresholds in carbon fibre reinforced composites. / Edwards, C.; Stratoudaki, T.; Dixon, S.; Palmer, S.

In: IEE Proceedings Science Measurement and Technology , Vol. 148, No. 4, 30.07.2001, p. 139-142.

Research output: Contribution to journalArticle

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