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.
| Language | English |
|---|---|
| Pages | 139-142 |
| Number of pages | 4 |
| Journal | IEE Proceedings Science Measurement and Technology |
| Volume | 148 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 30 Jul 2001 |
| Externally published | Yes |
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Keywords
- noncontact ultrasonic inspection
- carbon fiber reinforced composites
- high-power pulsed laser
- laser interferometer
- damage thresholds
- generation efficency
- optical parametric oscillator (OPO)
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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 journal › Article
TY - JOUR
T1 - Laser generated ultrasound
T2 - IEE Proceedings Science Measurement and Technology
AU - Edwards, C.
AU - Stratoudaki, T.
AU - Dixon, S.
AU - Palmer, S.
PY - 2001/7/30
Y1 - 2001/7/30
N2 - 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.
AB - 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.
KW - noncontact ultrasonic inspection
KW - carbon fiber reinforced composites
KW - high-power pulsed laser
KW - laser interferometer
KW - damage thresholds
KW - generation efficency
KW - optical parametric oscillator (OPO)
UR - http://www.scopus.com/inward/record.url?scp=0035386947&partnerID=8YFLogxK
UR - http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=2199
U2 - 10.1049/ip-smt:20010465
DO - 10.1049/ip-smt:20010465
M3 - Article
VL - 148
SP - 139
EP - 142
JO - IEE Proceedings Science Measurement and Technology
JF - IEE Proceedings Science Measurement and Technology
SN - 1350-2344
IS - 4
ER -