Defect visualization in carbon fiber composite using laser ultrasound

Journal Article · Sun Aug 01 04:00:00 EDT 1993 · Materials Evaluation; (United States)

OSTI ID:6092888

Dewhurst, R J; He, Ruhua; Shan, Qing ^[1]

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1. Univ. of Manchester Inst. of Science and Technology (United Kingdom). Dept. of Instrumentation and Analytical Science

A non-contacting laser ultrasound system has been developed to visualize laminar defects in carbon fiber composite materials. Laser-generated ultrasound (LGU) was produced from a Nd:YAG Q-switched laser. Ultrasound was detected with the use of an actively stabilized Fabry-Perot interferometer using a 400 mW argon-ion laser source. It detected ultrasound in a typical frequency range of 1 to 10 MHz. Through-transmission C-scan measurements were made in carbon fiber composite materials of thickness 1 to 20 mm. Peak-to-peak amplitudes of the first longitudinal ultrasonic pulse were measured, with attenuation used as the basis of defect examination. Digital filtering was adopted to enhance defect visibility. Results showed that images with size resolution better than 1 mm can be achieved. Such measurements take into account any variation of surface reflectivity which can arise in industrial materials.

• OSTI ID: 6092888
• Journal Information: Materials Evaluation; (United States), Journal Name: Materials Evaluation; (United States) Vol. 51:8; ISSN MAEVAD; ISSN 0025-5327
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420500* -- Engineering-- Materials Testing
ACOUSTIC TESTING
CARBON FIBERS
COMPOSITE MATERIALS
DEFECTS
DETECTION
DIGITAL FILTERS
FABRY-PEROT INTERFEROMETER
FIBERS
INTERFEROMETERS
LASERS
MATERIALS
MATERIALS TESTING
MEASURING INSTRUMENTS
NEODYMIUM LASERS
NONDESTRUCTIVE TESTING
SOLID STATE LASERS
TESTING
ULTRASONIC TESTING