Presenter Information

Peter W. Lorraine, General Electric

Location

La Jolla, CA

Start Date

1-1-1998 12:00 AM

Description

Laser ultrasound offers many advantages over conventional piezoelectric ultrasound including the potential for rapid wide-area scanning, non-contacting (no couplant) generation and sensing, and large bandwidth [1,2]. Ultrasonic surface waves may be easily generated by a laser and can travel extended distances when the part is not immersed and loss to a surrounding water bath is eliminated. In addition, the geometric attenuation is significantly less as the sound energy spreads out in a circular annulus rather than in a spherical shell giving rise to an amplitude decay proportional to r −1/2.We have shown that synthetic focusing of laser ultrasound data [3] permits us to use this information to create images of near-surface defects outside the scan area. A single scan line can be used to image the complete surface of part with high speed, resolution, and sensitivity (Figure 1).

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

17A

Chapter

Chapter 2: Emerging Technologies

Section

Laser/Optical Ultrasonics

Pages

603-609

DOI

10.1007/978-1-4615-5339-7_78

Language

en

File Format

application/pdf

Share

COinS
 
Jan 1st, 12:00 AM

Laser Ultrasound Imaging of Lamb Waves in Thin Plates

La Jolla, CA

Laser ultrasound offers many advantages over conventional piezoelectric ultrasound including the potential for rapid wide-area scanning, non-contacting (no couplant) generation and sensing, and large bandwidth [1,2]. Ultrasonic surface waves may be easily generated by a laser and can travel extended distances when the part is not immersed and loss to a surrounding water bath is eliminated. In addition, the geometric attenuation is significantly less as the sound energy spreads out in a circular annulus rather than in a spherical shell giving rise to an amplitude decay proportional to r −1/2.We have shown that synthetic focusing of laser ultrasound data [3] permits us to use this information to create images of near-surface defects outside the scan area. A single scan line can be used to image the complete surface of part with high speed, resolution, and sensitivity (Figure 1).