Location

La Jolla, CA

Start Date

1980 12:00 AM

Description

The electromagnetic acoustic transducer (EMAT) is a device of particular interest for rapid nondestructive evaluation (NDE) in assembly line applications because of its noncontact mode of operation. Speed is a crucial factor in the performance of an NDE system designed for the inspection of artillery projectiles where production rates may be on the order of several shells per minute. These requirements severely restrict the reliability of conventional ultrasonic techniques that use fluid couplants. A fully automated micro-processor based inpsection system utilizing multiple EMATs to launch shear vertical acoustic waves traveling at 30 degrees with respect to the surface normal is being assembled to inspect 155 mm projectiles for both ID and OD flaws. The system's ability to detect small defects has been demonstrated by locating semi-elliptical EDM notches having surface lengths of 2.5 mm (0.1 in.) and maximum depths of 0.8 mm (0.03 in.).

Book Title

Proceedings of the ARPA/AFML Review of Progress in Quantitative NDE

Chapter

13. New Technology Applications

Pages

581-582

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Rapid Ultrasonic Inspection of Army Projectiles

La Jolla, CA

The electromagnetic acoustic transducer (EMAT) is a device of particular interest for rapid nondestructive evaluation (NDE) in assembly line applications because of its noncontact mode of operation. Speed is a crucial factor in the performance of an NDE system designed for the inspection of artillery projectiles where production rates may be on the order of several shells per minute. These requirements severely restrict the reliability of conventional ultrasonic techniques that use fluid couplants. A fully automated micro-processor based inpsection system utilizing multiple EMATs to launch shear vertical acoustic waves traveling at 30 degrees with respect to the surface normal is being assembled to inspect 155 mm projectiles for both ID and OD flaws. The system's ability to detect small defects has been demonstrated by locating semi-elliptical EDM notches having surface lengths of 2.5 mm (0.1 in.) and maximum depths of 0.8 mm (0.03 in.).