Senior research engineer, United Technologies Research Center, East Hartford, CT
Pages: 11 Published: Jan 1988
Noncontacting electromagnetic acoustic transducers (EMATs) are used to generate and receive wideband pulses of ultrasound in graphite/aluminum (Gr/Al) plates and tubes. High precision velocity and attenuation measurements are used to locate defects and to determine elastic moduli. Both static global and scanned local values of the attenuation and velocity are measured by using large or small receiver EMAT separations, respectively. Nondispersive, shear horizontal, and lowest order symmetric Lamb waves are employed along with a four-transducer method which eliminates measurement uncertainties associated with EMAT lift-off variations. Elastic moduli of Gr/Al plates are determined from ultrasonic data.
metal matrix composites, graphite/aluminum, nondestructive evaluation, electromagnetic acoustic transducers (EMATs), elastic moduli evaluation
Paper ID: STP25955S