A NONLINEAR-INTERACTION OF 2 ACOUSTIC BEAMS ON THE SOLID INTERFACE

Two incident ultrasonic shear wave beams of 7.5 MHz interact at glass- metal interface, and the reflected longitudinal wave of 15 MHz normal to the interface are investigated. This effect is identified as a nonl inear interface effect and the sum frequency signal is the convolution of two input signals. The convolution efficiency is measured as about 106 dBm for glass-iron interface, The observation reveals that the qu ality of interface bending has a significant influence on the convolut ion output. So the nonlinear effect is found to be useful for implemen tation of convolution or nondestructive evaluation of bonding layer. T heoretical analysis and experimental measurements on the effect are pr esented in this letter. (C) 1996 American Institute of Physics.