Use of Ultrasonic Surface Waves in the Determination of Residual Stress in Metals

In some early experiments in ultrasonic reflectoscopy [F. A. Firestone and J. R. Frederick, J. Acoust. Soc. Am. 18, 204 (1946)] it was observed that residual stresses in metals cause a change in the velocity of surface (Rayleigh) waves by a few tenths of a percent. This work has been extended and the measurement techniques improved. Results obtained on various aluminum and steel alloys under different states of stress will be presented.