Application of Photoelasticity to Research on Effects of Ultrasonic Stress Waves on Metals

The photoelastic effect in plastics offers the possibility to study the influence of several parameters, such as geometry and environmental conditions, on stress‐wave patterns in solid rods irradiated by ultrasound. Irradiation of prototypes is accomplished through intimate contact of one end with an ultrasonic transducer operating at 20 kc/sec with intensities up to 200 W/cm². The dependence of the modes and amplitudes of stress waves on shape, constraints, and localized heating—such as found in tensile tests [F. Blaha and B. Langenecker Acta Met. 7, 93 (1959)], crystal growth from the melt [B. Langenecker and W. H. Frandsen, Phil. Mag. 7, 2079 (1962)], and zone refining [B. Langenecker et al., NAVWEPS Rept. 8482, NOTS TP 3447 (1964), U. S. Naval Ordnance Test Sta., China Lake, Calif.]—is presented. Potentials of these studies in which photoelectric prototypes are used in place of metals are discussed, including an examination of coupling between ultrasonic horns and prototypes and a photometric determination of stresses.