Effect of Shear Modes Interference in Anisotropic Materials

Ultrasonic signals transmitted through a plate by shear waves in weakly anisotropic materials are usually not separable in the time domain and thus interfere at the receiver. The interference signal bears information on material anisotropy due to texture or residual stresses. This dependence of the interference signals on material properties can be utilized practically. Blinka and Sachse [1] used interference of two shear waves to measure stress applied normally to the direction of wave propagation in an aluminum specimen. The phenomenon is also described in [2]. The change of acoustic microscopy contrast is attributed by Dreschler-Krasicka to stress induced interference [3]. Various interference phenomena in crystalline solids are described by Wolfe in [4]