Time-Averaged Photoelastic Stress Analysis of the Ultrasonic Wave in a Strip

In this paper, a digital photoelastic system was employed to observe the stress distribution generated by an ultrasonic wave impinged at the edge of a strip. According to the classical photoelastic theory, gray level distribution of the photoelastic fringe patterns was formulated and expressed in the form of , where J₀ is the zeroth-order Bessel function. This new technique is called the time-averaged photoelastic method. To verify the proposed method, the distribution of was superimposed onto the distribution of gray level of the experimentally obtained photoelastic fringe pattern caused by standing wave only. Except regions near the center of fringes, well-matched results were found.