Abstract
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 [1 - J 0 (Δ)] γ where J 0 is the zeroth-order Bessel function. This new technique is called the time-averaged photoelastic method. To verify the proposed method, the distribution of [1 - J 0 (Δ)] γ 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. © Society for Experimental Mechanics 2006.