Initial stress analysis by wavelet transform method

Initial stress would take place in transparent materials as glasses and polymers from casting, cementing or other processing [1][2]. Initial stress might cause cracks and ununiformity, which are not allowed particularly in some situations, such as glasses in lamp covers of the car, the recording media and transparent covers of planes' cabin [3]. It is very important to measure the initial stress in the transparent materials. In the paper, the wavelet method is applied to detect the initial stress of polymers, by which not only the initial stress would be tested but also the direction of the initial stress could be obtained simultaneously in the paper.