DEPENDENCE OF THE SONIC IR SIGNAL ON CRACK LENGTH AND CRACK CLOSURE

Sonic IR is garnering a great deal of interest from the nondestructive inspection industry because of its promise as a fast, reliable and environmentally benign technique for locating cracks. Many questions remain to be answered, however, before the technique can be widely adopted as an industry standard. In addition to practical characteristics, such as the probability of detection (POD), some fundamental questions need to be addressed. One such question is the mechanism of heat generation and its dependence on the prevailing test conditions and on defect characteristics. In this study, we present some early data on the dependence of the sonic IR signal on crack length and crack closure.