Edge-effects and defect sizing by transient thermography

Thermal edge-effects for crack-like defects have been calculated using the Wiener-Hopf technique. These lead to an experimentally verified prediction that transient thermographic defect images shrink systematically with elapsed time. A simple method of defect sizing is proposed based on accounting for defect shrinkage. Finite difference modeling is used to investigate the dependence of image shrinkage on defect size and depth.