Reconstruction and analysis of pulsed thermographic sequences for nondestructive testing of layered materials.

We develop a heat transfer model to reconstruct pulsed thermographic data of layered objects. One of its salient features is its incorporation of normalized variables for a generalized approach to such problems. Additionally, we establish a methodology to determine the spatial and temporal limits of the data reconstruction process. Moreover, we describe an effective nondestructive technique for detecting and characterizing internal defects in multilayer objects. This inspection technique is verified on the construction of physical models and their examination. The depth, transverse dimensions, and front-surface shape of the detected defects are straightforwardly obtained from 3D depthgrams.