Abstract
This paper describes a new data processing technique used in the pulse heating thermographic NDT. The surface temperature after heating is measured by high-speed infrared camera. The shape of transient temperature descent curve, which reflects defect parameters such as depth and size, was analyzed by the Fourier series. It was found that the coefficient of the Fourier series, a_n, b_n, were effectively used to determine depth and size of the defects. This method was applied successfully to the detection and quantitative measurement of impact delamination damages in the advance CFRP plates and material loss defects in steel plates.
