A defect shape reconstruction algorithm for pulsed thermography

An algorithm for the defect shape reconstruction from pulsed thermography data was developed. The aim was to reconstruct the defect shape in a test sample with known thermal properties. The algorithm consists of a defect shape correction unit and a simulation unit. The defect shape correction unit is designed to extract the defect shape roughly and refine it sequentially while the simulation unit models the heat conduction process in the inspected sample. The developed iterative algorithm is able to reconstruct 2D as well as 3D defect shapes. The algorithm was tested using experimental data obtained on a plate-shaped steel sample with a wall thickness profile. Robust defect shape reconstruction results were demonstrated.