Solving inverse geometry heat conduction problems by postprocessing steady thermograms.

• Efficient tool for postprocessing steady thermographic data for structural health monitoring. • New iterative method based on topological sensitivity computations. • Impressive reconstructions in very challenging scenarios where the size of the defects is very small and thermograms are highly noisy. This paper deals with the use of steady active thermographic inspection as a structural health monitoring method to detect defects and inclusions in a heat conductive medium. The proposed postprocessing method has the advantage of taking into account the whole physics of the problem instead of a reduced set of physical information, as most of the traditional methods do. In comparison with other non-destructive testing techniques like ultrasonics, thermographic inspection is non-contact, more non-intrusive, and safer. However, processing thermographic data is a fairly demanding problem because heat conduction is short range and exhibits a poor signal-to-noise ratio. Numerical experiments illustrate that the present postprocessing technique detects damage fairly well even in very challenging scenarios where the size of the defects is rather small and/or thermograms are highly noisy. [ABSTRACT FROM AUTHOR]