Detection and Characterization of Short Fatigue Cracks by Conduction Thermography

Stimulated thermography is a very common non-destructive testing (NDT) technique used for a wide range of applications and materials. An external excitation source is required to stimulate the component and detect defects. Electric currents can be used in this sense adopting two different approaches: induction thermography and conduction thermography. In this work, a preliminary investigation to evaluate the influence of some test parameters during experiments of conduction thermography, for the detection of short fatigue cracks, induced in thin specimens of different materials, is presented. The capability of the technique and crack detectability have been analysed and compared with the Thermoelastic Stress Analysis (TSA) considered as a well-established technique capable of quantifying short fatigue cracks in metal materials.