Lock-in infrared thermography has been identied as a highly suitable technique for a quantitative defect characterization. In this work, rst, a complete dimensionless reformulation of the thermographic investigation is provided. As a consequence, the constraints of particular experimental setups or material properties can be overcome preserving the full physical information of the experiment. The resulting model has been numerically solved and successfully validated by using experimental thermographic data. Second, the developed dimensionless model has been used as input for a global sensitivity analysis. Overall, the obtained results provide an experimental guideline for an optimized thermographic defect characterization.

In this work a thermodynamic peculiarities of fatigue crack propagation at titanium alloy Ti64 after laser shock peening were studied. The plane samples were weakened by notch to initiate fatigue crack. An area around notch was processed by laser shock peening. This made it possible to create a compress residual stress up to 1 mm depth. The infrared thermography method was used to analyze a temperature field at crack tip. An increase in heat dissipation during fatigue crack propagation after laser shock peening was found.