doi:10.1016/j.cma.2020.113523engOmella, Á.J.Celorrio, R.Pardo, D.Sensitivity and uncertainty analysis by discontinuous Galerkin of lock-in thermography for crack characterizationART-2021-121238This work focuses on the characterization of narrow vertical cracks of finite size using optically excited lock-in thermography (OLT). To characterize these cracks, we need to solve an ill-posed inverse problem. As a previous step to the solution of this inverse problem, we propose a sensitivity analysis to quantify the influence that the parameters involved in the model have on the surface temperature. Some of these parameters are estimated at the laboratory and they incorporate uncertainty that may severely affect the reconstruction of thin cracks. For this reason, we design a calibration criterion based on the sensitivity analysis to determine which parameters we need to include as unknowns of the inverse problem. We perform this analysis using a numerical discontinuous Galerkin method. Additionally, we propose a theoretical noise model for the thermograms. Then, we use a weighted least square method (WLS) to determine the parameters from the experimental thermograms. We also obtain a theoretical uncertainty of the reconstructed parameters in OLT-WLS fitting according to the used surface temperature dataset. Finally, we perform a numerical experiment with a 2.4 m-thick vertical crack to show the sensitivities of the surface temperature with respect to the model parameters. We also determine the uncertainty of the parameters under different datasets with known noise characteristics.2021http://zaguan.unizar.es/record/16948410.1016/j.cma.2020.113523http://zaguan.unizar.es/record/169484oai:zaguan.unizar.es:169484info:eu-repo/grantAgreement/ES/DGA-FEDER/E24-17Rinfo:eu-repo/grantAgreement/ES/FEDER/Interreg VA POCTEFA-2014–2020-PIXIL-EFA362/19info:eu-repo/grantAgreement/ES/FEDER-MCYT/MTM2016-75139-Rinfo:eu-repo/grantAgreement/EC/H2020/777778/EU/Multiscale Inversion of Porous Rock Physics using High-Performance Simulators: Bridging the Gap between Mathematics and Geophysics/MATHROCKSThis project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 777778-MATHROCKSinfo:eu-repo/grantAgreement/ES/MEC/BCAM-2019/00432-MATHMODE group IT1294-19info:eu-repo/grantAgreement/ES/MICINN-AEI-FEDER/PID2019-108111RB-I00info:eu-repo/grantAgreement/ES/MICINN-AEI-FEDER/PID2019-104347RB-I00info:eu-repo/grantAgreement/ES/MINECO/SEV-2017-0718Computer Methods in Applied Mechanics and Engineering 373 (2021), 113523 [14 pp]by-nc-ndhttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.esinfo:eu-repo/semantics/openAccess