TY - GEN A1 - Götschel, S. A1 - Weiser, M. A1 - Maierhofer, Christiane A1 - Richter, Regina A1 - Röllig, Mathias ED - Büyüköztürk, O. ED - Tasdemir, M.A. ED - Günes, O. ED - Akkaya, Y. T1 - Fast defect shape reconstruction based on the travel time in pulse thermography T2 - Nondestructive testing of materials and structures N2 - Pulse thermography is a non-destructive testing method based on ­infrared imaging of transient thermal patterns. Heating the surface of the structure under test for a short period of time generates a non-stationary temperature distribution and thus a thermal contrast between the defect and the sound material. In modern NDT, a quantitative characterization of hidden imperfections in materials is desired. In particular, defect depth and shape are of interest. The reconstruction of the defect from thermography data is a nonlinear inverse problem, and ill-posed. We propose an algorithm for the identification of subsurface defects based on the travel time of the reflected thermal pulse. Our work extends results by Lugin and Netzelmann, taking lateral thermal flows directly into account while retrieving the defect depth. This requires significantly less computational work. Quantitative information about the defect shape and depth is obtained. Application of our method to both thermography data generated by a finite element simulation and experimental heating of PVC test specimens with different defects yields good reconstruction of the actual defects. KW - Defect shape reconstruction KW - Finite element simulation KW - Pulsed thermography KW - Quantitative characterization KW - Thermal contrast KW - Inversion KW - Aktive Thermografie KW - Wanddicke KW - Rückwand KW - Minderdicken KW - Schichtdicken KW - Thermische Welle PY - 2013 SN - 978-94-007-0722-1 DO - https://doi.org/10.1007/978-94-007-0723-8_11 SN - 2211-0844 N1 - Serientitel: RILEM bookseries – Series title: RILEM bookseries VL - 6 SP - 83 EP - 89 PB - Springer AN - OPUS4-27619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -