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- Rekonstruktion (4)
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- Inverse Probleme (3)
- Inversion (3)
- Defect shape reconstruction (2)
- Minderdicken (2)
- Rückwand (2)
- Schichtdicken (2)
- Wanddicke (2)
- Aktive Thermografie (1)
- Aktive thermografie (1)
- Datenglättung (1)
- Defects (1)
- Echo defect shape (1)
- Finite element simulation (1)
- Impulse-thermography (1)
- Inverse problems (1)
- Levenberg-Marquardt method (1)
- Pulse thermography (1)
- Pulsed thermography (1)
- Quantitative characterization (1)
- Reconstruction (1)
- Thermal contrast (1)
- Thermische Welle (1)
- Wall thickness (1)
Eingeladener Vortrag
- nein (4)
The paper presents a numerical method to detect and characterise defects and inhomogeneities by means of active thermography. The objective was to determine the wall thickness of structure elements with an inaccessible back wall, e.g., elements of pipes or containers. As test specimens we used PVC samples with the thickness of about 2 cm that had spatial variations in the back wall geometry. Flash lamps provided the heating. To measure the thickness of the wall, we employed the LevenbergMarquardt method, which we applied here to experimental thermographic data for non-destructive testing. We started the inversion procedure by making a rough first estimation of the back wall geometry following the echo defect shape method, and then we calculated the thickness of the back wall. We found reasonable reconstruction results which differed from the real value significantly below 1 mm at the defect centre, whereas the error wais increased at the edge of the defect, depending on its shape and depth.