2014, ISBN: 9783863874490

[ED: Softcover], [PU: Mensch & Buch Verlag], The one-sided identification of wall thicknesses is important for safety and quality control of constructions in several industrial sectors. T… More...

[ED: Softcover], [PU: Mensch & Buch Verlag], The one-sided identification of wall thicknesses is important for safety and quality control of constructions in several industrial sectors. The aim is to guarantee the impermeability of a component, on the one hand to avoid the leakage of dangerous substances and on the other hand to prevent the loss of valuable fluids or gases. For testing purposes, pipes, pressure tanks, and chemical plants are generally only accessible from the outer wall - apart from pipe testings with e. g., an ultrasonic sensor (so-called go-devil), which is sent into the product stream longitudinally through the pipe. To detect the wall thickness, there exist several non-destructive testing methods (e. g., ultrasonic testing, x-ray methods, eddy current testing, thermography). One of the advantages of thermography is, that it runs contact-free. With active thermography, the test specimen is shortly heated or cooled and the thermal answer, measured by an infrared camera, is evaluated. The infrared camera measures electromagnetic radiation within its specific spectral range at discrete points in time. This leads to temperature information of the test specimen knowing certain surface parameters. Evaluating the spatial thermal distribution, the back wall geometry, i. e., the wall thickness for a profile or area-wide (2D/3D), can be determined to the sub-mm-scope. Mathematically, this is an inverse problem, which is defined as the reversion of a direct, uniquely and comparable easily solvable problem. In this thesis and for the first time, one of the classical methods for inverse problems, the Levenberg-Marquardt method, is successfully applied to experimentally obtained thermografic data of non-destructive testing. The back wall geometry is reconstructed as a profile and area-wide. The analysed test specimens were from different materials (PVC, steel) and had not only artificial defects (differently shaped notches, at bottom holes), but also defects which evolved naturally (corrosion defects in pipes). The Levenberg-Marquardt method has the advantage that it is based on a multidimensional consideration of the heat equation in comparison to the current direct methods furthermore, the Levenberg-Marquardt method is extendable to more complex defect shapes, like undercuttings or inner defects. By the application of the Levenberg-Marquardt method, the precision of the reconstruction is improved by up to 77% compared to the current direct methods. By the optimisation of the Levenberg-Marquardt method, the reconstruction error of the wall thickness (i.e., the mean difference of the reconstruction to the real back wall geometry) was below 0.5 mm (with 20 mm maximal thickness). The pointwise reconstruction error was dependant from thickness and was 2 mm at most (average value for the notch test specimens) for thicknesses below 10 mm, while it was 6 mm at most for thicknesses above 10 mm. This is true for the 2D reconstructions, i.e., for the determination of the wall thickness along profiles. For area-wide reconstructions (3D), an approximative variation of the Levenberg-Marquardt method was applied to limit the calculation period, using the numerical Broyden's method. In this case, the mean reconstruction error was below 1.2 mm (with 20 mm maximal thickness). Thereby, the Levenberg-Marquardt method might be used as a gold standard", which is a reliable-as-possible and all-purpose method for thermography to characterise materials and which is utilised as a reference method for time eficient and specialised reconstruction methods., DE, [SC: 2.40], Neuware, gewerbliches Angebot, A5, 240, [GW: 510g], [PU: Berlin], 1., Banküberweisung, Offene Rechnung, Nachnahme, PayPal, Selbstabholung und Barzahlung, Internationaler Versand<

ISBN: 3863874498

Taschenbuch, [EAN: 9783863874490], Mensch & Buch, Mensch & Buch, Book, [PU: Mensch & Buch], Mensch & Buch, 290523, Physik & Astronomie, 295007, Akustik, 295050, Astronomie & Astrophysik, … More...

Taschenbuch, [EAN: 9783863874490], Mensch & Buch, Mensch & Buch, Book, [PU: Mensch & Buch], Mensch & Buch, 290523, Physik & Astronomie, 295007, Akustik, 295050, Astronomie & Astrophysik, 290845, Biophysik, 519842, Chaosforschung, 295003, Elektromagnetismus, 295009, Festkörper, 294992, Geophysik, 294999, Hilfsmittel, 295014, Mathematische Physik, 295015, Mechanik, 295027, Mikrophysik, 295032, Optik, 295040, Quantenphysik, 295042, Theoretische Physik, 295047, Thermodynamik, 288100, Fachbücher, 541686, Kategorien, 186606, Bücher, 121, Naturwissenschaften & Technik, 189132, Anthropologie, 189133, Archäologie, 189134, Astronomie, 189135, Biologie, 189157, Chemie, 189168, Geologie, 189169, Ingenieurwissenschaft & Technik, 189275, Mathematik, 189312, Medizin, 189445, Physik, 15857051, Populärwissenschaft, 189467, Umwelt & Ökologie, 189499, Verschiedenes, 15857061, Wissenschaftsgeschichte, 541686, Kategorien, 186606, Bücher<

ISBN: 3863874498

Taschenbuch, [EAN: 9783863874490], Mensch & Buch, Mensch & Buch, Book, [PU: Mensch & Buch], Mensch & Buch, 13626311, Naturwissenschaft, 13626301, Wissenschaft, 187254, Biografien & Erinne… More...

Taschenbuch, [EAN: 9783863874490], Mensch & Buch, Mensch & Buch, Book, [PU: Mensch & Buch], Mensch & Buch, 13626311, Naturwissenschaft, 13626301, Wissenschaft, 187254, Biografien & Erinnerungen, 541686, Kategorien, 186606, Bücher, 121, Naturwissenschaften & Technik, 189132, Anthropologie, 189133, Archäologie, 189134, Astronomie, 15423967031, Astrophysik, 290517, Biowissenschaften, 189157, Chemie, 189168, Geologie, 189169, Ingenieurwissenschaft & Technik, 189275, Mathematik, 189445, Physik, 15857051, Populärwissenschaft, 189467, Umwelt & Ökologie, 189499, Verschiedenes, 15857061, Wissenschaftsgeschichte, 541686, Kategorien, 186606, Bücher<

ISBN: 3863874498

Taschenbuch, [EAN: 9783863874490], Mensch & Buch, Mensch & Buch, Book, [PU: Mensch & Buch], Mensch & Buch, 290523, Physik & Astronomie, 295007, Akustik, 295050, Astronomie & Astrophysik, … More...

Taschenbuch, [EAN: 9783863874490], Mensch & Buch, Mensch & Buch, Book, [PU: Mensch & Buch], Mensch & Buch, 290523, Physik & Astronomie, 295007, Akustik, 295050, Astronomie & Astrophysik, 290845, Biophysik, 519842, Chaosforschung, 295003, Elektromagnetismus, 295009, Festkörper, 294992, Geophysik, 294999, Hilfsmittel, 295014, Mathematische Physik, 295015, Mechanik, 295027, Mikrophysik, 295032, Optik, 295040, Quantenphysik, 295042, Theoretische Physik, 295047, Thermodynamik, 288100, Fachbücher, 541686, Kategorien, 186606, Bücher<