TY - CONF A1 - Boehm, Rainer A1 - Brackrock, Daniel A1 - Kitze, Jessica A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Advanced crack shape analysis using SAFT N2 - The spatial resolution in ultrasonic testing as a wave phenomenon in nature is limited to a certain fraction of the wavelength, usually defined to be close to the Rayleigh criterion. In case of complicated reflector surfaces – such as stress corrosion cracking - this limitation prevents an exact visualization of the defect shape. There exist a few approaches to improve the spatial resolution, whose reconstruction quality all in common also depend on the achieved signal-to-noise ratio of the raw data. In this work we present a specific SAFT analysis, in which a high number of different angles of incidence produce a sufficiently high number of different reflections at the crack edges resulting in an improved SNR. In doing so, we reconstruct a coherent crack structure. First investigations were made at artificially simulated crack configurations with different contours and curvatures in flat and cylindrical test blocks. The measurements results – visualized by representative scans – show details of crack design and crack orientation. We also will present a comparison of the SAFT analysis between modelling and phased array measurements. T2 - 36th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Kingston, RI, USA DA - 2009-07-26 KW - Ultrasonic testing KW - SAFT KW - Phased array PY - 2010 SN - 978-0-7354-0748-0 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings SP - 1 EP - 8 CY - Melville, NY AN - OPUS4-21816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Boehm, Rainer A1 - Brackrock, Daniel A1 - Kitze, Jessica A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc ED - Mazal, Pavel T1 - Saft for crack surface analysis - Comparison of modeling and phased array measurements T2 - 5th International workshop of NDT experts - NDT in progress 2009 CY - Prague, Czech Republic DA - 2009-10-12 KW - Ultrasonic testing KW - SAFT KW - Phased array PY - 2009 SN - 978-80-214-3968-9 SP - 1 EP - 10 AN - OPUS4-20341 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer A1 - Brackrock, Daniel A1 - Kitze, Jessica A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc T1 - The SAFT approach for advanced crack analysis T2 - NDE 2009 CY - Tiruchirappalli, India DA - 2009-12-10 PY - 2009 SP - 315 EP - 318 AN - OPUS4-20832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc A1 - Boehm, Rainer A1 - Kitze, Jessica A1 - Eggers, H. A1 - Böwe, M. T1 - Using UT-SAFT for analysis of stress corrosion cracking N2 - Stress corrosion cracking is a transcrystalline or intercrystalline crack formation in materials which occurs under the influence of static tensile stress or residual stress and a specific aggressive medium such as chloride containing substances. This special sort of crack formation is involved in complex crack configurations, which may only insufficiently be captured by conventional ultrasonic probes with fixed angles of incidence. Only a number of different beam angles produce sufficient reflection to reconstruct the complete defect shape from measured ultrasonic data. The SAFT algorithm, which was recently successfully used in many industrial NDT-applications, is a promising tool for the reconstruction process. In addition, the combination of phased array technique and SAFT was developed in several projects by BAM, Berlin. Investigations using phased array equipment were performed to look into crack configurations in test blocks with different surface curvatures. UT-SAFT has been used for the analysis of spark-eroded notches simulating stress corrosion cracks at the thermo sleeve weld of a nozzle. For comparison, UT-SAFT has also been applied for the analysis of real reflectors at the same position in a nozzle used in a power plant, which was repaired later on. SAFT-scans received from reconstructed ultrasonic measurement data confirm the practical usefulness of the SAFTalgorithm developed by BAM. T2 - 8th International conference on NDE in relation to structural integrity for nuclear and pressurised components CY - Berlin, Germany DA - 2010-09-29 KW - Stress corrosion cracking KW - Real and simulated cracks KW - D-nozzle KW - Phased array technique KW - SAFT reconstruction PY - 2010 SN - 978-3-940283-30-6 IS - DGZfP-BB 125 (Th.2.B.1) SP - 1 EP - 10 CY - Berlin AN - OPUS4-23594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brekow, Gerhard A1 - Boehm, Rainer A1 - Brackrock, Daniel A1 - Kreutzbruck, Marc T1 - Quantitative Defect Sizing on Components with Different Wall Thickness using UT-SAFT T2 - 17th World Conference on Non-Destructive Testing CY - Shanghai, China DA - 2008-10-25 KW - UT-SAFT KW - Reconstruction PY - 2008 IS - Paper 122 SP - 1 EP - 6 PB - International Committee for Non-Destructive Testing CY - Shanghai AN - OPUS4-18436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brekow, Gerhard A1 - Brackrock, Daniel A1 - Boehm, Rainer A1 - Kreutzbruck, Marc ED - Thompson, D. O. ED - Chimenti, D. E. T1 - Phased array-based SAFT for defect sizing on power plant components N2 - Quantitative NDE methods play a key role when it comes to inspect components, which requires high operational safety. UT-SAFT is one of the well-known reconstruction tools, which provides information about the defect size. In this work we studied the use of phased array technique in combination with the SAFT algorithm to inspect power plant components. As a first example we inspected a real-sized mock-up model representing a part of a reactor pressure vessel with a 180 mm-thick ferritic base material followed by a 6 mm-thick austenitic cladding layer. The phased array probe was coupled at the outer ferritic surface. We detected and sized fatigue cracks within the cladding with a depth ranging from 4 mm to 10 mm. Secondly, we investigated a mock-up model resembling a nozzle including a thermo sleeve inlet and a maximum wall thickness of about 37 mm. Artificially inserted notches with a depth of 3 mm could be detected and sized, where the thermo sleeve is welded at the inside of the nozzle. T2 - 35th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Chicago, IL, USA DA - 2008-07-20 KW - Ultrasonic testing KW - Phased arrays KW - SAFT KW - Power plant components PY - 2009 SN - 978-0-7354-0629-2 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1096 SP - 872 EP - 879 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-19435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer A1 - Brackrock, Daniel A1 - Kitze, Jessica A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc T1 - SAFT für die Rissflächenanalyse - Vergleich von Modellrechnungen und Gruppenstrahlermessungen T2 - DGZfP-Jahrestagung 2009 CY - Münster, Deutschland DA - 2009-05-18 KW - SAFT KW - Rissflächenanalyse PY - 2009 SN - 978-3-940283-16-0 IS - DGZfP-BB 115 (Mi.3.A.2) SP - 1 EP - 11 AN - OPUS4-20518 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kreutzbruck, Marc A1 - Thomas, Hans-Martin A1 - Sickert, Roland A1 - Casperson, Ralf A1 - Boehm, Rainer A1 - Allweins, K. A1 - Lemke, G. T1 - A numerical study of the inclusion problem in electromagnetic testing KW - FEM KW - Eddy Current Testing (ECT) KW - Eddy Current (EC) PY - 2009 SN - 0025-5300 VL - 51 IS - 11-12 SP - 819 EP - 827 PB - Hanser CY - München AN - OPUS4-20507 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schenk, Gottfried A1 - Brackrock, Daniel A1 - Boehm, Rainer A1 - Kreutzbruck, Marc A1 - Deutsch, W.A.K. A1 - Joswig, M. A1 - Maxam, K. A1 - Schuster, V. T1 - Untersuchungen zum Einfluss von Geometrie- und Temperaturabweichungen bei der Stangenprüfung mit Ultraschall-Gruppenstrahlertechnik N2 - Bei der automatisierten Prüfung von Stangen mit Ultraschall- Gruppenstrahlertechnik besteht grundsätzlich die Möglichkeit, Prüfkopfparameter wie Einschallwinkel, Fokustiefe und Schallbündelbreite programmgesteuert an sich verändernde Prüfbedingungen anzupassen. Zu diesen zählt die Temperatur des Koppelmediums (Wasser), die in einem Bereich von 10°C bis 50°C liegen kann, was zu unterschiedlichen Schallgeschwindigkeiten führt und den Einschallwinkel verändert. Mit der Folge, dass unter Umständen die geforderte 100%-Abdeckung des Prüfvolumens nicht mehr gewährleistet ist. Auch geometrische Abweichungen, wie sie durch die fertigungsbedingte Streuung des Prüflings gegeben sind, können Einfluss auf das Prüfergebnis nehmen. So führen Abweichungen vom idealen Geradheitszustand zu Fehlpositionierungen des Prüfkopfs, was wiederum Einfluss auf die Lage und Beschaffenheit des Schallbündels in der Stange hat. Ähnliches gilt für nicht vollkommen kreisförmig ausgebildete Stangendurchmesser, die unterschiedliche Schalleintrittsbedingungen bewirken und Abweichungen von den theoretisch ermittelten Werten zur Folge haben. Im Rahmen eines vom BMWi geförderten Forschungsvorhabens wurde der Einfluss dieser Parameter untersucht und ihre Auswirkungen für den Betrieb einer automatisierten Prüfanlage unter realen Betriebsbedingungen ermittelt. Dies betrifft vor allem den maximal möglichen Schallbündelversatz innerhalb des Arrays, der die Anzahl der erforderlichen Prüftakte bestimmt und damit die maximale Vorschubgeschwindigkeit des Prüflings. Des Weiteren werden Möglichkeiten zur programmgesteuerten Kompensation der untersuchten Temperatur- und Geometrieabweichungen durch eine flexible Anpassung der Gruppenstrahler- Prüfkopfparameter aufgezeigt. T2 - DGZfP-Jahrestagung 2010 CY - Erfurt, Deutschland DA - 2010-05-10 PY - 2010 SN - 978-3-940283-26-9 IS - DGZfP-BB 122 (Mi.4.A.1) SP - 1 EP - 8 CY - Berlin AN - OPUS4-21878 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brekow, Gerhard A1 - Boehm, Rainer A1 - Kreutzbruck, Marc T1 - Ultraschalluntersuchungen zur quantitativen Fehlergrößenbestimmung mit SAFT an dick- und dünnwandigen Anlagenkomponenten T2 - 33. MPA Seminar 2007 "Werkstoff- und Bauteilverhalten in der Energie- und Anlagentechnik" CY - Stuttgart, Deutschland DA - 2007-10-11 PY - 2007 SN - 1861-5414 IS - CD-ROM SP - 833 EP - 849 CY - Stuttgart AN - OPUS4-16441 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Daschewski, Maxim A1 - Boehm, Rainer A1 - Prager, Jens A1 - Kreutzbruck, Marc A1 - Harrer, Andrea T1 - Physics of thermo-acoustic sound generation N2 - We present a generalized analytical model of thermo-acoustic sound generation based on the analysis of thermally induced energy density fluctuations and their propagation into the adjacent matter. The model provides exact analytical prediction of the sound pressure generated in fluids and solids; consequently, it can be applied to arbitrary thermal power sources such as thermophones, plasma firings, laser beams, and chemical reactions. Unlike existing approaches, our description also includes acoustic near-field effects and sound-field attenuation. Analytical results are compared with measurements of sound pressures generated by thermo-acoustic transducers in air for frequencies up to 1 MHz. The tested transducers consist of titanium and indium tin oxide coatings on quartz glass and polycarbonate substrates. The model reveals that thermo-acoustic efficiency increases linearly with the supplied thermal power and quadratically with thermal excitation frequency. Comparison of the efficiency of our thermo-acoustic transducers with those of piezoelectric-based airborne ultrasound transducers using impulse excitation showed comparable sound pressure values. The present results show that thermo-acoustic transducers can be applied as broadband, non-resonant, high-performance ultrasound sources. KW - Thermophone KW - Ionophone KW - Thermo-acoustic effect KW - Non resonant ultrasound source PY - 2013 DO - https://doi.org/10.1063/1.4821121 SN - 0021-8979 SN - 1089-7550 VL - 114 SP - 114903-1 - 114903-12 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-29278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer A1 - Brackrock, Daniel A1 - Kitze, Jessica A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc A1 - Heinrich, W. T1 - Ultraschalluntersuchungen an einem Turbinenradscheibentestkörper mit Sägezahn-Arrays N2 - - Besondere Anforderungen der Prüfaufgabe - Elektronischer Scan für Tandemtechnik bzw. Pitch - Catch Technik - Der ebene Winkelprüfkopf, ein besonderer Gruppenstrahler (PA) - Charakterisierung des Prüfkopfes, Verifikation durch Messung - Messungen am Turbinenradscheibentestkörper T2 - DGZfP-Jahrestagung 2011 CY - Bremen, Germany DA - 30.05.2011 KW - Ultraschallprüftechnik KW - Phased array KW - Prüfkopfentwicklung KW - Turbinenradscheiben PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-252085 SN - 978-3-940283-33-7 IS - DGZfP-BB 127 (Di.1.A.3) SP - 1 EP - 21 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-25208 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -