TY - CONF A1 - Gaal, Mate A1 - Dohse, Elmar A1 - Bartusch, Jürgen A1 - Kreutzbruck, Marc T1 - Luftschallprüfung von CFK mit planaren und fokussierenden Wandlern T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 2015-05-11 KW - Air-coupled KW - Ultrasonic testing KW - Ferroelectret KW - Cellular polypropylene KW - Transducer KW - Adhesive joint PY - 2015 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - 1 EP - 9 AN - OPUS4-34629 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Bartusch, Jürgen A1 - Schadow, Florian A1 - Köppe, Enrico A1 - Dohse, Elmar ED - Chimenti, D. E. ED - Bond, L. J. T1 - Focusing of ferroelectret air-coupled ultrasound transducers N2 - Air-coupled ultrasound has been applied increasingly as a non-destructive testing method for lightweight construction in recent years. It is particularly appropriate for composite materials being used in automotive and aviation industry. Air-coupled ultrasound transducers mostly consist of piezoelectric materials and matching layers. However, their fabrication is challenging and their signal-to-noise ratio often not sufficient for many testing requirements. To enhance the efficiency, air-coupled ultrasound transducers made of cellular polypropylene have been developed. Because of its small density and sound velocity, this piezoelectric ferroelectret matches the small acoustic impedance of air much better than matching layers applied in conventional transducers. In our contribution, we present two different methods of spherical focusing of ferroelectret transducers for the further enhancement of their performance in NDT applications. Measurements on carbon-fiber-reinforced polymer (CFRP) samples and on metal adhesive joints performed with commercially available focused air-coupled ultrasound transducers are compared to measurements executed with self-developed focused ferroelectret transducers. T2 - 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Minneapolis, Minnesota, USA DA - 26.07.2015 KW - Ferroelectret KW - Transducer KW - Air-coupled KW - Ultrasonic KW - Focusing PY - 2016 SP - 080001 PB - AIP Publishing CY - Melville, NY, USA AN - OPUS4-35955 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Dohse, Elmar A1 - Bartusch, Jürgen A1 - Köppe, Enrico A1 - Kreutzbruck, Marc A1 - Hillger, W. A1 - Amos, J. M. T1 - Ultrasonic testing of adhesively bonded joints using air-coupled cellular polypropylene transducers N2 - In air-coupled ultrasonic testing, the impedance mismatch between the transducer and the air is commonly being solved by adding matching layers to composite transducers. To avoid the difficult technological procedure regarding matching layers, some new piezoelectric materials have been proposed. Most promising are ferroelectrets, which are charged cellular polymers, having ferroelectric and consequently piezoelectric properties. In particular, the extreme softness of cellular polypropylene (cPP) leads to a high piezoelectric constant and to a good impedance match with the air, making matching layers redundant. Its elasticity modulus below 1 MPa causes an additional effect not observed with common piezoelectric materials: that is the electrostrictive effect, here defined as the thickness change due to the attractive force between the transducer electrodes. This effect exceeds the piezoelectric effect at excitation voltages over 1 kV. The extreme softness of cPP leads also to high flexibility, enabling easy focusing by bending the transducer. We have developed air-coupled ultrasonic transducers based on cPP. This includes the electrical matching networks for the transmitter and for the receiver. The transmitter is excited with voltages up to 2.5 kV, so that the electrostrictive effect dominates, leading to sound pressure around 145dB at the transducer surface. These transducers have been applied for testing carbon-fiber-reinforced polymer plates, adhesive joints and other composite structures. Here we report about ultrasonic transmission of two types of adhesive joints. The first one is multi-layer aluminium components with some artificial disbonds, which are common in aerospace industry, and the second one is an aluminium-steel joint with polyurethane adhesive, which is used in automotive industry. T2 - ECNDT 2014 - 11th European conference on non-destructive testing CY - Prague, Czech Republic DA - 06.10.2014 KW - Air-coupled KW - Ultrasonic testing KW - Ferroelectret KW - Cellular polypropylene KW - Transducer KW - Adhesive joint PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-317204 SN - 978-80-214-5018-9 SP - 1 EP - 8 PB - Brno University of Technology AN - OPUS4-31720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Bartusch, Jürgen A1 - Dohse, Elmar A1 - Kreutzbruck, Marc A1 - Amos, J. M. ED - Chimenti, D.E. ED - Bond, L.J. ED - Thompson, D.O. T1 - Air-coupled ultrasonic testing of metal adhesively bonded joints using cellular polypropylene transducers N2 - Adhesively bonded aluminum components have been widely used in the aerospace industry for weight-efficient and damage-tolerant structures. Automated squirter jet immersion ultrasonic testing is a common inspection technique to assure the bond integrity of large, contoured assemblies. However, squirter jet inspection presents several limitations in scanning speed, related to water splash noise over protruding stiffeners and splash interference crosstalk in multi-channel inspection systems. Air-coupled ultrasonic testing has been evaluated as an alternative, possibly offering the benefits of increased throughput by enabling higher speeds, and eliminating the contamination concerns and maintenance issues of water couplant systems. Adhesive joints of multi-layer aluminum plates with artificial disbonds were inspected with novel air-coupled ultrasonic probes based on cellular polypropylene. Disbonds of various sizes were engineered in several multi-layer configurations and at various depths. Results were compared with squirter jet immersion and conventional piezoelectric transducer designs in terms of scan contrast, resolution and inspection time. T2 - 40th Annual review of progress in quantitative nondestructive evaluation CY - Baltimore, Maryland, USA DA - 21.07.2013 KW - Air-coupled KW - Ultrasonic KW - Metal bond KW - Ferroelectret PY - 2014 SN - 978-0-7354-1212-5 SN - 978-0-7354-1211-8 DO - https://doi.org/10.1063/1.4864857 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1581 33A SP - 471 EP - 478 PB - AIP Publishing AN - OPUS4-31362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Bartusch, Jürgen A1 - Döring, Joachim A1 - Dohse, Elmar A1 - Lange, Thorid A1 - Hillger, W. A1 - Kreutzbruck, Marc T1 - Air-coupled ferroelectret ultrasonic transducers applied to testing of fiber-reinforced polymers N2 - Air-coupled ultrasound is an emerging testing technique applied to materials with sensitive surfaces. One of the most important applications is on components made of carbon-fiber-reinforced polymers, which find their use in aerospace and increasingly in automotive industry. A promising alternative to piezoceramic transducers with matching layers is the use of ferroelectrets, which are charged cellular polymers exhibiting piezoelectric and ferroelectric properties. Ferroelectret transducers for air-coupled ultrasonic testing, including their electronic interface, were developed and compared with conventional air-coupled probes, all having a resonance frequency between 200 and 250 kHz. The cPP transducers were excited with square pulses of 2.5 kV, whereas two different piezoceramic transducers with similar properties were excited with 800 V. The signal-to-noise ratio was evaluated and compared. Two test blocks, (i) a sandwich-structured composite with a honeycomb core between plates of carbon-fiber-reinforced polymer (CFRP) containing an impact and (ii) a CFRP plate with an impact and several flat-bottom holes, were inspected in transmission. The ferroelectret transducers achieved a SNR at least 11 dB higher than the conventional probes. The impacts were clearly visible with all probes, but less noisy with ferroelectret transducers. The flat T2 - 12th International conference of the Slovenian society for non-destructive testing - Application of contemporary non-destructive testing in engineering CY - Portoroz, Slovenia DA - 04.09.2013 KW - Air-coupled ultrasound KW - Transducer KW - Ferroelectret KW - Cellular polypropylene KW - Fiber-reinforced polymers PY - 2013 SN - 978-961-93537-0-7 SP - 43 EP - 50 AN - OPUS4-29927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Bartusch, Jürgen A1 - Schadow, Florian A1 - Beck, Uwe A1 - Daschewski, M. A1 - Kreutzbruck, M. T1 - Airborne ultrasonic systems for one-sided inspection using thermoacoustic transmitters N2 - Airborne ultrasonic inspection is performed in through transmission, where the test piece (e.g. adhesive joint or polymer-based composite plate) is placed between the transmitter and the receiver. However, many structures with difficult shapes allow only one-sided inspection. The strong reflection of the signal from the surface overshadows the signals from the inside, so that broadband pulses are required. Thermoacoustic transmission, where the thermal energy of an electrically heated electrode is transformed into the acoustic energy of an ultrasonic wave, opens the possibility to excite broadband pulses and thus to inspect objects with one-sided access. We present various thermoacoustic transducers consisting of an electrically conductive film on a solid substrate. The first type of transducer is a transmitter with an indium-tin-oxide electrode on a glass substrate combined with a laser Doppler vibrometer as a receiver. The second type of transducer combines thermoacoustic transmission and piezoelectric reception, having a titanium electrode as a transmitter deposited onto charged cellular polypropylene serving as a piezoelectric receiver. Using a focusing thermoacoustic transmitter and a separate cellular polypropylene receiver, a through-transmission inspection of a 4 mm thick CFRP test piece with inserts as small as 1 mm was performed. The same emitter and a laser vibrometer as a receiver were used for a one-sided inspection of a Plexiglas block with a cross hole at 15 mm depth. A twin probe consisting of a thermoacoustic transmitter on a cellular polypropylene receiver was applied to a profile measurement on a step wedge with flat bottom holes. The smallest detected diameter of a flat bottom hole was 1 mm. Sound pressure level above 140dB was achieved with each of these transmitters. Thermoacoustic transmitters enable a step towards one-sided air-coupled ultrasonic inspection. T2 - IEEE International Ultrasonics Symposium CY - Tours, France DA - 18.09.2016 KW - Airborne KW - Air-coupled KW - Ultrasonic transducer KW - Thermoacoustic KW - Ferroelectret PY - 2016 SN - 978-1-4673-9897-8 SN - 1948-5719 SP - (online publication) 1 EP - 4 AN - OPUS4-37620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stark, Wolfgang A1 - Bartusch, Jürgen A1 - Döring, Joachim A1 - Mc Hugh, Jarlath T1 - Making cure visible: monitoring the crosslinking process using integrated ultrasound sensors N2 - A special ultrasonic measuring system was developed to monitor the cross-linking process, enabling interaction with the manufacturing process in order to optimise part quality and reduce cycle times. KW - Thermoset KW - Ultrasound sensors KW - Mould KW - Rtm KW - Gelation KW - Vitrification PY - 2008 SN - 1639-965X IS - 38 SP - 64 EP - 66 PB - JEC CY - Paris AN - OPUS4-18610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Döring, Joachim A1 - Bartusch, Jürgen A1 - Kreutzbruck, Marc T1 - Durchschallung von Textilien zum Nachweis verdeckter, nichtmetallischer Gegenstände T2 - DACH-Jahrestagung 2008 - Zerstörungsfreie Materialprüfung, ZfP in Forschung, Entwicklung und Anwendung CY - St. Gallen, Schweiz DA - 2008-04-28 PY - 2008 SN - 978-3-940283-09-2 IS - (Poster 48) SP - 1 EP - 8 AN - OPUS4-18789 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartusch, Jürgen T1 - Untersuchungen zum Einsatz von PP-Schaumfoliensensoren für die berührungslose Ultraschallprüfung mit Ankopplung über Luft T2 - DGZfP-Jahrestagung 2010 CY - Erfurt, Germany DA - 2010-05-10 PY - 2010 AN - OPUS4-21637 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Döring, Joachim A1 - Bovtun, Viktor Petrovic A1 - Bartusch, Jürgen A1 - Erhard, Anton A1 - Kreutzbruck, Marc A1 - Yakymenko, Y. T1 - Nonlinear electromechanical response of the ferroelectret ultrasonic transducers N2 - The ultrasonic transmission between two air-coupled polypropylene (PP) ferroelectret (FE) transducers in dependence on the amplitude of the high-voltage exciting pulse revealed a strongly nonlinear electromechanical response of the FE transmitter. This phenomenon is described by a linear increase of the inverse electromechanical transducer constant t33(1) of the PP FE film with an increase of the exciting electrical pulse amplitude. Enlargement of t33(1) by a factor of 4 was achieved by application of 3500 V exciting pulses. The electrostriction contribution to t33(1) can be attributed to the electrostatic force between electrodes and the Maxwell stress effect. The nonlinear electromechanical properties of the PP FE result in a strong increase of its air-coupled ultrasonic (ACUS) figure of merit (FOM) under the high-voltage excitation, which exceeds results of the PP FE technological optimization. The FOM increase can be related to the increase of PP FE coupling factor and/or to the decrease of its acoustic impedance. A significant enhancement of the ACUS system transmission (12 dB) and signal-to-noise ratio (32 dB) was demonstrated by the increase of excitation voltage up to 3500 V. The nonlinear electromechanical properties of the PP FEs seem to be very important for their future applications. KW - Airborne ultrasonics KW - Electret film KW - Transducer KW - Nonlinearity PY - 2010 DO - https://doi.org/10.1007/s00339-010-5752-7 SN - 0947-8396 VL - 100 IS - 2 SP - 479 EP - 485 PB - Springer CY - Berlin AN - OPUS4-21809 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartusch, Jürgen A1 - Döring, Joachim A1 - Sickert, Roland A1 - Wüstenberg, Hermann A1 - Albayrak, C. A1 - Rößling, G. T1 - Eine neue Methode zur Bestimmung des Rückstreuverhaltens disperser Systeme T2 - DGZfP-Jahrestagung 1994 CY - Timmendorfer Strand, Deutschland DA - 1994-05-09 PY - 1994 IS - DGZfP-BB 43 SP - 341 EP - 346 AN - OPUS4-22932 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döring, Joachim A1 - Lange, Karsten A1 - Bartusch, Jürgen A1 - Möhrle, Walter A1 - Wüstenberg, Hermann A1 - Fröhlich, H.-J. T1 - Fokussierende Wandlerzeile zur Ultraschall-Untersuchung kleiner Schweißnähte N2 - Die Ultraschallmikroskopie von kleinen Bauteilen mit fokussierenden Prüfköpfen ist seit Jahren gängige Praxis. Leider Ist sie für den Einsatz in der On-Line- Qualitätskontrolle zu zeitaufwändig. Deshalb wurde an der Bundesanstalt für Materialforschung und -prüfung (BAM) auf der Basis von Polyvinyliden-Fluorid (PVDF) wurde eine fokussierende Wandlerzeile entwickelt Sie ist Teil eines Prüfgerätes, das durch die Verbindung von mechanischer und elektronischer Steuerung des Ultraschallfeldes hohe Abtastgeschwindigkeiten erreicht. Dadurch, können die Prüfzeiten so stark reduziert werden, dass eine On-line-Nutzung möglich wird. Das Ultraschallfeld der Wandlerzeile wurde dreidimensional ausgemessen und das Ergebnis mit einem numerischen Modell /1/ verglichen. Die Übereinstimmung zwischen berechnetem und gemessenem Schallfeld war sehr gut. Eine Optimierung der elektronischen Ansteuerung führte darüberhinaus zu einer erheblichen Reduzierung der störenden Nebenmaxima. Die Mittenfrequenz der Prüfimpulse liegt über 15 MHz und der Fokus des Prüfkopfes beträgt weniger als 0,5 mm im Durchmesser. Mit dieser Wandlerzeile und der entsprechenden elektronischen Steuerung wurde eine Aluminium-Schweißnaht untersucht, die vorher mit einem konventionellen fokussierenden Prüfkopf abgetastet worden war. Beide Prüfergebnisse zeigen die gleiche Strukturauflösung, so dass der Zeitgewinn uneingeschränkt als Vorteil für die Wandlerzeile zu Buche schlägt. T2 - DGZfP-Jahrestagung 1998 CY - Bamberg, Deutschland DA - 1998-09-07 PY - 1998 SN - 3-931381-23-4 IS - DGZfP-BB 63 SP - 477 EP - 483 AN - OPUS4-22936 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döring, Joachim A1 - Stark, Wolfgang A1 - Mc Hugh, Jarlath A1 - Bartusch, Jürgen T1 - Erfassung des Fließ-Härtungs-Verhaltens von Duromeren mit Ultraschall N2 - Das Fließ-Härtungs-Verhalten von Duroplastformmassen wird gegenwärtig nur unvollständig durch empirische Größen beschrieben. Diese ungenauen und unsicheren Angaben können zu Schwierigkeiten bei der optimalen Einstellung der Fertigungsmaschinen des Verarbeiters führen. Insbesondere Veränderungen der Formmasseeigenschaften während des Transportes und der Lagerung stören die Produktion. Das vorgestellte Messverfahren mit Ultraschall-sensoren ermöglicht die schnelle und vollständige Erfassung des Fließ-Härtungs-Verhaltens, auch während des technologischen Prozesses. Experimentelle Ergebnisse zu Alterungs-erscheinungen dieser Formmassen illustrieren den Nutzen des Verfahrens für Formmasse-produzenten und -verarbeiter. T2 - DGZfP-Jahrestagung 1999 CY - Celle, Deutschland DA - 1999-05-10 PY - 1999 SN - 3-931381-27-7 IS - DGZfP-BB 68 SP - 221 EP - 228 AN - OPUS4-22937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döring, Joachim A1 - Bovtun, Viktor Petrovic A1 - Bartusch, Jürgen A1 - Erhard, Anton T1 - Eigenschaften von Polypropylen- und PVDF-Folien für Luftschall-Anwendungen N2 - An Methoden zur luftgekoppelten Ultraschallprüfung wird seit einigen Jahren mit großer Intensität gearbeitet. Probleme bei der praktischen Realisierung entstehen vor allem durch die großen Unterschiede in der akustischen Impedanz von Wandlermaterial und Luft. Sie führen zu erheblichen Signaldämpfungen. Durch die Verwendung von Kunststoff-Folien z.B. aus porösem Polypropylen kann dieser Unterschied stark reduziert werden. Im Beitrag werden die akustischen Eigenschaften dieser Folien untersucht und im Hinblick auf ihre Eignung für die Luftultraschall-Technik analysiert. T2 - DACH-Jahrestagung 2004 - ZfP in Forschung, Entwicklung und Anwendung CY - Salzburg, Österreich DA - 2004-05-17 KW - Luftschall-ZfP KW - Ultraschall-Wandler PY - 2004 UR - http://www.ndt.net/article/dgzfp04/papers/p11/p11.htm SP - 1 EP - 4 CY - Salzburg, Österreich AN - OPUS4-19059 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bovtun, Viktor Petrovic A1 - Döring, Joachim A1 - Wegener, M. A1 - Bartusch, Jürgen A1 - Beck, Uwe A1 - Erhard, Anton A1 - Borisov, V. T1 - Air-coupled ultrasonic applications of ferroelectrets KW - Air-coupled ultrasonics KW - Non-contact transducers KW - Ferroelectrets KW - Electromechanical properties PY - 2008 DO - https://doi.org/10.1080/00150190802380243 SN - 0015-0193 SN - 1563-5112 VL - 370 IS - 1 SP - 11 EP - 17 PB - Taylor & Francis CY - New York, NY AN - OPUS4-20924 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartusch, Jürgen T1 - Sicherheit in der Komposit-Produktion/Produktionskontrolle mit Ultraschall T2 - Aerospace 2008 CY - Munich, Germany DA - 2008-04-15 PY - 2008 AN - OPUS4-17440 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartusch, Jürgen T1 - Online certification of composites T2 - Aerospace 2008 CY - Munich, Germany DA - 2008-04-15 PY - 2008 AN - OPUS4-17443 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döring, Joachim A1 - Bovtun, V. A1 - Bartusch, Jürgen A1 - Beck, Uwe A1 - Kreutzbruck, Marc T1 - Cellular polypropylene ferroelectret film: piezoelectric material for non-contact ultrasonic transducers T2 - 17th World Conference on Non-Destructive Testing CY - Shanghai, China DA - 2008-10-25 KW - Air-coupled ultrasound KW - Ultrasonic transducers KW - Electromechanical properties KW - Piezoelectric materials KW - Impedance spectroscopy PY - 2008 IS - Paper 123 SP - 1 EP - 6 PB - International Committee for Non-Destructive Testing CY - Shanghai AN - OPUS4-18435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döring, Joachim A1 - Bartusch, Jürgen A1 - Kreutzbruck, Marc T1 - Spektroskopische Untersuchungen an Polypropylen-Schaumfolie mit Luftultraschall T2 - DGZfP-Jahrestagung 2009 CY - Münster, Deutschland DA - 2009-05-18 PY - 2009 SN - 978-3-940283-16-0 IS - DGZfP-BB 115 (Poster 39) SP - 1 EP - 2 AN - OPUS4-20509 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mc Hugh, Jarlath A1 - Döring, Joachim A1 - Bartusch, Jürgen A1 - Stark, Wolfgang T1 - Making Cure Visible T2 - Aerospace Testing Expo 2005 - Europe, April 5-7, 2005, Hamburg CY - Hamburg, Deutschland DA - 2005-04-05 PY - 2005 SP - 4 pages PB - UKIP Media & Events CY - Dorking AN - OPUS4-7379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Döring, Joachim A1 - Stark, Wolfgang A1 - Bartusch, Jürgen A1 - Mc Hugh, Jarlath T1 - Contribution to ultrasound cure control for composite manufacturing N2 - The curing conditions play an important role in the quality assurance of composite products. Especially as composite materials are widely used in high tech areas so that they are required to fulfil high quality Standards. Some problems which occur during curing, for instance undercuring, can hardly be detected using Standard NDT investigations, mainly because they are manifested only at high temperatures, particularly close to glass-rubber-transition. On-line eure monitoring has the outstanding advantage that it can monitor the material parameters even at the highest temperatures possible. In recent years eure monitoring with ultrasonic methods has become more populär. In comparison to dielectric methods mechanical parameters are measured directly. The quantities to be measured are the velocity and the attenuation of the sound wave. On this basis the storage and loss modulus can be calculated. Depending on the form of excitation with longitudinal or transversal waves these moduli are referred to as long wave or shear modulus. Well developed Computer based technology and sensor materials are available in the non-destructive testing (NDT) market. The measuring equipment employed a commercial NDT System, which worked computer-aided. With a special Software the demands of automatic Operation under industrial conditions was accomplished. This measurement equipment was tested on composites. Its structure, performance and some practical results will be presented in the following paper. T2 - 15th World Conference on Non-Destructive Testing (WCNDT) CY - Roma, Italy DA - 15.10.2000 PY - 2000 UR - http://www.ndt.net/article/wcndt00/papers/idn482/idn482.htm SN - 1435-4934 VL - 5 IS - 11 PB - NDT.net CY - Kirchwald AN - OPUS4-2136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -