@article{13881, author = {{Rautenberg, Jens and Bause, Fabian and Henning, Bernd}}, issn = {{0171-8096}}, journal = {{tm - Technisches Messen}}, pages = {{28--37}}, title = {{{Messsystem zur Bestimmung akustischer Kenngrößen stark absorbierender, transversal isotroper Kunststoffe}}}, doi = {{10.1524/teme.2013.0005}}, year = {{2013}}, } @article{13882, author = {{Schmitt, Martin and Olfert, Sergei and Rautenberg, Jens and Lindner, Gerhard and Henning, Bernd and Reindl, Leonhard}}, issn = {{1424-8220}}, journal = {{Sensors}}, pages = {{2777--2785}}, title = {{{Multi Reflection of Lamb Wave Emission in an Acoustic Waveguide Sensor}}}, doi = {{10.3390/s130302777}}, year = {{2013}}, } @article{13883, abstract = {{<p><strong>Abstract.</strong> In this paper, a new acoustic sensor principle for coating detection within liquid-filled tubes and containers based on mode conversion of leaky Lamb waves is introduced. Leaky Lamb waves are excited and detected by single-phase transducers, which are attached on the outer side of a tube or container. By transmission time and amplitude measurements, coating formation within the liquid-filled tube and container is detected non-invasively. This new sensor principle is subdivided into the separate considerations of Lamb wave excitation, mode conversion and inverse mode conversion. The Lamb wave excitation by a single-phase transducer is visualized by scanning laser Doppler vibrometer imaging. The mode conversion process of leaky Lamb waves is measured by membrane hydrophone measurements and Schlieren visualization; afterwards, the measured emission angles are compared with the theoretical one. The inverse mode conversion process of pressure waves back to leaky Lamb waves is visualized by Schlieren images. By merging the results of Lamb wave excitation, mode conversion and inverse mode conversion, the new sensor concept is explained. Theoretical considerations and measurement results of adhesive tape coating inside a liquid-filled plastic tube and a liquid-filled stainless steel container verify the new acoustic sensor principle. Finally the measuring sensitivity and the technical realization are discussed.</p>}}, author = {{Schmitt, M. and Schmidt, K. and Olfert, S. and Rautenberg, J. and Lindner, G. and Henning, Bernd and Reindl, L. M.}}, issn = {{2194-878X}}, journal = {{Journal of Sensors and Sensor Systems}}, pages = {{73--84}}, title = {{{Detection of coatings within liquid-filled tubes and containers by mode conversion of leaky Lamb waves}}}, doi = {{10.5194/jsss-2-73-2013}}, year = {{2013}}, } @article{13884, author = {{Schröder, Andreas and Henning, Bernd}}, issn = {{0171-8096}}, journal = {{tm - Technisches Messen}}, pages = {{196--200}}, title = {{{Luftultraschall-Abstandsmessung mit digitaler Signalverarbeitung zur Verkürzung des Mindestabstandes}}}, doi = {{10.1524/teme.2013.0022}}, year = {{2013}}, } @inproceedings{13885, author = {{Schröder, A. and Henning, Bernd}}, location = {{Nürnberg}}, publisher = {{LibreCat University}}, title = {{{B5.4 - Signal Processing for Single Transducer Distance Measurement Applications to Reduce the Blind Zone}}}, doi = {{10.5162/SENSOR2013/B5.4}}, year = {{2013}}, } @inproceedings{13949, abstract = {{The condensation polymer Polyamide 6 (PA 6) is a thermoplastic resin with high tensile strength and rigidity at comparatively low costs for raw material and processing. This is why PA 6 is a common material for the production of ropes, gears or bearings. Apart from that, a relative new application is the thermoforming of glass fibre laminate sheets with PA 6 as matrix material. The prediction the rest of life period of such high-tech materials is still a research objective. A first step, and also part of this contribution, is the nondestructive investigation of the matrix material. The ageing of PA 6 is mainly affected by thermo- and photo-oxidation as well as post-condensation, which e.g. results in a change of physical properties. For this contribution the acoustical and mechanical material parameters of artificially aged PA 6 have been determined with high frequency ultrasound (1 MHz) and quasi-static experiments. We will give a short description of both experimental setups as well as the ageing procedure. Finally we will discuss the correlation between the experimental results, finding that there is a good correlation between sound velocity and tensile strength.}}, author = {{Bause, Fabian and Budde, Christopher and Rautenberg, Jens and Henning, Bernd and Moritzer, Elmar}}, location = {{Czech Republic}}, pages = {{504--509}}, title = {{{Utilizing ultrasound material parameter determination for the characterization of different stages of ageing in Polyamide 6}}}, year = {{2013}}, } @inproceedings{13950, abstract = {{Due to the modal behavior of geometrically bounded media, ultrasonic guided waves propagate in waveguides as a combination of multiple dispersive wave packets, which can be simulated as a PDE-problem. Given an excitation in time and space, multiple eigen-modes derived from solving the PDE may propagate each with different dispersion characteristics and weight. Considering a broad-band pulse exciting from one side of a hollow cylindrical waveguide, the received signal at the other side consists of all propagating eigen-modes that can be considered approximately as the narrow band signals. The synchrosqueezed wavelet transform (SWT) is employed to sharpen the time-frequency representation (TFR) of the received waveguide signal. Using a ridge detection algorithm, we successively separate the synchrosqueezed TFR into several narrow band TFRs which can be identified as oscillatory components with time-varying frequency. Then those separated TFRs are reconstructed as narrow band signals using the inverse SWT. Based on an analytical model of the waveguide, we observe that the decomposed signals are similar to those dominant eigen-modes simulated above. Moreover, also the group delay and, therefore, the group velocity of each decomposed signal can be estimated well. This is of high interest when analyzing the characteristic of a given waveguide, such as acoustical property measurements or non-destructive testing.}}, author = {{Bause, Fabian and Huang, Boqiang and Kunoth, Angela and Henning, Bernd}}, location = {{Czech Republic}}, title = {{{Ultrasonic Waveguide Signal Decomposition Using the Synchrosqueezed Wavelet Transform for Modal Group Delay Computation}}}, year = {{2013}}, } @inproceedings{13951, author = {{Bause, Fabian and Unverzagt, Carsten and Walther, Andrea and Henning, Bernd}}, location = {{Singapore}}, pages = {{504--509}}, title = {{{Utilizing interval-Newton approach for the reliable computation of roots in analytical waveguide modeling}}}, year = {{2013}}, } @article{13952, author = {{Bause, Fabian and Walther, Andrea and Rautenberg, Jens and Henning, Bernd}}, journal = {{Transactions on Ultrasonics, Ferroelectrics, and Frequency Control}}, number = {{12}}, pages = {{2597--2606}}, title = {{{Reliable Computation of Roots in Analytical Waveguide Modeling Using an Interval-Newton Approach and Algorithmic Differentiation}}}, volume = {{60}}, year = {{2013}}, } @article{13954, abstract = {{Zur berührungslosen Materialfeuchtebestimmung wird unter anderem die Infrarotreflexionsmessung genutzt. Diese nichtinvasive und schnelle Methode ist geeignet sowohl zur Bestimmung der Feuchte von Schüttgütern als auch zur Charakterisierung von Trocknungsprozessen von Lacken. Die reflektierte Strahlung ist dabei abh{\"a}ngig von Absorption und Streuung in der Beschichtung sowie von den temporären und lokalen Reflexionseigenschaften des Messobjektes. ln dieser Untersuchung ist ein experimenteller Aufbau zur simultanen Messung der gerichteten und der diffus reflektierten Strahlungsanteile realisiert.}}, author = {{Hoof, Christian and Wetzlar, Dietmar and Henning, Bernd}}, journal = {{Technisches Messen}}, number = {{12}}, pages = {{435--441}}, title = {{{Modellgestützte NIR-Materialfeuchtemessung mittels Multidetektoranordnung}}}, year = {{2013}}, } @inproceedings{13955, author = {{Hoof, Christian and Wetzlar, Dietmar and Henning, Bernd}}, location = {{Weima}}, pages = {{27--38}}, title = {{{Untersuchung zum Trocknungsverhalten poröser Materialien durch NIR-Reflexionsmessungen}}}, year = {{2013}}, } @inproceedings{13956, author = {{Kulshreshtha, Kshitij and Bause, Fabian and Rautenberg, Jens and Unverzagt, Carsten}}, title = {{{A modified electrode topology with increased sensitivity of electrical impedance to piezoelectic material parameters}}}, year = {{2013}}, } @inproceedings{13957, abstract = {{Single transducer distance sensors have a blind zone because normally the electrical received signal cannot be detected during transmitting. There are several approaches to realize a simultaneous transmit and receive operation. Digital signal processing is the best solution for narrow band systems (air ultrasound transducer) especially when the transmitted signal is coded. Thereby a mathematical model is used to estimate the electrical received signal. A drawback of the digital signal processing is the required computing time to estimate the model and the time of flight of an echo. In this contribution the computing time is reduced significantly by using base band signals for the signal processing. The signal-processing is subdivided into the following steps: Preprocessing, model identification, estimation of the received signal and echo detection. Beside the model identification the signal-preprocessing is an important part of the system. It depends on the time of flight of an echo (close echo, far echo) and the state of the system (single measurement, averaging). The whole system is evaluated with measurements using a 40 kHz air ultrasound transducer in front of a reflector with varying distances between 0 mm and 1000 mm.}}, author = {{Schröder, Andreas and Henning, Bernd}}, booktitle = {{Proceedings of the International Conference on Acoustics}}, publisher = {{DEGA}}, title = {{{Improved Signal Processing for an Ultrasonic Distance Sensor with Reduced Blind Zone}}}, year = {{2013}}, } @inproceedings{13958, author = {{Unverzagt, Carsten and Rautenberg, Jens and Henning, Bernd and Kulshreshtha, Kshitij}}, booktitle = {{Proceedings of the 2013 International Congress on Ultrasonics}}, editor = {{Siong, Gan Woon and Piang, Lim Siak and Cheong, Khoo Boo}}, isbn = {{978-981-07-5938-4}}, pages = {{758--763}}, publisher = {{{Research Publishing}}}, title = {{{Modified electrode shape for the improved determination of piezoelectric material parameters}}}, year = {{2013}}, } @inproceedings{13959, author = {{Walther, Andrea and Bause, Fabian and Henning, Bernd}}, location = {{Novi Sad}}, title = {{{A Comparison of Alternative Ways to Identify Singular Matrices}}}, year = {{2013}}, } @article{13886, author = {{Rautenberg, Jens and Bause, Fabian and Henning, Bernd}}, issn = {{0171-8096}}, journal = {{tm - Technisches Messen}}, pages = {{135--142}}, title = {{{Geführte akustische Wellen zur Flüssigkeitscharakterisierung}}}, doi = {{10.1524/teme.2012.0176}}, year = {{2012}}, } @inproceedings{13960, author = {{Bause, Fabian and Walther, Andrea and Henning, Bernd}}, title = {{{Numerische Nullstellensuche in Determinantenfunktionen mittels Intervallarithmetik und algorithmischem Differenzieren}}}, year = {{2012}}, } @inproceedings{13961, abstract = {{Typical examples for the sensory use of ultrasound in industry are the measurement of flow, level, density, viscosity or concentration. Most commercial devices only provide one of these quantities but a microprocessor based evaluation of the measured information in connection with extended models of the measurement setup may also extend the functionality of those sensors. In this contribution some trends for further developments of ultrasound flowmeters and ultrasonic chemical sensors will be outlined. Focusing on flow measurement, some functional enhancements like flow profile correction and the simultaneous identification of the flowing medium are discussed in more detail.}}, author = {{Henning, Bernd and Rautenberg, Jens}}, title = {{{Ultrasonic sensors for process applications}}}, year = {{2012}}, } @inproceedings{13962, author = {{Henning, Bernd}}, title = {{{Trends im Design von Ultraschallsensoren}}}, year = {{2012}}, } @inproceedings{13963, abstract = {{Polyamid 6 (PA 6), stammend aus der Gruppe der Polykondensate, ist ein thermoplastischer Kunststoff und zeichnet sich u.a. durch eine hohe Festigkeit und Steifigkeit bei geringen Rohstoff- und Herstellungskosten aus. Das Einsatzgebiet von Polyamiden ist sehr vielseitig. Neben dem massiven Einsatz in der Textilindustrie sei beispielsweise auch der Einsatz in Seilen und Trassen, Zahnrädern und Lagern genannt. Weiterhin findet PA 6 kompositäre Verwendung als Matrixmaterial in thermoplastischen Faserverbundmaterialien (u. a. endlosfaserverstärkte Organobleche) und ist dabei vor allem für die Automobilindustrie von immens steigender Bedeutung. Neben der bei PA ausgeprägten reversiblen Polykondensation, d.h. der Reaktion des Kunststoffes mit Wasser aus der Umgebungsluft, treten irreversible Prozesse (Thermooxidation, Photooxidation, Nachkondensation, $\ldots$) auf, welche seine chemischen und mechanischen Eigenschaften beeinflussen. In diesem Beitrag sollen die Auswirkungen hydrothermischer Alterung durch Temperatur und Feuchtigkeit, auf die akustischen bzw. mechanischen Eigenschaften zum einen im hochfrequenten (Ultraschall) und zum anderen im quasistatischen Bereich charakterisiert werden. Dazu werden PA 6 Probekörper mittels Klimawechseltests künstlich gealtert und in zwei verschiedenen Versuchsaufbauten beurteilt. Zum einen werden hohlzylindrische Proben zur Charakterisierung im Ultraschallbereich (Schallgeschwindigkeit, Schallkennimpedanz, Schallabsorption) und zum anderen Schulterstäbe zur Charakterisierung der mechanischen Materialeigenschaften im quasistatischen Bereich verwendet. Die akustischen Materialkenngrößen der Ultraschallcharakterisierung und die mechanischen Materialkenngrößen aus dem quasistatischen Bereich, werden abschließend miteinander korreliert und Zusammenhänge dargestellt.}}, author = {{Bause, Fabian and Budde, Christopher and Rautenberg, Jens and Henning, Bernd and Moritzer, Elmar}}, location = {{Darmstadt}}, title = {{{Korrelation hochfrequenter und quasistatischer Materialkenngrössen zur Charakterisierung verschiedener Alterungsstadien von Polyamid 6}}}, year = {{2012}}, }