@phdthesis{6563, abstract = {{Designprozesse von Schallwandlern werden durch zunehmende Rechenkapazitäten immer mehr durch simulative Betrachtungen unterstützt. Dabei ist vor allem die Wahl der Materialparameter der verwendeten Materialien wichtig für ein realitätsnahes Simulationsergebnis. Bei Schallwandlern werden häufig Piezokeramiken als aktive Elemente genutzt, welche sich durch eine Verkopplung mechanischer und elektrischer Eigenschaften auszeichnen. Zur Bestimmung ihrer Materialparameter stellt der IEEE Standard on Piezoelectricity ein standardisiertes Verfahren dar. Dazu sind fünf Impedanzmessungen an vier unterschiedlich gefertigten Probekörpergeometrien notwendig. Da an jedem einzelnen Probekörper nur eine Untermenge aller notwendigen Materialparameter bestimmt werden kann, werden diese dann zu einem kompletten Materialparametersatz zusammengefügt. Aufgrund der unterschiedlichen Prozessbedingungen, bei denen die jeweiligen Probekörper hergestellt werden, ist dieser Materialparametersatz jedoch inkonsistent und kann nie das Verhalten einer einzelnen Probe beschreiben. Daher wird in der vorliegenden Arbeit ein Messverfahren entwickelt, mit dem es möglich ist, alle relevanten Materialparameter unter besonderer Berücksichtigung von Dämpfung an einem einzelnen Probekörper allein durch Impedanzmessungen zu bestimmen. Als Probekörper wird dazu eine in der Anwendung häufig verwendete Scheibengeometrie verwendet. Um eine hinreichend hohe Sensitivität auf alle Materialparameter zu gewährleisten, wird diese mit einer optimierten Elektrodentopologie gefertigt. Da in diesem Fall keine analytische Betrachtung mehr möglich ist, wird das Messverfahren durch einen inversen Ansatz realisiert.}}, author = {{Feldmann, Nadine}}, pages = {{184}}, publisher = {{Universität Paderborn}}, title = {{{ Ein modellbasiertes Messverfahren zur Charakterisierung von Piezokeramiken unter Verwendung eines einzelnen scheibenförmigen Probekörpers}}}, doi = {{10.17619/UNIPB/1-1264}}, year = {{2021}}, } @inproceedings{15363, abstract = {{The classical forms of noise present in the frequency of MEMS resonators have been recently investigated and described in detail. The present paper extends this investigation to 1/f noise. That is of fundamental nature in microelectromechanical systems (MEMS) resonators, and is given by the universal quantum 1/f effect. In recent years new piezoelectric and compound semiconductor materials have been developed along with advanced manufacturing technologies for MEMS including them. These technologies enable the deposition of thin compound semiconductor, or PZT films and their integration into MEMS devices.}}, author = {{Handel, Peter and Henning, Bernd}}, isbn = {{80-2272050-X}}, location = {{Smolenice, Slovakia}}, pages = {{88--89}}, title = {{{1/f-Frequency Fluctations and Phase Noise in MEMS Resonators}}}, year = {{2004}}, } @article{14009, abstract = {{The contribution presents the sensor application of a resonance-induced extraordinary transmission through a regular phononic crystal consisting of a metal plate with a periodic arrangement of holes in a square lattice at normal incidence of sound. The characteristic transmission peak has been found to strongly depend on sound velocity of the liquid the plate is immersed in. The respective peak maximum frequency can serve as measure for the concentration of a component in the liquid mixture, if a beneficial relation to the speed of sound of the liquid exists. Experimental verification has been performed with mixtures of water and propanol as model system. Here we especially pay attention to numerical calculations based on EFIT and COMSOL which reveal more insides to the wave propagation characteristics. Experimental investigations with Schlieren method and laser interferometry support the theoretical findings.}}, author = {{Zubtsoc, Mikhail and Lucklum, Ralf and Ke, Manzhu and Oseev, Alexandr and Grundmann, Ralf and Henning, Bernd and Hempel, Ulrike}}, journal = {{Sensors and Actuators A: Physical}}, pages = {{118--124}}, title = {{{2D phononic crystal sensor with normal incidence of sound}}}, volume = {{186}}, year = {{2012}}, } @inproceedings{13880, author = {{Hoof, C. and Wetzlar, D. and Henning, Bernd}}, location = {{Nürnberg}}, publisher = {{LibreCat University}}, title = {{{3.2 - Infrared reflectance measurements of thin films with time variable surface roughness or texture}}}, doi = {{10.5162/OPTO2013/O3.2}}, year = {{2013}}, } @inproceedings{13865, author = {{Ester, S. and Struschka, M. and Henning, Bernd}}, publisher = {{LibreCat University}}, title = {{{3.2.3 - Direktgravimetrischer Partikelmasse-Sensor zur quasikontinuierlichen Emissionsmessung}}}, doi = {{10.5162/SENSOREN2016/3.2.3}}, year = {{2016}}, } @inproceedings{13864, author = {{Bause, F. and Henning, Bernd}}, publisher = {{LibreCat University}}, title = {{{5.3.1 - Ein ultraschallbasiertes inverses Messverfahren zur Charakterisierung viskoelastischer Materialparameter von Polymeren}}}, doi = {{10.5162/SENSOREN2016/5.3.1}}, year = {{2016}}, } @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}}, } @inproceedings{12952, author = {{Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}}, keywords = {{piezoelectric materials, piezoelectric properties, DC bias field, non-linear material parameters}}, location = {{Nürnberg}}, publisher = {{AMA Service GmbH}}, title = {{{A DC bias approach to the characterisation of non-linear material parameters of piezoelectric ceramics}}}, doi = {{10.5162/sensoren2019/5.1.2}}, year = {{2019}}, } @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{19502, author = {{Hetkämper, Tim and Krumme, Matthias and Dreiling, Dmitrij and Claes, Leander}}, booktitle = {{SEFI 48th Annual Conference Proceedings - Engaging Engineering Education}}, location = {{Enschede}}, pages = {{1309--1313}}, publisher = {{SEFI}}, title = {{{A modular, scalable open-hardware platform for project-based laboratory courses in electrical engineering studies}}}, year = {{2020}}, } @article{13888, author = {{Unverzagt, Carsten and Olfert, Sergei and Henning, Bernd}}, issn = {{1875-3892}}, journal = {{Physics Procedia}}, pages = {{935--942}}, title = {{{A new method of spatial filtering for Schlieren visualization of ultrasound wave fields}}}, doi = {{10.1016/j.phpro.2010.01.120}}, year = {{2010}}, } @inproceedings{15164, author = {{Feldmann, Nadine and Jurgelucks, Benjamin and Claes, Leander and Henning, Bernd}}, booktitle = {{2019 International Congress on Ultrasonics}}, title = {{{A sensitivity-based optimisation procedure for the characterisation of piezoelectric discs}}}, doi = {{10.1121/2.0001070}}, year = {{2019}}, } @inproceedings{15365, abstract = {{The appliance of time-reversal acoustics to classical trans-ducer design, medical, technical or audible range applica-tions brings forward new ideas whenever we need both, focusing acoustical energy in time and space. Unfortunately, the spatiotemporal focusing is limited through the amount of applied transducer elements as well as the ergodicity and randomness of the cavity [1]. This paper will show how the simulated annealing technique, a multi-objec¬tive optimiza-tion algorithm [2], is used to increase the nar¬rowness of the refocused spot by breaking up randomness for the benefit of ergodicity in a predetermined cavity.}}, author = {{Rautenberg, Jens and Olszewski, Dirk and Henning, Bernd}}, booktitle = {{Proceedings of the Joint Congress CFA/DAGA 2004}}, isbn = {{2-9521105-2-2}}, pages = {{1021--1022}}, publisher = {{DEGA}}, title = {{{A Space Optimization Method for Time-Reversal Super-Focusing}}}, year = {{2004}}, } @inproceedings{6556, author = {{Claes, Leander and Chatwell, René Spencer and Vrabec, Jadran and Henning, Bernd}}, booktitle = {{PROCEEDINGS -- AMA Conferences 2017}}, isbn = {{978-3-9816876-4-4}}, pages = {{304--309}}, publisher = {{AMA Service GmbH}}, title = {{{A Spectral Approach to Acoustic Absorption Measurement}}}, doi = {{10.5162/sensor2017/C1.2}}, year = {{2017}}, } @inproceedings{13879, author = {{Bause, F. and Rautenberg, J. and Henning, Bernd}}, location = {{Nürnberg}}, publisher = {{LibreCat University}}, title = {{{A3.2 - Design, modeling and identification of an ultrasonic composite transducer for target impedance independent short pulse generation}}}, doi = {{10.5162/SENSOR2013/A3.2}}, year = {{2013}}, } @article{13143, author = {{Claes, Leander and Hülskämper, Lars Moritz and Baumhögger, Elmar and Feldmann, Nadine and Chatwell, René Spencer and Vrabec, Jadran and Henning, Bernd}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, pages = {{2--6}}, title = {{{Acoustic absorption measurement for the determination of the volume viscosity of pure fluids / Messverfahren für die akustischen Absorption zur Bestimmung der Volumenviskosität reiner Fluide}}}, doi = {{10.1515/teme-2019-0038}}, year = {{2019}}, } @inproceedings{6557, author = {{Claes, Leander and Jäger, Axel and Johannesmann, Sarah and Webersen, Manuel and Kupnik, Mario and Henning, Bernd}}, booktitle = {{PROCEEDINGS -- AMA Conferences 2017}}, isbn = {{978-3-9816876-4-4}}, pages = {{605--610}}, publisher = {{AMA Service GmbH}}, title = {{{Acoustic Material Characterization of Additively Manufactured Components}}}, doi = {{10.5162/sensor2017/P2.9}}, year = {{2017}}, } @inproceedings{6568, author = {{Johannesmann, Sarah and Brockschmidt, Tobias and Rump, Friedhelm and Webersen, Manuel and Claes, Leander and Henning, Bernd}}, booktitle = {{Sensoren und Messsysteme}}, pages = {{231--234}}, publisher = {{VDE Verlag GmbH}}, title = {{{Acoustic material characterization of prestressed, plate-shaped specimens}}}, year = {{2018}}, } @inproceedings{15358, abstract = {{In the 1950's many investigations have been made in measuring the Young's and the shear modus of isotropic materials with acoustic waves. Therefore both the longitudinal and transversal sound velocities have been determined with only one specimen, that had to be large in comparison to the wavelength (Brown, Reynolds, Dunegan). Therewith the method was suited only for low absorbing materials. In the 1990's further developments led to mono mode rods to describe viscoelastic properties. Their diameters had to be very small for high frequencies, thus giving practical values up to 65 kHz (Benatar). This contribution is about a tubular multi mode specimen and its application for the simultaneous measurement of the abovementioned acoustic properties at high frequencies.}}, author = {{Rautenberg, Jens and Henning, Bernd}}, location = {{Beijing, China}}, title = {{{Acoustic properties of highly attenuating isotropic media}}}, year = {{2005}}, } @inproceedings{15337, abstract = {{The continuous measurement of rheological properties (density and viscosity) or material properties (concentration of selected substances) of liquid mixtures in the chemical industry or in the food industry is a great challenge to this day. Standard chemical sensors are often not suitable for industrial processes because of their slow sensor response and their limited robustness due to the direct contact to process media. Ultrasonic sensor systems meet the practical requirements of a chemical sensor quite well. Current ultrasonic sensor systems are already widely used as acoustic chemical sensors to measure concentration of selected substances or to monitor the course of polymerization, crystallization or fermentation processes. Useable acoustic properties for the characterization of liquid mixtures are sound velocity, sound absorption and acoustic impedance in consideration of temperature. This contribution will give a short overview of the state of the art and several trends for the use of ultrasonic sensor systems in process applications. Currently there are many activities to use acoustic waveguides for above mentioned sensor applications. By means of two selected examples (density measurement and determination of acoustic properties of highly absorbing synthetic polymers) it will presented new developed measurement principles using acoustic waveguides.}}, author = {{Henning, Bernd and Rautenberg, Jens}}, location = {{Wien}}, title = {{{Acoustical waveguides for sensor applications}}}, year = {{2007}}, } @inproceedings{14552, author = {{Bause, Fabian and Henning, Bernd}}, title = {{{Adaptives Mode-Tracing und numerische Stabilisierung modellierter Anregungsstrukturen für die halbanalytische Simulation geführter Wellen}}}, year = {{2010}}, } @misc{6594, author = {{Claes, Leander and Zeipert, Henning and Koppa, Peter and Tröster, Thomas and Henning, Bernd}}, title = {{{Additiv gefertigte, akustische Diffusor-Strukturen für Ultraschallanwendungen}}}, year = {{2018}}, } @inproceedings{6559, author = {{Claes, Leander and Zeipert, Henning and Koppa, Peter and Tröster, Thomas and Henning, Bernd}}, booktitle = {{Proceedings of Meetings on Acoustics}}, pages = {{030004}}, title = {{{Additively manufactured acoustic diffuser structures for ultrasonic measurement applications}}}, doi = {{10.1121/2.0000688}}, year = {{2017}}, } @inproceedings{10135, author = {{Webersen, Manuel and Hüttner, Matthias and Woitschek, Fabian and Moritzer, Elmar and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2019}}, location = {{Rostock}}, title = {{{Akustische Charakterisierung der mechanischen Eigenschaften künstlich gealterter Polymere}}}, year = {{2019}}, } @inproceedings{6578, author = {{Webersen, Manuel and Johannesmann, Sarah and Düchting, Julia and Claes, Leander and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2018}}, pages = {{1263--1266}}, title = {{{Akustische Charakterisierung der richtungsabhängigen elastischen Eigenschaften faserverstärkter Kunststoffe}}}, year = {{2018}}, } @article{6567, author = {{Johannesmann, Sarah and Düchting, Julia and Webersen, Manuel and Claes, Leander and Henning, Bernd}}, issn = {{0171-8096}}, journal = {{tm - Technisches Messen}}, keywords = {{Continous-fibre reinforced plastics, material parameters, orthotropy, ultrasonics}}, number = {{85}}, pages = {{478--486}}, title = {{{An acoustic waveguide-based approach to the complete characterisation of linear elastic, orthotropic material behaviour}}}, doi = {{10.1515/teme-2017-0132}}, volume = {{2018}}, year = {{2018}}, } @article{27367, abstract = {{An approach for the non-destructive characterisation of adhesive bonds using guided ultrasonic waves is presented. Pulsed laser radiation is used to thermoacoustically excite broadband ultrasonic waves in a multi-layered sample, consisting of a metal plate adhesively joined to a polymeric layer using synthetic resin. The resulting signals are received by a purpose-built piezoelectric transducer. Varying the distance between excitation and detection yields spatio-temporal measurement data, from which the dispersive properties of the propagating waves can be inferred using a two-dimensional Fourier transform, assuming the plates to act as coupled waveguides. Coupled multi-layered waveguides show an effect referred to as mode repulsion, where the distance between certain modes in the frequency-wavenumber domain is assumed to be a measure of coupling strength. Measurements at different stages of curing of the adhesive layer are performed and evaluated. A comparison of the results shows changes in the dispersive properties, namely an increased modal bandwidth for the fully cured sample as well as an increased modal distance.}}, author = {{Zeipert, Henning and Claes, Leander and Johannesmann, Sarah and Lugovtsova, Yevgeniya and Nicolai, Marcel and Prager, Jens and Henning, Bernd}}, issn = {{2196-677X}}, journal = {{at - Automatisierungstechnik}}, pages = {{962--969}}, title = {{{An approach to adhesive bond characterisation using guided acoustic waves in multi-layered plates}}}, doi = {{10.1515/auto-2021-0089}}, year = {{2021}}, } @inproceedings{13215, author = {{Moritzer, Elmar and Hüttner, Matthias and Henning, Bernd and Webersen, Manuel}}, location = {{Lyon}}, title = {{{An Approach to Non-Destructive Testing of Aged Polymers}}}, year = {{2016}}, } @article{6579, abstract = {{An explicit approach using symplectic time integration in conjunction with traditional finite difference spatial derivatives to solve the wave equation in moving media is presented. A simple operator split of this second order wave equation into two coupled first order equations is performed, allowing these split equations to be solved symplectically. Orders of symplectic time integration ranging from first to fourth along with orders of spatial derivatives ranging from second to sixth are explored. The case of cylindrical acoustic spreading in air under a constant velocity in a 2D square structured domain is considered. The variation of the computed time-of-flight, frequency, and wave length are studied with varying grid resolution and the deviations from the analytical solutions are determined. It was found that symplectic time integration interferes with finite difference spatial derivatives higher than second order causing unexpected results. This is actually beneficial for unstructured finite volume tools like OpenFOAM where second order spatial operators are the state-of-the art. Cylindrical acoustic spreading is simulated on an unstructured 2D triangle mesh showing that symplectic time integration is not limited to the spatial discretization paradigm and overcomes the numerical diffusion arising with the in-built numerical methods which hinder wave propagation.}}, author = {{Inguva, Venkatesh and Feldmann, Nadine and Claes, Leander and Koturbash, Taras and Hahn-Jose, Thomas and Koutcherov, Vladimir and Kenig, Eugeny}}, journal = {{Engineering Reports}}, title = {{{An explicit symplectic approach to solving the wave equation in moving media}}}, doi = {{10.1002/eng2.12573}}, year = {{2022}}, } @inproceedings{14561, abstract = {{Semi-analytical approaches for the description of dispersion in acoustic waveguides are based on root finding in a characteristic function. A mode-tracing algorithm helps to find all solutions of this problem by consecutively bracketing single roots. In this contribution we present a multistage and adaptive mode-tracing algorithm, which uses an adaptive step size for the prediction of consecutive solutions as well as an adaptive estimation of the search space around these predictions. Furthermore we present a validation stage to ensure the correlation between consecutive solutions alias waveguide modes.}}, author = {{Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, location = {{San Diego, California}}, pages = {{719--722}}, title = {{{An improved mode-tracing algorithm to compute dispersion curves of acoustic waveguides}}}, year = {{2010}}, } @article{6562, author = {{Feldmann, Nadine and Jurgelucks, Benjamin and Claes, Leander and Schulze, Veronika and Henning, Bernd and Walther, Andrea}}, journal = {{tm - Technisches Messen}}, number = {{2}}, pages = {{59--65}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{An inverse approach to the characterisation of material parameters of piezoelectric discs with triple-ring-electrodes}}}, doi = {{10.1515/teme-2018-0066}}, volume = {{86}}, year = {{2018}}, } @inproceedings{13943, author = {{Krumme, Matthias and Webersen, Manuel and Claes, Leander and Webersen, Yvonne}}, booktitle = {{Fortschritte der Akustik - DAGA 2020}}, pages = {{542--545}}, title = {{{Analoge Klangsynthese zur Vermittlung von Grundkenntnissen der Signalverarbeitung an Studierende nicht-technischer Fachrichtungen}}}, year = {{2020}}, } @misc{13866, author = {{Olfert, Sergei and Henning, Bernd}}, title = {{{Analyse integral erfasster rotationssymmetrischer Schallwechseldruckverteilungen in Schlierenabbildungen}}}, year = {{2015}}, } @inbook{13877, author = {{Olfert, Sergei and Henning, Bernd}}, booktitle = {{XXIX Messtechnisches Symposium}}, isbn = {{9783110408539}}, title = {{{Analyse integral erfasster Schallwechseldruckverteilungen in Schlierenabbildungen}}}, doi = {{10.1515/9783110408539-010}}, year = {{2015}}, } @inproceedings{15261, author = {{Lugovtsova, Yevgeniya and Johannesmann, Sarah and Henning, Bernd and Prager, Jens}}, booktitle = {{2019 International Congress on Ultrasonics}}, location = {{Bruges}}, publisher = {{Acoustical Society of America}}, title = {{{Analysis of Lamb wave mode repulsion and its implications to the characterisation of adhesive bonding strength}}}, doi = {{10.1121/2.0001074}}, year = {{2019}}, } @inproceedings{14013, abstract = {{Modeling and simulation play a key-role in computer-assisted design of ultrasonic sensors. The accuracy of those numerical or analytical models highly depends on the material dataset chosen as well as on the digitized simplified geometry. Thus, researchers worked on techniques how to measure material datasets of piezoceramics or passive materials (i.e. polymers) for use in simulation [Rau08] [Rup09]. Most computer models neglect the influence of adhesive bonds between those active and passive material components used to form a complete ultrasonic transducer and thus imply perfect interface layers. To gain a more accurate model one need to go further and consider non-perfect interface layers between assembly parts. Because adhesive bonds are neither necessarily isotropic nor homogeneous and their geometric dimensions are very small, we need to define effective material datasets dependent on the model used in simulation. In this contribution the indicator under study is the electric impedance of the active element. We will show the influence of different adhesives used to adhere metal electrodes on piezoceramic discs. Therefore, we use several different types of adhesives (epoxies, cyanoacrylates and perfluorpolyether grease) and different sizes of piezoceramic discs (PIC 255, manufacturer: PI Ceramic GmbH) of the same batch (thickness, diameter). The electrodes have been cut from one plate made of stainless steel using a laser to avoid uncertainty effects due to variations in material-parameters. The probes have been prepared in an air-conditioned Lab with constant temperature and humidity. The indicators considered to identify the effect of those different adhesive films are extracted from the electric impedance of the electromechanical converter.}}, author = {{Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, location = {{Chengdu, China}}, pages = {{18--23}}, title = {{{Analyzing the effect of adhered metal electrodes on piezoelectric elements using different types of adhesives}}}, volume = {{3}}, year = {{2011}}, } @misc{13862, author = {{Olfert, Sergei and Henning, Bernd}}, publisher = {{LibreCat University}}, title = {{{Anwendungsm\"oglichkeiten der Schallfeldvisualisierung in der Ultraschallmesstechnik}}}, year = {{2016}}, } @inproceedings{25265, abstract = {{Waveguide-based methods can be used for the non-destructive determination of acoustic material parameters. One of these methods is based on transmission measurements of cylindrical polymeric specimens. Here, the experimental setup consists of two transducers, which excite and receive the waveguide modes at the faces of the cylinder. The measurement, as well as a forward model, are used to determine material parameters of the polymeric specimen in an inverse approach. 1-3 piezoelectric composites are used as an active element because they can be approximated by a thickness vibration only. This allows an easy identification of Mason model parameters to characterise the transducers’ vibration behaviour. However, sensitivity analysis shows a high uncertainty in the determination of the mechanical shear parameters due to the uniform excitation. To increase the sensitivity to these shear motions, arbitrary excitations were investigated by means of numerical simulation. In order to be able to realise the determined optimal excitation, new transducer prototypes were designed. By subdividing the electrodes of the active element, for example, ring-shaped excitation is feasible. Furthermore, it can be shown that modelling these transducers with a one-dimensional Mason model is sufficient.}}, author = {{Dreiling, Dmitrij and Itner, Dominik and Feldmann, Nadine and Scheidemann, Claus and Gravenkamp, Hauke and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2021}}, location = {{Wien}}, publisher = {{Deutsche Gesellschaft für Akustik e.V. (DEGA)}}, title = {{{Application and modelling of ultrasonic transducers using 1-3 piezoelectric composites with structured electrodes}}}, year = {{2021}}, } @misc{13220, author = {{Webersen, Manuel and Bause, Fabian and Henning, Bernd}}, title = {{{Application of Automatic Differentiation for the inverse parameter identification of complex-valued forward models}}}, year = {{2015}}, } @inproceedings{47138, author = {{Hetkämper, Tim and Koch, Kevin and Webersen, Manuel and Claes, Leander}}, booktitle = {{SEFI 51th Annual Conference Proceedings - Engineering Education for Sustainability}}, publisher = {{SEFI}}, title = {{{Application-based learning of signal analysis methods with the help of a graphical open-source software}}}, doi = {{10.21427/159K-G445}}, year = {{2023}}, } @inproceedings{15381, abstract = {{Currently there are ultrasonic sensors to measure flow, liquid level, concentrations or to monitor the process course. In several processes the investigated media is a mixture of liquid and solid ingredients. The use of ultrasonic sensor systems will become very complicated if gas bubbles appear at the measurement place caused by chemical reactions, high temperature or fast flow this means under typical process conditions. The appearance of gas bubbles falsifies the measured absorption and also the velocity. The sound propagation in liquid mixtures is influenced in a complex manner for instance by solid particles, rapid changes of temperature, and liquid droplets of other density in the measured liquid simultaneously. For the detailed investigation of the influence of bubbles on sound propagation, an experimental setup was build. This setup permits the comprehensive processing of transmitted and scattered signals. Using a smart signal processing it is possible to find a reliable indication for gas bubbles.}}, author = {{Gulsch, Michael and Henning, Bernd and Prange, Stefan and Auge, Jörg}}, editor = {{Cassereau, Didier}}, location = {{Paris, France}}, pages = {{243--246}}, title = {{{Approach of continuous characterisation of liquid multi-component mixtures}}}, year = {{2003}}, } @misc{8482, author = {{Jurgelucks, Benjamin and Schulze, Veronika and Feldmann, Nadine and Claes, Leander}}, title = {{{Arbitrary sensitivity for inverse problems in piezoelectricity}}}, year = {{2019}}, } @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{39640, author = {{Wetzlar, Dietmar and Krumme, Matthias}}, booktitle = {{4. CMM-Workshop Innovative Feuchtemessung in Forschung und Praxis}}, location = {{Bad Herrenalb}}, pages = {{101--111}}, title = {{{Berührungslose Materialfeuchtemessung nach dem NIR-Prinzip bei schnell variierendem Messgutabstand}}}, year = {{2009}}, } @inproceedings{43229, author = {{Claes, Leander}}, booktitle = {{Fortschritte der Akustik - DAGA 2023}}, location = {{Hamburg}}, pages = {{7--14}}, title = {{{Bestimmung der Volumenviskosität mittels akustischer Absorptionsmessung}}}, year = {{2023}}, } @misc{15352, abstract = {{Impulsbasierte Ultraschallsensorsysteme zur Messung von Füllstand, Durchfluss und Konzentration sind heutzutage aufgrund ihrer Robustheit und Wartungsfreundlichkeit weit verbreitet. Probleme treten immer dann auf, wenn sich Gasblasen im Medium befinden. Diese verändern das empfangene Signal derart, dass eine exakte Messung der Schallgeschwindigkeit des flüssigen Mediums nicht mehr möglich ist. Dieser Beitrag behandelt eine neue Art der Signalauswertung, die eine zuverlässige Bestimmung der Schallgeschwindigkeit auch in diesem Fall gewährleistet. Darüber hinaus können auch Rückschlüsse auf den Gasanteil innerhalb des flüssigen Mediums gewonnen werden.}}, author = {{Gulsch, Michael and Henning, Bernd}}, title = {{{Bestimmung des Anteils ungelöster Gase in flüssigen Medien}}}, year = {{2005}}, } @inproceedings{14006, abstract = {{Bei der Ultraschall-basierten Abstandsmessung mit einem einzelnen Schallwandler ergibt sich durch das Prinzip bedingt eine Blindzone. Während und unmittelbar nach der Anregung durch das Sendesignal ist es im Allgemeinen nicht möglich, das Empfangssignal am Ultraschallwandler auszuwerten. Eine Verwendung von codierten Sendesignalen (z.B. zur Unterscheidung verschiedener Sensoren) verlängert diesen Blindbereich zusätzlich. Dieser Beitrag zeigt eine Möglichkeit zur Realisierung eines simultanen Sende- und Empfangsbetriebs mit einem einzelnen Schallwandler. Dadurch wird es möglich, die Blindzone auch bei sehr langen Sendesignalen zu eliminieren. Dazu wird der Ultraschallwandler über einen Vorwiderstand betrieben und dessen Spannung gemessen. Mittels eines mathematischen Modells kann das elektrische Sendesignal, welches am Ultraschallwandler anliegt, bestimmt werden. Die Subtraktion dieses Signals von der gemessenen Schallwandlerspannung liefert das elektrische Empfangssignal. Aufgrund von z.B. Temperatureinflüssen ändern sich die elektrischen Eigenschaften des Ultraschallwandlers ständig, wodurch eine Anpassung des Modells notwendig wird. Daher kann die Modellidentifikation nicht im Vorfeld mit einer Freifeldmessung erfolgen, sondern ist permanent während des Betriebes notwendig. Tritt dabei ein Empfangssignal z.B. infolge einer Reflexion auf, so wird die Bestimmung der Modellparameter gestört. Durch eine Bewertung der ermittelten Modelle kann die Robustheit einer Abstandsmessung erhöht werden}}, author = {{Schröder, Andreas and Henning, Bernd}}, editor = {{Service GmbH, AMA}}, isbn = {{978-3-9813484-0-8}}, location = {{Nürnberg}}, pages = {{352--360}}, title = {{{Blindzonenfreie Ultraschall-Abstandsmessung mit codierten Sendesignalen}}}, year = {{2012}}, } @inproceedings{15353, abstract = {{Currently there are pulse based ultrasonic sensor systems used to measure flow, liquid level, concentration or in process monitoring. In several processes the investigated media are a mixture of liquid and solid ingredients (emulsions, suspensions). The use of ultrasonic sensor systems will be very complicated if gas bubbles appear at the measurement place caused by chemical reactions, high temperature or fast flow that means by typical process conditions. Firstly, the appearance of gas bubbles falsifies the measured absorption. Secondly, the measured velocity is influenced by gas bubbles. In figure 1 is visible that a volume fraction of 0.1 ppm of undissolved air decreases the sound velocity by 1.4 m s-1}}, author = {{Gulsch, Michael and Henning, Bernd}}, booktitle = {{2005 IEEE Ultrasonics Symposium}}, pages = {{780--782}}, title = {{{Bubble detection and gas volume measurement in bubble loaded liquids with pulse driven measurement devices}}}, year = {{2005}}, } @inproceedings{43234, author = {{Nicolai, Marcel and Zeipert, Henning and Lugovtsova, Yevgeniya and Bulling, Jannis and Johannesmann, Sarah and Prager, Jens and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2023}}, location = {{Hamburg}}, pages = {{823--826}}, title = {{{Characterization of adhesion strength using guided ultrasonic waves}}}, year = {{2023}}, } @inproceedings{6576, author = {{Webersen, Manuel and Johannesmann, Sarah and Claes, Leander and Henning, Bernd}}, booktitle = {{2016 IEEE IUS~Proceedings}}, title = {{{Characterization of Continuous-fiber Reinforced Thermoplastics Using Thermoacoustically Excited Ultrasonic Lamb Waves}}}, year = {{2016}}, } @inproceedings{9718, author = {{Johannesmann, Sarah and Webersen, Manuel and Düchting, Julia and Claes, Leander and Henning, Bernd}}, booktitle = {{45th Annual Review of Progress in Quantitative Nondestructive Evaluation }}, location = {{Burlington}}, title = {{{Characterization of the linear-acoustic material behavior of fiber-reinforced composites using lamb waves}}}, doi = {{10.1063/1.5099742}}, volume = {{38}}, year = {{2019}}, } @inproceedings{15359, abstract = {{In den bekannten grundlegenden Ausf¨uhrungen zur Erzeugung hörbaren Schalls durch Eigendemodulation amplitudenmodulierten Leistungsultraschalls (siehe u.a. Westervelt, Berktay) wird von zwei räumlich übereinander liegenden Wellen unterschiedlicher Frequenz im nichtlinearen Medium ausgegangen, so dass neben ihren Harmonischen auch Summen- und Differenzfrequenzen entstehen. Die perfekte räumliche Ueberdeckung der Wellen im Freifeld kann mit herkömmlichen Schallwandlern allerdings nur unzul¨anglich erreicht werden. Trotzdem sind in der Vergangenheit einige so genannte parametrische Lautsprecher entwickelt worden. Um annähernd die erwähnten Voraussetzungen zu gewährleisten, sind gängige Systeme mit einem Durchmesser von ca. 30 cm relativ groß. Dies soll auch dem angestrebten Sekundärschalldruck Rechnung tragen, der linear mit der effektiv abstrahlenden Fl¨ache wächst. Zum Aufbau dieser großen Flächen werden teilweise viele kleine Ultraschallwandler zu einem Array zusammengesetzt. Der hohe Preis einzelner Wandler aber auch die notwendige Sortierung beispielsweise bezüglich ihrer Mittenfrequenz macht den Aufbau solcher Systeme aufwändig. Erst am vollständig aufgebauten Array werden schließlich Frequenzgang und Richtcharakteristik des Sekundärschalls ermittelt. Im Sinne kürzerer Entwicklungszeiten und -kosten wäre es wünschenswert, bereits vor dem Aufbau des Arrays allein durch Untersuchung des einzelnen Ultraschallwandlers eine Prognose über die zu erwartenden Eigenschaften des Gesamtsystems vornehmen zu können. In diesem Beitrag wird ein Versuchsaufbau vorgestellt, der unter strenger Beachtung der anfangs erwähnten Voraussetzungen die parametrische Schallerzeugung mit nur einem Ultraschallwandler kleiner Baugröße erlaubt. Die Frequenzg änge des Sekundärschalls von Einzelelement und Array werden bei entsprechender Distanz gegen¨ubergestellt. Vorzüge des neuen Messaufbaus, beispielsweise die Möglichkeit zur Variation von Druck, Temperatur oder Luftfeuchtigkeit, um atmosphärische Einflüsse auf die parametrische Schallerzeugung zu untersuchen, werden skizziert}}, author = {{Rautenberg, Jens and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA '05}}, editor = {{Fastl, Hugo and Fruhmann, Markus}}, isbn = {{3-9808659-1-6}}, pages = {{491--492}}, publisher = {{Deutsche Gesellsch. f. Akustik}}, title = {{{Charakterisierung einzelner Ultraschallwandler für den Aufbau eines mehrelementigen parametrischen Lautsprechers}}}, year = {{2005}}, } @article{15241, abstract = {{In this contribution, possibilities and methods for computer-assisted design of ultrasound transducers are described. These transducers are essential for an ultrasonic sensor design, e.g. for continuous non-invasive determination of quantities that are important in process technology. To achieve technical reliability and robustness, the precise determination of all acoustic properties of the used sensor materials is of great importance. Problem-oriented modeling, numerical simulation, special optimization algorithms and improved methods for the visualization of propagating waves offer new and promising possibilities for developing ultrasonic transducers with enhanced properties.}}, author = {{Henning, Bernd and Rautenberg, Jens and Unverzagt, Carsten and Schröder, Andreas and Olfert, Sergei}}, journal = {{Journal of Measurement Science and Technology, MST}}, number = {{124012 (11pp)}}, title = {{{Computer assisted design of transducers for ultrasonic sensor systems}}}, volume = {{20}}, year = {{2009}}, } @inproceedings{14008, abstract = {{Computer aided simulation of guided acoustic waves in single- or multilayered waveguides is an essential tool for several applications of acoustics and ultrasonics (i.e. pipe inspection, noise reduction). To simulate wave propagation in geometrically simple waveguides (plates or rods), one may employ the analytical global matrix method [1]. This requires the computation of all roots of the determinate of a certain submatrix. The evaluation of all real or even complex roots is actually the methods most concerning restriction. Previous approaches base on so called mode-tracers which use the physical phenomenon that solutions (roots) appear in a certain pattern (waveguide modes) and thus use known solutions to limit the root finding algorithms searchspace with respect to consecutive solutions. As the limitation of searchspace might be unstable in some cases, we propose to replace the mode-tracer with a suitable version of an interval Newton method based on Intlab [2]. To apply this interval based method, we extended the interval and derivative computation provided by Intlab such that corresponding information is also available for Bessel functions used in the circular model (rods) of acoustic waveguides. We present numerical results of a simple acoustic waveguide and discuss extensions required for more realistic scenarios.}}, author = {{Walther, Andrea and Bause, Fabian and Henning, Bernd}}, location = {{Darmstadt}}, title = {{{Computing roots for the analytic modeling of guided waves in acoustic waveguides}}}, year = {{2012}}, } @article{13217, author = {{Moritzer, Elmar and Hüttner, Matthias and Henning, Bernd and Webersen, Manuel}}, journal = {{Kunststoffe International}}, number = {{4}}, pages = {{43--45}}, title = {{{Detecting Molecular Damage}}}, year = {{2016}}, } @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}}, } @inproceedings{6554, author = {{Claes, Leander and Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, booktitle = {{Proceedings SENSOR 2015}}, keywords = {{piezoceramics, strip transducers, plate waveguide, dispersion diagram}}, pages = {{775--779}}, title = {{{Detection of ultrasonic plate waves using ceramic strip transducers}}}, doi = {{10.5162/sensor2015/P3.3}}, year = {{2015}}, } @inproceedings{15264, author = {{Johannesmann, Sarah and Becker, Sebastian and Webersen, Manuel and Henning, Bernd}}, booktitle = {{SMSI 2020 - Measurement Science}}, isbn = {{978-3-9819376-2-6}}, location = {{Nuremberg}}, title = {{{Determination of Murnaghan constants of plate-shaped polymers under uniaxial tensile load}}}, doi = {{10.5162/SMSI2020/D6.1}}, year = {{2020}}, } @article{6555, author = {{Claes, Leander and Meyer, Thorsten and Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, issn = {{2194-878X}}, journal = {{Journal of Sensors and Sensor Systems}}, number = {{1}}, pages = {{187--196}}, title = {{{Determination of the material properties of polymers using laser-generated broadband ultrasound}}}, doi = {{10.5194/jsss-5-187-2016}}, volume = {{5}}, year = {{2016}}, } @inproceedings{6583, author = {{Feldmann, Nadine and Bause, Fabian and Henning, Bernd}}, booktitle = {{Proceedings – AMA Conferences 2017}}, title = {{{Determining fractional Zener model parameters from low frequency DMA measurements}}}, doi = {{10.5162/SENSOR2017/B1.4}}, year = {{2017}}, } @article{15364, author = {{Henning, Bernd}}, journal = {{Technisches Messen}}, number = {{9}}, pages = {{492--500}}, title = {{{Die akustische Impedanz als Messgröße zur Charakterisierung flüssiger Stoffsysteme}}}, volume = {{71}}, year = {{2004}}, } @inproceedings{14010, abstract = {{Die Modellierung bzw. das virtuelle Design von Ultraschallwandlern spielt gerade im Hinblick auf die Mannigfaltigkeit ihrer Einsatzgebiete und die stetig wachsenden Anforderungen der Industrie eine Schlüsselrolle bei der Entwicklung piezoelektrischer Sensor- und Aktorsysteme. Der jeweils für eine spezielle Anwendung zu erreichende Grad der Realitätsnähe der eingesetzten Modelle ist dabei essentielle Voraussetzung für die Legitimation des virtuellen Designs. Neben idealisierten Strukturen, welche der Modellbildung unweigerlich anhaften, wird die Realitätsnähe wesentlich durch die genutzten Materialmodelle und deren Parametrisierung beeinflusst. Viele Arbeiten wurden aus diesem Grund auf dem Gebiet der akustischen Materialdaten-bestimmung sowohl passiver als auch aktiver Materialien durchgeführt. Ein Ultraschallwandler besteht nun aus einer Komposition von aktiven und passiven Elementen, welche z. B. mittels Klebungen zusammengef{\"u}gt werden. Aktuelle Praxis ist die Vernachl{\"a}ssigung der Klebschichteigenschaften oder ggf. eine Korrektur der durch die Klebschichtdicke hervorgerufene Frequenzverschiebung durch eine virtuelle Vergr{\"o}{\ss}erung eines der F{\"u}geteile. Dabei werden die Koppelbedingungen zwischen den gef{\"u}gten Materialien als ideal angenommen, was in der Realit{\"a}t jedoch nicht der Fall ist. Klebungen sind weder isotrop noch homogen aufgebaut. Des Weiteren ist ihre Dicke sehr klein, was in der Computersimulation dazu f{\"u}hrt, dass sie {\"u}ber effektive Parameter und stark vereinfachte Modelle beschrieben werden.}}, author = {{Bause, Fabian}}, title = {{{Die Auswirkung verschiedener Klebungen auf das Verhalten eines piezoelektrischen Wandlers}}}, year = {{2011}}, } @misc{17090, author = {{Itner, Dominik and Gravenkamp, Hauke and Dreiling, Dmitrij and Birk, Carolin and Henning, Bernd}}, publisher = {{International Association for Computational Mechanics (IACM)}}, title = {{{Differentiation of an SBFE model in the context of material parameter determination}}}, year = {{2022}}, } @article{15324, author = {{Henning, Bernd}}, journal = {{Technisches Messen}}, number = {{4}}, pages = {{217--220}}, title = {{{Editorial: XXI. Messtechnisches Symposium des Arbeitskreises der Hochschullehrer für Messtechnik (AHMT), Paderborn, 20.--22.09.2007}}}, year = {{2008}}, } @inproceedings{6584, author = {{Feldmann, Nadine and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik}}, pages = {{1275--1278}}, title = {{{Efficient optimisation of initial values for characterising piezoelectric material parameters}}}, year = {{2018}}, } @article{21232, author = {{Itner, Dominik and Gravenkamp, Hauke and Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}}, issn = {{0041-624X}}, journal = {{Ultrasonics}}, title = {{{Efficient semi-analytical simulation of elastic guided waves in cylinders subject to arbitrary non-symmetric loads}}}, doi = {{10.1016/j.ultras.2021.106389}}, year = {{2021}}, } @misc{14554, author = {{Henning, Bernd}}, title = {{{Effizientes Ultraschalltransducerdesign und Methoden zur akustischen Materialdatenbestimmung}}}, year = {{2010}}, } @phdthesis{13860, author = {{Bause, Fabian}}, publisher = {{Universität Paderborn}}, title = {{{Ein ultraschallbasiertes inverses Messverfahren zur Charakterisierung viskoelastischer Materialparameter von Polymeren}}}, year = {{2016}}, } @phdthesis{14002, author = {{Rautenberg, Jens}}, keywords = {{akustische Wellenleiter, Kunststoffe, Materialdatenbestimmung, Transmissionsmessung}}, publisher = {{Elektrotechnik}}, title = {{{Ein wellenleiterbasiertes Verfahren zur Bestimmung von Materialdaten für die realitätsnahe Simulation von Schallausbreitungsphänomenen am Beispiel stark absorbierender Kunststoffe}}}, year = {{2012}}, } @misc{6596, author = {{Webersen, Manuel and Johannesmann, Sarah and Brockschmidt, Tobias and Rump, Friedhelm and Claes, Leander and Henning, Bernd}}, title = {{{Einfluss mechanischer Vorspannung auf das mechanische Materialverhalten von Polymeren}}}, year = {{2018}}, } @inproceedings{14563, abstract = {{Die computergestützte Simulation geführter elastischer Wellen in ein- oder mehrschichtigen Wellenleitern ist in vielen Bereichen der akustischen Forschung ein essentielles Modellierungswerkzeug. Sie ermöglicht, auch in komplexen Systemen, eine Beschreibung der Wellenausbreitungsvorgänge, deren analytische Lösung zu aufwendig oder nicht durchführbar ist. Im ersten Abschnitt dieses Beitrags wird auf den halbanalytischen Solver bzw. die mathematische Formulierung des die Wellenausbreitung beschreibenden Problems eingegangen. Der zweite Abschnitt beinhaltet den mehrstufigen Aufbau eines Tracing-Algorithmus, welcher den Lösungsraum des Solvers adaptiv einschränkt, so dass Leistungsfähigkeit und Robustheit des Gesamtalgorithmus gestärkt werden.}}, author = {{Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, isbn = {{978-3-9808659-8-2}}, location = {{Berlin}}, pages = {{1027--1028}}, title = {{{Entwicklung und Parametrisierung eines Mode-Tracing Algorithmus für halbanalytische Solver}}}, year = {{2010}}, } @inproceedings{13861, author = {{Olfert, Sergei and Becker, Sebastian and Henning, Bernd}}, booktitle = {{Deutsche Gesellschaft für Akustik e.V. 2017- Fortschritte der Akustik - DAGA 2017}}, isbn = {{9783939296126}}, pages = {{1015--1018}}, publisher = {{Deutsche Gesellschaft für Akustik e.V. (DEGA)}}, title = {{{Erweiterung des Mason-Modells zur Beschreibung eines Partikelbelags auf einer Quarzscheibe}}}, year = {{2017}}, } @article{13863, author = {{Olfert, Sergei and Henning, Bernd}}, journal = {{Technisches Messen}}, number = {{4}}, pages = {{219--224}}, title = {{{Erweiterung des Raman-Nath-Modells zur Analyse von Schlierenabbildungen}}}, doi = {{10.1515/teme-2015-0116}}, volume = {{83}}, year = {{2016}}, } @article{15489, author = {{Claes, Leander and Steidl, Carolin and Hetkämper, Tim and Henning, Bernd}}, journal = {{arXiv.org}}, publisher = {{Cornell University}}, title = {{{Estimation of acoustic wave non-linearity in ultrasonic measurement systems}}}, doi = {{10.48550/arXiv.2001.05708}}, year = {{2020}}, } @misc{6558, author = {{Friesen, Olga and Claes, Leander and Feldmann, Nadine and Henning, Bernd}}, title = {{{Estimation of piezoelectric material parameters of ring-shaped specimens}}}, year = {{2022}}, } @inproceedings{6588, author = {{Johannesmann, Sarah and Claes, Leander and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2022}}, location = {{Stuttgart}}, pages = {{1401--1404}}, title = {{{Estimation of viscoelastic material parameters of polymers using Lamb waves}}}, year = {{2022}}, } @inproceedings{6565, author = {{Jäger, Axel and Johannesmann, Sarah and Claes, Leander and Webersen, Manuel and Henning, Bernd and Kupnik, Mario}}, booktitle = {{2017 IEEE IUS~Proceedings}}, title = {{{Evaluating the Influence of 3D-Printing Parameters on Acoustic Material Properties}}}, year = {{2017}}, } @article{13887, author = {{Schröder, Andreas and Rautenberg, Jens and Henning, Bernd}}, issn = {{1875-3892}}, journal = {{Physics Procedia}}, pages = {{1003--1009}}, title = {{{Evaluation of cost functions for FEA based transducer optimization}}}, doi = {{10.1016/j.phpro.2010.01.129}}, year = {{2010}}, } @inproceedings{16076, author = {{Hetkämper, Tim and Claes, Leander and Henning, Bernd}}, booktitle = {{2019 International Congress on Ultrasonics}}, location = {{Bruges}}, title = {{{Evolutionary algorithm for the design of passive electric matching networks for ultrasonic transducers}}}, doi = {{10.1121/2.0001110}}, year = {{2019}}, } @inproceedings{6586, author = {{Thiel, Christian and Feldmann, Nadine and Henning, Bernd}}, booktitle = {{Sensoren und Messsysteme 2018}}, pages = {{536--539}}, publisher = {{VDE Verlag GmbH}}, title = {{{Extraction of Interpretable Features from Temporal Measurements using Approximate Prototypes}}}, year = {{2018}}, } @inproceedings{14550, abstract = {{For many applications like level measurement and industry robotics it is of advantage if the directional characteristic of an ultrasonic transducer is changeable or adaptable for the improvement of spatial resolution. Often this goal is reached with the use of ultrasonic transducer arrays, which elements are driven with phase shifted excitation signals. One disadvantage of these solutions is the great effort for building such an array and the multi-channel sensor electronics. In this contribution the directional characteristic of a single air transducer with segmented electrodes is analyzed. Therefore a variable script based finite element model is used to discover the influence of different electrode configurations on the directional characteristic of a single piezoceramic transducer. Especially the influence on the angle of beam and the near field length are evaluated. The used variable model permits an optimization of the configuration with regards to the mentioned criteria. The findings will be used for the development of a level measurement system for bulk solids.}}, author = {{Unverzagt, Carsten and Henning, Bernd}}, keywords = {{Elektrode}}, location = {{Gdansk, Poland}}, title = {{{Finite element simulation of single ultrasonic transducer with segmented electrodes to adjust the directional characteristic}}}, year = {{2011}}, } @inproceedings{15354, abstract = {{In vielen verfahrenstechnischen Prozessen ist die kontinuierliche Regelung von Prozessgrößen für einen stabilen und sicheren Betrieb eine wichtige Vorraussetzung. Die Erfassung der Zielgrößen geschieht aufgrund von hoher Robustheit und Wartungsfreundlichkeit zunehmend mit akustischen Messverfahren. Besonders impulsbasierte Messsysteme werden häufig zur Messung von Durchfluss, Füllstand und in der Flüssigkeitsanalytik auch zur Konzentrationsmessung benutzt. Dabei führen am Messort auftretende Gasblasen zu großen messtechnischen Problemen. Sie verändern die gemessenen akustischen Stoffkenngrößen, wodurch es zur fehlerhaften Regelung bestimmter Prozesszielgrößen kommt.}}, author = {{Gulsch, Michael and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA '05}}, editor = {{Fastl, Hugo and Fruhmann, Markus}}, isbn = {{3-9808659-1-6}}, pages = {{587--588}}, publisher = {{Deutsche Gesellsch. f. Akustik}}, title = {{{Gasvolumenmessung in blasenbeladenen Flüssigkeiten}}}, year = {{2005}}, } @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}}, } @article{14003, abstract = {{Das Spektrum akustischer Wellenleiter zur Flüssig-keitscharakterisierung reicht von der Seismologie und Geophysik mit Wellenleiterdimensionen von einigen km über die zerstörungsfreie Prüfung bis hin zur Prozessmesstechnik mit Sensordimensio-nen von wenigen mm. In diesem Beitrag wird ein phänomenologischer Weg zur Klassifizierung der Wellenleiter entwickelt, wobei stets die Oberflä-chenauslenkungen an der Wellenleitergrenze und die Anzahl der an der Wellenausbreitung beteiligten Moden Berücksichtigung finden. Im weiteren Verlauf werden Möglichkeiten zur Modellierung, Simulation und Messung multimodaler Wellenausbreitung im akustischen Wellenleiter gezeigt.}}, author = {{Rautenberg, Jens and Bause, Fabian and Henning, Bernd}}, journal = {{Technisches Messen}}, number = {{3}}, pages = {{135--142}}, title = {{{Geführte akustische Wellen zur Flüssigkeitscharakterisierung}}}, volume = {{79}}, year = {{2012}}, } @inproceedings{15242, abstract = {{In non-destructive testing (NDT) with ultrasound the emission of short pulses is essentially if the echoes of nearby obstacles should be separated from the emitted signal. In this contribution a new approach is shown how to gene-rate a short ultrasonic pulse using a 3$-$1 composite transdu-cer. Therefore the ceramic bars, which are embedded in a polymer matrix, will be regarded as an exciter for the entire structure. After the pulse excitation the same bars can also be used for active damping to increase the bandwidth of the entire system. The Mason model serves as a basis for the de-scription of the ultrasonic transducer and is extended to the composite structure. The excitation signal is adaptively mo-dified by a suitable signal processing. Therefore the changes of boundary conditions, like the ambient temperature or acoustic impedance of adjacent media are considered.}}, author = {{Rautenberg, Jens and Olfert, Sergei and Henning, Bernd}}, location = {{Rotterdam, Netherlands}}, pages = {{148--151}}, title = {{{Generating of short ultrasonic pulses using active damping}}}, year = {{2009}}, } @article{6577, author = {{Webersen, Manuel and Johannesmann, Sarah and Düchting, Julia and Claes, Leander and Henning, Bernd}}, journal = {{Ultrasonics}}, pages = {{53--62}}, title = {{{Guided ultrasonic waves for determining effective orthotropic material parameters of continuous-fiber reinforced thermoplastic plates}}}, doi = {{10.1016/j.ultras.2017.10.005}}, volume = {{84}}, year = {{2018}}, } @misc{15176, author = {{Feldmann, Nadine and Bause, Fabian and Henning, Bernd}}, title = {{{GUM-konforme Unsicherheitsabschätzung bei inversen Problemen am Beispiel akustischer Transmissionsmessungen}}}, year = {{2016}}, } @misc{14553, author = {{Bause, Fabian}}, title = {{{Halbanalytische Modellierung akustischer Wellenausbreitung im ein- und mehrschichtigen Wellenleiter}}}, year = {{2010}}, } @inproceedings{6553, author = {{Claes, Leander and Feldmann, Nadine and Schulze, Veronika and Jurgelucks, Benjamin and Walther, Andrea and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2022}}, location = {{Stuttgart}}, pages = {{1326--1329}}, title = {{{Identification of piezoelectric material parameters using optimised multi-electrode specimens}}}, year = {{2022}}, } @inproceedings{13222, abstract = {{When performing measurements, the effects of the measurement system itself on the measured data generally must be eliminated. Consequently, those effects, i.e. the system’s dynamic behavior, need to be known. For the piezo-composite transducers in an ultrasonic transmission line, a model based approach is used to describe their dynamic behavior and take into account its dependence on the environment temperature and the acoustic impedance of the target medium. Temperature-dependent model parameters are presented, which are obtained by performing a multiplepart identification process on the transducer model, based on electrical impedance measurements [1]. The identification process uses an inverse approach for optimizing a subset of the model parameters. Additionally, algorithmic differentiation methods are used to determine accurate derivatives. In a final optimization step, impedance measurements taken at different temperatures are used to determine the temperature dependencies of the model parameters. These can then be used to assess the plausibility of the identification results. Additionally, the parameters can be expressed as polynomials in the temperature to take different operating conditions into account.}}, author = {{Webersen, Manuel and Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, booktitle = {{AMA Conferences 2015}}, keywords = {{piezo-composite, transducer, temperature dependency, identification, plausibility}}, location = {{Nürnberg}}, pages = {{195--200}}, title = {{{Identification of temperature-dependent model parameters of ultrasonic piezo-composite transducers}}}, year = {{2015}}, } @misc{13224, author = {{Webersen, Manuel and Karzellek, Michael and Bause, Fabian and Henning, Bernd}}, title = {{{Implementation and uncertainty analysis of a test device for electrical impedance measurements using vector network analyzers}}}, year = {{2015}}, } @inproceedings{45205, author = {{Dreiling, Dmitrij and Itner, Dominik and Hetkämper, Tim and Birk, Carolin and Gravenkamp, Hauke and Henning, Bernd}}, booktitle = {{SMSI 2023 Conference}}, isbn = {{978-3-9819376-8-8}}, location = {{Nürnberg}}, pages = {{394 -- 395}}, publisher = {{AMA Association For Sensors And Measurement}}, title = {{{Improved determination of viscoelastic material parameters using a pulse-echo measurement setup}}}, doi = {{10.5162/SMSI2023/P59}}, year = {{2023}}, } @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{14565, abstract = {{In single transducer applications it would be desirable if the received electrical signal (echo signal) could be evaluated during transmitting. Thereby it is possible to measure very short distances. There are some solutions to realize this, but they have one limitation which prevents the usage in many industrial application. They need a calibration without an echo. The main problem is that this calibration has to be repeated whenever the process parameters like temperature or acoustic load change. This contribution presents an approach which uses a model identification based on different successive measurements which may include echoes. It is done by an impulse response decomposition followed by a principle component analysis. Results of measurements with sine burst excitation and a reflector in front of the transducer are presented.}}, author = {{Schröder, Andreas and Henning, Bernd}}, location = {{San Diego, California}}, pages = {{141--144}}, title = {{{Improved system identification for simultaneous transmitting and receiving in single transducer applications}}}, year = {{2010}}, } @article{13812, author = {{Püttmer, A. and Lucklum, R. and Henning, Bernd and Hauptmann, P.}}, issn = {{0924-4247}}, journal = {{Sensors and Actuators A: Physical}}, pages = {{8--12}}, title = {{{Improved ultrasonic density sensor with reduced diffraction influence}}}, doi = {{10.1016/s0924-4247(97)01720-2}}, year = {{2002}}, } @article{15389, abstract = {{Recently there has been increased demand for chemicaJ sensors measuring in-line the concentration of selected substances in complex liquids in order to guarantee a high product quality in the process industry. At present there is a great interest in acoustic sensor systems for concentration measurements. This article presents a new ultrasonic sensor system consisting of a miniaturized multi-sensor arrangement for the comprehensive acoustic characterization of liquid mixtures. The sensor system measures sound velocity, impedance coefficient, attenuation coefficient an9 temperature.}}, author = {{Henning, Bernd and Daur, Peter-Christoph and Prange, Stefan and Dierks, Karsten and Hauptmann, Peter}}, journal = {{Ultrasonics}}, pages = {{799--803}}, title = {{{In-line concentration measurement in complex liquids using ultrasonic sensors}}}, doi = {{10.1016/s0041-624x(99)00190-0}}, year = {{2000}}, } @misc{15390, author = {{Henning, Bernd and Daur, Peter-Christoph and Prange, Stefan and Dierks, Karsten}}, pages = {{165--172}}, title = {{{In-Line-Flüssigkeitsanalysator für verfahrenstechnische Prozesse}}}, year = {{1998}}, } @inproceedings{17089, author = {{Dreiling, Dmitrij and Itner, Dominik Thor and Feldmann, Nadine and Gravenkamp, Hauke and Henning, Bernd}}, location = {{Nürnberg}}, publisher = {{AMA Service GmbH}}, title = {{{Increasing the sensitivity in the determination of material parameters by using arbitrary loads in ultrasonic transmission measurements}}}, doi = {{10.5162/SMSI2020/D1.3}}, year = {{2020}}, } @article{13895, author = {{Kulshreshtha, Kshitij and Jurgelucks, Benjamin and Bause, Fabian and Rautenberg, Jens and Unverzagt, Carsten}}, issn = {{2194-878X}}, journal = {{Journal of Sensors and Sensor Systems}}, pages = {{217--227}}, title = {{{Increasing the sensitivity of electrical impedance to piezoelectric material parameters with non-uniform electrical excitation.}}}, volume = {{4}}, year = {{2015}}, } @misc{6569, author = {{Jurgelucks, Benjamin and Claes, Leander}}, title = {{{Increasing the Sensitivity of Impedance with Respect to Material Parameters of Triple-Ring Electrode Piezoelectric Transducers using Algorithmic Differentiation}}}, year = {{2016}}, } @inproceedings{6573, author = {{Olfert, Sergei and Claes, Leander and Henning, Bernd}}, booktitle = {{Proceedings of the International Conference on Acoustics}}, pages = {{477--480}}, publisher = {{DEGA}}, title = {{{Influence of angular radiated ultrasound waves on the Schlieren tomogram}}}, year = {{2013}}, } @inproceedings{51117, author = {{Scheidemann, Claus and Hemsel, Tobias and Friesen, Olga and Claes, Leander and Sextro, Walter}}, location = {{Jeju, Korea}}, title = {{{Influence of Temperature and Pre-Stress on the Piezoelectric Material Behavior of Ring-Shaped Ceramics}}}, year = {{2023}}, } @inproceedings{51118, author = {{Scheidemann, Claus and Hemsel, Tobias and Friesen, Olga and Claes, Leander and Sextro, Walter}}, location = {{Incheon, Korea}}, title = {{{Influence of Temperature and Pre-Stress on the Piezoelectric Material Behavior of Ring-Shaped Ceramics}}}, year = {{2023}}, } @inproceedings{14566, abstract = {{In der Ultraschallmesstechnik (Abstandsmessung, NDT) ist es zur Detektion naheliegender Reflektoren bzw. zur Erfassung der Medienrückwirkung (Wirkung der akustischen Last) notwendig, die Empfangssignale auszuwerten, noch während der Schallwandler mit dem Sendesignal angesteuert wird oder die Sendesignalenergie am Schallwandler noch nicht ausreichend abgeklungen ist. In diesem Beitrag wird eine Schaltung zur Kompensation des Sendesignals beschrieben, welche die unmittelbare Auswertung des Empfangssignals ermöglicht.}}, author = {{Schröder, Andreas and Henning, Bernd}}, isbn = {{978-3-9808659-8-2}}, pages = {{1025--1026}}, title = {{{Interfaceschaltung für einen simultanen Sende- und Empfangsbetrieb mit einem einzelnen Ultraschallwandler}}}, year = {{2010}}, } @article{19313, abstract = {{The increasingly simulation-driven design process of ultrasonic transducers requires several reliable parameters for the description of the material behaviour. Exact results can only be achieved when a single specimen is used in the identification process, which typically is prone to the problem of low sensitivities to certain material parameters and thus high uncertainties. Therefore, a custom electrode topology for increased sensitivity is proposed for a piezoceramic disc. The thereupon conducted measurements of the electric impedance can be used as a starting point for an inverse approach where an equivalent simulation model is used to identify fitting material parameters. An optimisation strategy based on a preliminary sensitivity analysis is presented that leads to a good agreement between measurement and simulation. Furthermore, the proposed measurement procedure is able to evaluate the quality of the simulation model. Hence, different frequency-dependent damping models are presented and evaluated.}}, author = {{Feldmann, Nadine and Schulze, Veronika and Claes, Leander and Jurgelucks, Benjamin and Walther, Andrea and Henning, Bernd}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, pages = {{50--55}}, title = {{{Inverse piezoelectric material parameter characterization using a single disc-shaped specimen}}}, doi = {{10.1515/teme-2020-0012}}, year = {{2020}}, } @article{45445, author = {{Claes, Leander and Feldmann, Nadine and Schulze, Veronika and Meihost, Lars and Kuhlmann, Henrik and Jurgelucks, Benjamin and Walther, Andrea and Henning, Bernd}}, journal = {{Journal of Sensors and Sensor Systems}}, number = {{1}}, pages = {{163–173}}, title = {{{Inverse procedure for measuring piezoelectric material parameters using a single multi-electrode sample}}}, doi = {{10.5194/jsss-12-163-2023}}, volume = {{12}}, year = {{2023}}, } @misc{45455, author = {{Claes, Leander and Meihost, Lars and Jurgelucks, Benjamin}}, title = {{{Inverse procedure for the identification of piezoelectric material parameters supported by dense neural networks}}}, year = {{2023}}, } @inproceedings{6566, author = {{Johannesmann, Sarah and Claes, Leander and Webersen, Manuel and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2017}}, pages = {{999--1002}}, publisher = {{Deutsche Gesellschaft für Akustik e.V. 2017}}, title = {{{Inverser Ansatz zur akustischen Charakterisierung plattenförmiger Materialproben}}}, year = {{2017}}, } @misc{6560, author = {{Johannesmann, Sarah}}, title = {{{Inverses Verfahren zur Bestimmung viskoelastischer Materialparameter}}}, year = {{2022}}, } @article{21067, abstract = {{Acoustic waves in plates have proven a viable tool for testing and material characterisation purposes. There are a multitude of options for excitation and detection of theses waves, such as optical and piezoelectric systems. While optical systems, with thermoelastic excitation and interferometric detection, have the benefit of being contactless, they usually require rather complex and expensive experimental setups. Piezoelectric systems are more easily realised but require direct contact with the specimen and usually have a limited bandwidth, especially in case of piezoelectric excitation. In this work, the authors compare the properties of piezoelectric and optical detection methods for broad-band acoustic signals. The shape (e. g. the displacement) of a propagating plate wave is given by its frequency and wave number, allowing to investigate correlations between mode shapes and received signal strengths. This is aided by evaluations in normalised frequency and wavenumber space, facilitating comparisons of different specimens. Further, the authors explore possibilities to utilise the specific properties of the detection methods to determine acoustic material parameters.}}, author = {{Claes, Leander and Schmiegel, Hanna and Grünsteidl, Clemens and Johannesmann, Sarah and Webersen, Manuel and Henning, Bernd}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, number = {{3}}, pages = {{147--155}}, title = {{{Investigating peculiarities of piezoelectric detection methods for acoustic plate waves in material characterisation applications}}}, doi = {{10.1515/teme-2020-0098}}, volume = {{88}}, year = {{2021}}, } @inproceedings{43233, author = {{Zeipert, Henning and von Germeten, Christian and Friesen, Olga and Claes, Leander and Johannesmann, Sarah and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2023}}, location = {{Hamburg}}, pages = {{819--822}}, title = {{{Investigation of change in dispersive behaviour during adhesive curing in multi-layered structures}}}, year = {{2023}}, } @inproceedings{15351, abstract = {{Today's automotive headlights are built with transparent cover lenses. Therefore condensation of water leads to a visible optical defect. This paper presents a new approach for determination of the droplet size using colour phenomena in totally reflected light. It is based on a model of the generation of colour patterns by interference of several rays of light each multiple totally reflected inside condensed droplets. The droplet size may be determined by the colour if the contact angle is known. Measurement of both droplet size and colour all}}, author = {{Wetzlar, Dietmar and Henning, Bernd and Nolte, Sascha and Klahold, Jens}}, isbn = {{978-3-9810993-0-0}}, location = {{Nürenberg}}, title = {{{Investigation of colour phenomena in condensed water droplets}}}, year = {{2006}}, } @inproceedings{14000, abstract = {{In optischen Messeinrichtungen (Abstandsmessung, NIR-Materialfeuchtemessung) werden häufig in einem schmalen Wellenlängenbereich strahlende, gepulste Infrarot-Emitter eingesetzt. Leistungsstarke Strahlungspulse sind notwendig, führen aber zu einer thermisch bedingten Abnahme der emittierten Strahlungsleistung und zu einer Verschiebung der Maximumwellenlänge. Die hierdurch entstehenden Messunsicherheiten werden aufgezeigt und Konzepte zu deren Verringerung dargestellt.}}, author = {{Hoof, Christian and Schlottmann, J{\ and Wetzlar, Dietmar and Henning, Bernd}}, booktitle = {{16. GMA/ITG-Fachtagung. Sensoren und Messsysteme}}, editor = {{Service GmbH}, AMA}}, isbn = {{978-3-9813484-0-8}}, pages = {{748--757}}, title = {{{Konzepte zur Regelung der Strahlungsleistung pulsbetriebener IR-Emitter}}}, 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}}, } @article{30863, abstract = {{Abstract In this paper a measurement procedure to identify viscoelastic material parameters of plate-like samples using broadband ultrasonic waves is presented. Ultrasonic Lamb waves are excited via the thermoelastic effect using laser radiation and detected by a piezoelectric transducer. The resulting measurement data is transformed to yield information about multiple propagating Lamb waves as well as their attenuation. These results are compared to simulation results in an inverse procedure to identify the parameters of an elastic and a viscoelastic material model.}}, author = {{Johannesmann, Sarah and Claes, Leander and Feldmann, Nadine and Zeipert, Henning and Henning, Bernd}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, keywords = {{Electrical and Electronic Engineering, Instrumentation}}, number = {{7 - 8}}, pages = {{493 -- 506}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Lamb wave based approach to the determination of acoustic material parameters}}}, doi = {{10.1515/teme-2021-0134}}, volume = {{89}}, year = {{2022}}, } @article{23791, author = {{Johannesmann, Sarah and Claes, Leander and Henning, Bernd}}, journal = {{tm - Technisches Messen}}, number = {{s1}}, pages = {{s28--s33}}, publisher = {{Walter de Gruyter {GmbH}}}, title = {{{Lamb wave based approach to the determination of elastic and viscoelastic material parameters}}}, doi = {{10.1515/teme-2021-0070}}, volume = {{88}}, year = {{2021}}, } @misc{15335, author = {{Henning, Bernd}}, title = {{{Liquid analysis using acoustical sensors}}}, year = {{2007}}, } @inproceedings{15360, abstract = {{One method to generate focused sound is to transmit amplitude modulated ultrasound of high energy in a nonlinear medium, so that sum and difference frequencies develop. Practically wide arrays of many small ultrasonic transducers are used, but the generation of very low frequencies is always weak. This contribution is about the experimental investigation of the {\textquotedbl}generation zone{\textquotedbl} -- that is the distance between the ultrasonic loudspeaker and the listener -- and the decrease of the lower frequency bound of the audible sound beam with distance. The main focus is on the experimental setup, which permits the parametric sound generation with only one ultrasonic transducer and a waveguide. In addition, the new measurement setup enables to show an additional effect: The de-coherence of the primary ultrasound wave which may be caused by saturation of air. This is why the lower frequency bound decreases as well if we approach the ultrasonic transducer.}}, author = {{Rautenberg, Jens and Henning, Bernd}}, location = {{Paderborn}}, title = {{{Lower Frequency Bound of Parametric Arrays}}}, year = {{2005}}, } @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{14007, abstract = {{Ultraschall-Abstandssensoren besitzen meist nur einen Schallwandler und dadurch Prinzip bedingt einen Mindestabstand. Eine Möglichkeit diesen Mindestabstand zu reduzieren, besteht in der Realisierung eines simultanen Sendeund Empfangsbetriebes. In diesem Beitrag wird dies durch eine digitale Signalverarbeitung realisiert. Hierzu ist es notwendig, das Schallwandlersignal und das elektrische Sendesignal zu digitalisieren. Mit der Kenntnis des Schallwandlerverhaltens sowie des elektrischen Sendesignals wird das zu erwartende Schallwandlersignal modellbasiert berechnet und vom gemessenen Schallwandlersignal subtrahiert, um so das Empfangssignal zu bestimmen. Dabei liegen die Herausforderungen in der Ermittlung der Parameter eines repräsentativen Schallwandlermodells sowie der Gewährleistung einer robusten Echodetektion.}}, author = {{Schröder, Andreas and Henning, Bernd}}, isbn = {{978-3-8440-1312-2}}, location = {{Aachen}}, pages = {{143--152}}, title = {{{Luftultraschall-Abstandsmessung mit digitaler Signalverarbeitung zur Verkürzung des Mindestabstandes}}}, year = {{2012}}, } @inproceedings{14548, abstract = {{Bei der Luftultraschall-Abstandsmessung mit einem einzelnen Schallwandler ist der Mindestabstand durch die Sendesignaldauer und die Ausschwingzeit des Schallwandlers begrenzt. Daher führt die Verwendung von codierten Sendesignalen, wie sie z.B. für die Unterscheidung mehrerer Sender genutzt werden können, im Allgemeinen zu einer Vergrößerung des Mindestabstandes. Dieser Beitrag zeigt, dass der Mindestabstand bei codierten Sendesignalen durch eine geeignete Signalverarbeitung, bei der eine Trennung des Sende- und Empfangssignals erfolgt, deutlich verringert werden kann.}}, author = {{Schröder, Andreas and Henning, Bernd}}, location = {{Düsseldorf}}, title = {{{Luftultraschall-Abstandsmessung mit verkürztem Mindestabstand}}}, year = {{2011}}, } @inproceedings{6572, author = {{Jurgelucks, Benjamin and Feldmann, Nadine and Claes, Leander and Henning, Bernd and Walther, Andrea}}, booktitle = {{Proceedings of Meetings on Acoustics}}, pages = {{030010}}, title = {{{Material parameter determination of a piezoelectric disc with triple-ring-electrodes for increased sensitivity}}}, doi = {{10.1121/2.0000707}}, year = {{2017}}, } @misc{6593, author = {{Claes, Leander and Feldmann, Nadine and Henning, Bernd}}, title = {{{Materialparameter von bleihaltigen und bleifreien Piezokeramiken und ihre Bedeutung in der Anwendung}}}, year = {{2018}}, } @inproceedings{22013, author = {{Zeipert, Henning and Claes, Leander and Johannesmann, Sarah and Webersen, Manuel and Lugovtsova, Yevgeniya and Prager, Jens and Henning, Bernd}}, location = {{Nürnberg}}, pages = {{91 -- 92}}, title = {{{Measurement and Simulation of Lamb Waves in Adhesive-bonded Multilayer Systems}}}, doi = {{10.5162/SMSI2021/A8.2}}, year = {{2021}}, } @inproceedings{15338, abstract = {{There are a couple of acoustic systems that are well suited for continuous and reliable concentration measurement of liquids, but the reliability is a great challenge: Most systems determine the amplitude ratio of deflected ultrasound bursts at different boundaries as well as the sound velocity of the liquid in order to calculate its acoustic impedance and therewith its density. The problem is the sensitivity of variations of reference material properties as well as abrasion or soiling of the boundaries. This contribution is about a new model-based method that uses the whole surface of an acoustic waveguide as reference boundary. On the one hand the integral over a large boundary decreases influence of small boundary defects. On the other hand it is possible to analyze different modes of sound in the fluid. This redundancy can be used to increase reliability. The decomposition of the received signal in its modal components by means of principle component analysis will be discussed in detail. It will be shown that it is possible to determine the amplitudes of each mode by means of one measured signal at the end of the waveguide, even if the transducer and the electronic components are of very simple kind}}, author = {{Rautenberg, Jens and Henning, Bernd}}, booktitle = {{Proceedings of the International Congress on Ultrasonics}}, title = {{{Measurement of the acoustic properties of highly absorbing synthetic polymers}}}, year = {{2007}}, } @article{22925, author = {{Claes, Leander and Chatwell, René Spencer and Baumhögger, Elmar and Hetkämper, Tim and Zeipert, Henning and Vrabec, Jadran and Henning, Bernd}}, issn = {{0263-2241}}, journal = {{Measurement}}, title = {{{Measurement procedure for acoustic absorption and bulk viscosity of liquids}}}, doi = {{10.1016/j.measurement.2021.109919}}, year = {{2021}}, } @misc{14567, author = {{Schröder, Andreas and Rautenberg, Jens and Behlen, H. and Ziegler, Horst and Unverzagt, Carsten and Gaugler, Ulrich and Glatter, T. and Horrn, R. and Kroemer, H. and Schmidt-Schoenian, Axel and Sonnenberg, Hans-Michael and Henning, Bernd}}, title = {{{Messrohr für einen Ultraschall-Durchflussmesser und Ultraschall Durchflussmesser}}}, year = {{2010}}, } @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}}, } @inproceedings{14004, abstract = {{Es wird ein Wellenleiter basiertes Messsystem vorgestellt, mit dem anhand einer einzigen Transmissionsmessung alle Daten bestimmt werden können, die zur Simulation von Schallausbreitungsphänomenen in stark absorbierenden und schwach anisotropen Materialien erforderlich sind. Auf diese Weise ist es fortan möglich die akustischen Kenngrößen (winkel- und frequenzabhängige Schallgeschwindigkeiten und frequenzabhängige Absorption) verschieden konditionierter Materialproben (Temperatur, Feuchtigkeit, Alter) simultan zu erfassen. Genutzt wird dazu die mehrmalige Modekonversion an den Mantelflächen eines hohlzylindrischen akustischen Wellenleiters, wonach ein Empfangssignal mehrere Signalgruppen aufweist, deren absolute Laufzeit, Laufzeitdifferenzen und Amplituden in Abhängigkeit der Materialkenngrößen stark variieren. Grundlegend für die realisierte und in diesem Beitrag beschriebene inverse Bestimmung der akustischen Kenngrößen ist ein ganzheitliches Modell der Schallanregung, -ausbreitung und -detektion, welches die schnelle Berechnung der Empfangssignale erlaubt. Die gezielte Variation der Modell-Eingangsgrößen führt schließlich zu einer bestmöglichen Übereinstimmung zwischen berechneten und gemessenen Empfangssignalen, sodass die final angesetzten Modell-Eingangsgrößen eine gute Approximation der gesuchten materialspezifischen akustischen Kenngrößen darstellen. Im Rahmen dieses Beitrags werden der Messaufbau, wesentliche Teile der Modellierung sowie die grundätzliche Vorgehensweise zur Anwendung der inversen Messmethode gezeigt. Anhand gemessener, berechneter und mittels Finiter Elemente Methode simulierter Signale wird das Verfahren für einen Werkstoff, spritzgegossenes Polypropylen, demonstriert.}}, author = {{Rautenberg, Jens and Bause, Fabian and Henning, Bernd}}, editor = {{Service GmbH, AMA}}, isbn = {{978-3-9813484-0-8}}, location = {{Nürnberg}}, pages = {{332--343}}, title = {{{Messsystem zur Bestimmung akustischer Kenngrößen stark absorbierender, transversal isotroper Kunststoffe}}}, year = {{2012}}, } @inproceedings{15349, abstract = {{Die kontinuierliche und zuverlässige Konzentrationsmessung in Flüssigkeiten ob zur Dosierung oder Prozessverfolgung stellt auch heute noch eine große messtechnische Herausforderung dar. Akustische Sensorsysteme sind für diese Messaufgabe insbesondere unter industriellen Einsatzbedingungen prädestiniert. Es gibt eine Vielzahl verschiedener sorgfältig entworfener Ultraschallsensoren, die diese Aufgabe durch Bestimmung der Schallgeschwindigkeit und der akustischen Impedanz lösen. Sie basieren meist auf senkrechten Durchgängen des Schalls durch Grenzschichten, was sie sehr empfindlich gegenüber Ablagerungen macht. Dieser Beitrag liefert einen neuen Ansatz, indem die gesamte Oberfläche des Messraumes als akustischer Wellenleiter gestaltet und genutzt wird. Es hat sich gezeigt, dass sich durch Ausnutzen verschiedener Simulationswerkzeuge die Hauptkomponenten eines Empfangssignals berechnen lassen, die eindeutig den verschiedenen modalen Anteilen zugeordnet werden können. Damit ist es möglich, allein aus dem Empfangssignal eines herkömmlichen Ultraschallwandlers auf die modalen Anteilsfaktoren zu schließen. Mit Hilfe dieser Koeffizienten und eines Modells des akustischen Wellenleiters lässt sich ein Gleichungssystem aufstellen, das den Zusammenhang zwischen Dissipation in der Flüssigkeit sowie der durch Wellenleitergeometrie und Impedanzverhältnisse bedingten Signaldämpfung und den Amplituden der modalen Anteilsfaktoren beschreibt.}}, author = {{Rautenberg, Jens and Henning, Bernd}}, isbn = {{978-3-8322-5419-3}}, location = {{Bayreuth}}, pages = {{55--73}}, title = {{{Messung der akustischen Impedanz einer Flüssigkeit in einem akustischen Wellenleiter}}}, year = {{2006}}, } @phdthesis{21502, abstract = {{Die vollständige Beschreibung fluiddynamischer und akustischer Vorgänge setzt voraus, dass die Eigenschaften des Fluids hinlänglich bekannt sind.Während Fluidkenngrößen, wie etwa die Schallgeschwindigkeit oder die Scherviskosität, für viele Flüssigkeiten über weite Bereiche des thermodynamischen Zustandsraums bekannt sind, existieren für die Volumenviskosität nur eine geringe Anzahl Messdaten.In dieser Arbeit wird daher ein Messverfahren zur selektiven Bestimmung der Volumenviskosität von Flüssigkeiten, basierend auf der Absorption von Ultraschallwellen, entwickelt und realisiert.Schwerpunkte bilden dabei der simulationsgestützte Entwurf von Algorithmen zur Auswertung der Messsignale sowie die Analyse und Weiterentwicklung einer Messanordnung, basierend auf dem Puls-Echo-Verfahren. Neben der Absorption im Fluid treten dabei weitere Effekte (zum Beispiel Beugung oder unvollständige Reflexion) auf, die das akustische Signal schwächen oder anderweitig beeinflussen. Die Entwicklung von Verfahren zur Trennung dieser Effekte von der akustischen Absorption bildet daher einen weiteren Schwerpunkt dieser Arbeit.Abschließend wird die Volumenviskosität aus der gemessenen akustischen Absorption für unterschiedliche Fluide in verschiedenen thermodynamischen Zuständen unter Zuhilfenahme anderer bekannter Fluidkenngrößen bestimmt sowie eine Unsicherheitsbetrachtung durchgeführt.}}, author = {{Claes, Leander}}, pages = {{223}}, publisher = {{Universiät Paderborn}}, title = {{{Messverfahren für die akustische Absorption in reinen Fluiden zur Bestimmung der Volumenviskosität}}}, doi = {{10.17619/UNIPB/1-1104}}, year = {{2021}}, } @misc{6592, author = {{Claes, Leander}}, title = {{{Messverfahren für die akustische Absorption zur Bestimmung der Volumenviskosität}}}, year = {{2022}}, } @misc{15238, author = {{Henning, Bernd}}, title = {{{Methoden und Werkzeuge für einen effizienten Ultraschallsensorentwurf}}}, year = {{2009}}, } @misc{6550, author = {{Bause, Fabian and Rautenberg, Jens and Feldmann, Nadine and Claes, Leander and Henning, Bernd}}, title = {{{Methoden zur Zeit-Frequenz-Analyse bei der Untersuchung dispersionsbehafteter Signale}}}, volume = {{8}}, year = {{2014}}, } @inproceedings{6564, author = {{Fischer, Balthasar and Claes, Leander}}, booktitle = {{INTER-NOISE 2016}}, publisher = {{Deutsche Gesellschaft für Akustik e.V.}}, title = {{{Miniaturized all-optical Sound Pressure Sensor}}}, year = {{2016}}, } @inproceedings{13892, abstract = {{Several ultrasonic approaches for material determination are formulated in terms of an (nonlinear) inverse problem, e.g. immersion technique (Castaings et al. (2000)) or plate-waveguide techniques (Marzani et al. (2012)). In this contribution we focus on cylindrical waveguides for ultrasonic material determination and especially on the sensitivity of recorded transmission signals to the material properties. We utilize composite scaled sensitivities to determine the information content that can be achieved by the setup to certain parameters and discuss the limitations of the approach.}}, author = {{Bause, Fabian and Gravenkamp, Hauke and Rautenberg, Jens and Henning, Bernd}}, keywords = {{Sensitivity inverse problem ultrasonic material determination}}, pages = {{204--207}}, title = {{{Model based sensitivity analysis in the determination of viscoelastic material properties using transmission measurements through circular waveguides}}}, year = {{2015}}, } @inproceedings{13945, author = {{Bause, Fabian and Brückner, Christoph and Miedl, Jens and Henning, Bernd}}, booktitle = {{Beiträge der 17. ITG/GMA-Fachtagung}}, editor = {{Gesellschaft im VDE}, Informationstechnische}}, isbn = {{9783800736225}}, publisher = {{{VDE Verlag}}}, title = {{{Model based sensitivity analysis of Leaky-Lamb wave propagation to the variation of viscous lubricant properties}}}, year = {{2014}}, } @inproceedings{14549, abstract = {{Simultaneous transmitting and receiving (STaR) enhances the utilization of single transducer ultrasound measurement systems. In distance measurement applications the dead zone can be reduced to nearly zero, independent of the transmitted signal. So it is possible to transmit codedsignals to identify different sensors without increasing the minimum distance. The electrical transducer signal consists of the electrical transmitted and received signal. A separation of these two signals can be done with a mathematical model of the electrical system. For this purpose it is necessary to digitize the electrical transducer signal. Due to the relative small amplitude of the received signal compared to the transmitted signal amplitude, a high resolution analog to digital converter (ADC) is needed. This leads to high requirements for the ADC. The necessary resolution limits the sample rate of the ADC. By down mixing the transducer signal using a coherent quadrature demodulation (CQD), as used in many high frequency ultrasound applications, the sample rate of the ADC can be reduced. In this contribution an airborne ultrasound distance measurement system with reduced dead zone is used to analyze the effects of this concept to the signal conditioning, system identification and system performance. The approach is compared with a system without CQD and an ADC with a lower resolution but a higher sample rate. By analyzing the pros and cons of both systems the usability of a CQD based system for a STaR application is evaluated. The distance measurement system used for the experiments is based on a 40 kHz airborne ultrasonic transducer. A gyrator based transmit amplifier delivers a system bandwidth of about 10 kHz. In the experiments, coded transmitted signals are used to measure the distance to a metal reflector. The main objectives are short distances between 0 mm and 200 mm. Here a separation of transmitted and received signal is necessary. The reflector distance is calculated by a cross correlation between transmitted and received signal.}}, author = {{Schröder, Andreas and Henning, Bernd}}, title = {{{Model based separation of transmitted and received signal for single transducer distance measurement applications}}}, year = {{2011}}, } @misc{13213, author = {{Bause, Fabian and Webersen, Manuel and Rautenberg, Jens and Henning, Bernd}}, title = {{{Modeling and inverse identification of a high bandwidth ultrasonic measurement setup based on piezoelectric 1-3 composites}}}, year = {{2014}}, } @misc{13214, author = {{Bause, Fabian and Webersen, Manuel and Rautenberg, Jens and Henning, Bernd}}, title = {{{Modellbasierte inverse Identifikation von Ultraschall-Transducern anhand der elektrischen Eingangsimpendanz}}}, year = {{2014}}, } @inproceedings{13947, abstract = {{Zur schnellen und berührungslosen Materialfeuchtebestimmung wird unter anderem die Infrarotreflexionsmessung ge-nutzt. In dieser Untersuchung wird das Trocknungsverhalten von Dispersionslack auf einem rauen Substrat mit einer Multidetektoranordnung untersucht. Durch diese Anordnung ist es möglich, gerichtete und diffuse Strahlungsanteile zu detektieren, wodurch zeitvariable Glanzeffekte an der Lackoberfläche miterfasst werden. Mit Hilfe eines Raytracing-Algorithmus wird die Trocknung eines Dispersionslackes simuliert und anhand von Messdaten mit einem FTIR-Spekt-rometer verifiziert.}}, author = {{Hoof, Christian and Appelhans, Silke and Henning, Bernd}}, location = {{Nürnberg}}, title = {{{Modellgestützte Analyse des Trocknungsverhaltens von Dispersionslacken aus Daten einer NIR-Multidetektoranordnung}}}, year = {{2014}}, } @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}}, } @article{21341, abstract = {{The progress in numerical methods and simulation tools promotes the use of inverse problems in material characterisation problems. A newly developed procedure can be used to identify the behaviour of piezoceramic discs over a wide frequency range using a single specimen via fitting simulated and measured impedances by optimising the underlying material parameters. Since there is no generally accepted damping model for piezoelectric ceramics, several mechanical damping models are examined for the material identification. Three models have been chosen and their ability to replicate the measured impedances is evaluated. On the one hand, the common Rayleigh model is considered as a reference. On the other hand, a Zener model and a model using complex constants are extended to model the transversely isotropic material. As the Rayleigh model is only valid for a limited frequency range, it fails to model the broadband behaviour of the material. The model using complex constants leads to the best fit over a wide frequency range while at the same time only adding three additional parameters for modelling damping. Thus, damping can be assumed approximately frequency-independent in piezoceramics.}}, author = {{Feldmann, Nadine and Schulze, Veronika and Claes, Leander and Jurgelucks, Benjamin and Meihost, Lars and Walther, Andrea and Henning, Bernd}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, number = {{5}}, pages = {{294 -- 302}}, title = {{{Modelling damping in piezoceramics: A comparative study}}}, doi = {{10.1515/teme-2020-0096}}, volume = {{88}}, year = {{2021}}, } @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}}, } @article{13216, author = {{Moritzer, Elmar and Hüttner, Matthias and Henning, Bernd and Webersen, Manuel}}, journal = {{Kunststoffe}}, number = {{4}}, pages = {{94--96}}, title = {{{Molekularen Schäden auf der Spur}}}, year = {{2016}}, } @inproceedings{15361, abstract = {{The determination of small liquid volumes and their changes over a period of time is a measuring problem with increasing importance considering the growing market of micro-systems. In this paper, experimental investigations are described which aim to observe the growth of droplets at the end of a micro channel, such as a cannula or capillary. The main focus of the work lies on the calculation of flow rates below 1 millilitre per hour. Furthermore, the potential of the measuring equipment for liquid level and surface tension measurement is described.}}, author = {{Auge, Jörg and Dierks, Karsten and Prange, Stefan and Henning, Bernd}}, location = {{Prag}}, pages = {{375--378}}, title = {{{Monitoring of droplet growth with nano-litre resolution for liquid flow rate, level or surface tension measurement}}}, volume = {{5-12}}, year = {{2002}}, } @inproceedings{15386, abstract = {{The determination of small liquid volumes and their changes over a period of time is a measuring problem with increasing importance considering the growing market of micro-systems. In this paper, experimental investigations are described which aim to observe the growth of droplets at the end of a micro channel, such as a cannula or capillary. The main focus of the work lies on the calculation of flow rates below 1 millilitre per hour. Furthermore, the potential of the measuring equipment for liquid level and surface tension measurement is described.}}, author = {{Auge, Jörg and Dierks, Karsten and Prange, Stefan and Henning, Bernd}}, location = {{Prag}}, pages = {{375--378}}, title = {{{Monitoring of droplet growth with nano-litre resolution for liquid flow rate, level or surface tension measurement}}}, volume = {{5-12}}, year = {{2002}}, } @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}}, } @inproceedings{15362, abstract = {{In der industriellen Messtechnik werden optische, chemische und akustische Messverfahren zur Ermittlung von Prozessgrößen eingesetzt. Dabei haben die akustischen Messverfahren aufgrund ihrer Robustheit und Wartungsfreundlichkeit ein sehr großes Einsatzgebiet. Impulsbasierte Ultraschallmesssysteme werden unter anderem zur Messung von Durchfluss und Füllstand eingesetzt. Zunehmend werden sie aber auch in der Flüssigkeitsanalytik zur Konzentrationsmessung und Stoffanalyse herangezogen. Dabei führen Gasblasen in den zu untersuchenden flüssigen Medien immer wieder zu Problemen, da bei Anwesenheit von Gasblasen die akustischen Stoffkenngrößen verändert werden. Diese Probleme können ihre Ursache auch in der Signalverarbeitung haben. Dieser Beitrag soll zeigen, welche Methoden zur Signalverarbeitung geeignet sind um dieses Problem zu lösen. }}, author = {{Gulsch, Michael and Henning, Bernd}}, location = {{ Ludwigsburg}}, pages = {{31}}, title = {{{Neue Methoden der Signalauswertung für Ultraschall-Messsysteme}}}, year = {{2004}}, } @inproceedings{15339, abstract = {{Continuous and reliable concentration measurement of liquids still is a great challenge as the sensor systems have to meet high industrial requirements. Apart from chemical sensors there are a couple of acoustic systems [1] that are well suited for a lot of industrial applications. Most of them determine the amplitude ratio of deflected ultrasound bursts at different boundaries as well as the sound velocity of the liquid in order to calculate its acoustic impedance and therewith its density. The advantages of acoustic sensors are their robustness and their fast response. Their disadvantages are sensitivity against variations of the reference material properties as well as abrasion or soiling of the boundaries. This contribution is about a new model-based method that uses the whole surface of an acoustic waveguide as reference boundary: It has turned out that the principal components of a signal at the end of the waveguide can be assigned to the different propagative acoustic modes (Fig. 1). Therefore it is necessary to use different simulation tools, e.g. FEM and modal analysis (Fig. 2). With this it is possible to determine the amplitudes of each mode by means of one measured signal at the end of the waveguide and Gauss Algorithm even if the transducer is of very simple kind [2]. Therewith it is possible to get redundant information -- one amplitude for each mode -- for the liquid impedance. In addition to that it is possible to generate an acoustic reference signal without information about the liquid impedance but dissipation if we use the fundamental mode. The different signal amplitudes and a model of acoustic wave propagation [2, 3] offer the possibility to distinguish between dissipation in the liquid and attenuation due to the impedance relations. Moreover, if there are enough analysable amplitudes available, variations of the reference material properties can be determined.}}, author = {{Rautenberg, Jens and Henning, Bernd}}, isbn = {{978-3-9810993-2-4}}, location = {{Nürnberg}}, pages = {{87--92}}, title = {{{New approach for the reliable measurement of acoustic impedance of liquids in an acoustic waveguide}}}, volume = {{II}}, year = {{2007}}, } @inproceedings{13218, author = {{Moritzer, Elmar and Hüttner, Matthias and Henning, Bernd and Webersen, Manuel}}, isbn = {{978-0-692-71961-9}}, location = {{Indianapolis}}, title = {{{Non-destructive characterization of hygrothermally aged polymers}}}, year = {{2016}}, } @inproceedings{13960, author = {{Bause, Fabian and Walther, Andrea and Henning, Bernd}}, title = {{{Numerische Nullstellensuche in Determinantenfunktionen mittels Intervallarithmetik und algorithmischem Differenzieren}}}, year = {{2012}}, } @article{13953, author = {{Gravenkamp, Hauke and Bause, Fabian and Chongmin, Song}}, journal = {{Computers and Structures}}, pages = {{46--55}}, title = {{{On the computation of dispersion curves for axisymmetric elastic waveguides using the Scaled Boundary Finite Element Method}}}, volume = {{131}}, year = {{2014}}, } @misc{21564, author = {{Itner, Dominik and Gravenkamp, Hauke and Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}}, title = {{{On the forward simulation and cost functions for the ultrasonic material characterization of polymers }}}, year = {{2021}}, } @misc{13867, author = {{Kulshreshtha, Kshitij and Jurgelucks, Benjamin and Bause, Fabian and Rautenberg, Jens and Unverzagt, Carsten}}, title = {{{On the optimal configuration of triple-ring-electrodes on piezoceramic transducers towards increased parameter sensitivity of impedance}}}, year = {{2015}}, } @misc{13891, author = {{Jurgelucks, Benjamin and Kulshreshtha, Kshitij and Bause, Fabian and Rautenberg, Jens and Unverzagt, Carsten}}, title = {{{On the optimal configuration of triple-ring-electrodes on piezoceramic transducers towards increased parameter sensitivity of impedance}}}, year = {{2015}}, } @misc{21233, author = {{Schulze, Veronika and Schmidt, Stephan and Jurgelucks, Benjamin and Feldmann, Nadine and Claes, Leander}}, title = {{{Optimal experiment design with respect to electrode configurations for a piezoelectric problem}}}, year = {{2021}}, } @inproceedings{6570, author = {{Jurgelucks, Benjamin and Claes, Leander}}, booktitle = {{AD2016 The 7th International Conference on Algorithmic Differentiation}}, location = {{Christ Church, Oxford, United Kingdom}}, pages = {{99--102}}, title = {{{Optimisation of triple-ring-electrodes on piezoceramic transducers using algorithmic differentiation}}}, year = {{2016}}, } @inproceedings{22012, author = {{Claes, Leander and Feldmann, Nadine and Jurgelucks, Benjamin and Schulze, Veronika and Schmidt, Stephan and Walther, Andrea and Henning, Bernd}}, location = {{Nürnberg}}, pages = {{237--238}}, title = {{{Optimised Multi-Electrode Topology for Piezoelectric Material Characterisation}}}, doi = {{10.5162/SMSI2021/A10.1}}, year = {{2021}}, } @article{6571, author = {{Jurgelucks, Benjamin and Claes, Leander and Walther, Andrea and Henning, Bernd}}, issn = {{1055-6788}}, journal = {{Optimization Methods and Software}}, number = {{4-6}}, pages = {{868----888}}, publisher = {{Taylor and Francis Ltd.}}, title = {{{Optimization of triple-ring electrodes on piezoceramic transducers using algorithmic differentiation}}}, doi = {{10.1080/10556788.2018.1435652}}, volume = {{33}}, year = {{2018}}, } @inproceedings{15350, abstract = {{In many different ultrasound applications mirrors are often used to deflect ultrasonic waves. The dimensions of the mirror and the applied materials have an essential influence on the output signal characteristics and the obtained measuring quantities. The extension of mirror geometry is not necessarily associated with a higher reflection coefficient. This can be explained with the aid of coincidence condition. A second criterion aims at the avoidance of the mirror resonance. This two conditions lead to an optimal dimensioning of mirror geometry with given material properties and operation mode, as exemplified for a rectangular mirror.}}, author = {{Unverzagt, Carsten and Rautenberg, Jens and Kehl, Romina and Henning, Bernd}}, booktitle = {{2006 IEEE International Ultrasonics Symposium}}, pages = {{1390--1393}}, title = {{{Optimization of ultrasound reflecting mirrors}}}, year = {{2006}}, } @inproceedings{15488, abstract = {{The continuous refinement of sensor technologies enables the manufacturing industry to capture increasing amounts of data during the production process. As processes take time to complete, sensors register large amounts of time-series-like data for each product. In order to make this data usable, a feature extraction is mandatory. In this work, we discuss and evaluate different network architectures, input pre-processing and cost functions regarding, among other aspects, their suitability for time series of different lengths.}}, author = {{Thiel, Christian and Steidl, Carolin and Henning, Bernd}}, booktitle = {{20. GMA/ITG-Fachtagung. Sensoren und Messsysteme 2019}}, isbn = {{978-3-9819376-0-2}}, keywords = {{Dynamic Time Warping, Feature Extraction, Masking, Neural Networks}}, title = {{{P2.9 Comparison of deep feature extraction techniques for varying-length time series from an industrial piercing press}}}, doi = {{10.5162/SENSOREN2019/P2.9}}, year = {{2019}}, } @inproceedings{14551, author = {{Henning, Bernd}}, title = {{{PC gestützte Entwicklung von Ultraschallsensoren}}}, year = {{2010}}, } @article{37543, author = {{Hetkämper, Tim and Koch, Kevin and Claes, Leander and Henning, Bernd}}, journal = {{tm - Technisches Messen}}, keywords = {{Schlierentechnik}}, number = {{2}}, pages = {{103--112}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Phase-preserving methods to visualise ultrasonic fields with schlieren imaging}}}, doi = {{10.1515/teme-2022-0112}}, volume = {{90}}, year = {{2023}}, } @misc{23462, author = {{Schulze, Veronika and Schmidt, Stephan and Jurgelucks, Benjamin and Feldmann, Nadine and Claes, Leander}}, title = {{{Piezoelectric BC Modeling for Electrode Shapes with OED}}}, year = {{2021}}, } @misc{15328, author = {{Rautenberg, Jens and Ziegler, Horst and Gaugler, Ulrich and Dietz, Gerhard and Unverzagt, Carsten and Kehl, Romina and Henning, Bernd}}, title = {{{Piezosensor zur Temperaturmessung}}}, year = {{2008}}, } @article{15357, author = {{Henning, Bernd and Rautenberg, Jens}}, journal = {{Ultrasonics}}, number = {{44}}, pages = {{e1395--e1399}}, title = {{{Process monitoring using ultrasonic sensor systems}}}, year = {{2006}}, } @misc{12950, author = {{Claes, Leander and Webersen, Manuel}}, publisher = {{GitHub, Inc.}}, title = {{{pyfds 0.1.6 - modular field simulation tool}}}, doi = {{10.5281/ZENODO.2649826}}, year = {{2023}}, } @inproceedings{15388, abstract = {{Nowadays the use of ultrasonic sensors for process control for flow, level or concentration measurement is wide spread. In this application there are high demands for a defined and stable quality of the properties of such ultrasonic sensors. For the detailed investigation and characterization of ultrasonic sensor properties an efficient PC-controlled measuring system has been developed at ifak. In this report this new high performance approach will be presented to make the vibrating ultrasonic sensor surface and also the sound field in front of acoustic sensors in liquids visible.}}, author = {{Henning, Bernd and Prange, Stefan and Dierks, Karsten and Daur, Peter-Christoph}}, location = {{Nürnberg}}, title = {{{Quality inspection and characterisation of ultrasonic sensor properties using a PC-controlled scanning measuring system}}}, volume = {{A8.2}}, year = {{2001}}, } @inproceedings{13647, author = {{Claes, Leander and Johannesmann, Sarah and Baumhögger, Elmar and Henning, Bernd}}, booktitle = {{2019 International Congress on Ultrasonics}}, location = {{Bruges}}, title = {{{Quantification of frequency-dependent absorption phenomena}}}, doi = {{10.1121/2.0001043}}, year = {{2019}}, } @inproceedings{6590, author = {{Nicolai, Marcel and Zeipert, Henning and Lugovtsova, Yevgeniya and Bulling, Jannis and Johannesmann, Sarah and Prager, Jens and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2022}}, location = {{Stuttgart}}, pages = {{1394--1397}}, title = {{{Quantification of the adhesive coupling of layered structures using guided ultrasonic waves}}}, year = {{2022}}, } @inproceedings{26033, author = {{Zeipert, Henning and Johannesmann, Sarah and Nicolai, Marcel and Lugovtsova, Yevgeniya and Prager, Jens and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2021}}, location = {{Wien}}, title = {{{Quantifying the coupling strength of adhesively bonded materials by investigating mode repulsion regions}}}, year = {{2021}}, } @article{15356, author = {{Handel, Peter and Tournier, Adam and Henning, Bernd}}, journal = {{IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control}}, number = {{9}}, pages = {{1461--1467}}, title = {{{Quantum 1/f Effect in Resonant Biochemical Piezoelectric and MEMS Sensors}}}, volume = {{52}}, year = {{2005}}, } @article{18850, abstract = {{

The impact of the recombination mechanisms in luminescent materials is discussed with regard to luminescence based gas-sensing applications and the use of semiconducting materials, as an alternative to organic–metal complexes, is outlined.

}}, author = {{Poeplau, Michael and Ester, Stephan and Henning, Bernd and Wagner, Thorsten}}, issn = {{1463-9076}}, journal = {{Physical Chemistry Chemical Physics}}, title = {{{Recombination mechanisms of luminescence type gas sensors}}}, doi = {{10.1039/d0cp02269a}}, year = {{2020}}, } @inproceedings{15490, author = {{Claes, Leander and Baumhögger, Elmar and Rüther, Torben and Gierse, Jan and Tröster, Thomas and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2020}}, pages = {{1077--1080}}, title = {{{Reduction of systematic measurement deviation in acoustic absorption measurement systems}}}, year = {{2020}}, } @inproceedings{14001, abstract = {{In der Ultraschallakustik besteht häufig die Notwendigkeit die räumliche und zeitliche Ausbreitung von Ultraschall zu charakterisieren. Das Schlierenverfahren ist ein schnelles und nichtinvasives Verfahren zur Visualisierung von Ultraschallfeldern in Flüssigkeiten. Bei diesem Verfahren wird eine ebene elektromagnetische Welle an einer Ultraschallwelle gebeugt. Das Beugungsmuster wird durch ein optisches System in der Fourierebene abgebildet. Um die mittlere Helligkeit in der Darstellung der Ultraschallwellen zu eliminieren, erfolgt eine Ortsfilterung in der Fourierebene. Als Ortsfilter werden in der Regel eine Messerschneide oder eine Punktblende eingesetzt. Hierbei wird ein Teil der Fourierebene ausgeblendet und der unbeeinflusste Anteil in Richtung des Bildaufnahmesensors transmittiert. Der Einsatz solcher Amplitudenfilter hat den Nachteil, dass die Phaseninformation einer Schallwelle in der Abbildung der Ultraschallwelle nicht erfasst wird. Der am Fachgebiet Elektrische Messtechnik der Universität Paderborn entwickelte Schlierenmessplatz ist durch ein variables Amplitudenfilter gekennzeichnet. In diesem Beitrag wird ein Verfahren vorgestellt, wie durch Kombination von unterschiedlichen Filtern die Phaseninformation einer Ultraschallwelle rekonstruiert werden kann. Hierzu werden die mathematischen Grundlagen zur Rekonstruktion der Phase hergeleitet und die ersten Messergebnisse vorgestellt.}}, author = {{Olfert, Sergei and Henning, Bernd}}, pages = {{939--940}}, title = {{{Rekonstruktion der Phaseninformation aus Schlierenaufnahmen}}}, year = {{2012}}, } @inproceedings{6574, author = {{Olfert, Sergei and Claes, Leander and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2014}}, pages = {{541--542}}, title = {{{Rekonstruktion der räumlichen Schallwechseldruckverteilung unter Berücksichtigung der Orthogonalität optischer und akustischer Achsen beim Schlierenverfahren}}}, year = {{2014}}, } @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}}, } @misc{13896, author = {{Olfert, Sergei and Henning, Bernd}}, isbn = {{978-3-939296-08-9}}, pages = {{1560--1561}}, publisher = {{DEGA and {Deutsche Gesellschaft f{\"u}r Akustik e.V}}}, title = {{{Schallfeldcharakterisierung mittels Schlierentechnik}}}, year = {{2015}}, } @misc{15336, abstract = {{Ultraschallsensoren werden heute in der industriellen Messtechnik vielfach eingesetzt, zum Beispiel für die Durchflussmessung, Füllstandmessung, Konzentrationsanalyse, zerstörungsfreie Werkstoffdiagnostik und anderes mehr. Dabei wachsen die Anforderungen hinsichtlich der zu gewährleistenden Messunsicherheit, der Zuverlässigkeit sowie einer erweiterter Funktionalität ständig. Erreichen lassen sich diese Ziele natürlich nur mit Hilfe verbesserter Ultraschallsensoren und optimal gestalteter Messanordnungen. Die permanente Forderung, die Produktentwicklungszeiten sowie die Produktherstellungskosten deutlich zu minimieren, macht den Einsatz moderner Entwicklungswerkzeuge für das Sensordesign unumgänglich. }}, author = {{Henning, Bernd}}, pages = {{40--42}}, title = {{{Schallfeldsimulation für die Ultraschallmesstechnik}}}, year = {{2007}}, } @inproceedings{31331, author = {{Hetkämper, Tim and Claes, Leander and Henning, Bernd}}, booktitle = {{Sensoren und Messsysteme - Beiträge der 21. ITG/GMA-Fachtagung}}, isbn = {{978-3-8007-5835-7}}, location = {{Nürnberg}}, publisher = {{VDE Verlag GmbH}}, title = {{{Schlieren imaging with fractional Fourier transform to visualise ultrasonic fields}}}, year = {{2022}}, } @inproceedings{15347, abstract = {{Um das Schwingungsverhalten eines mit Flüssigkeit gefüllten zylindrischen Stahltanks mit beliebiger Füllhöhe zu modellieren, werden Ansätze aus der Schalentheorie genutzt. Verschiedene analytische Modelle und Vereinfachungen werden gegenübergestellt und für den leeren sowie komplett gefüllten Zylinder gelöst. Zudem wird ein semianalytisches Modell für den teilweise gefüllten Zylinder entworfen. Simulationsergebnisse aus FEM-Simulationen sowie Ergebnisse aus Testmessungen werden den Modellwerten gegenübergestellt.}}, author = {{Kehl, Romina and Rautenberg, Jens and Henning, Bernd}}, location = {{Braunschweig}}, pages = {{407--408}}, title = {{{Schwingungsverhalten eines flüssigkeitsgefüllten Tanks}}}, year = {{2006}}, } @inproceedings{13948, abstract = {{Simulationen mittels der Finiten Element Methode (FEM) sind heute ein fester Bestandteil im Entwicklungsprozess von Ultraschallsystemen. Durch die simulative Ermittlung der transienten Schwingungsvorgänge können Optimierungen bezüglich gewünschter Zielkriterien vorgenommen werden. Hierdurch lassen sich die aufwendige Prototypenfertigung reduzieren und günstige Entwurfspunkte schneller ermitteln.}}, author = {{Unverzagt, Carsten and Henning, Bernd}}, pages = {{95--102}}, title = {{{Sensitivitätssteigerung im Rahmen eines inversen Ansatzes zur Materialparameterbestimmung für Piezokeramiken durch Elektrodenmodifikationen}}}, year = {{2014}}, } @misc{13999, abstract = {{A very promising approach for the ultrasonic identification of highly damping viscoelastic polymers has been proposed by Rautenberg. He uses transmission measurements through hollow cylindrical shaped test samples which are modeled as waveguides. The measurement effect relies on multiple mode-conversions at the waveguide's outer and inner boundaries and is evaluated based on an inverse approach. In this contribution we discuss different signal characteristics of the obtained dispersed signals with respect to their sensitivity to certain material parameters. Based on these sensitivities we propose a multiphase optimization scheme to increase the optimization's convergence.}}, author = {{Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, title = {{{Sensitivity study of signal characteristics for an inverse waveguide based approach of material characterization}}}, year = {{2012}}, } @inproceedings{15342, abstract = {{In der Ultraschallmesstechnik ist der Einsatz des Impuls-Echoverfahrens verbreitet. Wird nur ein Ultraschallwandler eingesetzt, benötigt man für das sequentielle Senden und Empfangen einen Sende-/Empfangsumschalter. Häufig werden aber nicht nur Impulse gesendet, sondern auch sogenannte Bursts, die aus mehreren Wellenzügen bestehen. Die während des Sendebetriebs empfangenen Ultraschallwellen, die z. B. durch Reflexionen von nahe gelegenen Hindernissen entstehen, können bei diesen umschaltenden Systemen nicht ausgewertet werden. In diesem Beitrag wird eine Sensor-Interface-Elektronik vorgestellt, die das gleichzeitige Senden und Empfangen von Ultraschallsignalen mit nur einem Ultraschallwandler erlaubt. Die dazu erforderliche Trennung von Sende- und Empfangssignal wird durch einen Richtkoppler ermöglicht, der mit vergleichsweise geringem technischem Aufwand aus Breitbandübertragern aufgebaut ist. Eine geeignete Dimensionierung für die verkoppelten Übertrager wurde durch die Analyse der zugehörigen Streumatrix dieses Aufbaus gefunden. Die Arbeitsweise sowie die Bedeutung der Anpassung der Tore des Richtkopplers wird anhand der Ankopplung verschiedener Medien an den Wandler erläutert. Die angekoppelte akustische Last beeinflusst dabei auch die elektrischen Eigenschaften des Sensors. Durch den Einsatz dieser Sensorelektronik wird es möglich, Reflexionen in unmittelbarer Nähe der Sensoroberfläche aufzunehmen, ohne dass z. B. Vorlaufkörper eingesetzt werden müssen. Möglichkeiten zur selbsttätigen Abstimmung der Sensorelektronik auf den angeschlossenen Ultraschallwandler bzw. dessen Parameteränderungen werden diskutiert.}}, author = {{Vössing, Torsten and Rautenberg, Jens and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik}}, editor = {{Mehra, Schew-Ram}}, isbn = {{9783980865937}}, publisher = {{Dt. Ges. für Akustik}}, title = {{{Sensorelektronik zur Bestimmung von Reflexionen sensoroberflächennaher Schichten}}}, year = {{2007}}, } @inproceedings{15343, abstract = {{In der Ultraschallmesstechnik ist der Einsatz des Impuls-Echoverfahrens verbreitet. Wird nur ein Ultraschallwandler eingesetzt, benötigt man für das sequentielle Senden und Empfangen einen Sende-/Empfangsumschalter. Häufig werden aber nicht nur Impulse gesendet, sondern auch sogenannte Bursts, die aus mehreren Wellenzügen bestehen. Die während des Sendebetriebs empfangenen Ultraschallwellen, die z. B. durch Reflexionen von nahe gelegenen Hindernissen entstehen, können bei diesen umschaltenden Systemen nicht ausgewertet werden. In diesem Beitrag wird eine Sensor-Interface-Elektronik vorgestellt, die das gleichzeitige Senden und Empfangen von Ultraschallsignalen mit nur einem Ultraschallwandler erlaubt. Die dazu erforderliche Trennung von Sende- und Empfangssignal wird durch einen Richtkoppler ermöglicht, der mit vergleichsweise geringem technischem Aufwand aus Breitbandübertragern aufgebaut ist. Eine geeignete Dimensionierung für die verkoppelten Übertrager wurde durch die Analyse der zugehörigen Streumatrix dieses Aufbaus gefunden. Die Arbeitsweise sowie die Bedeutung der Anpassung der Tore des Richtkopplers wird anhand der Ankopplung verschiedener Medien an den Wandler erläutert. Die angekoppelte akustische Last beeinflusst dabei auch die elektrischen Eigenschaften des Sensors. Durch den Einsatz dieser Sensorelektronik wird es möglich, Reflexionen in unmittelbarer Nähe der Sensoroberfläche aufzunehmen, ohne dass z. B. Vorlaufkörper eingesetzt werden müssen. Möglichkeiten zur selbsttätigen Abstimmung der Sensorelektronik auf den angeschlossenen Ultraschallwandler bzw. dessen Parameteränderungen werden diskutiert.}}, author = {{Vössing, Torsten and Rautenberg, Jens and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik}}, editor = {{Mehra, Schew-Ram}}, isbn = {{9783980865937}}, location = {{Stuttgar}}, publisher = {{Dt. Ges. für Akustik}}, title = {{{Sensorelektronik zur Bestimmung von Reflexionen sensoroberflächennaher Schichten}}}, year = {{2007}}, } @inproceedings{15340, abstract = {{There are a couple of acoustic systems that are well suited for continuous and reliable concentration measurement of liquids, but the reliability is a great challenge: Most systems determine the amplitude ratio of deflected ultrasound bursts at different boundaries as well as the sound velocity of the liquid in order to calculate its acoustic impedance and therewith its density. The problem is the sensitivity of variations of reference material properties as well as abrasion or soiling of the boundaries. This contribution is about a new model-based method that uses the whole surface of an acoustic waveguide as reference boundary. On the one hand the integral over a large boundary decreases influence of small boundary defects. On the other hand it is possible to analyze different modes of sound in the fluid. This redundancy can be used to increase reliability. The decomposition of the received signal in its modal components by means of principle component analysis will be discussed in detail. It will be shown that it is possible to determine the amplitudes of each mode by means of one measured signal at the end of the waveguide, even if the transducer and the electronic components are of very simple kind.}}, author = {{Rautenberg, Jens and Henning, Bernd}}, booktitle = {{Proceedings of the International Congress on Ultrasonics}}, title = {{{Separation of mode-specific signals in a fluid-filled circular waveguide}}}, year = {{2007}}, } @inproceedings{15326, abstract = {{In this contribution it is shown that the modal components of the received signal at the end of an acoustic waveguide can be suppressed or intensified if the two electrodes of a piezo-electric ceramic are shaped in a special way. With this it is possible to measure different signals which can be used to differ between the liquids dissipation and the signal attenuation caused by the waveguide geometry as well as impedance conditions. With the help of the principal component analysis it should be possible to infer the modal amplitudes from the received signals of one ultrasonic transducer and to calculate the acoustic impedance of the liquid that is included in the wave guide.}}, author = {{Rautenberg, Jens and Henning, Bernd}}, isbn = {{978-3-18-092011-5}}, title = {{{Separation und Bewertung verschiedener Moden der Schallausbreitung im akustischen Wellenleiter}}}, year = {{2008}}, } @article{21082, author = {{Itner, Dominik and Gravenkamp, Hauke and Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}}, issn = {{1617-7061}}, journal = {{PAMM}}, title = {{{Simulation of guided waves in cylinders subject to arbitrary boundary conditions for applications in material characterization}}}, doi = {{10.1002/pamm.202000232}}, year = {{2021}}, } @inproceedings{40541, author = {{Itner, D. and Gravenkamp, H. and Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}}, booktitle = {{14th WCCM-ECCOMAS Congress}}, publisher = {{CIMNE}}, title = {{{Simulation of Guided Waves in Cylinders Subject to Arbitrary Boundary Conditions Using the Scaled Boundary Finite Element Method}}}, doi = {{10.23967/wccm-eccomas.2020.307}}, volume = {{700}}, year = {{2021}}, } @inproceedings{15327, abstract = {{This contribution is about different types of sonagram processing and their application for the simultaneous direct and indirect measurement of both the longitudinal and the transversal ultrasound velocities of highly absorbing isotropic synthetic polymers. Therefore, the pulse transmission of an initially longitudinal wave through a hollow cylindrical specimen is investigated experimentally and theoretically.}}, author = {{Rautenberg, Jens and Henning, Bernd}}, location = {{Dresden}}, pages = {{148--151}}, title = {{{Simultaneous direct and indirect measurement of sound velocities}}}, year = {{2008}}, } @inproceedings{15344, abstract = {{In many applications ultrasonic transducers are used for transmitting and receiving ultrasonic waves. Ultrasonic sensor systems meet the practical requirements of industrial applications quite well. Typical sensor applications are for example the measurement of distance and thickness. Especially if only one ultrasonic transceiver and the well-known pulse-echo-method are used, the sensor electronics has to switch from transmitting to receiving mode. This is one of the most limiting properties because the probe can not receive echoes from nearby obstacles or thin material layers. This contribution deals with the development of an electronic interface circuit for ultrasonic sensors allowing transmitting and receiving of acoustic signals simultaneously. There are already several methods to separate the transmitted from the received signal for instance the well-known circulator in the telephone, the differential transformer mentioned by Bradfield [1] or a directional coupler [2]. The directional coupler consists of two broadband transformers linked with each other in such a way that it equally distributes the input power at port one to the third and fourth port, while port two is isolated. This circuit is also known as 3 dB directional coupler and makes it possible to get reference echoes directly from the interface between the sensor and the medium of interest. Several reflectors or multiple sound paths such as used in ultrasonic density measurement systems are unnecessary [3].}}, author = {{Vössing, Torsten and Rautenberg, Jens and Kehl, Romina and Henning, Bernd}}, isbn = {{978-3-9810993-2-4}}, location = {{Nuremberg}}, title = {{{Simultaneous transmitting and receiving with ultrasonic sensors}}}, year = {{2007}}, } @inproceedings{15163, author = {{Feldmann, Nadine and Schulze, Veronika and Jurgelucks, Benjamin and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2020}}, pages = {{1125--1128}}, title = {{{Solving piezoelectric inverse problems using Algorithmic Differentiation}}}, year = {{2020}}, } @misc{6591, author = {{Claes, Leander and Feldmann, Nadine and Henning, Bernd}}, title = {{{Spektrale Verfahren zur Bestimmung der akustischen Absorption in fluiden Medien}}}, year = {{2017}}, } @inproceedings{10042, author = {{Johannesmann, Sarah and Springer, Dimitri and Thiel, Christian and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2019}}, editor = {{Gesellschaft für Akustik e.V., Deutsche}}, location = {{Rostock}}, pages = {{1055--1058}}, publisher = {{Deutsche Gesellschaft für Akustik}}, title = {{{Störeffektunterdrückung in 2D-Messdaten mittels DiscoGAN}}}, volume = {{45}}, year = {{2019}}, } @inproceedings{15348, abstract = {{In spite of the outstanding importance of neuronavigational techniques the neurosurgeon has still highly to rely on his visual as well as tactile sense and his experience in distinguishing tumor tissue from intact brain parenchyma. All the more - as neuronavigation is based on preoperative imaging scans - considerable brain shift may occur during surgery and that will lead to erroneous results. Furthermore the surgeon loses his tactile sense during endoscopic surgery. Therefore control of tissue manipulation is limited today to the fiberoptic image techniques, possibly ensured by neuronavigational supervision or haptic feedback systems. In robotic guided surgery the missing tactile sensing will be particularly crucial. The human sense of touch is a highly complex sensory perception comprising epicritical and propiozeptive information processing. The development of a tool for intraoperative tactile perception will be a highly challenging task to improve the safety during surgery. Different sensor concepts (elasticity probe and resonant piezoelectric sensor) have been set up and adapted to distinguish elasticity differences in soft tissue mimicking gel phantoms. The elasticity probe is based on two leaf springs of different bending stiffness. The two tips of the beams act both on the material to be tested. The two deflections measured by strain gauges are processed in a mathematical model calculating the phantoms' stiffness. In contrast to this differential sensing concept the piezoelectric sensor, which is driven at its resonance, measures stiffness and damping of the phantoms by evaluating frequency or phase shift and amplitude change. Gelatine gels of different concentrations (5{\%}, 10{\%}, 20{\%} of gelatine) have been used for a characterization of sensor elements and their sensitivity to elasticity distinctions. Using the hand-guided elasticity probe the determination of gel elasticity is performed with high reliability. By constant mechanical load the piezoelectric sensor also presents a proportional dependency of tissue elasticity.}}, author = {{Kehl, Romina and Stroop, Ralf and Oliva Uribe, David and Hemsel, Tobias and Henning, Bernd}}, location = {{Hannover}}, title = {{{Tactile sensors for determination of elastic properties of brain tissue mimicking phantoms}}}, year = {{2006}}, } @inbook{17352, author = {{Moritzer, Elmar and Hüttner, Matthias and Henning, Bernd and Webersen, Manuel}}, booktitle = {{Advances in Polymer Processing 2020}}, editor = {{Hopmann, Christian and Dahlmann, Rainer}}, isbn = {{9783662608081}}, location = {{Aachen}}, publisher = {{Springer}}, title = {{{The Influence of Hydrothermal Aging on the Material Properties of Continuous Fiber-Reinforced Thermoplastics and its Non-Destructive Characterization}}}, doi = {{10.1007/978-3-662-60809-8_16}}, year = {{2020}}, } @inproceedings{15385, abstract = {{One of the most widely spread measuring tasks in chemistry or food technology is the continuous determination of fill levels in liquid tanks. The aim of this paper is to present a new contactless and noninvasive measuring method based on ultrasonic time-reversal and correlation techniques. The novel method enables asserted fill levels to be identified and small deviations of them to be calculated even if the direct path from the sensor to the liquid surface is obstructed. This article will present the structure and principle of the measuring system as well as the procedure of signal processing. A simulative approach is used to demonstrate the excitation of a virtual sound source in the liquid and to show both the advantages and limits of the new technique. In addition a simplified model is developed where the solutions of the simulations are applied to.}}, author = {{Henning, Bernd and Rautenberg, Jens and Gulsch, Michael and Klüppel, Stefan}}, booktitle = {{SENSOR~Proceedings}}, publisher = {{AMA Service GmbH}}, title = {{{The Use of Time-Reversal Technology for Level Measurement in Liquid Tanks}}}, year = {{2003}}, } @inproceedings{13878, author = {{Bause, Fabian and Schroder, Andreas and Rautenberg, Jens and Henning, Bernd and Gravenkamp, Hauke}}, booktitle = {{2014 IEEE International Ultrasonics Symposium}}, isbn = {{9781479970490}}, title = {{{Time-causal material modeling in the simulation of guided waves in circular viscoelastic waveguides}}}, doi = {{10.1109/ultsym.2014.0333}}, year = {{2014}}, } @misc{15323, author = {{Henning, Bernd}}, title = {{{Tomografische Ultraschallmessverfahren für die Prozessmesstechnik}}}, year = {{2008}}, }