@article{48053, author = {{Hetkämper, Tim and Claes, Leander and Henning, Bernd}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, keywords = {{Electrical and Electronic Engineering, Instrumentation}}, number = {{s1}}, pages = {{49--54}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Vorzeichenrichtige tomographische Rekonstruktion von Ultraschallfeldern mit Hilfe der Schlierentechnik}}}, doi = {{10.1515/teme-2023-0069}}, volume = {{90}}, year = {{2023}}, } @article{34221, abstract = {{Unter dem Begriff der Auflösung wird für gewöhnlich das kleinste messbare Merkmal eines Messsystems verstanden. In der dimensionellen Computertomografie hingegen haben sich in den vergangenen Jahren mehrere Auflösungskonzepte etabliert, die aufgrund der fehlenden Normung zueinander im Kontrast stehen. In diesem Beitrag werden die drei häufigsten Konzepte, die Voxelgröße, die Ortsauflösung und die metrologische Strukturauflösung in Kürze vorgestellt. Anschließend wird eine Abgrenzung zwischen den Konzepten getroffen und ein Integration der bestehenden Konzepte in ein gemeinsames Amplituden-Wellenlängen Diagramm diskutiert.}}, author = {{Binder, Felix and Hausotte, Tino}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, keywords = {{Electrical and Electronic Engineering, Instrumentation}}, number = {{s1}}, pages = {{20--24}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Über die Abgrenzung von Auflösungskonzepten in der industriellen Computertomografie}}}, doi = {{10.1515/teme-2022-0065}}, volume = {{89}}, year = {{2022}}, } @article{34220, abstract = {{Die Erkennbarkeit von Rissen und geometrischen Qualitätskennwerten von Fügeverbindungen mittels Computertomografie ist von der Interfacestrukturauflösung abhängig, welche mittels geeigneter Prüfkörper untersucht wird. Die Reduktion von Abbildungsartefakten im Bereich von Bauteilzwischenräumen und -oberflächen verbessert deren dimensionelle Erfassbarkeit.}}, author = {{Busch, Matthias and Butzhammer, Lorenz and Hausotte, Tino}}, issn = {{2196-7113}}, journal = {{tm - Technisches Messen}}, keywords = {{Electrical and Electronic Engineering, Instrumentation}}, number = {{s1}}, pages = {{83--88}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Herausforderungen bei computertomografischen Untersuchungen von Fügeverbindungen}}}, doi = {{10.1515/teme-2022-0061}}, volume = {{89}}, year = {{2022}}, } @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{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}}, } @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}}, } @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{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}}, } @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{6552, author = {{Bause, Fabian and Claes, Leander and Webersen, Manuel and Johannesmann, Sarah and Henning, Bernd}}, issn = {{0171-8096}}, journal = {{tm - Technisches Messen}}, number = {{3}}, title = {{{Viskoelastizität und Anisotropie von Kunststoffen: Ultraschallbasierte Methoden zur Materialparameterbestimmung}}}, doi = {{10.1515/teme-2016-0056}}, volume = {{84}}, year = {{2017}}, } @article{6582, author = {{Feldmann, Nadine and Bause, Fabian and Henning, Bernd}}, issn = {{0171-8096}}, journal = {{tm - Technisches Messen}}, number = {{4}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Uncertainty estimation for linearised inverse problems comparing Bayesian inference and a pseudoinverse approach for acoustic transmission measurements}}}, doi = {{10.1515/teme-2016-0022}}, volume = {{84}}, year = {{2016}}, } @article{13881, author = {{Rautenberg, Jens and Bause, Fabian and Henning, Bernd}}, issn = {{0171-8096}}, journal = {{tm - Technisches Messen}}, pages = {{28--37}}, title = {{{Messsystem zur Bestimmung akustischer Kenngrößen stark absorbierender, transversal isotroper Kunststoffe}}}, doi = {{10.1524/teme.2013.0005}}, year = {{2013}}, } @article{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}}, } @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}}, }