@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}}, } @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{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}}, } @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}}, } @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}}, } @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{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}}, } @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{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}}, } @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}}, } @inproceedings{51879, author = {{Poeplau, Michael and Ester, Stephan and Henning, Bernd and Wagner, Thorsten}}, publisher = {{AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf}}, title = {{{Zinkoxid als photostabiler Luminophor zur optischen Sauerstoffdetektion}}}, doi = {{10.5162/sensoren2019/5.2.3}}, year = {{2020}}, } @inbook{24479, author = {{Moritzer, Elmar and Hüttner, M. and Henning, Bernd and Webersen, Manuel}}, booktitle = {{Advances in Polymer Processing 2020}}, 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}}, } @misc{15489, author = {{Claes, Leander and Steidl, Carolin and Hetkämper, Tim and Henning, Bernd}}, publisher = {{Cornell University}}, title = {{{Estimation of acoustic wave non-linearity in ultrasonic measurement systems}}}, doi = {{10.48550/arXiv.2001.05708}}, year = {{2020}}, } @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}}, } @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{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{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{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{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}}, } @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}}, }