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Photo: Paderborn University, Johannes Pauly

Dr.-Ing. Manuel Webersen

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Publications
Dr.-Ing. Manuel Webersen

Measurement Engineering

Former - Research Assistent 11/2014 - 02/2021


Open list in Research Information System

2021

Investigating peculiarities of piezoelectric detection methods for acoustic plate waves in material characterisation applications

L. Claes, H. Schmiegel, C. Grünsteidl, S. Johannesmann, M. Webersen, B. Henning, tm - Technisches Messen (2021)

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.


    Zerstörungsfreie Charakterisierung der elastischen Materialeigenschaften thermoplastischer Polymerwerkstoffe mittels Ultraschall

    M. Webersen, Universitätsbibliothek Paderborn, 2021

    Precise knowledge of material properties is a great concern in the design of technical systems, and in the monitoring of such systems during operation. Therefore, metrological processes are required for materials characterisation with respect to specific physical properties, operational conditions and classes of materials. In the work presented herein, a measurement procedure for the ultrasonic characterization of mechanical properties of homogeneous and fiber-reinforced thermoplastic polymer materials is presented, considering the different degrees of anisotropy. For this, acoustic Lamb waves are excited in a plate-shaped specimen using high-energy laser pulses, and then recorded.Based on the dispersive characteristics of the detected waveguide modes, an inverse procedure is applied to identify the parameters of a linear-elastic material model. Further, a procedure for completely characterising the orthotropy of materials like fiber-reinforced composites using a two-dimensional simulation model is presented. The measurement procedure is verified by examining artificially aged homogeneous polymers and composites, also considering the applicability of results to the quasistatic case. Comparing to the results of corresponding mechanical tensile tests, preconditions and limitations of the procedure are discussed, specifically regarding the assumption of an ideal-elastic material model.


      2020

      Analoge Klangsynthese zur Vermittlung von Grundkenntnissen der Signalverarbeitung an Studierende nicht-technischer Fachrichtungen

      M. Krumme, M. Webersen, L. Claes, Y. Webersen, in: Fortschritte der Akustik - DAGA 2020, 2020, pp. 542-545


      The Influence of Hydrothermal Aging on the Material Properties of Continuous Fiber-Reinforced Thermoplastics and its Non-Destructive Characterization

      E. Moritzer, M. Hüttner, B. Henning, M. Webersen, in: Advances in Polymer Processing 2020, Springer, 2020


      pyfds 0.1.3 - modular field simulation tool

      L. Claes, M. Webersen. pyfds 0.1.3 - modular field simulation tool. 2020.


      Determination of Murnaghan constants of plate-shaped polymers under uniaxial tensile load

      S. Johannesmann, S. Becker, M. Webersen, B. Henning, in: SMSI 2020 - Measurement Science, 2020


      2019

      Akustische Charakterisierung der mechanischen Eigenschaften künstlich gealterter Polymere

      M. Webersen, M. Hüttner, F. Woitschek, E. Moritzer, B. Henning, in: Fortschritte der Akustik - DAGA 2019, 2019


      Characterization of the linear-acoustic material behavior of fiber-reinforced composites using lamb waves

      S. Johannesmann, M. Webersen, J. Düchting, L. Claes, B. Henning, in: 45th Annual Review of Progress in Quantitative Nondestructive Evaluation , 2019


      2018

      Guided ultrasonic waves for determining effective orthotropic material parameters of continuous-fiber reinforced thermoplastic plates

      M. Webersen, S. Johannesmann, J. Düchting, L. Claes, B. Henning, Ultrasonics (2018), 84, pp. 53-62


      Einfluss mechanischer Vorspannung auf das mechanische Materialverhalten von Polymeren

      M. Webersen, S. Johannesmann, T. Brockschmidt, F. Rump, L. Claes, B. Henning, 2018


      Akustische Charakterisierung der richtungsabhängigen elastischen Eigenschaften faserverstärkter Kunststoffe

      M. Webersen, S. Johannesmann, J. Düchting, L. Claes, B. Henning, in: Fortschritte der Akustik - DAGA 2018, 2018, pp. 1263-1266


      An acoustic waveguide-based approach to the complete characterisation of linear elastic, orthotropic material behaviour

      S. Johannesmann, J. Düchting, M. Webersen, L. Claes, B. Henning, tm - Technisches Messen (2018), 2018(85), pp. 478-486


      Acoustic material characterization of prestressed, plate-shaped specimens

      S. Johannesmann, T. Brockschmidt, F. Rump, M. Webersen, L. Claes, B. Henning, in: Sensoren und Messsysteme, VDE Verlag GmbH, 2018, pp. 231-234


      2017

      Evaluating the Influence of 3D-Printing Parameters on Acoustic Material Properties

      A. Jäger, S. Johannesmann, L. Claes, M. Webersen, B. Henning, M. Kupnik, in: 2017 IEEE IUS~Proceedings, 2017


      Inverser Ansatz zur akustischen Charakterisierung plattenförmiger Materialproben

      S. Johannesmann, L. Claes, M. Webersen, B. Henning, in: Fortschritte der Akustik - DAGA 2017, Deutsche Gesellschaft für Akustik e.V. 2017, 2017, pp. 999-1002



      Ultrasonic measurements in the characterization of viscoelasticity and aging of polymers

      F. Bause, L. Claes, M. Webersen, B. Henning, in: PROCEEDINGS -- AMA Conferences 2017, 2017, pp. 414


      Viskoelastizität und Anisotropie von Kunststoffen: Ultraschallbasierte Methoden zur Materialparameterbestimmung

      F. Bause, L. Claes, M. Webersen, S. Johannesmann, B. Henning, tm - Technisches Messen (2017), 84(3)


      Acoustic Material Characterization of Additively Manufactured Components

      L. Claes, A. Jäger, S. Johannesmann, M. Webersen, M. Kupnik, B. Henning, in: PROCEEDINGS -- AMA Conferences 2017, AMA Service GmbH, 2017, pp. 605-610


      2016

      An Approach to Non-Destructive Testing of Aged Polymers

      E. Moritzer, M. Hüttner, B. Henning, M. Webersen, 2016


      Molekularen Schäden auf der Spur

      E. Moritzer, M. Hüttner, B. Henning, M. Webersen, Kunststoffe (2016)(4), pp. 94-96


      Zerstörungsfreie Charakterisierung des hydrothermischen Alterungsverhaltens von Polymeren

      M. Webersen, M. Hüttner, F. Bause, E. Moritzer, B. Henning, 2016, pp. 683-688

      In der zerstörungsfreien Werkstoffprüfung sind bereits zahlreiche Verfahren etabliert, deren Ziel die Detektion makroskopischer Defekt- und Fehlstellen (z.B. Risse, Poren, Fremdeinschlüsse) ist. Insbesondere bei Polymerwerkstoffen muss jedoch auch die Materialalterung auf molekularer Ebene berücksichtigt werden, die sich (zumeist negativ) auf die Materialkenngrößen auswirkt. Gängige Verfahren zur Bestimmung dieser Kenngrößen arbeiten jedoch üblicherweise zerstörend und sind somit beispielsweise für die vorbeugende Instandhaltung oder die Online-Komponentenüberwachung nur eingeschränkt geeignet. In diesem Beitrag wird ein Verfahren zur zerstörungsfreien Charakterisierung des Alterungszustandes von Polymeren vorgestellt. Dazu wird der Zusammenhang zwischen akustisch (zerstörungsfrei, mittels Ultraschall-Transmissionsmessung) bestimmten Kenngrößen und klassisch (zerstörend, z.B. mittels Zugprüfung) bestimmten hydrothermischer Alterung auf das Material Polyamid 6 (PA6) untersucht. Die Ergebnisse Kenngrößen betrachtet. Exemplarisch werden die Auswirkungen zeigen einen engen Zusammenhang zwischen der zerstörend bestimmten Viskositätszahl, die ein Maß für die mittlere Molekülkettenlänge darstellt, und der akustischen Longitudinalwellengeschwindigkeit. Das Molekülkettenabbau (Depolymerisation) bestimmt ist, kann somit auch akustisch und zerstörungsfrei charakterisiert werden. Auf dieser Basis können neuartige, zerstörungsfrei arbeitende Messsysteme entwickelt werden.


        Detecting Molecular Damage

        E. Moritzer, M. Hüttner, B. Henning, M. Webersen, Kunststoffe International (2016)(4), pp. 43-45


        Non-destructive characterization of hygrothermally aged polymers

        E. Moritzer, M. Hüttner, B. Henning, M. Webersen, 2016


        Ultrasonic transmission measurements in the characterization of viscoelasticity utilizing polymeric waveguides

        F. Bause, J. Rautenberg, N. Feldmann, M. Webersen, L. Claes, H. Gravenkamp, B. Henning, Measurement Science and Technology (2016), 27(10)


        Ultraschallbasierte Charakterisierung von gealterten Polymeren

        E. Moritzer, M. Hüttner, B. Henning, M. Webersen, in: Jahresmagazin Kunststofftechnik 2016, 2016, pp. 2-7


        Characterization of Continuous-fiber Reinforced Thermoplastics Using Thermoacoustically Excited Ultrasonic Lamb Waves

        M. Webersen, S. Johannesmann, L. Claes, B. Henning, in: 2016 IEEE IUS~Proceedings, 2016


        2015

        Identification of temperature-dependent model parameters of ultrasonic piezo-composite transducers

        M. Webersen, F. Bause, J. Rautenberg, B. Henning, in: AMA Conferences 2015, 2015, pp. 195-200

        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.




          2014



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