---
_id: '63800'
abstract:
- lang: eng
  text: In this contribution, we address the estimation of the frequency-dependent
    elastic parameters of polymers in the ultrasound range, which is formulated as
    an inverse problem. This inverse problem is implemented as a nonlinear regression-type
    optimization problem, in which the simulation signals are fitted to the measurement
    signals. These signals consist of displacement responses in waveguides, focusing
    on hollow cylindrical geometries to enhance the simulation efficiency. To accelerate
    the optimization and reduce the number of model evaluations and wait times, we
    propose two novel methods. First, we introduce an adaptation of the Levenberg–Marquardt
    method derived from a geometrical interpretation of the least-squares optimization
    problem. Second, we introduce an improved objective function based on the autocorrelated
    envelopes of the measurement and simulation signals. Given that this study primarily
    relies on simulation data to quantify optimization convergence, we aggregate the
    expected ranges of realistic material parameters and derive their distributions
    to ensure the reproducibility of optimizations with proper measurements. We demonstrate
    the effectiveness of our objective function modification and step adaptation for
    various materials with isotropic material symmetry by comparing them with the
    Broyden–Fletcher–Goldfarb–Shanno method. In all cases, our method reduces the
    total number of model evaluations, thereby shortening the time to identify the
    material parameters.
author:
- first_name: Dominik
  full_name: Itner, Dominik
  last_name: Itner
- first_name: Dmitrij
  full_name: Dreiling, Dmitrij
  id: '32616'
  last_name: Dreiling
- first_name: Hauke
  full_name: Gravenkamp, Hauke
  last_name: Gravenkamp
- first_name: Bernd
  full_name: Henning, Bernd
  id: '213'
  last_name: Henning
- first_name: Carolin
  full_name: Birk, Carolin
  last_name: Birk
citation:
  ama: Itner D, Dreiling D, Gravenkamp H, Henning B, Birk C. A modified Levenberg–Marquardt
    method for estimating the elastic material parameters of polymer waveguides using
    residuals between autocorrelated frequency responses. <i>Mechanical Systems and
    Signal Processing</i>. 2026;247:113904. doi:<a href="https://doi.org/10.1016/j.ymssp.2026.113904">https://doi.org/10.1016/j.ymssp.2026.113904</a>
  apa: Itner, D., Dreiling, D., Gravenkamp, H., Henning, B., &#38; Birk, C. (2026).
    A modified Levenberg–Marquardt method for estimating the elastic material parameters
    of polymer waveguides using residuals between autocorrelated frequency responses.
    <i>Mechanical Systems and Signal Processing</i>, <i>247</i>, 113904. <a href="https://doi.org/10.1016/j.ymssp.2026.113904">https://doi.org/10.1016/j.ymssp.2026.113904</a>
  bibtex: '@article{Itner_Dreiling_Gravenkamp_Henning_Birk_2026, title={A modified
    Levenberg–Marquardt method for estimating the elastic material parameters of polymer
    waveguides using residuals between autocorrelated frequency responses}, volume={247},
    DOI={<a href="https://doi.org/10.1016/j.ymssp.2026.113904">https://doi.org/10.1016/j.ymssp.2026.113904</a>},
    journal={Mechanical Systems and Signal Processing}, author={Itner, Dominik and
    Dreiling, Dmitrij and Gravenkamp, Hauke and Henning, Bernd and Birk, Carolin},
    year={2026}, pages={113904} }'
  chicago: 'Itner, Dominik, Dmitrij Dreiling, Hauke Gravenkamp, Bernd Henning, and
    Carolin Birk. “A Modified Levenberg–Marquardt Method for Estimating the Elastic
    Material Parameters of Polymer Waveguides Using Residuals between Autocorrelated
    Frequency Responses.” <i>Mechanical Systems and Signal Processing</i> 247 (2026):
    113904. <a href="https://doi.org/10.1016/j.ymssp.2026.113904">https://doi.org/10.1016/j.ymssp.2026.113904</a>.'
  ieee: 'D. Itner, D. Dreiling, H. Gravenkamp, B. Henning, and C. Birk, “A modified
    Levenberg–Marquardt method for estimating the elastic material parameters of polymer
    waveguides using residuals between autocorrelated frequency responses,” <i>Mechanical
    Systems and Signal Processing</i>, vol. 247, p. 113904, 2026, doi: <a href="https://doi.org/10.1016/j.ymssp.2026.113904">https://doi.org/10.1016/j.ymssp.2026.113904</a>.'
  mla: Itner, Dominik, et al. “A Modified Levenberg–Marquardt Method for Estimating
    the Elastic Material Parameters of Polymer Waveguides Using Residuals between
    Autocorrelated Frequency Responses.” <i>Mechanical Systems and Signal Processing</i>,
    vol. 247, 2026, p. 113904, doi:<a href="https://doi.org/10.1016/j.ymssp.2026.113904">https://doi.org/10.1016/j.ymssp.2026.113904</a>.
  short: D. Itner, D. Dreiling, H. Gravenkamp, B. Henning, C. Birk, Mechanical Systems
    and Signal Processing 247 (2026) 113904.
date_created: 2026-01-29T08:53:42Z
date_updated: 2026-02-02T12:44:47Z
department:
- _id: '49'
doi: https://doi.org/10.1016/j.ymssp.2026.113904
intvolume: '       247'
keyword:
- Material parameter estimation
- Waveguide
- Nonlinear optimization
- Inverse problem
- Least squares
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.sciencedirect.com/science/article/pii/S0888327026000610/pdfft?md5=16e8493b44527f4ab0a6d13f634a01c3&pid=1-s2.0-S0888327026000610-main.pdf
oa: '1'
page: '113904'
project:
- _id: '89'
  name: Vollständige Bestimmung der akustischen Materialparameter von Polymeren
publication: Mechanical Systems and Signal Processing
publication_identifier:
  issn:
  - 0888-3270
publication_status: published
status: public
title: A modified Levenberg–Marquardt method for estimating the elastic material parameters
  of polymer waveguides using residuals between autocorrelated frequency responses
type: journal_article
user_id: '32616'
volume: 247
year: '2026'
...
---
_id: '55159'
abstract:
- lang: eng
  text: "We introduce a method based on Gaussian process regression to identify discrete
    variational principles from observed solutions of a field theory. The method is
    based on the data-based identification of a discrete Lagrangian density. It is
    a geometric machine learning technique in the sense that the variational structure
    of the true field theory is reflected in the data-driven model by design. We provide
    a rigorous convergence statement of the method. The proof circumvents challenges
    posed by the ambiguity of discrete Lagrangian densities in the inverse problem
    of variational calculus.\r\nMoreover, our method can be used to quantify model
    uncertainty in the equations of motions and any linear observable of the discrete
    field theory. This is illustrated on the example of the discrete wave equation
    and Schrödinger equation.\r\nThe article constitutes an extension of our previous
    article  arXiv:2404.19626 for the data-driven identification of (discrete) Lagrangians
    for variational dynamics from an ode setting to the setting of discrete pdes."
author:
- first_name: Christian
  full_name: Offen, Christian
  id: '85279'
  last_name: Offen
  orcid: 0000-0002-5940-8057
citation:
  ama: Offen C. Machine learning of discrete field theories with guaranteed convergence
    and uncertainty quantification.
  apa: Offen, C. (n.d.). <i>Machine learning of discrete field theories with guaranteed
    convergence and uncertainty quantification</i>.
  bibtex: '@article{Offen, title={Machine learning of discrete field theories with
    guaranteed convergence and uncertainty quantification}, author={Offen, Christian}
    }'
  chicago: Offen, Christian. “Machine Learning of Discrete Field Theories with Guaranteed
    Convergence and Uncertainty Quantification,” n.d.
  ieee: C. Offen, “Machine learning of discrete field theories with guaranteed convergence
    and uncertainty quantification.” .
  mla: Offen, Christian. <i>Machine Learning of Discrete Field Theories with Guaranteed
    Convergence and Uncertainty Quantification</i>.
  short: C. Offen, (n.d.).
date_created: 2024-07-10T13:43:50Z
date_updated: 2024-08-12T13:43:32Z
ddc:
- '510'
department:
- _id: '636'
external_id:
  arxiv:
  - '2407.07642'
file:
- access_level: open_access
  content_type: application/pdf
  creator: coffen
  date_created: 2024-07-10T13:39:32Z
  date_updated: 2024-07-10T13:39:32Z
  description: |-
    We introduce a method based on Gaussian process regression to identify discrete
    variational principles from observed solutions of a field theory. The method is based on the data-based identification of a discrete Lagrangian density. It is a geometric machine learning technique in the sense that the variational structure of the true field theory is reflected in the data-driven model by design.
    We provide a rigorous convergence statement of the method.
    The proof circumvents challenges posed by the ambiguity of discrete Lagrangian densities in the inverse problem of variational calculus.
    Moreover, our method can be used to quantify model uncertainty in the equations of motions and any linear observable of the discrete field theory.
    This is illustrated on the example of the discrete wave equation and Schrödinger equation.
    The article constitutes an extension of our previous article for the data-driven identification of (discrete) Lagrangians for variational dynamics from an ode setting to the setting of discrete pdes.
  file_id: '55160'
  file_name: L_Collocation.pdf
  file_size: 4569314
  relation: main_file
  title: Machine learning of discrete field theories with guaranteed convergence and
    uncertainty quantification
file_date_updated: 2024-07-10T13:39:32Z
has_accepted_license: '1'
keyword:
- System identification
- inverse problem of variational calculus
- Gaussian process
- Lagrangian learning
- physics informed machine learning
- geometry aware learning
language:
- iso: eng
oa: '1'
page: '28'
project:
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication_status: submitted
related_material:
  link:
  - description: GitHub
    relation: software
    url: https://github.com/Christian-Offen/Lagrangian_GP_PDE
status: public
title: Machine learning of discrete field theories with guaranteed convergence and
  uncertainty quantification
type: preprint
user_id: '85279'
year: '2024'
...
---
_id: '13892'
abstract:
- lang: eng
  text: 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:
- first_name: Fabian
  full_name: Bause, Fabian
  last_name: Bause
- first_name: Hauke
  full_name: Gravenkamp, Hauke
  last_name: Gravenkamp
- first_name: Jens
  full_name: Rautenberg, Jens
  last_name: Rautenberg
- first_name: Bernd
  full_name: Henning, Bernd
  id: '213'
  last_name: Henning
citation:
  ama: 'Bause F, Gravenkamp H, Rautenberg J, Henning B. Model based sensitivity analysis
    in the determination of viscoelastic material properties using transmission measurements
    through circular waveguides. In: ; 2015:204-207.'
  apa: Bause, F., Gravenkamp, H., Rautenberg, J., &#38; Henning, B. (2015). Model
    based sensitivity analysis in the determination of viscoelastic material properties
    using transmission measurements through circular waveguides (pp. 204–207).
  bibtex: '@inproceedings{Bause_Gravenkamp_Rautenberg_Henning_2015, title={Model based
    sensitivity analysis in the determination of viscoelastic material properties
    using transmission measurements through circular waveguides}, author={Bause, Fabian
    and Gravenkamp, Hauke and Rautenberg, Jens and Henning, Bernd}, year={2015}, pages={204–207}
    }'
  chicago: Bause, Fabian, Hauke Gravenkamp, Jens Rautenberg, and Bernd Henning. “Model
    Based Sensitivity Analysis in the Determination of Viscoelastic Material Properties
    Using Transmission Measurements through Circular Waveguides,” 204–7, 2015.
  ieee: F. Bause, H. Gravenkamp, J. Rautenberg, and B. Henning, “Model based sensitivity
    analysis in the determination of viscoelastic material properties using transmission
    measurements through circular waveguides,” 2015, pp. 204–207.
  mla: Bause, Fabian, et al. <i>Model Based Sensitivity Analysis in the Determination
    of Viscoelastic Material Properties Using Transmission Measurements through Circular
    Waveguides</i>. 2015, pp. 204–07.
  short: 'F. Bause, H. Gravenkamp, J. Rautenberg, B. Henning, in: 2015, pp. 204–207.'
date_created: 2019-10-16T14:23:19Z
date_updated: 2022-01-06T06:51:46Z
department:
- _id: '49'
keyword:
- Sensitivity inverse problem ultrasonic material determination
language:
- iso: eng
page: 204-207
status: public
title: Model based sensitivity analysis in the determination of viscoelastic material
  properties using transmission measurements through circular waveguides
type: conference
user_id: '15911'
year: '2015'
...
---
_id: '13893'
abstract:
- lang: eng
  text: In this contribution, we present an efficient approach for the transient and
    time-causal modeling of guided waves in viscoelastic cylindrical waveguides in
    the context of ultrasonic material characterization. We use the scaled boundary
    finite element method (SBFEM) for efficient computation of the phase velocity
    dispersion. Regarding the viscoelastic behavior of the materials under consideration,
    we propose a decomposition approach that considers the real-valued frequency dependence
    of the (visco-)elastic moduli and, separately, of their attenuation. The modal
    expansion approach is utilized to take the transmitting and receiving transducers
    into account and to propagate the excited waveguide modes through a waveguide
    of finite length. The effectiveness of the proposed simulation model is shown
    by comparison with a standard transient FEM simulation as well as simulation results
    based on the exact solution of the complex-valued viscoelastic guided wave problem.
    Two material models are discussed, namely the fractional Zener model and the anti-Zener
    model; we re-interpret the latter in terms of the Rayleigh damping model. Measurements
    are taken on a polypropylene sample and the proposed transient simulation model
    is used for inverse material characterization. The extracted material properties
    may then be used in computer-aided design of ultrasonic systems.
author:
- first_name: Fabian
  full_name: Bause, Fabian
  last_name: Bause
- first_name: Hauke
  full_name: Gravenkamp, Hauke
  last_name: Gravenkamp
- first_name: Jens
  full_name: Rautenberg, Jens
  last_name: Rautenberg
- first_name: Bernd
  full_name: Henning, Bernd
  last_name: Henning
citation:
  ama: Bause F, Gravenkamp H, Rautenberg J, Henning B. Transient modeling of ultrasonic
    guided waves in circular viscoelastic waveguides for inverse material characterization.
    <i>Measurement Science and Technology</i>. 2015;26(095602 (17pp)). doi:<a href="https://doi.org/10.1088/0957-0233/26/9/095602">10.1088/0957-0233/26/9/095602</a>
  apa: Bause, F., Gravenkamp, H., Rautenberg, J., &#38; Henning, B. (2015). Transient
    modeling of ultrasonic guided waves in circular viscoelastic waveguides for inverse
    material characterization. <i>Measurement Science and Technology</i>, <i>26</i>(095602
    (17pp)). <a href="https://doi.org/10.1088/0957-0233/26/9/095602">https://doi.org/10.1088/0957-0233/26/9/095602</a>
  bibtex: '@article{Bause_Gravenkamp_Rautenberg_Henning_2015, title={Transient modeling
    of ultrasonic guided waves in circular viscoelastic waveguides for inverse material
    characterization}, volume={26}, DOI={<a href="https://doi.org/10.1088/0957-0233/26/9/095602">10.1088/0957-0233/26/9/095602</a>},
    number={095602 (17pp)}, journal={Measurement Science and Technology}, author={Bause,
    Fabian and Gravenkamp, Hauke and Rautenberg, Jens and Henning, Bernd}, year={2015}
    }'
  chicago: Bause, Fabian, Hauke Gravenkamp, Jens Rautenberg, and Bernd Henning. “Transient
    Modeling of Ultrasonic Guided Waves in Circular Viscoelastic Waveguides for Inverse
    Material Characterization.” <i>Measurement Science and Technology</i> 26, no.
    095602 (17pp) (2015). <a href="https://doi.org/10.1088/0957-0233/26/9/095602">https://doi.org/10.1088/0957-0233/26/9/095602</a>.
  ieee: F. Bause, H. Gravenkamp, J. Rautenberg, and B. Henning, “Transient modeling
    of ultrasonic guided waves in circular viscoelastic waveguides for inverse material
    characterization,” <i>Measurement Science and Technology</i>, vol. 26, no. 095602
    (17pp), 2015.
  mla: Bause, Fabian, et al. “Transient Modeling of Ultrasonic Guided Waves in Circular
    Viscoelastic Waveguides for Inverse Material Characterization.” <i>Measurement
    Science and Technology</i>, vol. 26, no. 095602 (17pp), 2015, doi:<a href="https://doi.org/10.1088/0957-0233/26/9/095602">10.1088/0957-0233/26/9/095602</a>.
  short: F. Bause, H. Gravenkamp, J. Rautenberg, B. Henning, Measurement Science and
    Technology 26 (2015).
date_created: 2019-10-16T14:24:43Z
date_updated: 2022-01-06T06:51:46Z
department:
- _id: '49'
doi: 10.1088/0957-0233/26/9/095602
intvolume: '        26'
issue: 095602 (17pp)
keyword:
- viscoelasticity
- ultrasonics
- guided waves
- inverse problem
- scaled boundary finite element method
language:
- iso: eng
publication: Measurement Science and Technology
publication_identifier:
  issn:
  - 0957-0233
status: public
title: Transient modeling of ultrasonic guided waves in circular viscoelastic waveguides
  for inverse material characterization
type: journal_article
user_id: '15911'
volume: 26
year: '2015'
...
