Publications
163 results found
Stender M, Hoffmann N, 2021, bSTAB: an open-source software for computing the basin stability of multi-stable dynamical systems, NONLINEAR DYNAMICS, ISSN: 0924-090X
Chabchoub A, Slunyaev A, Hoffmann N, et al., 2021, The Peregrine Breather on the Zero-Background Limit as the Two-Soliton Degenerate Solution: An Experimental Study, Frontiers in Physics, Vol: 9
<jats:p>Solitons are coherent structures that describe the nonlinear evolution of wave localizations in hydrodynamics, optics, plasma and Bose-Einstein condensates. While the Peregrine breather is known to amplify a single localized perturbation of a carrier wave of finite amplitude by a factor of three, there is a counterpart solution on zero background known as the degenerate two-soliton which also leads to high amplitude maxima. In this study, we report several observations of such multi-soliton with doubly-localized peaks in a water wave flume. The data collected in this experiment confirm the distinctive attainment of wave amplification by a factor of two in good agreement with the dynamics of the nonlinear Schrödinger equation solution. Advanced numerical simulations solving the problem of nonlinear free water surface boundary conditions of an ideal fluid quantify the physical limitations of the degenerate two-soliton in hydrodynamics.</jats:p>
Klein M, Clauss GF, Hoffmann N, 2021, Introducing envelope soliton solutions for wave-structure investigations, OCEAN ENGINEERING, Vol: 234, ISSN: 0029-8018
Neidhardt M, Ohlsen J, Hoffmann N, et al., 2021, Parameter Identification for Ultrasound Shear Wave Elastography Simulation, Current Directions in Biomedical Engineering, Vol: 7
Elasticity of soft tissue is a valuable information to physicians in treatment and diagnosis of diseases. The elastic properties of tissue can be estimated with ultrasound (US) shear wave imaging (SWEI). In US-SWEI, a force push is applied inside the tissue and the resulting shear wave is detected by high-frequency imaging. The properties of the wave such as the shear wave velocity can be mapped to tissue elasticity. Commonly, wave features are extracted by tracking the peak of the shear wave, estimating the phase velocity or with machine learning methods. To tune and test these methods, often simulation data is employed since material properties and excitation can be accurately controlled. Subsequent validation on real US-SWEI data is in many cases performed on tissue phantoms such as gelatine. Clearly, validation performance of these procedures is dependent on the accuracy of the simulated tissue phantom and a thorough comparison of simulation and experimental data is needed. In this work, we estimate wave parameters from 400 US-SWEI data sets acquired in various homogeneous gelatine phantoms. We tune a linear material model to these parameters. We report an absolute percentage error for the shear wave velocity between simulation and phantom experiment of <2.5%. We validate our material model on unknown gelatine concentrations and estimate the shear wave velocity with an error <3.4% for in-range concentrations indicating that our material model is in good agreement with US-SWEI measurements.
Papangelo A, Putignano C, Hoffmann N, 2021, Critical thresholds for mode-coupling instability in viscoelastic sliding contacts, NONLINEAR DYNAMICS, Vol: 104, Pages: 2995-3011, ISSN: 0924-090X
Niedergesass B, Papangelo A, Grolet A, et al., 2021, Experimental observations of nonlinear vibration localization in a cyclic chain of weakly coupled nonlinear oscillators, JOURNAL OF SOUND AND VIBRATION, Vol: 497, ISSN: 0022-460X
- Author Web Link
- Cite
- Citations: 2
Stender M, Adams C, Wedler M, et al., 2021, Explainable machine learning determines effects on the sound absorption coefficient measured in the impedance tubea), JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 149, Pages: 1932-1945, ISSN: 0001-4966
Fontanela F, Vizzaccaro A, Auvray J, et al., 2021, Nonlinear vibration localisation in a symmetric system of two coupled beams, Nonlinear Dynamics, Vol: 103, Pages: 3417-3428, ISSN: 0924-090X
We report nonlinear vibration localisation in a system of two symmetric weakly coupled nonlinear oscillators. A two degree-of-freedom model with piecewise linear stiffness shows bifurcations to localised solutions. An experimental investigation employing two weakly coupled beams touching against stoppers for large vibration amplitudes confirms the nonlinear localisation.
Stender M, Tiedemann M, Spieler D, et al., 2021, Deep learning for brake squeal: Brake noise detection, characterization and prediction, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, Vol: 149, ISSN: 0888-3270
- Author Web Link
- Cite
- Citations: 6
Nitti A, Stender M, Hoffmann N, et al., 2021, Spatially localized vibrations in a rotor subjected to flutter, NONLINEAR DYNAMICS, Vol: 103, Pages: 309-325, ISSN: 0924-090X
- Author Web Link
- Cite
- Citations: 2
Ohlsen J, Neidhardt M, Schlaefer A, et al., 2021, Modelling shear wave propagation in soft tissue surrogates using a finite element‐ and finite difference method, PAMM, Vol: 20, ISSN: 1617-7061
Stender M, Hoffmann N, Papangelo A, 2020, The Basin Stability of Bi-Stable Friction-Excited Oscillators, LUBRICANTS, Vol: 8
- Author Web Link
- Cite
- Citations: 1
Tonazzi D, Passafiume M, Papangelo A, et al., 2020, Numerical and experimental analysis of the bi-stable state for frictional continuous system, NONLINEAR DYNAMICS, Vol: 102, Pages: 1361-1374, ISSN: 0924-090X
- Author Web Link
- Cite
- Citations: 3
Papangelo A, Putignano C, Hoffmann N, 2020, Self-excited vibrations due to viscoelastic interactions, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, Vol: 144, ISSN: 0888-3270
- Author Web Link
- Cite
- Citations: 9
Stender M, Jahn M, Hoffmann N, et al., 2020, Hyperchaos co-existing with periodic orbits in a frictional oscillator, JOURNAL OF SOUND AND VIBRATION, Vol: 472, ISSN: 0022-460X
- Author Web Link
- Cite
- Citations: 9
Hartmann MCN, Polach FVBU, Ehlers S, et al., 2020, Investigation of Nonlinear Wave-Ice Interaction Using Parameter Study and Numerical Simulation, JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING-TRANSACTIONS OF THE ASME, Vol: 142, ISSN: 0892-7219
Klein M, Dudek M, Clauss GF, et al., 2020, On the Deterministic Prediction of Water Waves, FLUIDS, Vol: 5
- Author Web Link
- Cite
- Citations: 7
Jahn M, Stender M, Tatzko S, et al., 2020, The extended periodic motion concept for fast limit cycle detection of self-excited systems, COMPUTERS & STRUCTURES, Vol: 227, ISSN: 0045-7949
- Author Web Link
- Cite
- Citations: 4
Wollmann T, Dannemann M, Langkamp A, et al., 2020, Combined experimental-numerical approach for the 3D vibration analysis of rotating composite compressor blades: An introduction
© CCM 2020 - 18th European Conference on Composite Materials. All rights reserved. As compressor blades are subjected to highly dynamic loads, there is a particular interest in determining their modal properties under operating condition. Furthermore, intensive research is conducted for the development of fibre-reinforced epoxy blades due to the high specific stiffness and strength as well as the high damping of composite materials. Traditional modal analysis techniques are state of the art to determine the vibration behaviour of non-rotating/stationary blades, where some new approaches show the vibration analysis of rotating blades. These approaches for rotating structures have the disadvantage, that either the excitation or the measurement method are influencing the dynamic behaviour of the investigated structure or the method itself cannot be applied for composite materials. Other techniques do not allow a continuous or full-field measurement of the rotating structure. To determine the vibration behaviour of rotating composite compressor blades, a combined experimental-numerical approach is introduced. Therefore, an experimental system for the vibration excitation and a 3-dimensional determination of the vibration behaviour of rotating components are presented. An overview of the main addressed research topics is given.
Stender M, Hoffmann N, 2020, Deep learning for predicting brake squeal, International Conference on Noise and Vibration Engineering (ISMA) / International Conference on Uncertainty in Structural Dynamics (USD), Publisher: KATHOLIEKE UNIV LEUVEN, DEPT WERKTUIGKUNDE, Pages: 3327-3337
Shiroky IB, Papangelo A, Hoffmann N, et al., 2020, Nucleation and propagation of excitation fronts in self-excited systems, PHYSICA D-NONLINEAR PHENOMENA, Vol: 401, ISSN: 0167-2789
- Author Web Link
- Cite
- Citations: 4
Wollmann T, Dannemann M, Langkamp A, et al., 2020, Combined experimental-numerical approach for the 3D vibration analysis of rotating composite compressor blades: An introduction
© CCM 2020 - 18th European Conference on Composite Materials. All rights reserved. As compressor blades are subjected to highly dynamic loads, there is a particular interest in determining their modal properties under operating condition. Furthermore, intensive research is conducted for the development of fibre-reinforced epoxy blades due to the high specific stiffness and strength as well as the high damping of composite materials. Traditional modal analysis techniques are state of the art to determine the vibration behaviour of non-rotating/stationary blades, where some new approaches show the vibration analysis of rotating blades. These approaches for rotating structures have the disadvantage, that either the excitation or the measurement method are influencing the dynamic behaviour of the investigated structure or the method itself cannot be applied for composite materials. Other techniques do not allow a continuous or full-field measurement of the rotating structure. To determine the vibration behaviour of rotating composite compressor blades, a combined experimental-numerical approach is introduced. Therefore, an experimental system for the vibration excitation and a 3-dimensional determination of the vibration behaviour of rotating components are presented. An overview of the main addressed research topics is given.
Wollmann T, Dannemann M, Langkamp A, et al., 2020, Combined experimental-numerical approach for the 3D vibration analysis of rotating composite compressor blades: An introduction
As compressor blades are subjected to highly dynamic loads, there is a particular interest in determining their modal properties under operating condition. Furthermore, intensive research is conducted for the development of fibre-reinforced epoxy blades due to the high specific stiffness and strength as well as the high damping of composite materials. Traditional modal analysis techniques are state of the art to determine the vibration behaviour of non-rotating/stationary blades, where some new approaches show the vibration analysis of rotating blades. These approaches for rotating structures have the disadvantage, that either the excitation or the measurement method are influencing the dynamic behaviour of the investigated structure or the method itself cannot be applied for composite materials. Other techniques do not allow a continuous or full-field measurement of the rotating structure. To determine the vibration behaviour of rotating composite compressor blades, a combined experimental-numerical approach is introduced. Therefore, an experimental system for the vibration excitation and a 3-dimensional determination of the vibration behaviour of rotating components are presented. An overview of the main addressed research topics is given.
Stender M, Di Bartolomeo M, Massi F, et al., 2019, Revealing transitions in friction-excited vibrations by nonlinear time-series analysis, NONLINEAR DYNAMICS, Vol: 98, Pages: 2613-2630, ISSN: 0924-090X
- Author Web Link
- Cite
- Citations: 9
Stender M, Tiedemann M, Hoffmann N, 2019, Energy harvesting below the onset of flutter, JOURNAL OF SOUND AND VIBRATION, Vol: 458, Pages: 17-21, ISSN: 0022-460X
- Author Web Link
- Cite
- Citations: 2
Stender M, Oberst S, Tiedemann M, et al., 2019, Complex machine dynamics: systematic recurrence quantification analysis of disk brake vibration data, NONLINEAR DYNAMICS, Vol: 97, Pages: 2483-2497, ISSN: 0924-090X
- Author Web Link
- Cite
- Citations: 11
Gnanasambandham C, Stender M, Hoffmann N, et al., 2019, Multi-scale dynamics of particle dampers using wavelets: Extracting particle activity metrics from ring down experiments, JOURNAL OF SOUND AND VIBRATION, Vol: 454, Pages: 1-13, ISSN: 0022-460X
- Author Web Link
- Cite
- Citations: 4
Stender M, Tiedemann M, Hoffmann L, et al., 2019, Determining growth rates of instabilities from time-series vibration data: Methods and applications for brake squeal, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, Vol: 129, Pages: 250-264, ISSN: 0888-3270
- Author Web Link
- Cite
- Citations: 9
Chabchoub A, Hoffmann N, Tobisch E, et al., 2019, Drifting breathers and Fermi-Pasta-Ulam paradox for water waves, WAVE MOTION, Vol: 90, Pages: 168-174, ISSN: 0165-2125
- Author Web Link
- Cite
- Citations: 4
Didonna M, Stender M, Papangelo A, et al., 2019, Reconstruction of Governing Equations from Vibration Measurements for Geometrically Nonlinear Systems, LUBRICANTS, Vol: 7
- Author Web Link
- Cite
- Citations: 4
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.