Ändra sökning
Avgränsa sökresultatet
123 51 - 100 av 110
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51.
    Lopez Arteaga, Ines
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg. Department of Mechanical Engineering, Eindhoven University of Technology.
    Vinken, Esther
    Eindhoven University of Technology.
    Example of good practice of a learning environment with a classroom response system in a mechanical engineering bachelor course2013Ingår i: European Journal of Engineering Education, ISSN 0304-3797, E-ISSN 1469-5898, nr 6, s. 652-660Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Results of a successful pilot study are presented, in which quizzes are introduced in a second year bachelor course for mechanical engineering students. The pilot study course entailed the basic concepts of mechanical vibrations in complex, realistic structures. The quiz is held weekly using a SharePoint application. The purpose of the quizzes is to repeat important course material, give instantaneous feedback (i.e. formative assessment), stimulate peer instruction and, as a consequence, increase the students’ comprehension of the basic concepts taught in the course so that their deeper understanding of the subject matter improves. Students can earn half a point bonus, on a scale from 0 to 10, on top of their exam mark if they correctly answer 55% of all the quiz questions. The efficacy of the pilot study is determined by investigating the percentage of students that pass the course on their first attempt, i.e. the first time pass rate, and asking students for feedback through questionnaires. The first time pass rate of the students in the pilot study groups has, on average, increased significantly in comparison to groups in which the quizzes are not performed. Students indicated that the feedback from the quizzes helps them to identify gaps in their knowledge. Therefore, the pilot study is considered effective.

  • 52.
    Lundberg, Oskar E.
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Nordborg, Anders
    Arteaga, Ines Lopez
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design. Eindhoven Univ Technol, Netherlands.
    The influence of surface roughness on the contact stiffness and the contact filter effect in nonlinear wheel-track interaction2016Ingår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 366, s. 429-446Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A state-dependent contact model including nonlinear contact stiffness and nonlinear contact filtering is used to calculate contact forces and rail vibrations with a time-domain wheel-track interaction model. In the proposed method, the full three-dimensional contact geometry is reduced to a point contact in order to lower the computational cost and to reduce the amount of required input roughness-data. Green's functions including the linear dynamics of the wheel and the track are coupled with a point contact model, leading to a numerically efficient model for the wheel-track interaction. Nonlinear effects due to the shape and roughness of the wheel and the rail surfaces are included in the point contact model by pre-calculation of functions for the contact stiffness and contact filters. Numerical results are compared to field measurements of rail vibrations for passenger trains running at 200 kph on a ballast track. Moreover, the influence of vehicle pre-load and different degrees of roughness excitation on the resulting wheel-track interaction is studied by means of numerical predictions.

  • 53.
    Lundberg, Oskar
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Finnveden, Svante
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Björklund, Stefan
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Pärssinen, M.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    A nonlinear state-dependent model for vibrations excited by roughness in rolling contacts2015Ingår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 345, nr 9, s. 197-213Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A state-dependent method to model contact nonlinearities in rolling contacts is proposed. By pre-calculation of contact stiffness and contact filters as functions of vertical relative displacement, a computationally efficient modelling approach based on a moving point force description is developed. Simulations using the state-dependent model have been analysed by comparison with measurements. Results from the investigated case consisting of a steel ball rolling over a steel beam having two different degrees of roughness - show good agreement between nonlinear simulations and measured beam vibrations. The promising results obtained with the proposed method are potentially applicable to wheel rail interaction and rolling element bearings.

  • 54.
    Lundberg, Oskar
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Finnveden, Svante
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Björklund, Stefan
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Non-linear contact forces for beam/ball-interaction and its influence on the dynamic response of the beam2013Ingår i: 42nd International Congress and Exposition on Noise Control Engineering 2013, INTER-NOISE 2013: Noise Control for Quality of Life, OAL-Osterreichischer Arbeitsring fur Larmbekampfung , 2013, s. 238-247Konferensbidrag (Refereegranskat)
    Abstract [en]

    A well-defined rolling contact problem is studied with the intention to cover interesting aspects of tyre-road contact modeling and rolling contact in general. More specifically, the dynamic response in a steel beam caused by a steel ball rolling over it is studied by theoretical modeling of the beam- And ball dynamics as well as the contact forces. Validation of the dynamic response simulations is achieved by comparison with measurements. The contact model is shown to be greatly dependent on an accurate estimate of the real contact stiffness. A method to estimate the contact stiffness which leads to good accuracy in dynamic response simulations is presented. Although the contact stiffness is significantly lower for rubber- Asphalt interaction than for steel-steel contact, the results give useful insight for tyre-road contact modeling.

  • 55.
    Lundberg, Oskar
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Finnveden, Svante
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Björklund, Stefan
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Non-linear contact stiffness and dynamic contact filter for rolling contacts2014Ingår i: FISITA 2014 World Automotive Congress - Proceedings, FISITA , 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Rolling contacts present in passenger cars such as in bearings and transmission elements are sources of noise and vibration, principally for interior comfort concerns. Moreover, tyre/road noise is the main source of road traffic noise which in turn leads to sleep disturbance and annoyance. In order to simulate friction losses as well as generated noise and vibrations in any rolling contact, it is crucial to have a correct description of the dynamic excitation caused by the roughness of the surfaces in contact. In this paper, a state-dependent modelling approach previously proposed by the authors is applied to a well-defined steel-steel rolling contact. A parametric study investigating the influence of rolling speed on contact conditions is performed, indicating the limits for the use of linear point force expressions for the rolling contact investigated. The state-dependent method is based on pre-calculation of contact stiffness and contact filtering as functions of vertical relative displacement. This leads to a computationally efficient way to include the influence of surface roughness and shape of the contacting bodies in a point force expression. Only vertical contact forces are studied within the scope of this work. Tangential friction forces are likely to affect the resulting vibrations and should therefore be further studied. 

  • 56.
    Lundberg, Oskar
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Kari, Leif
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    A compact internal drum test rig for measurements of rolling contact forces between a single tread block and a substrate2017Ingår i: Measurement, ISSN 0263-2241, E-ISSN 1873-412X, Vol. 103, s. 370-378Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel test rig design is presented which enables detailed studies of the three force components generated in the impact and release phase of rolling contact between a tyre tread block and a substrate. The design of the compact internal drum test rig provides realistic impact and release angles for the tread block-substrate contact and enables force measurements at high rolling speeds with a high signal-to-noise ratio. Measurements of the rolling contact forces are presented for different values of rolling velocity, static pre-load and acceleration. It is demonstrated that this test rig provides results which contribute to the understanding of tyre road interaction and can be used as input to modelling-based development of both tyres and roads aiming for improved handling, safety, energy efficiency and comfort.

  • 57.
    Lundberg, Oskar
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design. Eindhoven University of Technology, The Netherlands.
    Kari, Leif
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    A compact internal drum test rig for measurements of rolling contact forces between a single treadblock and a substrateManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    A novel test rig design is presented which enables detailed studies of the three force components generated in the impact and release phase of rolling contact between a tyre tread block and a substrate. The design of the compact internal drum test rig provides realistic impact and release angles for the tread block-substrate contact and enables force measurements at high rolling speeds with a high signal-to-noise ratio. Measurements of the rolling contact forces are presented for different values of rolling velocity, static pre-load and acceleration. It is demonstrated that this test rig provides results which contribute to the understanding of tyre--road interaction and can be used as input to modelling-based development of both tyres and roads aiming for improved handling, safety, energy efficiency and comfort.

  • 58.
    Lundberg, Oskar
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Nordborg, A.
    Finnveden, Svante
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Estimation of nonlinearities in the wheel-rail rolling noise generation process2014Ingår i: Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics, 2014, s. 3485-3496Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The dynamics of wheel-rail interaction is predicted using a time-domain rolling contact model and a state-dependent method to model nonlinear contact forces in the wheel-rail interaction. Contact stiffness and contact filters are pre-calculated as functions of the vertical wheel-rail relative displacement (state-dependency) using three-dimensional surface data in quasi-static contact computations. By including the state-dependent functions in time-domain prediction of wheel-rail interaction, a computationally efficient method to include nonlinear effects is obtained. Results from predictions of contact forces as well as rail vibrations are presented for two conditions; first, both wheel and rail have surface roughness of broadband character and secondly, a rail corrugation is simulated by superimposing a sinusoidal component on the broadband rail roughness. For a train speed of 200 kph, the contact forces and the dynamic response of the rail exhibit nonlinear contact conditions for both the broadband roughness case as well as for the case where a rail corrugation is simulated.

  • 59.
    Manzari, Luca
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Göransson, Peter
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Cuenca, Jacques
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Fordonsdynamik. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    A fully automated high-speed optical rig for in vacuo, full field, non-contact vibration measurements for viscoelastic, anisotropic materials2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, a setup for measuring the three-dimensional displacement field of a test object un-dergoing controlled dynamic excitation in a vacuum chamber is presented. The setup has beendesigned with porous materials in mind, yet is suitable for the measurement of anisotropic vis-coelastic solids in general. To achieve non-contact data acquisition, a stereo high-speed camerasystem measures the displacement of the foundation and of the test object. A laser Doppler vi-brometer is used before the actual measurement to choose an excitation level that maximizes thesignal-to-noise ratio while allowing to ensure that the test object is fully relaxed and stable at thebeginning of every measurement. The setup, comprising both commercial and in-house hardwareand software solutions, addresses the challenges of measuring in vacuum with non-contact tech-niques. All these aspects are discussed in the current paper, and preliminary results are presented.The ultimate objective is to estimate the dynamic properties of a material using inverse methodsand the data obtained.

  • 60.
    Manzari, Luca
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Göransson, Peter
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Cuenca, Jacques
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Toward fully anisotropic viscoelastic material models using an automated high-speed optical rig2018Ingår i: 13TH INTERNATIONAL CONFERENCE ON VIBRATION MEASUREMENTS BY LASER AND NONCONTACT TECHNIQUES, 2018 / [ed] Tomasini, E P, IOP PUBLISHING LTD , 2018, artikel-id 012003Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes some of the algorithms that are employed in the post-processing of the data obtained from an automated high-speed optical rig. The setup, entirely designed by some of the authors, is used for measuring the full field displacement in time of anisotropic viscoelastic solids undergoing controlled dynamic excitation. The setup main goal is to provide complex transfer functions relating the three-dimensional sinusoidal displacement on the surface of the sample to the sinusoidal motion of the foundation, suitable for the inverse estimation of the dynamic properties of the material under analysis. The complete automation of the measurement process aims at maximizing repeatability and signal-to-noise ratio. In particular, a stereo high-speed camera system is responsible for the actual measurement, while a laser Doppler vibrometer is used for a preliminary autoranging procedure and for data validation. The camera system does not directly output the high-quality data that is needed for a successful, physically meaningful inverse estimation. Hence, here the algorithms described in this paper come into play. Since digital image correlation (DIC) may fail in some frames or in some regions of the pictures, a mask is applied and calculated for every measurement run to preserve information only where the success rate of the DIC algorithm is higher than a specified threshold. The sample is mounted on a foundation whose sides are flat: random sample consensus (RANSAC) and principal component analysis (PCA) are used to respectively eliminate outliers and find the best fitting plane to the foundation side - the measured displacement field can then be expressed in a local coordinate system, truly relative to the foundation. The transfer functions are now obtained in two steps: first an optimizer is used to fit a cosine to all the measured displacement time-series, then the complex amplitudes representing the motion of the sample faces are divided by the average of the complex amplitudes representing the motion of the foundation.

  • 61.
    Manzari, Luca
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Mao, Huina
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Göransson, Peter
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Cuenca, Jacques
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. Siemens Industry Software, Leuven Belgium.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Experimental-numerical methods for inverse characterization of the anisotropic-anelastic properties of porous materials, based on dynamic Digital Image Correlation2018Ingår i: Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics, 2018, s. 687-695Konferensbidrag (Refereegranskat)
    Abstract [en]

    One of the major challenges in accurately modeling poroelastic materials is the choice of the parametersrequired for their modeling, immediately followed by the practical difficulty in obtaining them. The direc-tional dependencies of the physical properties further complicate the task of designing experimental setupscapable of providing the macroscopic properties. In the work presented here, the focus has been set on theacquisition of high quality displacement data by means of two high-speed cameras and 3D Digital ImageCorrelation. The obtained displacement field, is fed into a general inverse formulation which is guided by anoptimization tool that minimizes the difference between the predicted and the measured data. As a minimumis found, the corresponding parameters are interpreted as material properties for a certain physical model.The solutions for each iteration are calculated with numerical prediction tools, in the cases discussed herethe finite element method, where it must be ascertained that the numerical errors are kept to a minimal level

  • 62. Moers, E. M. T.
    et al.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. Eindhoven University of Technology, Netherlands .
    van Dalen, P. L.
    Scholte, R.
    Nijmeijer, H.
    Detection of plate vibration modes by means of Near-field Acoustic Holography in the presence of reflective surfaces2012Ingår i: International Conference on Noise and Vibration Engineering 2012, ISMA 2012, including USD 2012: International Conference on Uncertainty in Structure Dynamics, Katholieke Universiteit Leuven , 2012, Vol. 5, s. 3571-3584Konferensbidrag (Refereegranskat)
    Abstract [en]

    A numerical and experimental study is presented on the influence of reflections on the reconstruction accuracy of the surface velocity of vibrating plates by means of Fourier-based Planar Near-field Acoustic Holography (PNAH) and a single-layer microphone array. At low frequencies (well below coincidence), it is shown that the effect of the presence of the reflective surface on the reconstruction depends on the source. When measuring close to the source, the classical PNAH transformation, based on the free-field radiation assumption, provides a good quantitative reconstruction of the surface vibration velocity. The effectiveness of a modified propagator is investigated which includes the effect of reflections on the inverse propagation from measured pressure at the hologram plane to surface vibration velocity at the source plane. This is done by simulations and measurements for sources that differ in velocity profile and size and that are radiating well below coincidence. Measurements are performed for a free plate in a large baffle in front of a granite block which is less than one acoustic wavelength apart.

  • 63.
    Peerlings, Luck
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Boij, Susann
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Bodén, Hans
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Arteaga, Ines Lopez
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Aero-acoustic characterization of the sudden area expansion2014Ingår i: 21st International Congress on Sound and Vibration 2014, ICSV 2014, 2014, s. 2174-2181Konferensbidrag (Refereegranskat)
    Abstract [en]

    In combustion devices, thermo-acoustic instabilities are often encountered and are formed by the complex interaction between acoustics, hydrodynamics and combustion. A common geometrical feature found in these devices is the sudden area expansion. Downstream of the area expansion a recirculation zone is formed together with an unstable shear layer when flow is present. This shear layer creates a pathway for interactions between the acoustic and the hydrodynamic field and this interaction could be a precursor for thermo-acoustic instabilities. The work presented here takes a step to gain more insight into these interactions by experimentally investigating the aero-acoustic properties of a sudden area expansion with mean flow. The aero-acoustic properties are characterized by a linear two port model and the scattering matrix representation is used to relate the state variables up-and downstream of the area expansion. The scattering coefficients of the area expansion have been determined for frequencies up to the first cut on frequency of the duct system and for a range of subsonic flow speeds. The measurements have been performed by applying a stepped sine excitation as sound excitation and by using the multi-microphone method.

  • 64. Ruty, N.
    et al.
    Cisonni, J.
    Pelorson, X.
    Van Hirtum, A.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Hirschberg, A.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Experimental validation of some additional issues in physical vocal folds models2005Ingår i: Forum Acusticum 2005 / [ed] EAA,, 2005Konferensbidrag (Övrigt vetenskapligt)
  • 65. Ruty, N.
    et al.
    Pelorson, X.
    Van Hirtum, A.
    Lopez-Arteaga, Ines
    Eindhoven University of Technology.
    Hirschberg, A.
    An in vitro setup to test the relevance and the accuracy of low-order vocal folds models2007Ingår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 121, nr 1, s. 479-490Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An experimental setup and human vocal folds replica able to produce self-sustained oscillations are presented. The aim of the setup is to assess the relevance and the accuracy of theoretical vocal folds models. The applied reduced mechanical models are a variation of the classical two-mass model, and a simplification inspired on the delayed mass model for which the coupling between the masses is expressed as a fixed time delay. The airflow is described as a laminar flow with flow separation. The influence of a downstream resonator is taken into account. The oscillation pressure threshold and fundamental frequency are predicted by applying a stability analysis to the mechanical models. The measured frequency response of the mechanical replica together with the initial (rest) area allows us to determine the model parameters (spring stiffness, damping, geometry, masses). Validation of theoretical model predictions to experimental data shows the relevance of low-order models in gaining a qualitative understanding of phonation. However, quantitative discrepancies remain large due to an inaccurate estimation of the model parameters and the crudeness in either flow or mechanical model description. As an illustration it is shown that significant improvements can be made by accounting for viscous flow effects.

  • 66. Scholte, R.
    et al.
    Lopez Arteaga, Ines
    Eindhoven University of Technology.
    Bert Roozen, N.
    Nijmeijer, H.
    Truncated aperture extrapolation for Fourier-based near-field acoustic holography by means of border-padding2009Ingår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 125, nr 6, s. 3844-3854Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although near-field acoustic holography (NAH) is recognized as a powerful and extremely fast acoustic imaging method based on the inverse solution of the wave-equation, its practical implementation has suffered from problems with the use of the discrete Fourier transformation (DFT) in combination with small aperture sizes and windowing. In this paper, a method is presented that extrapolates the finite spatial aperture before the DFT is applied, which is based on the impulse response information of the known aperture data. The developed method called linear predictive border-padding is an aperture extrapolation technique that greatly reduces leakage and spatial truncation errors in planar NAH (PNAH). Numerical simulations and actual measurements on a hard-disk drive and a cooling fan illustrate the low error, high speed, and utilization of border-padding. Border-padding is an aperture extrapolation technique that makes PNAH a practical and accurate inverse near-field acoustic imaging method.

  • 67. Scholte, R.
    et al.
    Lopez Arteaga, Ines
    Eindhoven University of Technology.
    Roozen, N. B.
    Nijmeijer, H.
    Experimental application of high precision k-space filters and stopping rules for fully automated near-field acoustical holography2008Ingår i: International Journal of Acoustics and Vibration, ISSN 1027-5851, Vol. 13, nr 4, s. 157-164Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In general, inverse acoustics problems are ill-posed. Without proper regularization action taken noisy measurements result in an increasingly disturbed solution of the inverse acoustics wave equation as the distance from the measurement plane to the desired source grows. Two distinctive steps take place in the regularization process for planar near-field acoustical holography (PNAH): first, a low-pass filter function is defined and secondly a stopping rule is applied to determine the parameter settings of the filter. In acoustical imaging practice, it turns out to be very hard to determine the right filter for a certain case, ideally by means of an automatic search for the (near-) optimal parameters. This paper presents the practical application of a novel automated method that combines fitted filters for a broad number of possible experimental sources combined with highly efficient stopping rules by taking advantage of k-space. Also, a number of well-known and newly developed filter functions and stopping rules are discussed and compared with one another. Results based on actual measurements demonstrate the effectiveness, applicability, and precision of the fully implemented and automated regularization process for PNAH. Practical results even show acoustic source visualization below one millimeter primarily by successful application of k-space regularization. Implementations include modifications of Tikhonov, exponential and truncation low-pass filters, L-curve Generalised Cross-Validation (GCV) and the novel Cut-Off and Slope (COS) parameter selection methods for PNAH COS iteration in combination with either a modified exponential or Tikhonov low-pass filter results in an automated selection of the regularization parameters and eventually a fully automated PNAH system.

  • 68. Scholte, R.
    et al.
    Lopez Arteaga, Ines
    Eindhoven University of Technology.
    Roozen, N. B.
    Nijmeijer, H.
    Wavenumber domain regularization for near-field acoustic holography by means of modified filter functions and cut-off and slope iteration2008Ingår i: Acta Acoustica united with Acustica, ISSN 1610-1928, E-ISSN 1861-9959, Vol. 94, nr 3, s. 339-348Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Planar Near-field Acoustic Holography (PNAH) is an acoustic imaging method based on the inverse solution of the wave equation. Wavenumber domain low-pass filtering is an essential operation in the PNAH process. An increasingly higher wavenumber filter cut-off results in a "blow-up" of the inverse solution, which is a characteristic of an ill-posed problem. On the other hand, lower cut-off wavenumbers result in spatial acoustic data at very low resolution, where highly detailed information is discarded. Thus, an optimal solution for the cut-off wavenumber somewhere in between is needed. This paper introduces two modified filter functions, namely a modified exponential and a modified Tikhonov filter, that are specifically designed for application in PNAH and compares them with a number of more general applied filter functions. Regularization methods are introduced that exploit the k-space to obtain near-optimal low-pass filter parameter selection at high computational efficiency. These filter functions are discussed and their parameters are selected by k-space application of L-curve, Generalised Cross-Validation and the newly introduced and well-applicable Cut-Off and Slope iteration. Simulations of various sources show that the optimal regularization method is highly dependent on the type of source, the spatial distribution and measurement noise. Finally, a robust regularization strategy is proposed which automatically produces high quality results for a wide range of practical conditions.

  • 69.
    Scholte, R.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Quantitative and qualitative verification of pressure and velocity based near-field acoustic holography2006Ingår i: Proceedings of the Thirtheenth International Congress on Sound and Vibration (ICSV13) / [ed] J. Eberhardsteiner, H.A. Mang, and H. Waubke, 2006Konferensbidrag (Övrigt vetenskapligt)
  • 70.
    Scholte, R.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Applications of Near-field Acoustic Holography on Small Apertures2008Ingår i: Proceedings of Acoustics 2008, 2008Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Small, finite measurement apertures are a major impediment for accurate and fast application of near-field acoustic holography (NAH). In theory, FFT-based NAH methods are very powerful and acquire extremely fast inverse calculations of the sound field. However, in practice the usually small amount of sensors in a measurement array limit the possibilities of classical implementations of NAH, especially near the edges of the array or measurement grid. An alternative method to, for example, spatial windowing, patch NAH, SONAH, etc. is the recently introduced border-padding technique. This method makes it possible to apply FFT-based NAH with a large increase of accuracy compared to the original methods, specifically at the measurement grid edges, while maintaining the high speed of the inverse process PNAH is known for. This work focuses on the application of border-padding and the practical implementation in a newly developed PNAH system. It illustrates a large variety of extend ed possibilities for PNAH that border-padding enables. Apart from the earlier introduced standard border-padding, experimental results are shown for a highly improved border-padding method. Measurements and calculations on industrial products illustrate the wide applicability of the presented method.

  • 71.
    Scholte, R.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Experimental Application of High Precision K-space Filters and Stopping Rules for Fully Automated PNAH2007Ingår i: Proceedings of the 14th International Congress on Sound and Vibration / [ed] Bob Randall, Cairns, Australia, 2007Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In general, inverse acoustic problems are ill-posed. Without any proper regularization actiontaken, noisy measurements result in an increasingly useless solution as the distance from themeasurement plane to the desired source grows. Two distinctive steps take place in the regularizationprocess for planar near-field acoustic holography (PNAH); first the low-pass filterfunction is defined and secondly a stopping rule is applied to determine the parameter settingsof said filter. A number of well-known and newly developed filter functions and stopping rulesare discussed and compared to one another, carefully listing the pros and cons. In acousticimaging practice it has proven to be very hard to determine the right filter for a certain casecombined with the automatic search for the near-optimal parameters. This paper presents anovel method that combines fitted filters for a broad number of possible experimental sourcescombined with highly efficient stopping rules, by taking advantage of k-space. Results basedon actual measurements demonstrate the effectiveness, applicability and precision of the fullyimplemented and automated regularization process for PNAH. Implementations include modificationsof Tikhonov, exponential and truncation low-pass filters, L-curve, Generalised Cross-Validation (GCV) and the novel Cut-Off and Slope (COS) parameter selection methods forPNAH.

  • 72.
    Scholte, R.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    On spatial sampling and aliasing in acoustic imaging2005Ingår i: Twelfth International Congress on Sound and Vibration / [ed] J. L. Bento Coelho and D. Alarcão, 2005Konferensbidrag (Övrigt vetenskapligt)
  • 73.
    Scholte, R.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Regularization in PNAH by means of L-curve2005Ingår i: Forum Acusticum 2005 / [ed] EAA,, 2005Konferensbidrag (Övrigt vetenskapligt)
  • 74. Scholte, Rick
    et al.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Acoustic holography2008Patent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    A method of performing near- field acoustic holography comprises the following steps. Establishing (102) acoustic data representing a set of near-field acoustic holography measurements at a first set of positions. Extrapolating (204) acoustic data using a model-based extrapolation to obtain extrapolated acoustic data relating to a plurality of positions outside the aperture. Applying (108) a spatial frequency transform to the padded acoustic data to obtain data in a spatial frequency domain. Propagating (110) the Fourier transformed acoustic data. Applying (112) a regularization in a wavenumber domain. Performing (114) an inverse spatial frequency transform.

  • 75.
    Stoelinga, C.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Peeters, B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    The bouncing of balls: Influences of spectral and temporal variations on perception2004Ingår i: Proceedings of the Joint Congress CDA/DAGA '04, 2004, s. 261-262Konferensbidrag (Övrigt vetenskapligt)
  • 76.
    Sun, Jia
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Kari, Leif
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    A dynamic rotating blade model at an arbitrary stagger angle based on classical plate theory and the Hamilton's principle2013Ingår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 332, nr 5, s. 1355-1371Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A dynamic model based on classical plate theory is presented to investigate the vibration behavior of a rotating blade at an arbitrary stagger angle and rotation speed. The Hamilton's principle is applied to derive the equations of motion, which are discretised by a novel implementation of the fast and efficient collocation method for rotating structures and by the traditional Extended Galerkin method. The results obtained with these methods are compared and validated with results found in the literature and from commercial finite element software. The proposed collocation method leads to a significantly lower computation time than the Extended Galerkin method for the same accuracy. The results show a good agreement with those of the finite element method. Finally, the forced response analysis is determined for two cases; a point force and a distribution force, using a proportional damping model.

  • 77.
    Sun, Jia
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik. Eindhoven University of Technology, The Netherlands.
    Kari, Leif
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Dynamic modeling of a multilayer rotating blade via quadratic layerwise theory2013Ingår i: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 99, s. 276-287Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel dynamic model for a multilayer rotating blade mounted at an arbitrary stagger angle using a quadratic layerwise theory is developed to study structural dynamics of the blade, particularly damping properties, using various coating layer configurations. A reduced two-dimensional (2D) model is used to describe the dynamic behavior of each layer in the weak form, while the quadratic layerwise theory is applied to interpolate the transverse shear stresses along the thickness direction. Results of numerical simulations with the reduced 2D model are compared to the full three-dimensional (3D) model showing an excellent agreement, comparable to the cubic layerwise theory, for both modal analysis and frequency response calculations. Moreover, damping analyses are performed on two types of multilayer blades: two-layer (free damping) and three-layer (constrained layer), in both non-rotating and rotating situations, and, parametric analyses with varying coating thickness and rotation speed are carried out. It is shown that damping decreases as the rotation speed increases due to inertial and Coriolis effects. Furthermore, frequency loci veering as a result of the rotation speed is observed. The proposed model gives an efficient and accurate way to study the dynamic behavior of rotating multilayer structures, such as compressor blades.

  • 78.
    Sun, Jia
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Kari, Leif
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    General shell model for a rotating pretwisted blade2013Ingår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 332, nr 22, s. 5804-5820Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel dynamic model for a pretwisted rotating compressor blade mounted atan arbitrary stagger angle using general shell theory and including the rotationalvelocity is developed to study the eigenfrequencies and damping properties of thepretwisted rotating blade. The strain-displacement relation and constitutive modelbased on the general (thick) shell theory are applied to bring out the strain energyof the rotating blade. Using the Hamilton’s principle, the variational form of thetotal energy is derived in order to obtain the corresponding weak form for thenumerical simulation. The model is validated by comparing to literature resultsand Ansys results, showing good agreement. Parametric analyses are carried outto study the influence of the rotation velocity, the stagger angle and the radius ofthe disk on the eigenfrequencies of the pretwisted blade. Proportional dampingis included into the proposed model to investigate the influence of rotational velocityon the damping characteristics of the pretwisted rotating blade system. It isshown that, due to inertial and Coriolis eects, damping decreases as the rotation velocity increases for the lower part of the velocity range considered and eitherdecreases or increases depending on the mode order for higher velocities. Furthermore,frequency loci veering as a result of the rotation velocity is observed.The proposed model is an ecient and accurate tool for predicting the dynamicbehavior of compressor blades of arbitrary thickness, stagger angle and pretwist,potentially during the early designing stage of turbomachinery.

  • 79. Temiz, M. A.
    et al.
    Tournadre, J.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Martínez-Lera, P.
    Hirschberg, A.
    Numerical estimation of the absorption coefficient of flexible micro-perforated plates in an impedance tube2016Ingår i: ICSV 2016 - 23rd International Congress on Sound and Vibration: From Ancient to Modern Acoustics, International Institute of Acoustics and Vibrations , 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this study, we numerically model a vibro-acoustic system consisting of a flexible micro-perforated plate (f-MPP) and an acoustic medium. Combined with a back-cavity, micro-perforated plates are considered as a promising noise control technology due to their tunable, wide-band sound absorption characteristics and robust performance. An MPP consists of a plate with uniformly distributed perforations whose diameters are in the order of a millimeter. These perforations are small enough to dissipate the acoustic perturbations due to the viscous effects caused by the presence of the Stokes layers. When the plate is rigid, the sound dissipation mechanism for a specific frequency bandwidth is determined by the perforation diameter, plate thickness, plate porosity and the back cavity depth. Yet, when the plate is flexible, additional absorption peaks, which cannot be determined by the parameters mentioned before, are observed in the measurements. This phenomenon is due to the vibro-acoustic coupling of the flexible plate and the acoustic medium. To model the vibro-acoustic system numerically, we couple two 3D cylindrical acoustic mediums, i.e. incident and back cavity regions, with a flexible plate consisting of shell elements. The perforations are separately located on the plate as independent transfer admittance elements with impedance values obtained from existing models. The system is disturbed with a plane wave excitation and the assessment of the model is done by comparing the calculated absorption coefficient with the experimental results from the literature. In the future, we plan to investigate the effect of perforation positions with the help of the model built in this study.

  • 80. Temiz, Muttalip Askin
    et al.
    Tournadre, Jonathan
    Arteaga, Ines Lopez
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg. Eindhoven Univ Technol, Netherlands.
    Hirschberg, Avraham
    Non-linear acoustic transfer impedance of micro-perforated plates with circular orifices2016Ingår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 366, s. 418-428Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A practical description of the transitional behavior of micro -perforated plates (MPPs) is provided between the linear and strongly non-linear regimes. Micro -perforated plates are efficient sound absorbers whose application areas vary from room acoustics to duct acoustics. Although there are accurate models for the linear and strongly non-linear acoustic behavior of MPPs, the transition from one to another has not been a focus of interest so far. A series of measurements are performed with MPP samples for various excitation amplitudes. The deviation from the linear impedance is found to be a function of excitation amplitude and oscillating viscous boundary layer thickness, expressed in terms of the Strouhal number and the Shear number. Typical for MPPs is a Shear number of order unity, implying that the viscous boundary layer thickness is in the order of the perforation radius. Using the measurement data, expressions are proposed for calculating the non-linear acoustic resistance and reactance for circular perforations with sharp square edges. Some additional data is provided for the higher Shear number range. The behavior at low amplitudes for high Shear numbers deviates strongly from the typical MPP behavior. This is due to local vortex shedding at the sharp edges of the perforation.

  • 81. Temiz, Muttalip Askin
    et al.
    Tournadre, Jonathan
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg. Eindhoven University of Technology, Netherlands.
    Hirschberg, Avraham
    Modelling vibro-acoustic coupling in flexible micro-perforated plates by a patch-impedance approach2017Ingår i: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 125, s. 80-90Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study proposes a Finite Element (FE)-based efficient numerical model of the vibro-acoustic coupling in flexible micro-perforated plates (f-MPPs) where each perforation is described as an imposed impedance boundary condition (uniform impedance patch) on the plate. This approach opens the possibility of predicting the influence of perforation distribution on the acoustic performance of f:MPP. Micro perforated plates have been a topic of interest as a promising sound absorber in a wide range of applications, from room acoustics to combustion systems. One great advantage of these plates is that it gives the designer the freedom of choice on material in production. Depending on the material and the dimensions, the acoustical modes of the medium can couple with the structural modes of the plate. This coupling changes the number of absorption peaks, frequency and amplitude of the Helmholtz resonance of the system, therefore the coupling becomes an extra parameter in the design process. Current analytical models superpose the mechanical impedance of the plate with the acoustic impedance of the perforations to compute this coupling. This approach works fairly well for plates with uniform perforation distribution. This study proposes a numerical method which assumes perforations as discrete impedance patches on the flexible plate so that they can be considered separately. The method couples the solution of the Helmholtz equation in air with shell plate theory to model the vibro-acoustic effects and the impedance patches are represented as imposed transfer impedance boundary conditions. The assessment of the method is performed in terms of comparing the calculated absorption coefficient values from the simulations of several test cases, fundamental theories and measurement results from the literature. The simulation results agree both with these theoretical limits and measurement results. The use of the method is illustrated by considering an example of the influence of modification of the spatial distribution of perforations on the sound absorption of a membrane.

  • 82.
    Thompson, David
    et al.
    Institute of Sound and Vibration Research, University of Southampton.
    Squicciarini, Giacomo
    Institute of Sound and Vibration Research, University of Southampton.
    Zhang, Jin
    Institute of Sound and Vibration Research, University of Southampton.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Zea, Elias
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Dittrich, Michael
    TNO, Den Haag, The Netherlands.
    Jansen, Erwin
    TNO, Den Haag, The Netherlands.
    Arcas, Kevin
    Ingeniería para el Control del Ruido, Barcelona, Spain.
    Cierco, Ester
    Ingeniería para el Control del Ruido, Barcelona, Spain.
    Magrans, Francesc Xavier
    Ingeniería para el Control del Ruido, Barcelona, Spain.
    Malkoun, Antoine
    Alstom Transport, Reichshoffen, France.
    Iturritxa, Egoitz
    CAF, Beasain, Spain.
    Guiral, Ainara
    CAF, Beasain, Spain.
    Stangl, Matthias
    DB Systemtechnik, München, Germany.
    Schleinzer, Gerald
    Siemens, Graz, Austria.
    Martin Lopez, Beatriz
    Patentes Talgo S.L., Madrid, Spain.
    Chaufour, Claire
    SNCF Innovation & Recherche, Paris, France.
    Wändell, Johan
    Bombardier Transportation Acoustic Department, Hennigsdorf, Germany.
    Assessment of measurement-based methods for separating wheel and track contributions to railway rolling noise2018Ingår i: Applied Acoustics, ISSN 0003-682x, Vol. 140, s. 48-62Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The noise produced during a train pass-by originates from several different sources such as propulsion noise, noise from auxiliary equipment, aerodynamic noise and rolling noise. The rolling noise is radiated by the wheels and the track and is excited by the wheel and rail unevenness, usually referred to as roughness. The current TSI Noise certification method, which must be satisfied by all new mainline trains in Europe, relies on the use of a reference track to quantify the noise from new vehicles. The reference track is defined by an upper limit of the rail roughness and a lower limit of the track decay rate (TDR). However, since neither the rail roughness nor the track radiation can be completely neglected, the result cannot be taken as representing only the vehicle noise and the measurement does not allow separate identification of the noise radiated by wheel and track. It is even likely that further reductions in the limit values for new rolling stock cannot be achieved on current tracks. There is therefore a need for a method to separate the noise into these two components reliably and cheaply. The purpose of the current study is to assess existing and new methods for rolling noise separation. Field tests have been carried out under controlled conditions, allowing the different methods to be compared. The TWINS model is used with measured vibration data to give reference estimates of the wheel and track noise components. Six different methods are then considered that can be used to estimate the track component. It is found that most of these methods can obtain the track component of noise with acceptable accuracy. However, apart from the TWINS model, the wheel noise component could only be estimated directly using three methods and un- fortunately these did not give satisfactory results in the current tests.

  • 83. Vael, G.E.M.
    et al.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Achten, P.
    Reducing flow pulsation with the floating cup pump: theoretical analysis2004Ingår i: Bath Workshop on Power Transmission and Motion Control (PTMC 2004) / [ed] Burrows, CR; Edge, KA; Johnson, DN, 2004, s. 123-141Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    With the recent introduction of the floating cup (FC) displacement principle, axial piston units can be realised using low cost mass production techniques instead of the more machine shop type of production techniques used to date. As a consequence, a far larger number of displacement volumes can be realised at the same or lower unit costs. An obvious advantage of a larger number of pistons is the reduction of flow pulsation from the unit. This paper focuses on this flow pulsation. In the ideal theoretical case that two out of phase halves of an FC pump directly deliver to the pump outlet, the odd harmonics in the 12 piston based flows from each pump half, will cancel out totally. In reality however, both sides are connected by a duct of finite length. The geometry of that duct and the location of the pump outlet, can significantly influence both the 'external' flow pulsation - at the pump outlet - and the 'internal' flow pulsation - in the duct. The paper shows that if the outlet duct is arranged symmetrical with respect to the two pump halves, perfect cancellation of the odd harmonics is indeed reached but only at the cost of high resonant pressure peaks within the duct. These pressure peaks might cause pump noise. They can be attenuated by either arranging the outlet in a non-symmetrical position or by adding Helmholtz resonators to the duct. Both options were studied; both show potential.

  • 84. van Blokland, G.J.
    et al.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Boere, S.W.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schwanen, W.
    Influence of road surface characteristics on rolling resistance2009Konferensbidrag (Övrigt vetenskapligt)
  • 85. van Dalen, P. L.
    et al.
    Scholte, R.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. Eindhoven University of Technology, Netherlands.
    Moers, E. M. T.
    Nijmeijer, H.
    Experimental reconstruction of non-stationary sound and vibration sources by means of Transient Planar Near-field Acoustic Holography2012Ingår i: International Conference on Noise and Vibration Engineering 2012, ISMA 2012, including USD 2012: International Conference on Uncertainty in Structure Dynamics, Katholieke Universiteit Leuven , 2012, Vol. 5, s. 3631-3643Konferensbidrag (Refereegranskat)
    Abstract [en]

    A novel algorithm called Transient Planar Near-field Acoustic Holography is presented to analyse nonstationary sound and vibration sources. The method is able to obtain the time-dependent pressure, particle velocity and intensity field at the source plane without any pre-knowledge of the source by inverse propagation of measured pressure fields. This makes it possible to analyse phenomena like transients and run-ups for all kinds of vibrating and sound radiating objects. Transient responses of thin plates are analysed to experimentally validate the performance of the algorithm. The determined velocity at the center of the plate is validated using a laser vibro-meter directed at the center of the plate and the spatial fields are qualitatively compared with theoretical mode shapes. It is shown that the algorithm is able to analyse transient responses of plates with good quantitative as well as qualitative results.

  • 86.
    van den Boom, J.D.B.J
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Kornilov, V.N.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    de Goey, L.P.H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Active control of oscillations in a Rijke tube-like flat flame configurations2007Ingår i: Proceeding of the European Combustion Meeting, 2007Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The use of low NOx premixed surface burners with a large modulation range in modern central heating systemsoften to noise problems. In order to make any further advance in the development of these systems the noise problemhas to be solved. Therefore, the possibility of suppression (and stabilization) of these instabilities is in investigatedusing active model-based control strategies. A model for the condensing gas-fired boiler is derived first. based on anacoustic network approach. Special attention is paid to the flame dynamics. Second, a H1 controller is synthesized,where also modelling uncertainties are taken into account. In the end the performance and the robustness of thecontroller is validated during experiments.

  • 87.
    van den Boom, J.D.B.J
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Kornilov, V.N.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    de Goey, L.P.H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Application of modal parameter derivation in active suppression of thermo acoustic instabilities2007Ingår i: Proceedings of the Fourteenth International Congress on Sound and Vibration / [ed] Bob Randall, 2007Konferensbidrag (Övrigt vetenskapligt)
  • 88.
    van den Boom, J.D.B.J
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schreel, K.R.A.M.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    de Goey, L.P.H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Linear Control Strategies for the Suppression of Flame Instabilities2005Ingår i: Proceedings of the European Combustion Meeting 2005 / [ed] J. Vandooren, Louvain-la-Neuve,, 2005Konferensbidrag (Övrigt vetenskapligt)
  • 89.
    van den Boom, J.D.B.J
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schreel, K.R.A.M.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    de Goey, L.P.H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Towards active stabilization of thermo-acoustic instabilities in laminar combustion2006Ingår i: Proceedings of the Thirtheenth International Congress on Sound and Vibration (ICSV13) / [ed] J. Eberhardsteiner, H.A. Mang, and H. Waubke, 2006Konferensbidrag (Övrigt vetenskapligt)
  • 90.
    van den Boom, J.D.B.J
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schreel, K.R.A.M.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    de Goey, L.P.H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Towards active suppression of thermo-acoustics instabilities in laminar combustion2005Ingår i: Twelfth International Congress on Sound and Vibration / [ed] J.L. Bento Coelho and D. Alarcão,, 2005Konferensbidrag (Övrigt vetenskapligt)
  • 91.
    van der Steen, R.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    de Bruijn, B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schmeitz, A.J.C.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    FE modeling of rubber friction on rough roads2008Ingår i: Proceedings of the WCCM8, ECCOMAS / [ed] B.A. Schrefler, U. Perego, 2008Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The cornering, braking, traction, rolling resistance and wear performance of tires depend on the generatedfriction forces. These friction forces depend not only on a specific compound, but also on theunderlying road surface. One of the challenges in numerical simulations is a correct prediction of thesefrictional forces. In commercial FEM packages, where usually only the Coulomb friction model ispresent, the surface roughness is not accounted for. It is well-known that for cornering under high slipangles the results with a Coulomb friction model are less accurate. By incorporating surface roughnessa more realistic friction model can be obtained, which should provide a better correlation between FEAand real road experiments.Recently a theory for contact mechanics and sliding friction of rubber has been developed (see Persson[1], [2]). In this work hysteresis friction is assumed, which is caused by the viscoelastic modulus of therubber and the excitation of the road surface. It is possible to calculate a friction coefficient for a set ofsliding velocities considering the mechanical-dynamical material properties and the specific roughnessof the interacting surface.To illustrate this approach an Laboratory Abrasion and skid Tester (LAT 100, [3]) is used, see figure 1.In this setup a small solid tire, with adjustable slip angle, is pressed on an abrasive disk. The appliednormal force on the tire, temperature, speed and surface texture of the disk can be controlled. Thepresent friction between the abrasive disk and tire drives the tire and the resulting forces are measuredwith a tri-axial force sensor.The relevant parts of this setup are modeled in ABAQUS [4], taking into account the non-linear materialbehavior, see figure 2. A 2D cross section of the tire is revolved to create the 3D model. To evaluate thesteady state performance of the wheel under different slip angles, the steady state transport capabilityof ABAQUS is used. Therefore only a dense mesh in the contact area is required, which makes this anefficient approach to calculate the responses.For the contacting surface in the FE model a smooth rigid surface is used. The effect of surfaceroughness is incorporated in the obtained friction model, using the method proposed by Persson, andis implemented into the user-subroutine FRIC. The implementation of the friction law itself is doneanalogous to a plasticity material model by using a return mapping algorithm. Therefore the slidingvelocity is split into a small elastic and an inelastic part [5].Finally the results of this method are compared with the available Coulomb model in ABAQUS andmeasured side-force characteristics on the LAT 100.

  • 92. Van Der Steen, R.
    et al.
    Lopez Arteaga, Ines
    Eindhoven University of Technology.
    Nijmeijer, H.
    Experimental and numerical study of friction and stiffness characteristics of small rolling tires2011Ingår i: Tire Science and Technology, ISSN 0090-8657, Vol. 39, nr 1, s. 5-19Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Virtual testing is nowadays the standard in the design process of new tires. Besides modeling the static response of the tire itself, the dynamics of a rolling tire in contact with the road needs to be incorporated. Due to the uncontrollable environmental conditions and the complex structure of the tires, it is advantageous to use small-scale testing under more controlled conditions. Experimental characterization of frictional properties of rubber compounds is, however, limited due to the necessity of complex measurement systems. In this paper a commercially available laboratory abrasion and skid tester is used to identify both friction and stiffness characteristics of the same rubber compound. The obtained friction properties are implemented in a finite element model of the setup, and different validation steps are presented. Finally, a steady-state transport approach is used to efficiently compute a steady-state solution, which is compared with the experimental results. The numerical results show a good qualitative agreement with the experimental results.

  • 93. Van Der Steen, R.
    et al.
    Lopez Arteaga, Ines
    Eindhoven University of Technology.
    Nijmeijer, H.
    Schmeitz, A. J. C.
    De Bruijn, B.
    Experimental and numerical study of friction and braking characteristics of rolling tires2011Ingår i: Tire Science and Technology, ISSN 0090-8657, Vol. 39, nr 2, s. 62-78Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Throughout the tire industry, virtual testing has been widely adopted in the design process. Both static deformation and dynamic response of the tire rolling on the road must be accurately predicted to evaluate the handling performance of a tire. Unfortunately, experimental characterization of rubber compound frictional properties is limited, and therefore, the Coulomb friction model is still often used in finite element (FE) simulations. To overcome this limitation, a different strategy is developed to capture observed effects of dry friction. The proposed friction model is decomposed into the product of a contact pressure dependent part and a slip velocity dependent part. The identification of the parameters of the slip velocity dependent part, using measured axle forces, is presented in this paper. The complete phenomenological friction model is coupled to a FE model of the tire under testing. A steady-state transport approach is used to efficiently compute the steady-state longitudinal slip characteristics, which show good quantitative agreement with experiments.

  • 94.
    van Doorn, R.R.J.J.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    van der Steen, R.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Frequency loci veering in deformed rotating tires2008Konferensbidrag (Övrigt vetenskapligt)
  • 95.
    van Doorn, R.R.J.J.
    et al.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    van der Steen, R.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Roozen, N.B.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Nijmeijer, H.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Transmissibility of a deformed rotating tire2008Ingår i: Proceedings of Acoustics 2008, 2008Konferensbidrag (Övrigt vetenskapligt)
  • 96. Van Hirtum, A.
    et al.
    Cisonni, J.
    Ruty, N.
    Pelorson, X.
    Lopez Arteaga, Ines
    Eindhoven University of Technology.
    Van Uittert, F.
    Experimental validation of some issues in lip and vocal fold physical models2007Ingår i: Acta Acoustica united with Acustica, ISSN 1610-1928, E-ISSN 1861-9959, Vol. 93, nr 2, s. 314-323Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Insight into vocal fold and lip oscillation mechanisms is important for the understanding of phonation and the sound generation process in brass musical instruments. In general, a simplified analysis of the physical 3D fluid-structure interaction process between the living tissues and the airflow is favoured by most workers. Several simple models (lumped parameter models) have been proposed and these represent the tissues as a distribution of elastic mass(es). The mass-spring-damper system is acted on by a driving force resulting from the pressure exerted by the airstream. The results from these theoretical models have been validated 'in-vitro' using rigid or deformable replicas mounted in a suitable experimental set-up. Previous research by the authors focused on the prediction of the pressure threshold and oscillation frequency of an 'in-vitro' replica, in the absence and presence of acoustical feedback. In the theoretical model a lip or vocal fold is represented as a simple lumped mass system. The model yielded accurate prediction of the oscillation threshold and frequency. In this paper a new 'in-vitro' set-up is presented, which overcomes some of the limitations of the previous study. By the use of a digital camera synchronised with a light source and of pressure sensors, this set-up allows 1) measurement of the area of the replica opening and 2) imposition of independent initial conditions, such as height of the initial opening and internal pressure in the replica. The impact of these findings on physical modelling is discussed.

  • 97. Van Hirtum, A.
    et al.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Schellekens, M.H.
    Pelorson, X.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Driessen, N.M.
    Hirschberg, A.
    Department of Mechanical Engineering, Eindhoven University of Technology.
    The effect of acoustical feedback on buzzing: From lips to vocal folds?2004Ingår i: Proceedings of the Joint Congress CFA/DAGA '04, 2004, s. 1137-1138Konferensbidrag (Övrigt vetenskapligt)
  • 98. Viñolas, J.
    et al.
    Nieto, J.
    Lopez Arteaga, Ines
    Department of Mechanical Engineering, Eindhoven University of Technology.
    Egaña, J.
    The effect of damping the wheels and varying wheel/rail friction coefficient on railway noise2007Ingår i: 19th International Congress on Acoustics, 2007Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The main noise source when a rail vehicle is circulating under approximately 280 km/h is theinteraction between wheel and rail. This paper presents a summary of different solutions thatcould be envisaged to reduce the level of this source. Being the wheel the most criticalcomponent for noise emission, particular attention is being paid to existing solutions to adddamping to the wheel. A wheel including a friction damping solution –a modified ring damper- isanalysed in detail. Ring dampers are steel rings fitted inside grooves cut under the wheel rim,usually one at each side of the tread; in this case it is a heavier ring at one side of the wheel.The paper includes some experimental results obtained in the laboratory aiming at verifying themodal damping for the different modes with this “damped wheel” and some on track test for aglobal evaluation of the solution. Additionally, an analysis of the effectiveness of modifying thefriction coefficient between the rail and the wheel is also reported. A “friction modifier” is addedat the top of the rail and noise and vibration measurements have been carried out on the trackfor an experimental evaluation of its effectiveness.

  • 99.
    Zea, Elias
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. Department of Mechanical Engineering, Eindhoven University of Technology, The Netherlands.
    A single-layer formulation of Fourier-based planar NAH for enclosed spaces2014Ingår i: Proceedings of EAA, European Acoustics Association (EAA), 2014Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    One of the limitations of Fourier-based planar near-field acoustic holography (P-NAH) is that the wave-field extrapolation only holds for outgoing waves, making the study of certain vibro-acoustic sources in reverberant environments a costly and difficult procedure. The present paper is concerned with a single-layer formulation of Fourier-based P-NAH that accounts for the presence of partially absorbing surfaces. The underlying theory is based on the WRW model, which is a rather popular technique in the seismic processing community. Unlike P-NAH, the WRWmodel proposes a solution to the forward acoustic problem, by performing the spatial convolutions via matrix multiplications. The aim of this paper is to investigate the use of the WRW model for inverse acoustics, particularly in the context of P-NAH. Numerical reconstructions with baffled point sources are carried out, investigating a geometrical case with one reflector under noise-free conditions. Several combinations of frequencies, reflection coefficients, measurement apertures and reflector positions are explored. Opportune observations are made regarding the influence of the propagation distances on the numerical implementation of the Green’s functions. The source reconstructions are performed via free-field P-NAH and via the present formulation, aiming towards a quantitative and qualitative understanding of the influence of the partially absorbing surfaces.

  • 100.
    Zea, Elias
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Experimental Assessment of a Single-layer Near-field Acoustic Holography Method in an Enclosed Space2015Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Planar near-field acoustic holography (PNAH) is preferably performed in anechoic spaces, since the wave-field extrapolation only holds for outgoing waves, which makes the study of certain vibro- acoustic sources a troublesome pursuit. To overcome this limitation, a number of imaging alternatives have been investigated in recent years with the use of double-layer pressure (or particle velocity) measurements, as well as of single-layer pressure and velocity measurements. Unlike these methods, our approach is to use single-layer pressure measurements and extend the PNAH method such that it is valid in the presence of a parallel reflector. In this paper we address the experimental validation of the extended PNAH formulation by means of reconstructing the pressure radiated by an omnidirectional source and exploring a few excitation frequencies. The reconstruction performance is investigated via both the free-field and the extended PNAH techniques.

123 51 - 100 av 110
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf