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  • 51.
    Guastavino, Rémi
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    A 3D displacement measurement methodology for anisotropic porous cellular foam materials2007In: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 26, no 6, p. 711-719Article in journal (Refereed)
    Abstract [en]

    This paper presents a new testing methodology for three dimensional (3D) full-field displacement mapping at the surface of elastic materials under static loading, here with a special focus on macroscopic behaviour of an anisotropic porous cellular foam. Three displacement components on four adjacent surfaces are estimated for cubic samples of the foam using a dual-camera 3D image correlation system. The critical feature of the proposed method is the provision made for efficient mapping of the four visible sides of the cubic sample, involving a rotating table and a common lateral reference frame. The overall setup used is described in some detail, together with the main steps of the measurement procedure and including remarks on the experience made during the development. Observations made concerning specific deformation phenomena occurring at discontinuities are discussed.

  • 52.
    Guastavino, Rémi
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    A methodology for identification of general orthotropic elastic models of porous foam2008Report (Other academic)
  • 53.
    Guastavino, Rémi
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Vibroacoustic measurements and simulations of a flat panel loudspeaker2006Report (Other academic)
  • 54.
    Guastavino, Rémi
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    A 3D anisotropic flow resistivity estimation for soft porous foam2008Report (Other academic)
  • 55.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Acoustic and vibrational damping in porous solids2006In: Philosophical Transactions. Series A: Mathematical, physical, and engineering science, ISSN 1364-503X, E-ISSN 1471-2962, Vol. 364, no 1838, p. 89-108Article in journal (Refereed)
    Abstract [en]

    A porous solid may be characterized as an elastic-viscoelastic and acoustic-viscoacoustic medium. For a flexible, open cell porous foam, the transport of energy is carried both through the sound pressure waves propagating through the fluid in the pores, and through the elastic stress waves carried through the solid frame of the material. For a given situation, the balance between energy dissipated through vibration of the solid frame, changes in the acoustic pressure and the coupling between the waves varies with the topological arrangement, choice of material properties, interfacial conditions, etc. Engineering of foams, i.e. designs built on systematic and continuous relationships between polymer chemistry, processing, micro-structure, is still a vision for the future. However, using state-of-the-art simulation techniques, multiple layer arrangements of foams may be tuned to provide acoustic and vibrational damping at a low-weight penalty. In this paper, Biot's modelling of porous foams is briefly reviewed from an acoustics and vibrations perspective with a focus on the energy dissipation mechanisms. Engineered foams will be discussed in terms of results from simulations performed using finite element solutions. A layered vehicle-type structure is used as an example.

  • 56.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Advanced materials and structures for noise control2006In: EURONOISE 2006 - The 6th European Conference on Noise Control: Advanced Solutions for Noise Control, 2006Conference paper (Refereed)
    Abstract [en]

    Lightweight porous automotive acoustic multilayer trim components have been traditionally specified in terms of sound absorption and sound transmission loss performance targets. These targets are valid for airborne noise excitation only, in the medium to high frequency ranges. Unfortunately, this neglects the fact that in real-world applications, these components are also subjected to low-medium frequency structural vibration inputs from the mechanical components, which is typically an acoustic sound radiation problem. For a flexible, open cell porous foam, the transport of energy is carried both through the sound pressure waves propagating through the fluid in the pores, and through the elastic stress waves carried through the solid frame of the material. For a given situation, the balance between energy dissipated through vibration of the solid frame, changes in the acoustic pressure and the coupling between the waves varies with the topological arrangement, choice of material properties, interfacial conditions, etc. This opens for the possibility of tailoring the performance by tuning the different dissipation mechanisms accordingly. This paper then presents some recent developments and results, Finite Element (FE) numerical simulation and material modelling, which allow the tuning and prediction of the of porous multilayer trim components.

  • 57.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Convergence aspects in finite element solutions of multi-layered, heterogeneous porous materials2011Conference paper (Other academic)
  • 58.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Exploring multi-functionality in poro-elastic materials with consideration given to some aspects related to the influence of scale, shape and space2014Conference paper (Refereed)
  • 59.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Mid frequency NVH analysis: FE modelling of acoustic and vibrational damping in porous solids2007Conference paper (Other academic)
  • 60.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Modelling of anisotropic porous materials: sensitivity in response to & influence of non-aligned material directions2014Conference paper (Other academic)
  • 61.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Simulation of multilayered porous foam structures with integrated actuators2005Conference paper (Other academic)
  • 62.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tailored acoustic and vibrational damping in porous solids - Engineering performance in aerospace applications2008In: Aerospace Science and Technology, ISSN 1270-9638, E-ISSN 1626-3219, Vol. 12, no 1, p. 26-41Article in journal (Refereed)
    Abstract [en]

    A porous solid, saturated with fluid, may be described as an elastic-viscoelastic and acoustic-viscoacoustic medium. The transport of vibroacoustic energy is carried both through the sound pressure waves propagating through the fluid in the pores, and through the elastic stress waves, carried through the solid frame of the material. For most porous materials, used to reduce sound and vibration, these waves are coupled to each other, i.e. they simultaneously propagate in both the fluid and the solid frame but with different strengths. A characteristic of this coupled wave propagation, is that the vibroacoustic energy is dissipated and converted into heat as the wave travels through the material. Clearly for a given situation, the balance between energy dissipated through vibration of the solid frame and changes in the acoustic pressure varies with the topological arrangement, choice of material properties, interfacial conditions, etc. This paper illustrates the influence such a balancing has on the performance of a multi-layer sound proofing arrangement applicable for an aircraft interior.

  • 63.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Tailoring structural and acoustic performance of poroelastic, open cell foams2009Conference paper (Other academic)
  • 64.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    The Multifunctional and Multidisciplinary Design Paradigm: noise & vibration research within the Centre for ECO2 Vehicle Design2012Conference paper (Other academic)
  • 65.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    The Multifunctional and Multidisciplinary Design Paradigm: ongoing research within the Centre for ECO2 Vehicle Design2011Conference paper (Other academic)
  • 66.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Siemens Industry Software, Leuven Belgium.
    Lähivaara, Timo
    University of Eastern Finland.
    Parameter estimation in modelling frequency response of coupled systems using a stepwise approach2019In: Mechanical systems and signal processing, ISSN 0888-3270, E-ISSN 1096-1216, Vol. 126, p. 161-175Article in journal (Refereed)
    Abstract [en]

    This paper studies the problem of parameter estimation in resonant, acoustic fluid-structure interaction problems over a wide frequency range. Problems with multiple resonances are known to be subjected to local minima, which represents a major challenge in the field of parameter identification. We propose a stepwise approach consisting in subdividing the frequency spectrum such that the solution to a low-frequency subproblem serves as the starting point for the immediately higher frequency range. In the current work, two different inversion frameworks are used. The first approach is a gradient-based deterministic procedure that seeks the model parameters by minimising a cost function in the least squares sense and the second approach is a Bayesian inversion framework. The latter provides a potential way to assess the validity of the least squares estimate. In addition, it presents several advantages by providing invaluable information on the uncertainty and correlation between the estimated parameters. The methodology is illustrated on synthetic measurements with known design variables and controlled noise levels. The model problem is deliberately kept simple to allow for extensive numerical experiments to be conducted in order to investigate the nature of the local minima in full spectrum analyses and to assess the potential of the proposed method to overcome these. Numerical experiments suggest that the proposed methods may present an efficient approach to find material parameters and their uncertainty estimates with acceptable accuracy.

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  • 67.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics. Centre for ECO2 Vehicle Design.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics. Siemens Industry Software, Leuven Belgium.
    Lähivaara, Timo
    University of Eastern Finland.
    Some Observations on Parameter Estimation in Strongly Coupled Fluid-Structure Interaction Problems2018Conference paper (Other academic)
  • 68.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics. Siemens Industry Software Leuven Belgium.
    Van der Kelen, Christophe
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    EXPERIMENTAL-NUMERICAL METHODS FOR INVERSE CHARACTERISATION OF SOME MATERIAL PROPERTIES OF ANISTROPIC-ANELASTIC POROUS MATERIALS2015Conference paper (Refereed)
  • 69.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Deü, Jean-Francois
    LMSSC, Structural Mechanics and Coupled Systems Laboratory, France.
    Dazel, Olivier
    Université du Maine.
    Sensitivity of Vibroacoustic Response in  Multi-Layered Anisotropic Poro-Elastic Panels with Non-Aligned Properties2013Conference paper (Refereed)
  • 70.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Guastavino, Remi
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Measurement and inverse estimation of 3D anisotropic flow resistivity for porous materials2009In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 327, no 3-5, p. 354-367Article in journal (Refereed)
    Abstract [en]

    This paper presents a new methodology for estimating the anisotropic flow resistivity for porous materials. From pressure measurements on a cubic or parallelepiped sample of a porous material, the flow resistivities are determined using inverse estimation. The core of the estimation is a series of 3D solutions to Darcy's law, where the flow resistivity tensor is varied until the sum of the quadratic errors between measured and computed pressures is minimised. The overall approach and experimental set-up used, enabling efficient measurements of high quality, are described in some detail together with the main steps of the measurement and estimation procedures. Results from a fibrous glass wool and a polyurethane foam are discussed and compared to standard measurement data.

  • 71.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Guastavino, Rémi
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Identification of a general orthotropic, viscoelastic model of a porous foam2008Report (Other academic)
  • 72.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Guastavino, Rémi
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    A 3D anisotropic flow resistivity measurement method for fibrous wool materials2008Report (Other academic)
  • 73.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Anisotropic porous materials, and then?2008Conference paper (Other academic)
  • 74.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Vibro-acoustic modelling of anisotropic porous elastic materials: A preliminary study of the influence of anisotropy on the predicted performancein a multi-layer arrangement.2010In: Acta Acoustica united with Acustica, ISSN 1610-1928, E-ISSN 1861-9959, Vol. 96, p. 258-265Article in journal (Refereed)
    Abstract [en]

    During the recent years considerable efforts have been spent on developing numerical models and performing the necessary characterisation of elastic, dynamic and acoustic properties of porous materials. Originally having been considered to be isotropic, such materials have lately also been studied in terms of their anisotropic properties. In this paper, the influence of anisotropy on the vibroacoustic performance is illustrated and evaluated for a multi-layer configuration with varying boundary conditions between the porous material and a solid plate. The paper starts with a brief review of a recently published anisotropic, mixed displacement pressure weak formulation with a particular emphasis on the anisotropic properties. Using the material properties for a hypothetical porous foam model, the predicted response is evaluated. The influence of anisotropy is found to be significant in terms of response amplitude and apparent damping. For some boundary conditions the predicted response is an order of magnitude lower for the anisotropic material model, in particular for frequency ranges where the dynamics of the foam are significant.

  • 75.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Semeniuk, Bradley
    Rieter Automotive Managment AG, Switzerland].
    Influence of surface porosity on the radiated sound from multilayer automotive trim components2005In: SAE 2005 Noise and Vibration Conference and Exhibition, May 2005, 2005Conference paper (Refereed)
    Abstract [en]

    Lightweight porous automotive acoustic multilayer trim components have been traditionally specified in terms of sound absorption and sound transmission loss performance targets. These targets are valid for airborne noise excitation only, in the medium to high frequency ranges. Unfortunately, this neglects the fact that in real-world vehicle applications, these components are also subjected to low-medium frequency structural vibration inputs from the mechanical components of the vehicle, which is typically an acoustic sound radiation problem.

  • 76.
    Göransson, Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Lind Nordgren, Eleonora
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Vibro-acoustic energy propagation in anisotropic, anelastic porous materials2014In: Proceedings of the 9th International Conference on Structural Dynamics, EURODYN 2014, 2014, p. 83-90Conference paper (Refereed)
    Abstract [en]

    Historically, the modelling of the acoustics of poro-elastic materials (APEMs) has assumed the materials to be isotropic in both their elastic as well as their acoustic properties including the dissipative mechanisms related to viscous, inertialand thermal interactions. While this is a reasonable approximation when the absorption of sound is of interest, it fails to provide meaningful results for most foamed materials in general and for certain sets of boundary conditions involving elastic contact with solids or other APEMs in particular. A general modelling of fully anisotropic APEMs will be reviewed and taken as a starting point for a series of numerical experiments focussing on aspects of propagation of vibro-acoustic energy, in a homogeneous layer as well as in multiple layer arrangements. From previous works it is known that the influence of anisotropy may be quite significant, in particular for structure-borne vibro-acoustic energy. In addition, it is known that the alignment of principal directions may have substantial influence on the transmission of vibro-acoustic energy. These findings will be recalled in order to prepare for a discussion on the aspects of the directional dependence of the anelastic moduli which will be the core of the presentation at the conference. Real material tensors may be constructed from a superposition of these anisotropic contributions, in the most general case, not necessarily sharing the same principal directions. Starting from these fully anisotropic constitutive tensors with general symmetry properties, studies of optimal alignment between conservative and dissipative tensors, as well as between different materials in various configurations of interest, will be illustrated in the lecture.

  • 77.
    Hörlin, Nils-Erik
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Weak, anisotropic symmetric formulations of Biot's equations for vibro-acoustic modelling of porous elastic materials2010In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 84, no 12, p. 1519-1540Article in journal (Refereed)
    Abstract [en]

    In this paper a fully anisotropic symmetric weak formulation of Biot's equations for vibro-acoustic modelling of porous elastic materials in the frequency domain is proposed. Starting from Biot's equations in their anisotropic form, a mixed displacement-pressure formulation is discussed in terms of Cartesian tensors. The anisotropic equation parameters appearing in the differential equations are derived from material parameters which are possible to determine through experimental testing or micro-structural simulations of the fluid and the porous skeleton. Solutions are obtained by applying the finite element method to the proposed weak form and the results are verified against a weak displacement-based formulation for a foam and plate combination.

  • 78.
    Hörlin, Nils-Erik
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Guastavino, Remi
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Finite element modelling of multi-layered trim components: possibilities and difficulties2005Conference paper (Other academic)
  • 79.
    Hörlin, Nils-Erik
    et al.
    KTH, Superseded Departments, Vehicle Engineering.
    Nordström, M.
    KTH, Superseded Departments, Vehicle Engineering.
    Göransson, Peter
    KTH, Superseded Departments, Vehicle Engineering.
    A 3-D hierarchical Fe formulation of Biot's equations for elasto-acoustic modelling of porous media2001In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 245, no 4, p. 633-652Article in journal (Refereed)
    Abstract [en]

    A three-dimensional hierarchical finite element formulation of Biot's equation for low frequency elasto-acoustic wave propagation in fluid saturated porous media based on a weak formulation with fluid displacement and solid displacement as dependent variables is presented. A global error measure for evaluation of the convergence is proposed. Numerical simulations of an air saturated polyurethane foam material show faster convergence for the hierarchical extensions than for linear and quadratic serendipity finite element mesh refinement extensions.

  • 80.
    Ihle, Alexander
    et al.
    HPS GmbH.
    Ernst, Thomas
    HPS GmbH.
    Datashvili, Leri
    TU Munich.
    Hoffmann, Jürgen
    TU Munich.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Large porous antenna and spacecraft structures: Thermo-elastic and vibroacoustic modelling and effects and its verification via test.2009Conference paper (Other academic)
  • 81.
    Jank, Merle-Hendrikje
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    O'Reilly, Ciarán J.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Baumgartner, Rupert J.
    University of Graz, Institute of Systems Sciences Innovation & Sustainability Research, Austria.
    Schöggl, Josef-Peter
    University of Graz, Institute of Systems Sciences Innovation & Sustainability Research, Austria.
    Potting, José
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms). PBL Netherlands Environmental Assessment Agency, The Netherlands.
    Advancing energy efficient early-stage vehicle design through inclusion of end-of-life phase in the life cycle energy optimisation methodology2017In: 12th International Conference on Ecological Vehicles and Renewable Energies Conference, EVER, 2017Conference paper (Refereed)
    Abstract [en]

    Environmentally-friendly energy-efficient vehicles are an important contributor to meet future global transportation needs. To minimise the environmental impact of a vehicle throughout its entire life cycle, the life cycle energy optimisation (LCEO) methodology has been proposed. Using the proxy of life cycle energy, this methodology balances the energy consumption of vehicle production, operation and end-of-life scenarios. The overall aim is to design a vehicle where life cycle energy is at a minimum. While previous work only included vehicle production and operation, this paper aims at advancing the LCEO methodology by including an end-of-life phase. A simplified design study was conducted to illustrate how vehicle design changes when end-of-life treatment is included. Landfilling, incineration and recycling have been compared as end-of-life treatments, although the focus was put on recycling. The results reveal that the optimal design not only changes with the inclusion of an end-of-life phase but it changes with specific end-of-life treatment. 

  • 82.
    Kellonemi, Anti
    et al.
    VTT, Finland.
    Mellin, V.
    VTT, Finland.
    Finnveden, Svante
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Gustavini, Remi
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Mechanical study of a plane wave transducer for active noise control2007In: Turkish Acoustical Society - 36th International Congress and Exhibition on Noise Control Engineering, INTER-NOISE 2007 ISTANBUL, 2007, p. 1608-1617Conference paper (Refereed)
    Abstract [en]

    An electrostatic transducer is created by attaching a metallized diaphragm between two porous stator layers. A loudspeaker element constructed this way exhibits a dipole radiation pattern due to its symmetric structure. When the transducer dimensions are large compared to wavelength of the produced sound, the sound field exhibits minimal spatial spreading. When the movement of a radiating surface is in same phase over the whole area, plane waves are produced. The discussed electrostatic transducer exhibits excellent impulse and phase response characteristics, which makes it highly suitable for active noise control. The accuracy of the response is affected by the mechanical behavior of the whole structure. To study the movement of the stators and the diaphragm, laser scanner measurements and simulations were performed. The movement of the stators was noted to play a significant role in the sound creation in addition to the diaphragm movement.

  • 83.
    Krank, Benjamin
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Ohlsson, Ulrika
    Volvo Group Trucks Technology.
    Hedlund, Anders
    Volvo Group Trucks Technology.
    Nordström, Lars
    Volvo Group Trucks Technology.
    Englund, Thomas
    Volvo Group Trucks Technology.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Tuning spot weld models for vehicle body structural dynamics2012In: Proceedings Of International Conference On Noise And Vibration Engineering (ISMA2012) / International Conference On Uncertainty In Structural Dynamics (USD2012), Katholieke Universiteit Leuven , 2012, p. 3915-3926Conference paper (Refereed)
    Abstract [en]

    Efforts focussing on modelling of spot welds in typical automotive structures have been spent during the last decades resulting in a number of different modelling techniques. One of the crucial aspects common to all these approaches is the difficulties related to the local complexity of the modelling of the actual connections. In order to handle this complexity, spot weld models are often dependent on parameters tuning their characteristics. This paper discusses the tuning of two different spot weld models with respect to certain parameters; the RBE3-Hexa-RBE3 model (also known as the ACM 2) and the Spider2 model available in the pre-processor Ansa. With the current trend towards increasingly refined finite element model meshes, current guide lines need to be updated and elaborated further in order to identify the best performing models. In this paper, model studies are discussed targeting tuning of spot weld parameters together with a new proposal for an exact method for updating the Young's modulus and density of isotropic shell structures analytically using an initial FE calculation.

  • 84.
    Laudato, Marco
    et al.
    University of L'Aquila, Italy.
    Di Cosmo, Fabio
    University of L'Aquila, Italy.
    Drobnicki, Rafał
    University of L'Aquila, Italy.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Dynamical Vector Fields on Pantographic Sheet: Experimental Observations.2019In: New Achievements in Continuum Mechanics and Thermodynamics: Advanced Structured Materials / [ed] Abali, Bilen Emek; Altenbach, Holm; dell’Isola, Francesco; Eremeyev, Victor A.; Öchsner, Andreas, Springer International Publishing , 2019, p. 257-269Chapter in book (Other academic)
    Abstract [en]

    In this work, we will present and discuss some experimental observations of the dynamical displacement vector field on a pantographic sheet. We will sketch the experimental setup and we will qualitatively describe the observed behavior for a set of relevant frequencies.

  • 85.
    Laudato, Marco
    et al.
    University of L'Aquila, Italy.
    Manzari, Luca
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Barchiesi, E.
    University of L'Aquila, Italy.
    Cosmo, F. Di
    University of L'Aquila, Italy.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    First experimental observation of the dynamical behavior of a pantographic metamaterial2018In: Mechanics research communications, ISSN 0093-6413, E-ISSN 1873-3972, Vol. 94, p. 125-127Article in journal (Refereed)
    Abstract [en]

    The first experimental observation of the dynamical behavior of a pantographic sheet is presented. The experimental setup and the measurement procedures are accurately described. Finally, a qualitative description of the displacement vector field in time for a set of relevant frequencies is presented.

  • 86.
    Lee, Joong Seok
    et al.
    Seoul National University, Republic of Korea.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Kim, Yoon Young
    Seoul National University, Republic of Korea.
    Topology optimization for three-phase materials distribution in a dissipative expansion chamber by unified multiphase modeling approach2015In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 287, p. 191-211Article in journal (Refereed)
    Abstract [en]

    The sound attenuation performance of a dissipative expansion chamber is a combinational result of reflective and dissipative effects. Although it is well known that the performance can be substantially improved by altering the distribution of constituent materials, the process of finding an optimal distribution of the materials still remains a challenge. This work proposes a new design method for interior space of a dissipative expansion chamber by using topology optimization method. Different from the existing topology optimizations for expansion chamber designs based on simplified material modeling, the present design deals with fully-modeled multiphase constituent materials, such as acoustic, poroelastic and elastic one. Difficulties in the optimization formulation for the multiphase material distribution arise from extremely-different acoustic behavior of the materials and the use of various governing equations for different phase materials. To systematically vary the attributes of the chamber interior space, a unified multiphase modeling approach that allows continuous variations between the three-phase materials within the same implementation is employed with an elaborately-derived penalty parameters of material interpolation functions. Various design examples are successfully solved for wide frequency bands and the optimal configurations clearly demonstrate the importance of using specific configurations tuned to different target frequencies.

  • 87.
    Lind, Eleonora
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Optimising Open Porous Foam for Acoustical and Vibrational Performance2008Conference paper (Other academic)
  • 88.
    Lind Nordgren, Elenora
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Deü, Jean-Francois
    Alignment of anisotropic poro-elasticlayers: Sensitivity in vibroacoustic response due to angular orientation of anisotropicelastic and acoustic propertiesManuscript (preprint) (Other academic)
  • 89.
    Lind Nordgren, Eleonora
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Parametric relations for porous foams and their use in optimization of structural acoustic performance of multilayer trim components2006Conference paper (Other academic)
  • 90.
    Lind Nordgren, Eleonora
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Deü, Jean-Francois
    National Conservatory of Arts and Crafts, Laboratoire de Mécanique des Structures et des Systémes Couplés (LMSSC), Conservatoire National des Arts et Metiérs, France.
    Dazel, Olivier
    University of Maine, Laboratoire d'Acoustique de l'Université du Maine, France.
    Vibroacoustic response sensitivity due to relative alignment of two anisotropic poro-elastic layers2013In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 133, no 5, p. EL426-EL430Article in journal (Refereed)
    Abstract [en]

    The effects of relative alignment of two different types of anisotropic open cell porous materials are investigated in terms of the acoustic response of a multi-layered configuration. Numerical experiments, where gradient based optimization techniques were used, are conducted to find possible extremal values. It is shown that, depending on the degree of anisotropy of the porous material properties, their angular orientations have a significant and frequency dependent influence on the measured response. The results highlight the importance of further advancing the knowledge of anisotropic porous material behavior.

  • 91.
    Lindberg, Eskil
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    An Experimental Study of Interior Vehicle Roughness Noise from Disc Brake Systems2011Manuscript (preprint) (Other academic)
  • 92.
    Lindberg, Eskil
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    An experimental study of interior vehicle roughness noise from disc brake systems2013In: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 74, no 3, p. 396-406Article in journal (Refereed)
    Abstract [en]

    An experimental study of the friction-induced noise generated by the disc brake system of a passenger car is presented. In particular, the brake noise usually referred to as wire brush or roughness noise is studied. This is, in terms of frequency spectral content a broadband phenomenon, resulting from the interaction of multiple asperities in the tribological contact. A new experimental method for measurements of disc brake roughness noise is proposed, and is used in a lab environment where the vehicle speed and the brake pressure are accurately controlled. The aim is to study the influence of vehicle speed and brake pressure on the roughness noise inside the vehicle. It is shown for the specific test case that the transmission from the source to the interior is a vibro-acoustic structure-borne phenomenon. Measurements show that there is a, as expected, strong correlation between increased interior noise and both increased vehicle speed and brake pressure.

  • 93.
    Lindberg, Eskil
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Component mode synthesis using undeformed interface coupling modes to connect soft and stiff substructures2013In: Shock and Vibration, ISSN 1070-9622, E-ISSN 1875-9203, Vol. 20, no 1, p. 157-170Article in journal (Refereed)
    Abstract [en]

    Classical component mode synthesis methods for reduction are usually limited by the size and compatibility of the coupling interfaces. A component mode synthesis approach with constrained coupling interfaces is presented for vibro-acoustic modelling. The coupling interfaces are constrained to six displacement degrees of freedom. These degrees of freedom represent rigid interface translations and rotations respectively, retaining an undeformed interface shape. This formulation is proposed for structures with coupling between softer and stiffer substructures in which the displacement is chiefly governed by the stiffer substructure. Such may be the case for the rubber-bushing/linking arm assembly in a vehicle suspension system. The presented approach has the potential to significantly reduce the modelling size of such structures, compared with classical component mode synthesis which would be limited by the modelling size of the interfaces. The approach also eliminates problems of nonconforming meshes in the interfaces since only translation directions, rotation axes and the rotation point need to be common for the coupled substructures. Simulation results show that the approach can be used for modelling of systems that resemble a vehicle suspension. It is shown for a test case that adequate engineering accuracy can be achieved when the stiffness properties of the connecting parts are within the expected range of rubber connected to steel.

  • 94.
    Lindberg, Eskil
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Component Mode Synthesis Using Undeformed InterfaceCoupling Modes to Connect Soft and Sti Substructures2011Manuscript (preprint) (Other academic)
  • 95.
    Lindberg, Eskil
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Östberg, Martin
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Hörlin, Nils-Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    A vibro-acoustic reduced order model using undeformed coupling interface substructuring - Application to rubber bushing isolation in vehicle suspension systems2014In: Applied Acoustics, ISSN 0003-682x, Vol. 78, p. 43-50Article in journal (Refereed)
    Abstract [en]

    A vibro-acoustic reduced order model (ROM) based on a substructuring method using undeformed coupling interfaces (UCI) is proposed. The method may be used to reduce the order of a global problem, this by subdividing the global system to substructures interacting through UCI's. The local dynamic stiffness of each substructure may then be modelled with a, for that particular problem, best suited description. The feasibility of the method is demonstrated by a sensitivity analysis of the vibro-acoustic power isolation in a vehicle suspension system, comprising of a link arm connected to a vehicle car body through two rubber bushings. The link arm ROM is a component mode synthesis (CMS)-UCI, the rubber bushing model is a UCI-ROM derived from a 2D axisymmetric model using a frequency dependent visco-elastic material model. Finally the car body model is a frequency dependent UCI-ROM from a full car body finite element model. It is shown that the UCI-ROM approach efficiently can be used for parametric studies on a substructure level. The results suggest that the performed reorientation of the rubber bushings can alter, with orders of magnitude, the energy flow into the car.

  • 96.
    Lind-Nordgren, Eleonora
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Optimising open porous foam for acoustical and vibrational performance2010In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 329, no 7, p. 753-767Article in journal (Refereed)
    Abstract [en]

    A computational method for designing optimal arrangements of multilayer noise and vibration treatments in general and porous open cell foam in particular is discussed. The method uses finite element solutions to Biot's equations for poroelastic materials and provides data to evaluate cost functions and gradients. The porous material is parameterised using scaling laws linking the microscopic properties to the classical parameters, i.e. averaged elasticity, flow resistivity and characteristic viscous and thermal lengths. The cost function is either in terms of weight or in terms of the pressure response in a finite cavity, complemented with constraints on the other. However, care must be taken when choosing the cost function, as this will greatly affect the outcome of the optimisation. Observations made during the optimisation process indicate a limited number of minima within the parameter range of interest as well as beneficial continuity around these minima, thus enabling a meaningful optimisation. The results suggest that if alterations of the microscopic properties of the foam are made, the foam may be adapted to specific environmental conditions and thereby achieve improved acoustic behaviour as well as reduced weight.

  • 97.
    Lundberg, Eva
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Micro model for calculating flow resistivity for anisotropic open cell materials with high aspect ratio of struts2016Report (Other academic)
    Abstract [en]

    Micro-structure models for calculating flow resistivity for open cell materials with high aspect ratio of struts are presented.  Two micro-geometries are analyzed and compared: the hexahedral model, with the solid frame in shape of a cube for the isotropic case, and the tetrakaidecahedron (Kelvin cell). For flow resistivity calculations the solid frame is assumed to be rigid. The models are elongated in one direction to study the influence of micro-structural anisotropy on the macro level flow resistivity. In order to evaluate how the redistribution of material affects the flow resistivity, the porosity of the material is kept constant. Since the porosity is defined as unity minus the ratio of strut volume of the cell to the total volume of the cell, there are different ways of linking the micro level properties to the macro level. The first approach presented here is to let strut thickness be uniform and adjust the volume of the cell to a constant ratio compared to the isotropic case. The second approach is to let the strut volume be constant, i.e. if a strut is elongated, it is also thinner. In this case the cell volume must equal the isotropic volume. For uniform strut thickness the flow resistivity increases substantially with increasing height to width ratio for the hexahedral model, and decreases for the Kelvin cell. For constant strut volume the flow resistivity perpendicular to the flow direction increases, and the other direction (where the strut thickness increases) will be reduced. The average flow resistivity will in this case be almost constant. The method of scaling the micro-cell properties has a high influence on the resulting average flow resistivity, as does the cell volume in relation to the isotropic volume. For open porous materials which are approximately isotropic, the choice of micro geometry is not so critical and can be determined by other considerations, such as elasticity.

  • 98.
    Lundberg, Eva
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Orrenius, Ulf
    Bombardier Transportation.
    Semeniuk, Bradley
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Marcus Wallenberg Laboratory for Sound and Vibration Research.
    Sensitivity of macroscopic properties of a multi-layer panel including porous material on the micro-level parameters of an open cell porous material2014In: PROCEEDINGS OF INTERNATIONAL CONFERENCE ON NOISE AND VIBRATION ENGINEERING (ISMA2014) AND INTERNATIONAL CONFERENCE ON UNCERTAINTY IN STRUCTURAL DYNAMICS (USD2014), 2014, p. 2135-2149Conference paper (Refereed)
    Abstract [en]

    The micro-structure of an open cell porous material is modelled as an idealized, periodic structure, allowing anisotropic properties to form on the micro-scale. Using simple analytic descriptions of acoustic and elastic properties calculated from micro-structure geometry, the microstructural properties can be linked to averaged macroscopic elasto-acoustic properties, which can be measured and observed. These macro level properties may be deduced from measurements on a sample of a porous material which is at least a few centimetres across. The most common of the acoustic properties are the flow resistivity or the (dynamic) permeability, the porosity and the viscous and thermal characteristic lengths, together with the tortuosity. For the elasticity, the moduli of the Hooke's law are the most important. The underlying motivation for the current work is that the quantities are interdependent since they all depend on the micro geometry. Thus, to design the macro level acoustic properties for a required performance, physically relevant models linking these to the micro structure would be necessary. In this paper, a set of such models are proposed and utilising these, the influence of the anisotropy on acoustic properties of the foam as well as the transmission loss of a multi-layer plate is investigated. Typical macro level acoustic properties of open cell poro-elastic materials calculated from micro structure parameters are found to give results of the same order of magnitude as measured data found in the literature. Further, the model is applied to evaluate transmission loss of roof constructions with isotropic and anisotropic foam. It is shown that the sound reduction can be improved without changing the overall surface weight of the structure by making use of the anisotropy of the foam. The results Underline the importance of anisotropy and in addition provide guidance for further research.

  • 99.
    Lundberg, Eva
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. GKN Driveline, Box 981, Köping, Sweden.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. Centre for ECO2 Vehicle Design.
    Orrenius, Ulf
    Bombardier Transportation.
    Wennhage, Per
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Comparison of two different simplified micro structures for calculating flow resistivity of anisotropic open cell porous foams.2016In: International Conference on Noise and Vibration Engineering and USD2016 - International Conference on Uncertainty in Structural Dynamics, 2016, p. 485-499Conference paper (Refereed)
    Abstract [en]

    Open porous materials, with more than 90% air, are often included in multi-layer vehicle structures, like a car door or a train floor, to improve acoustic and thermal performance without adding much weight. Here the acoustic performance of open cell porous materials, with focus on flow resistivity, is modeled and evaluated based on simplified micro-structure models to investigate the effect of anisotropy. Two micro-geometries are analyzed and compared: the hexahedral model and the tetrakaidecahedron (Kelvin cell). The micro-models are elongated in one direction to study the influence of micro-structural anisotropy on the macro level flow resistivity. To evaluate how the redistribution of material effects on the flow resistivity, the porosity is kept constant. Both models can be used to predict average flow resistivity in the same range as measured materials. The flow resistivity components show large variations in different directions with increasing anisotropy, while the averaged flow resistivity is close to the isotropic value.

  • 100.
    Lundberg, Eva
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Bombardier Transportation.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Orrenius, Ulf
    Bombardier Transportation.
    Wennhage, Per
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Predicted and measured anisotropic acoustic and elastic properties for open cell porous material and their influence on typical train applications2015Conference paper (Refereed)
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