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  • 101.
    Manzari, Luca
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics.
    Cuenca, Jacques
    KTH.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Full-field harmonic deformation measurement using short-time stereo high-speed imaging — with application to anisotropic viscoelastic porous mediaManuscript (preprint) (Other academic)
    Abstract [en]

    This paper proposes a method for the measurement of full-field three-dimensional displacement transfer functions using short-time harmonic high-speed imaging. The methodology makes use of stereo digital image correlation and enables high-precision harmonic observations, for instance when stationary conditions are unavailable. An optimization algorithm is used as a search procedure for the point-wise amplitude, phase and frequency of the full-field motion, thus avoiding the intrinsic limitations of a Fourier-based approach for short acquisitions. In addition, the proposed approach enables the identification of mechanical non-linearities within the sample of interest and is robust to momentary data loss. Furthermore, an adaptive framework for extracting the coordinate system of the setup is proposed, thus allowing for the measured displacement field to be expressed therein. The method is demonstrated on a sample of sound-absorbing melamine foam, which poses a number of challenges, including the observability of its motion due to its high porosity and the inaccessibility of true stationary conditions due to relaxation processes. Selected results are presented and discussed, with a particular focus on computational costs and advantages with respect to existent techniques in terms of resolving power and amount of information retrieved.

  • 102.
    Manzari, Luca
    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. 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.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, 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 materials2018Conference paper (Refereed)
    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.

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    manzari-novem2018
  • 103.
    Manzari, Luca
    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. 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.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, 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 materials2018In: Proceedings of NOVEM 2018 Noise and vibration emerging methods, 2018, p. 91-102, article id 175109Conference paper (Refereed)
    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.

    Download full text (pdf)
    fulltext
  • 104.
    Manzari, Luca
    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.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Toward fully anisotropic viscoelastic material models using an automated high-speed optical rig2018In: 13TH INTERNATIONAL CONFERENCE ON VIBRATION MEASUREMENTS BY LASER AND NONCONTACT TECHNIQUES, 2018 / [ed] Tomasini, E P, IOP PUBLISHING LTD , 2018, article id 012003Conference paper (Refereed)
    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.

  • 105.
    Manzari, Luca
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Cuenca, Jacques
    Siemens Ind Software, Interleuvenlaan 68, B-3001 Leuven, Belgium..
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    A method for the observation of the anelastic behaviour of anisotropic porous materials using digital image correlation2020In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 474, article id 115244Article in journal (Refereed)
    Abstract [en]

    This paper proposes an experimental method for observing the anelastic anisotropic behaviour of poroelastic media. The setup relies on three-dimensional digital image correlation, enabling the acquisition of full-field displacement data from the visible faces of a vibrating cubic material sample. The latter is placed in a vacuum chamber, loaded with a seismic mass and excited uniaxially. The observability and relevance of the three-dimensional displacement field is assessed by means of a numerical simulation. A homogenised fully anisotropic model is used, implemented using the finite element method. Thus, a set of material properties obtained using single-point data is considered as the reference configuration for the numerical method. Selected experimental and numerical results are presented, highlighting the importance and the advantages that full-field observations yield over single-point measurements.

  • 106.
    Manzari, Luca
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Mao, Huina
    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. 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.
    Lopez Arteaga, Ines
    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.
    Experimental-numerical methods for inverse characterization of the anisotropic-anelastic properties of porous materials, based on dynamic Digital Image Correlation2018In: Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics, 2018, p. 687-695Conference paper (Refereed)
    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

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    fulltext
  • 107.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Rumpler, Romain
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    An inverse method for characterisation of the static elastic Hooke's tensors of solid frame of anisotropic open-cell materials2020In: International Journal of Engineering Science, ISSN 0020-7225, E-ISSN 1879-2197, Vol. 147, article id 103198Article in journal (Refereed)
    Abstract [en]

    This paper proposes an inverse estimation method for the extraction of the equivalent, static elastic, Hooke's tensor. The inversion is based on a fitting of the displacements, obtained from a combination of static compression and shear traction loads, on the faces of a sample specimen. An equivalent, homogenised material model is found by varying the elastic moduli until a defined cost function, based on the error measured as the difference between the displacement fields, has reached a minimum, at which an anisotropic constitutive solid model has been identified. The method is built on a multi-level step-wise approach, both from a computational as well as an assumed constitutive model symmetry point of view. The principle of the method is validated for a target anisotropic solid material model. The proposed multi-level approach is developed and refined for a known open-cell structure based on the Kelvin cell geometry. The accuracy of the method is verified and various strategies for increasing the rate of convergence in the inversion are discussed.

  • 108.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics.
    Rumpler, Romain
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics.
    Göransson, Peter
    KTH, Superseded Departments (pre-2005), Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    An inverse method for design and characterisation of acoustic materials2019Conference paper (Refereed)
    Abstract [en]

    This paper presents applications of an inverse method for the design and characterisation of anisotropic elastic material properties of acoustic porous materials. Full field 3D displacements under static surface loads are used as targets in the inverse estimation to fit a material model of an equivalent solid to the measurement data. Test cases of artificial open-cell foams are used, and the accuracy of the results are verified. The method is shown to be able to successfully characterise both isotropic and anisotropic elastic material properties. The paper demonstrates a way to reduce costs by characterising material properties based on the design model without a need for manufacturing and additional experimental tests.

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    fulltext
  • 109.
    Nadampalli, Ravi V.
    et al.
    DAIMLER AG.
    Dovstam, K.
    DAIMLER AG.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Glandier, C.
    DAIMLER AG.
    Damping Modelling in Complex Built-up StructuresIn: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568Article in journal (Other academic)
    Abstract [en]

    Damping in a given structure can be characterized and attributed to mechanisms like internal material dissipation and non material damping. While material damping is well understood and rather straightforward to model, the losses occurring at interfaces are less accessible and representable in simulations of realistic built-up body structures. Here, an approach based on linear modelling is discussed. The main objective of the work is to investigate the modelling of interface damping in a spot-welded structure by numerical simulations. Damping due to surface contact and movement of air through unsealed gaps is included. The results are promising in terms of the losses predicted for a realistic structure.

  • 110.
    Nadampalli, Ravi V.
    et al.
    DAIMLER AG.
    Glandier, C.
    DAIMLER AG.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Implementing Linear Modelling of Interface Damping in a Finite Element SoftwareIn: Finite elements in analysis and design (Print), ISSN 0168-874X, E-ISSN 1872-6925Article in journal (Other academic)
    Abstract [en]

    In the automotive industry virtual modelling of losses in a built-up structure is still a challenge. A body-in-white car structure consists of many spot-welded parts and the modelling of their associated losses is highly interesting. For this purpose, the dissipation of mechanical energy is here modelled in the frame of large scale computations using linear techniques with commercially available finite element software. Mechanical, vibration damping is introduced through external forces which are pairwise applied such that they oppose the relative motion at the contact interfaces between two parts. Two aspects are investigated, first if the proposed modelling captures the main mechanisms of the damping on a system level. Second, if the predicted local vibration responses at different locations correlate well between predicted and previously measured (in vacuo) spectra. Initial simulations show promising results and the level of damping observed in the predictions are similar to the measured spectra, fo rvibration shapes which involve significant relative motion along the spot-welded surfaces. An advantage with this technique is that it helps in understanding of different sources of total system damping, i.e. due to material and other sources of damping. It is verified that non-material damping due to mechanical contact is a significant contributor to the losses in a built-up structure which may be simulated with the proposed technique. In the paper the overall approach is discussed together with the specific aspects of the finite element implementation technique proposed.

  • 111.
    Nadampalli, Ravi Varma
    et al.
    Daimler AG.
    Dovstam, Krister
    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 Numerical acoustics.
    Glandier, Christian
    Daimler AG.
    On linear modelling of interface damping in a complex vibrating structure2012Conference paper (Refereed)
  • 112.
    Nadampalli, Ravi Varma
    et al.
    Daimler AG.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Glandier, Christian
    Daimler AG.
    Finite element formulation and implementation of poroelastic materials in an unbonded case2012In: 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. 3, p. 1815-1825Conference paper (Refereed)
    Abstract [en]

    Porous material modelling in the automotive industry is gaining more importance due to the ever increasing need for reducing the weight of the car body. This trend towards weight reduction makes it all the more important to optimize acoustic treatments. Extensive research has been done on understanding the physical behaviour of porous materials and their applications. However, when it comes to design, efficient predictive tools are needed in order to allow industrial applications to be performed at a reasonable costs, i.e. time and computation resources. During the product development cycle for the computations with trim body, a good correlation can be found between the measurements and the simulations in the low frequency region. But there is more effort needed in understanding the physical behaviour of trim components when coupled with structural parts, to improve prediction accuracy in the mid frequency region. Finite element techniques are widely used in computing trimmed vehicle bodies but modelling of poroelastic materials frequently requires refined meshes. This implies an increased amount of resources needed to solve the problem, both in terms of computational time and memory allocation. As a consequence, the computational costs increase substantially when a fully trimmed car body is analysed and compared to a body-in-white structure. This paper discusses one particular aspect in the modelling of trimmed vehicle bodies, namely the coupling conditions along the surfaces where the trim and the sheet metal are interfacing. These conditions are known to vary for a number of reasons, mostly production related, and bring in sources of variation among similar car bodies leading to a higher degree of uncertainty in the NVH behaviour, potentially affecting the possibilities of optimizing the overall system performance. In this paper, an investigation of the interfacial boundary conditions in general and the partially bonded and partially un-bonded coupling conditions in particular, will be discussed. The sensitivity to variations in the contact, both area and location will be illustrated, in order to increase the level of understanding in the modelling of the trim components, when compared by numerical simulations on a CAE model and a simplified test set-up.

  • 113.
    Nadampalli, Ravi Varma
    et al.
    Daimler AG.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Glandier, Christian
    Daimler AG.
    Modelling and implementation of interface loss models for linear response simulation in a complex structure.2012Conference paper (Refereed)
  • 114.
    O'Reilly, Ciarán J.
    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.
    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.
    Economic and ecological influences on the design and adoption of new vehicle concepts2016In: 22nd International Sustainable Development Research Society Conference, ISDRS, 2016, Vol. 2, p. 413-420Conference paper (Refereed)
    Abstract [en]

    Integration of economic and ecological considerations with engineering ones in new vehicle concepts presents many challenges, not least of which is overcoming long established expectations of vehicles and their performance. Design choices are not only influenced by clear rational factors but also by many imperfectly rational ones, which interact in a complex way to shape the final vehicle artefact. It should therefore be of interest to model and explore how such factors interact and influence the design process, particularly when it comes to targeting limited resources towards achieving the maximum improvement in the design. The aim is to find out under what circumstances can specific improvements penetrate into the established vehicle design and where are the critical phase boundaries over which significant advancement may be achieved. This is especially relevant in light of the on-going adoption of new technologies aimed at reducing the environmental impacts of vehicles. This insight may enable the design and adoption of radically different vehicles that represent a tipping point for sustainable transportation. A methodology is introduced to dynamically explore the trade-offs in vehicle design. The engineered vehicle is recognised as being a sub-system within a much wider surrounding world. A broad model is introduced to include both rational performance properties and imperfectly rational forces, and the system is stepped forward in time. The methodology is applied to a case study in which new knowledge is introduced into the established design paradigm and its adoption is tracked under a number of starting conditions and assumptions. The results illustrate where a targeted improvement that compensates for inherent inertia may lead to greater adoption that is beneficial from a broader long-term perspective. The model behaves reasonably in the vicinity of boundary conditions but more work is needed to explore and refine the behaviour across multiple variables. 

  • 115.
    O'Reilly, Ciarán J.
    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.
    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.
    Funazaki, Atsushi
    Japan Automobile Research Institute.
    Suzuki, Tetsuya
    Japan Automobile Research Institute.
    Edlund, Stefan
    Volvo Group Trucks Technology.
    Gunnarsson, Cecilia
    Volvo Group Trucks Technology.
    Lundow, Jan-Olov
    Bombardier Transportation.
    Cerin, Pontus
    Swedish Energy Agency.
    Cameron, Christopher J.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Swerea SICOMP.
    Wennhage, Per
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    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.
    Life-cycle energy optimisation: A proposed methodology for integrating environmental considerations early in the vehicle engineering design process2016In: Journal of Cleaner Production, ISSN 0959-6526, Vol. 135, p. 750-759Article in journal (Refereed)
    Abstract [en]

    To enable the consideration of life cycle environmental impacts in the early stages of vehicle design, a methodology using the proxy of life cycle energy is proposed in this paper. The trade-offs in energy between vehicle production, operational performance and end-of-life are formulated as a mathematical problem, and simultaneously balanced with other transport-related functionalities, and may be optimised. The methodology is illustrated through an example design study, which is deliberately kept simple in order to emphasise the conceptual idea. The obtained optimisation results demonstrate that there is a unique driving-scenario-specific design solution, which meets functional requirements with a minimum life cycle energy cost. The results also suggest that a use-phase focussed design may result in a solution, which is sub-optimal from a life cycle point-of-view.

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    fulltext
  • 116.
    O'Reilly, Ciarán J.
    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.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Potting, José
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms).
    Cameron, Christopher J.
    Swerea SICOMP, Sweden.
    Wennhage, Per
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Life-cycle energy optimisation for sustainable vehicle design2014In: FISITA World Automotive Congress, 2014Conference paper (Other academic)
    Abstract [en]

    A methodology is presented in this paper, in which the trade-offs in energy between vehicle production, operational performance and end-of-life are formulated as a mathematical problem that may be optimised. This methodology enables the consideration of the life-cycle environmental impact, through the proxy of life-cycle energy, in the very first stages of transport vehicle design where it can be concurrently balanced with other functionalities. The methodology is illustrated through a sandwich panel design case study. The optimisation results for this case demonstrate that a design solution does exist, which meets functional requirements with a minimum life-cycle energy cost. They also highlight that a pure lightweight design may result in a solution, which is sub-optimal from a life cycle point-of-view. 

  • 117. Palma, Giorgio
    et al.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burghignoli, Lorenzo
    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.
    Iemma, Umberto
    Acoustic Metamaterials in Aeronautics2018In: Applied Sciences, E-ISSN 2076-3417, Vol. 8, no 6, article id 971Article in journal (Refereed)
    Abstract [en]

    Metamaterials, man-made composites that are scaled smaller than the wavelength, have demonstrated a huge potential for application in acoustics, allowing the production of sub-wavelength acoustic absorbers, acoustic invisibility, perfect acoustic mirrors and acoustic lenses for hyper focusing, and acoustic illusions and enabling new degrees of freedom in the control of the acoustic field. The zero, or even negative, refractive sound index of metamaterials offers possibilities for the control of acoustic patterns and sound at sub-wavelength scales. Despite the tremendous growth in research on acoustic metamaterials during the last decade, the potential of metamaterial-based technologies in aeronautics has still not been fully explored, and its utilization is still in its infancy. Thus, the principal concepts mentioned above could very well provide a means to develop devices that allow the mitigation of the impact of civil aviation noise on the community. This paper gives a review of the most relevant works on acoustic metamaterials, analyzing them for their potential applicability in aeronautics, and, in this process, identifying possible implementation areas and interesting metabehaviors. It also identifies some technical challenges and possible future directions for research with the goal of unveiling the potential of metamaterials technology in aeronautics.

  • 118.
    Parra Martinez, Juan Pablo
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Siemens Industry Software.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Dazel, Olivier
    LAUM UMR CNRS 6613.
    Optimal alignment of anisotropic poroelastic cores in multilayered systems for acoustic performance2016In: Article in journal (Other academic)
  • 119.
    Parra Martinez, Juan Pablo
    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. LAUM, UMR CNRS, France.
    Dazel, Oliver
    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.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Acoustic behaviour and internal energies of multilayer systems including anisotropic poroelastic materialsManuscript (preprint) (Other academic)
  • 120.
    Parra Martinez, Juan Pablo
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Dazel, Olivier
    LAUM UMR CNRS 6613.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Siemens Industry Software.
    Acoustic analysis of anisotropic poroelastic multilayered systems2016In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, ISSN 1089-7550, Vol. 119, no 8, p. 084907-Article in journal (Refereed)
    Abstract [en]

    The proposed method allows for an extended analysis of the wave analysis, internal powers, and acoustic performance of anisotropic poroelastic media within semi-infinite multilayered systems under arbitrary excitation. Based on a plane wave expansion, the solution is derived from a first order partial derivative as proposed by Stroh. This allows for an in-depth analysis of the mechanisms controlling the acoustic behaviour in terms of internal powers and wave properties in the media. In particular, the proposed approach is used to highlight the influence of the phenomena intrinsic to anisotropic poroelastic media, such as compression-shear coupling related to the material alignment, the frequency shift of the fundamental resonance, or the appearance of particular geometrical coincidences in multilayered systems with such materials.

  • 121.
    Parra Martinez, Juan Pablo
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Dazel, Olivier
    LAUM UMR CNRS 6613.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Siemens Industry Software.
    Derivation of the state matrix for dynamic analysis of linear homogeneous media2016In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 140, no 2, p. EL218-EL220Article in journal (Refereed)
    Abstract [en]

    A method to obtain the state matrix of an arbitrary linear homogeneous medium excited by a plane wave is proposed. The approach is based on projections on the eigenspace of the governing equations matrix. It is an alternative to manually obtaining a linearly independent set of equations by combining the governing equations. The resulting matrix has been validated against previously published derivations for an anisotropic poroelastic medium.

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  • 122.
    Parra Martinez, Juan Pablo
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. LAUM - UMR CNRS.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Dazel, Olivier
    LAUM - UMR CNRS.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Analysis of the frequency response behaviour of anisotropic multilayered structures and potential acoustic performance optimizations2014In: Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics, Leuven, Belgium: KU Leuven , 2014, p. 4279-4290Conference paper (Refereed)
    Abstract [en]

    Anisotropy of elastic and acoustic properties increases the potential for performance tailoring of multilayered structures including poroelastic materials. An intrinsic part of such a design optimization is to understand the frequency response behaviour of such configurations in general and those including anisotropic porous layers in particular. In this work a plane wave method for anisotropic multilayered structures has been used to study the response sensitivity for anisotropic porous materials as a function of their material coordinate orientation. It is shown that, depending on the frequency range of interest, the sensitivity to the orientation of the anisotropic porous material varies. 

  • 123.
    Parra Martinez, Juan Pablo
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. LAUM UMR CNRS 6613.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Dazel, Olivier
    LAUM UMR CNRS 6613.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Siemens Industry Software.
    Calculation of internal powers for anisotropic porous materials within multilayered structures based on plane wave approximation2015Conference paper (Other academic)
    Abstract [en]

    This paper presents a method for calculating internal powers of multilayered configurations with anisotropic porous materials. The methodology takes a plane wave solution for anisotropic multilayered structures as a mathematical base for the derivation of the corresponding integral expressions. Different physical phenomena within the assessed structure can be then studied in detail as a whole or in terms of partial contributions to the total power balance. In the paper, an analysis of the dissipation in an anisotropic porous material as a function of its material coordinate orientation is performed.

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  • 124.
    Parra Martinez, Juan Pablo
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Dazel, Olivier
    LAUM UMR CNRS 6613.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Siemens Industry Software.
    Jaouen, Luc
    Matelys-Research Lab.
    Wave analysis of intrinsic phenomena related to anisotropic poroelastic materials in multilayered systems2016Conference paper (Refereed)
    Abstract [en]

    An analysis of intrinsic dynamic phenomena in anisotropic poroelastic media is presented, based on a plane wave formulation. The latter is derived from the Stroh formalism on the state variables governing the beha- viour of such media. A particular interest is given to the compression-shear coupling related to the material alignment of the anisotropic poroelastic core. This coupling motion can be directly correlated to the ma- terial mechanical parameters and affects the response of the overall structure in specific frequency ranges. Furthermore, the effect of the anisotropic poroelastic material coordinate orientation on the the acoustic and elastical response of multilayered systems with such material cores is investigated under diffuse field excita- tion conditions (i.e. only a part the mechanics which doesnt include maximum stress at rupture). An insight into other effects of anisotropy is provided, such as the frequency shift of the fundamental resonance related to the core material alignment and the appearance of particular geometrical coincidences in the acoustic behaviour of the system.

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  • 125.
    Rice, H. J.
    et al.
    Trinity Coll Dublin, Dept Mech Engn, Dublin, Ireland..
    Kennedy, J.
    Trinity Coll Dublin, Dept Mech Engn, Dublin, Ireland..
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Dowling, L.
    Trinity Coll Dublin, Dept Mech Engn, Dublin, Ireland..
    Trimble, D.
    Trinity Coll Dublin, Dept Mech Engn, Dublin, Ireland..
    Design of a Kelvin cell acoustic metamaterial2020In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 472, article id 115167Article in journal (Refereed)
    Abstract [en]

    Advancements in 3D print technology now allow the printing of structured acoustic absorptive materials at appropriate microscopic scales and sample sizes. Optimisation of parameter sets associated with a Kelvin Cell structure have the potential to develop various metabehaviours in the associated acoustic responses. The repeatability of the fundamental cell unit also provide a route for the development of viable macro models to simulate built up structures based on detailed models of the individual cell units. This paper describes a process to model, print and test such a sample. Manufacturing restraints will initially guide the optimised design and introduce response uncertainties associated with surface finishes and critical geometric dimensions. A "micro to macro" model is developed using a full visco thermal acoustic model of a single cell to develop a frequency dependent cell transfer matrix. The transfer matrices for the repeated cells may then be combined until sufficient material depth is achieved and efficiently generate an absorptivity for the material layer. Two prints using different processes (digital light processing (DLP) and selective laser melting (SLM)) of nominally the same kelvin cell structure. For the metal print the model predicts the absorptivity well once an allowance is made for the surface roughness. The DLP has a smoother finish with a lower geometric fidelity; however the DLP sample is still well modelled by the process.

  • 126.
    Rice, H. J.
    et al.
    Trinity College Dublin.
    Kennedy, John
    Trinity College Dublin.
    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. Centre for ECO2 Vehicle Design.
    Design of a Kelvin Cell Acoustic Metamaterial2018In: Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics, KU Leuven - Departement Werktuigkunde , 2018, p. 1081-1090Conference paper (Refereed)
    Abstract [en]

    Advancements in 3D print technology now allows the printing of structured acoustic absorbent materials at appropriate microscopic scale and sample sizes. Optimisation of parameter sets associated with a Kelvin Cell structure have the potential to develop various metabehaviours in the associated acoustic responses. The repeatability of the fundamental cell unit also provide a route for the development of viable macro models to simulate built up structures based on detailed models of the individual cell units. This paper describes a process to model, print and test of such a sample. Manufacturing restraints will initially guide the optimised design. Micro to macro models based on a single cell structure which are cross checked against a full visco thermal acoustic finite element model of the individual cell. A macro model based on a reduced lossy helmholtz system is then used to predict the absorptive response response under normal incidence and checked against a manufactured sample under experimental test.

  • 127. Rice, H.
    et al.
    Rumpler, Romain
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    A development on fast frequency sweep methods for acoustic radiation problems2016In: Proceedings of ISMA 2016 - International Conference on Noise and Vibration Engineering and USD2016 - International Conference on Uncertainty in Structural Dynamics, KU Leuven, Departement Werktuigkunde , 2016, p. 521-533Conference paper (Refereed)
    Abstract [en]

    The direct point by point swept solution of the discretised Helmholtz equation over a broad frequency range can become computationally expensive for large systems when fine frequency increments are required. Approaches involving reduced-order models using Padé-or waveform-based methods such as the well conditioned asymptotic waveform evaluation (WCAWE) can be used to significantly reduce this and can also be applied to systems with non-quadratic frequency dependency. In this paper WCAWE expansions are performed on a finite element based dynamical model of a two microphone open flanged impedance tube test. The use of an approximate loss-factor-based PML type approach to model the radiating section of the system is considered which eliminates dependency on reciprocal frequency terms. This allows for an efficient high order expansion as the frequency derivative terms need to be retained only up to second order. It is then shown that the method efficiently gives robust predictions of the end impedance with simple non-specialized elements.

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  • 128.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Deü, Jean-Francois
    Conservatoire des Arts et Metiers.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    A Padé approximant reconstruction scheme for fast resolution of structural-acoustic finite element models including porous materials.2012Conference paper (Refereed)
    Abstract [en]

    In this work, an efficient solution strategy is investigated for the resolution of multi-frequency structural-acoustic problems including 3D modelling of poroelastic materials. The finite element method is used, together with a combination of a modal-based reduction of the poroelastic domain and a Pad´e-based reconstruction approach. It thus takes advantage of the reduced-size of the problem while further improving the computational efficiency by limiting the number of frequency resolutions of the original problem. An adaptive procedure is proposed for the discretization of the frequency range into frequency intervals of reconstructed solution. The validation is presented on a 3D poro-acoustic example.

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    Rumpler_Novem
  • 129.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Deü, Jean-Francois
    Conservatoire des Arts et Metiers.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    A substructuring FE model for structural-acoustic problems with modal-based reduction of poroelastic interface2011In: Proceedings of the 4th International Conference on Computational Methods for Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2011, INT CENTER NUMERICAL METHODS ENGINEERING , 2011Conference paper (Refereed)
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  • 130.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Deü, Jean-Francois
    Conservatoire National des Arts et Metiers.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    An enhanced modal-based reduction of 3D porous materials modelling for efficient computation of structural-acoustic finite element applications2012Conference paper (Refereed)
    Abstract [en]

    In this work, a modal reduction, based on real-valued modes, is used to improve the computational efficiency of Finite Element problems including 3D modelling of sound absorbing poroelastic materials. A mode selection procedure is proposed and tested in order to downsize the basis including only the most significant contributions. The results are presented in terms of the level of efficacy reached.

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    Rumpler_Comvebonov
  • 131.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Deü, Jean-Francois
    Conservatoire des Arts et Metiers.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Efficient solution strategies for structural-acoustic FE applications with 3D modelling of porous materials2011Conference paper (Refereed)
  • 132.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Deü, J.-F
    Conservatoire National des Arts et Métiers, Paris France.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    A modal-based reduction method for sound absorbing porous materials in poro-acoustic finite element models2012In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 132, no 5, p. 3162-3179Article in journal (Refereed)
    Abstract [en]

    Structural-acoustic finite element models including three-dimensional (3D) modeling of porous media are generally computationally costly. While being the most commonly used predictive tool in the context of noise reduction applications, efficient solution strategies are required. In this work, an original modal reduction technique, involving real-valued modes computed from a classical eigenvalue solver is proposed to reduce the size of the problem associated with the porous media. In the form presented in this contribution, the method is suited for homogeneous porous layers. It is validated on a 1D poro-acoustic academic problem and tested for its performance on a 3D application, using a subdomain decomposition strategy. The performance of the proposed method is estimated in terms of degrees of freedom downsizing, computational time enhancement, as well as matrix sparsity of the reduced system.

  • 133.
    Rumpler, Romain
    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.
    Glav, Ragnar
    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. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Off-Peak Hours Deliveries: An Acoustic Perspective on the Stockholm Pilot Study2018In: Noise News International, ISSN 1021-643X, Vol. 26, no 2, p. 18-20Article in journal (Other (popular science, discussion, etc.))
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  • 134.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. Creo Dynamics AB, Sweden.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Vibration monitoring.
    A fast frequency sweep approach with a priori choice of padé approximants and control of their interval of convergence2015In: COUPLED PROBLEMS 2015: Proceedings of the 6th International Conference on Coupled Problems in Science and Engineering, CIMNE , 2015, p. 881-892Conference paper (Refereed)
    Abstract [en]

    In this work, a solution strategy based on the use of Padé approximants is investigated for efficient solution of parametric finite element problems such as, for example, frequency sweep analyses. An improvement to the Padé-based expansion of the solution vector components is proposed, suggesting the advantageous a priori estimate of the poles of the solution. This allows for the intervals of approximation to be chosen a priori in connection with the Padé approximants to be used. The choice of these approximants is supported by the Montessus de Ballore theorem, proving the convergence of a series of approximants with fixed denominator degrees. An acoustic case study is presented in order to illustrate the potential of the approach proposed by the authors.

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  • 135.
    Rumpler, Romain
    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. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    A finite element solution strategy based on Padé approximants for fast multiple frequency sweeps of coupled elastic, poroelastic, and internal acoustic problems2013In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 133, no 5, p. 3241-3241Article in journal (Refereed)
    Abstract [en]

    Analyses involving structural-acoustic finite element models including three-dimensional modeling of porous media are, in general, computationally costly. While being the most commonly used predictive tool in the context of noise and vibrations reduction, efficient solution strategies enabling the handling of large-size multiphysics industrial problems are still lacking, particularly in the context where multiple frequency response estimations are required, e.g., for topology optimization, multiple load cases analysis, etc. In this work, an original solution strategy is presented for the solution of multi-frequency structural-acoustic problems including poroelastic damping. Based on the use of Padé approximants, very accurate interpolations of multiple frequency sweeps are performed, allowing for substantial improvements in terms of computational resources, i.e., time and memory allocation. The method is validated and demonstrated for its potential on 3D applications involving coupled elastic, poroelastic, and internal acoustic domains.

  • 136.
    Rumpler, Romain
    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.
    A finite element solution strategy based on Padé approximants for fast multiple frequency sweeps of multivariate problems2013In: Proceedings of Meetings on Acoustics: Volume 19, 2013, Acoustical Society of America (ASA), 2013, p. 065003-Conference paper (Refereed)
    Abstract [en]

    Analyses involving structural-acoustic finite element models including three-dimensional modelling of porous media are, in general, computationally costly. While being the most commonly used predictive tool in the context of noise and vibrations reduction, efficient solution strategies enabling the handling of large-size multiphysics industrial problems are still lacking, particularly in the context where multiple frequency response estimations are required, e.g. for topology optimization, multiple load cases analysis, etc. In this work, an original solution strategy is presented for the solution of multi-frequency structural-acoustic problems including poroelastic damping. Based on the use of Padé approximants, very accurate interpolations of multiple frequency sweeps are performed, allowing for substantial improvements in terms of computational ressources, i.e. time and memory allocation. The method is validated and will be demonstrated for its potential on 3D applications involving coupled elastic, poroelastic and internal acoustic domains.

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    ICA_2013_Rumpler
  • 137.
    Rumpler, Romain
    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.
    An assessment of two popular Padé-based approaches for fast frequency sweeps of time-harmonic finite element problems2017In: Proceedings of Meetings on Acoustics, ISSN 1939-800X, Vol. 30, article id 022003Article in journal (Refereed)
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  • 138.
    Rumpler, Romain
    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. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Comparison of the component-wise and projection-based Padé approximant methods for acoustic coupled problems2017In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 141, no 5, p. 4033-4033Article in journal (Refereed)
    Abstract [en]

    Several Padé-based computational methods have been recently combined with the finite element method for the efficient solution of complex time-harmonic acoustic problems. Among these, the component-wise approach, which focuses on the fast-frequency sweep of individual degrees of freedom in the problem, is an alternative to the projection-based approaches. While the former approach allows for piecewise analytical expressions of the solution for targeted degrees of freedom, the projection-based approaches may offer a wider range of convergence. In this work, the two approaches are compared for a range of problems varying in complexity, size and physics. This includes for instance the modeling of coupled problems with non-trivial frequency dependence such as for the modeling of sound absorbing porous materials. Conclusions will be drawn in terms of computational time, accuracy, memory allocation, implementation, and suitability of the methods for specific problems of interest.

  • 139.
    Rumpler, Romain
    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.
    Fast frequency sweeps using Padé approximants for the finite element solution of multivariate structural-acoustic problems2013Conference paper (Refereed)
  • 140.
    Rumpler, Romain
    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. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Towards a robust a priori choice of Padé approximants for fast frequency sweeps of finite element problems2015In: Towards a robust a priori choice of Padé approximants for fast frequency sweeps of finite element problems, Lyon, France, 2015Conference paper (Refereed)
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  • 141.
    Rumpler, Romain
    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.
    Deü, Jean-Francois
    Conservatoire National des Arts et Métiers, Paris France.
    A residue-based mode selection and sorting procedure for efficient poroelastic modeling in acoustic finite element applications2013In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 134, no 6, p. 4730-4741Article in journal (Refereed)
    Abstract [en]

    Analysis of three-dimensional sound propagation in porous elastic media with the Finite Element (FE) method is, in general, computationally costly. Although it is the most commonly used predictive tool in complex noise control applications, efficient FE solution strategies for large-size industrial problems are still lacking. In this work, an original procedure is proposed for the sorting and selection of the modes in the solution for the sound field in homogeneous porous domains. This procedure, validated on several 2D and 3D problems, enables to reduce the modal basis in the porous medium to its most physically significant components. It is shown that the size of the numerical problem can be reduced, together with matrix sparsity improvements, which lead to the reduction in computational time and enhancements in the efficacy of the acoustic response computation. The potential of this method for other industrial-based noise control problems is also discussed.

  • 142.
    Rumpler, Romain
    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.
    Deü, J.-F
    Conservatoire National des Arts et Métiers, Paris France.
    A finite element approach combining a reduced-order system, Pade approximants, and an adaptive frequency windowing for fast multi-frequency solution of poro-acoustic problems2014In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 97, no 10, p. 759-784Article in journal (Refereed)
    Abstract [en]

    In this work, a solution strategy is investigated for the resolution of multi-frequency structural-acoustic problems including 3D modeling of poroelastic materials. The finite element method is used, together with a combination of a modal-based reduction of the poroelastic domain and a Pade-based reconstruction approach. It thus takes advantage of the reduced-size of the problem while further improving the computational efficiency by limiting the number of frequency resolutions of the full-sized problem. An adaptive procedure is proposed for the discretization of the frequency range into frequency intervals of reconstructed solution. The validation is presented on a 3D poro-acoustic example.

  • 143.
    Rumpler, Romain
    et al.
    Creo Dynam AB, Sweden.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Rice, H. J.
    Trinity College, Department of Mechanical and Manufacturing Engineering, Ireland.
    An adaptive strategy for the bivariate solution of finite element problems using multivariate nested Pade approximants2014In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 100, no 9, p. 689-710Article in journal (Refereed)
    Abstract [en]

    Most engineering applications involving solutions by numerical methods are dependent on several parameters, whose impact on the solution may significantly vary from one to the other. At times an evaluation of these multivariate solutions may be required at the expense of a prohibitively high computational cost. In the present paper, an adaptive approach is proposed as a way to estimate the solution of such multivariate finite element problems. It is based upon the integration of so-called nested Pade approximants within the finite element procedure. This procedure includes an effective control of the approximation error, which enables adaptive refinements of the converged intervals upon reconstruction of the solution. The main advantages lie in a potential reduction of the computational effort and the fact that the level of a priori knowledge required about the solution in order to have an accurate, efficient, and well-sampled estimate of the solution is low. The approach is introduced for bivariate problems, for which it is validated on elasto-poro-acoustic problems of both academic and more industrial scale. It is argued that the methodology in general holds for more than two variables, and a discussion is opened about the truncation refinements required in order to generalize the results accordingly.

  • 144.
    Rumpler, Romain
    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.
    Rice, H J
    Trinity College Dublin.
    Nested Padé approximants as a tool formultivariate finite element problems with porous media2014In: SAPEM 2014, 2014Conference paper (Refereed)
  • 145.
    Rumpler, Romain
    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.
    Rice, Henry
    Trinity College Dublin.
    Nested Padé approximants as a tool for multivariate finite element problems with porous media 2014Conference paper (Refereed)
  • 146.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Herweijer, Jur
    Eindhoven University of Technology, The Netherlands.
    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.
    A CFD-based methodology to calculate the acoustic transfer impedance of thin triaxial woven fabrics2016Conference paper (Refereed)
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  • 147.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Rodriguez Sanchéz, Raul
    TU Munich.
    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. Centre for ECO2 Vehicle Design.
    A multivariate, well-conditioned asymptotic waveform evaluation for finite element solutions with complex parametric dependence2018In: Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics, 2018Conference paper (Refereed)
    Abstract [en]

    Most engineering applications involving solutions by numerical methods are dependent on several parameters, whose impact on the solution may significantly vary from one to the other. At times an evaluation of these multivariate solutions may be required at the expense of a prohibitively high computational cost. In the present work, a multivariate finite element approach is proposed, allowing for a fast evaluation of parametric responses. It is based on the construction of a reduced basis spanning a subspace able to capture rough variations of the response. The method consists in an extension of the Well-Conditioned Asymptotic Waveform Evaluation (WCAWE) to multivariate problems, by an appropriate choice of derivative sequences, and a selection of the most relevant basis components. It is validated and demonstrated for its potential on a semi-industrial sized 3D application involving coupled poroelastic and internal acoustic domains.

    Download full text (pdf)
    fulltext
  • 148.
    Rumpler, Romain
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Rodrı́guez Sánchez, Raúl
    Chair of Structural Mechanics, Technical University of Munich.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    MULTIVARIATE PADÉ APPROXIMANTS FOR FINITE ELEMENT SOLUTIONS WITH COMPLEX PARAMETRIC DEPENDENCE2019Conference paper (Refereed)
    Abstract [en]

    Most engineering applications involving solutions by numerical methods are dependent on several parameters, whose impact on the solution may significantly vary from one to the other. At times an evaluation of these multivariate solutions may be required at the expense of a prohibitively high computational cost. In the present work, a multivariate finite element approach is proposed, allowing for a fast evaluation of parametric responses. It is based on the construction of a reduced basis spanning a subspace able to capture rough variations of the response. The method consists in an extension of the Well-Conditioned Asymptotic Waveform Evaluation (WCAWE) to multivariate problems, by an appropriate choice of derivative sequences, and a selection of the most relevant basis components. It is validated and demonstrated for its potential on a semi-industrial sized 3D application involving coupled poroelasticand internal acoustic domains.

    Download full text (pdf)
    fulltext
  • 149.
    Schöggl, Josef-Peter
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. University of Graz, Institute of Systems Sciences Innovation & Sustainability Research, Austria.
    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.
    A design-theoretic review of Sustainable Product Development literature2019In: 22nd International Conference on Sustainable Innovation, 2019Conference paper (Other academic)
    Abstract [en]

    Improving the socio-ecological performance of products in the design stage is essential for achieving sustainable patterns of production and consumption in line with the aims of the UN Sustainable Development Goals or the EU Action Plan for a Circular Economy. However, the uptake of available methods for sustainable product development (SPD) in practice is still low. Therefore, this paper explores if and how the integration of such methods with theories and models of design can contribute to overcoming the lagging adoption of SPD practices. The systematic review that was conducted on the intersection SPD and design theory research reveals that out of 2849 peer-reviewed publications on SPD, only 27 have a design-theoretic foundation. In fact, only the Theory of Inventive Problem Solving (TRIZ) and Axiomatic Design were utilised in SPD methods. The majority of the reviewed publications address cross-functional conflicts and provide exemplary cases but mainly focus on environmental aspects. Adoptions on a large scale are not reported. We conclude that underpinning SPD methods with theories and models of design constitutes a considerable research gap and that the addressing of it has the potential to further advance their integration with conventional engineering and design tasks.

  • 150.
    Seifzadeh, Alireza
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Pietrzyk, A.
    Volvo Cars Corporation, Gothenburg Sweden.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Numerical acoustics.
    Ramakrishnan, R.
    Department of Architectural Science, Toronto Canada.
    Effect of coupling between passenger compartment and trunk of a car on coupled system natural frequencies using acoustic frequency response function2014In: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 76, p. 310-318Article in journal (Refereed)
    Abstract [en]

    Conventional numerical techniques, used to study the acoustics of a car passenger cabin, treat the cabin as an isolated cavity excited by the cavity boundaries. Realistically, other cavity volumes such as the trunk communicate with the cabin through the holes in the parcel shelf of the car. An extended acoustic model of a car is formed by the cavity volumes of the passenger compartment and the trunk as well as air leakages through the holes provided for electrical devices and ventilation on the parcel shelf. In this study, the dynamic influence of air leakages between the passenger and trunk compartments on the first and second coupled system modes was investigated experimentally using acoustic frequency response function. The response to the acoustic excitation was measured for four different configurations of trim and holes of the parcel shelf. The natural frequencies of the first and second coupled system modes increased with increasing holes size with and without the trim of the parcel shelf. The experimental results were in good agreement with the reported results of coupling effects of double cavities connected by a neck. In the low frequency region since the wavelength is longer compared to the holes dimension, these holes act as point sources.

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