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  • 1.
    de Conchard, Antoine Vermeil
    et al.
    Univ Nantes, Dept Mech Mat & Civil Engn, Ecole Cent Nantes, Nantes, France..
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Rumpler, Romain
    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 perfectly matched layer formulation adapted for fast frequency sweeps of exterior acoustics finite element models2019In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 398, article id UNSP 108878Article in journal (Refereed)
    Abstract [en]

    Effective treatment of unbounded domains using artificial truncating boundaries are essential in numerical simulation, e.g. using the Finite Element Method (FEM). Among these, Perfectly Matched Layers (PML) have proved to be particularly efficient and flexible. However, an efficient handling of frequency sweeps is not trivial with such absorbing layers since the formulation inherently contains coupled space-and frequency-dependent terms. Using the FEM, this may imply generating system matrices at each step of the frequency sweep. In this paper, an approximation is proposed in order to allow for efficient frequency sweeps. The performance and robustness of the proposed approximation is presented on 2D and 3D acoustic cases. A generic, robust way to truncate the acoustic domain efficiently is also proposed, tested on a range of test cases and for different frequency regions. All rights reserved.

  • 2.
    Dowling, Luke
    et al.
    Trinity College Dublin.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Flanagan, Lara
    Trinity College Dublin.
    Kennedy, John
    Trinity College Dublin.
    Rice, H J
    Trinity College Dublin.
    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.
    Cuenca, Jacques
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Siemens Industry Software, Leuven Belgium.
    A combined design-manufacturing-testing investigation of micro- to macro-scale tailoring of open poroelastic materials based on perturbed kelvin cell micro-geometries2018In: Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics, 1177 , 2018, p. 1163-1177Conference paper (Refereed)
    Download full text (pdf)
    fulltext
  • 3.
    Gaborit, Mathieu
    et al.
    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. Le Mans Université, CNRS, UMR 6613, Laboratoire d'Acoustique de l'Université du Mans (LAUM), Institut d'Acoustique - Graduate School (IA-GS), Avenue Olivier Messiaen, 72085 Le Mans Cedex 09, France, Avenue Olivier Messiaen.
    Lundberg, Eva
    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. Volvo Construction Equipment, Eskilstuna, Sweden.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Engineering Mechanics.
    Controlled anisotropy materials and 3D printing: experimentations and analyses2022In: Proceedings of ISMA 2022 - International Conference on Noise and Vibration Engineering and USD 2022 - International Conference on Uncertainty in Structural Dynamics, KU Leuven, Departement Werktuigkunde , 2022, p. 477-481Conference paper (Refereed)
    Abstract [en]

    Novel computational tools and optimisation strategies offer an unprecedented framework to explore large design spaces within a short time frame. In the scope of material design, these new possibilities have completely revolutionized the research horizon, leading amongst other things to controlled anisotropy media with a finer granularity than ever seen before. However, a question arises regarding the manufacturability of such media which most of the time relies on 3D printing and the agreement between modelled and printed geometry. In the recent years, the authors published several articles on the properties of Kelvin Cell packings and the possibility to control their anisotropy. In the last few months, an effort towards printing the designed media has been made in search for experimental validation of the numerical results. This contribution describes the printing process for kelvin cell packing samples with controlled anisotropy and analyses their agreement with the model both from a geometric and from a physical response standpoint. Depending on the advances of current research, information on the dynamic behaviour of such systems will be discussed.

  • 4.
    Kleine-Wächter, Lukas
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL. Technical University of Munich, Department of Civil and Environmental Engineering, Arcisstr. 21, D-80333, Munich, Germany, Arcisstr. 21.
    Rumpler, Romain
    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.
    Mao, Huina
    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.
    Müller, G.
    Technical University of Munich, Department of Civil and Environmental Engineering, Arcisstr. 21, D-80333, Munich, Germany, Arcisstr. 21.
    Numerical study of Kelvin cells for the design of periodic lattice metamaterials2022In: Proceedings of ISMA 2022 - International Conference on Noise and Vibration Engineering and USD 2022 - International Conference on Uncertainty in Structural Dynamics, KU Leuven, Departement Werktuigkunde , 2022, p. 2960-2974Conference paper (Refereed)
    Abstract [en]

    Artificially-composed materials, often called metamaterials, are an increasingly considered measure for vibration control. By carefully arranging the material micro-structure, significant vibration attenuation is achievable in targeted frequency bands from resonant and wave scattering effects. An approach in designing materials for vibration control are micro-structures assembled from periodic cellular lattices. Such architectures result from the spatial repetition of cellular units that can be dynamically tuned by controlling the lattice characteristics. This contribution investigates the prospects of a three-dimensional lattice structure for application in vibration control. A unit cell design strategy is proposed based on the isometric Kelvin cell. By imposing twists on the faces of the Kelvin cell, a potential tuning mechanism for the cell's dispersive properties is introduced. Selected unit cell designs obtained from this approach are investigated in terms of the dispersion characteristics of 1D-infinite structures.

  • 5.
    Li, Jiejie
    et al.
    College of Engineering and Computer Science, the Australian National University, Australia.
    Chen, Bo
    School of Mechanics and Aerospace, Southwest Jiaotong University, China.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics.
    Exact closed-form solution for vibration characteristics of multi-span beams on an elastic foundation subjected to axial force2024In: Structures, E-ISSN 2352-0124, Vol. 60, article id 105884Article in journal (Refereed)
    Abstract [en]

    This paper investigates the vibration characteristics of multi-span beams resting on an elastic foundation and subjected to axial forces. A comprehensive analytical expression of the dynamic response of multi-span beams on an elastic foundation that is developed to address various boundary conditions. The vibration equation is derived by employing Newton's second law. By Laplace transformations and the Green's function method, the solution of this governing equation can be obtained. Subsequently, a unified description is implemented for distinct types of boundary conditions using matrix representations. The correctness is verified through reference results and finite element methods (FEM). The effects of different parameters such as support stiffness, foundation elastic and shear layer stiffness, and axial force on the vibration characteristics are analyzed. This study demonstrates two findings: First, there are two thresholds for support stiffness, and the stiffness value is divided into three intervals. In the same interval, multi-span beams show the same properties. Second, for a rigidly supported multi-span beam, the critical axial force with a natural frequency of zero is just the corresponding Euler's buckling load; for elastically supported multi-span beams, the critical axial force falls between the Euler's buckling load corresponding to single-span and multi-span beams.

  • 6.
    Lundberg, Eva
    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. Volvo Construction Equipment.
    Mao, Huina
    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.
    Gaborit, Mathieu
    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. Le Mans Université, CNRS, LAUM, UMR 6613, IA-GS.
    Rumpler, Romain
    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.
    Semeniuk, Bradley
    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.
    Tuning sound transmission loss for multi-layer panels with anisotropic foams2022Manuscript (preprint) (Other academic)
    Abstract [en]

    Multilayer panels consisting of a load carrying structure, a porous material for thermal and acoustic insulation and an interior trim panel is a very common type of design for vehicles. Weight as well as total build height are usually limiting constraints on the design. The idea of using an anisotropic porous material instead of an isotropic one to improve the sound transmission loss without adding a lot of weight or thickness is explored in the paper. By using a state space formulation of the transfer matrix method transmission loss it is possible to include anisotropic material properties in the calculation. The anisotropic material is modelled by a combination of a simplified analytical model for the acoustic losses and inverse estimation of the 21 independent elastic constants of the Hooke’s tensor. The porous material, which has typical dimensions possible to 3D print, is based on a Kelvin cell micro model that has a controlled degree of anisotropy. 

  • 7.
    Lundberg, Eva
    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. Volvo Construction Equipment, Eskilstuna,Sweden.
    Mao, Huina
    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.
    Gaborit, Mathieu
    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. Le Mans Université, CNRS, LAUM, UMR 6613, IA-GS, Le Mans, France.
    Rumpler, Romain
    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.
    Semeniuk, Bradley
    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.
    Tuning sound transmission loss for multi-layer panels with aniso-tropic foams2022In: Proceedings of ISMA 2022 - International Conference on Noise and Vibration Engineering and USD 2022 - International Conference on Uncertainty in Structural Dynamics, KU Leuven, Departement Werktuigkunde , 2022, p. 429-441Conference paper (Refereed)
    Abstract [en]

    Multilayer panels consisting of a load carrying structure, a porous material for thermal and acoustic insulation and an interior trim panel is a very common type of design for vehicles. Weight as well as total build height are usually limiting constraints on the design. The idea of using an anisotropic porous material instead of an isotropic one to improve the sound transmission loss without adding a lot of weight or thickness is explored in the paper. By using a state space formulation of the transfer matrix method transmission loss it is possible to include anisotropic material properties in the calculation. The anisotropic material is modelled by a combination of a simplified analytical model for the acoustic losses and inverse estimation of the 21 independent elastic constants of the Hooke's tensor. The porous material, which has typical dimensions possible to 3D print, is based on a Kelvin cell micro model that has a controlled degree of anisotropy.

  • 8.
    Lundberg, Eva
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. AB Volvo, Volvo Construction Equipment.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. 1.
    Semeniuk, Bradley
    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.
    Tunable absorption of micro-structure based anisotropic opencell materialsManuscript (preprint) (Other academic)
    Abstract [en]

    A simplified analytical model based on the Kelvin cell micro geometry has been developed for estimating the dynamic drag impedance of a periodic open cell material based on a Kelvincell based micro structure. The calculated dynamic drag impedance estimates similar properties as the static flow resistivity, but is based on dynamic micro scale estimates of the viscous losses neglecting interactions between struts. The Kelvin cell model can have a controlled degree ofanisotropy. Implementing the micro model in a state space transfer matrix method allows for absorption calculations of anisotropic micro material including stiffness to be calculated with limited input information. In addition to the solid constituent material parameters only cell height,strut thickness and twist angle, determining the degree of anisotropy, are required. The modelling allows for fast computations making optimization feasible, which is demonstrated by optimizing a two-layer porous material with the degree of anistropy as a design variable. An optimized design with enhanced absorption at lower frequencies, where the two layers have different anisotropic cell geoemetry, is discussed.

  • 9.
    Lundberg, Eva
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Semeniuk, Bradley
    KTH, School of Engineering Sciences (SCI).
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. 1.
    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.
    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.
    Analytical method for predicting micro-geometry based flow resistivity in anisotropic foams to improve sound absorption of vehicle panels2021In: Proceedings of the Resource Efficient Vehicles Conference - 2021 (rev2021) / [ed] O'Reilly, Ciarán J. et al., Stockholm, Sweden, 2021Conference paper (Other academic)
    Abstract [en]

    Vehicle structures such as train floors or car roofs are usually built as multi-layer panels, where a foam is placed between a load-carrying structure and an interior panel. The foam adds acoustical and thermal performance, but very little weight. In most contributions introducing foams for acoustic treatment, these have been considered isotropic, with acoustic losses mainly dependingon properties in the thickness direction. Another mechanism investigated here is the possibilityfor the acoustic flow in the foam to change from acting only in the thickness direction but rather to be re-directed to also travel in-plane, where dimensions are substantially larger than in the thickness direction, permitting more losses as the wave travels through the material. That kind of effect would result in higher acoustic losses without increasing the thickness of the vehicle panel and better use of the allowable space to achieve acoustic and functional requirements, i.e. a better functional density. A first step is to investigate how the absorption properties of an anisotropic foam differs from an isotropic foam. The chosen approach is to use an analytical micro-modelto calculate the dynamic drag impedance (flow resistivity on micro-scale) for an anisotropic opencell foam material. Based on a simple micro-scale geometry of Kelvin cells, it has been shown that  simple cell alterations to the micro-geometry, such as stretching, twisting and tilting results in an anisotropic foam structure. The anisotropic flow resistivity tensor is not diagonal and uniform, but different directions can have different magnitudes and it can display off-diagonal coupling terms. The influence of such micro-scale distortions on the flow resistivity, and on the resulting sound absorption is investigated with the purpose of improving the acoustic performance without adding volume. Future steps include to modify the functional density and tailor the sound transmission loss to a specific application.

  • 10.
    Mallol, Pau
    et al.
    KTH. Inkonova AB, Sweden.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Experiments and simulations of the deployment of a bistable composite boom2018In: Journal of Spacecraft and Rockets, ISSN 0022-4650, E-ISSN 1533-6794, Vol. 55, no 2, p. 292-302Article in journal (Refereed)
    Abstract [en]

    The rapidly growing use of small satellites for space missions requires deployable systems to be highly storable yet large and with adequate mechanical properties when deployed. This paper focuses on the modeling and simulation of a meter-class passively deployable boom, based on the self-contained linear meter-class deployable boom, exploiting the bistable nature of composite shells. Experimental tests were performed on a boom prototype suspended in a gravity offloading system. The strain energy level, deployment time, and spacecraft displacements calculated from the finite element method agree well with analytical analyses, confirming the theoretical accuracy of the finite element method. Because friction and strain energy relaxation were not included in the model, the finite element simulations predicted deployment times up to five times shorter than those of the gravity offloaded boom experiments. The quick deployment and violent end-of-deployment shock created boom deployment dynamics that were not seen in the experiments. The observed differences between the finite element model and the tests were mainly due to inaccurate material and friction models.

  • 11.
    Mallol, Pau
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Experiments and Simulations of the Deploymentof a Bi-stable Composite BoomManuscript (preprint) (Other (popular science, discussion, etc.))
    Abstract [en]

    The rapidly growing use of nano- and pico-satellites for space missions requires de-ployable systems to be highly storable yet large and with adequate mechanical properties when deployed. This paper focuses on the modeling and simulation of a meter-class passively deployable boom, based on the self-contained linear meter-class deployable(SIMPLE) boom by Thomas W. Murphey, exploiting the bi-stable nature of compositeshells. Experimental tests were carried on a boom prototype suspended in a gravityo-offloading system. The strain energy level, deployment time and spacecraft displacements calculated from the finite element method agree well with analytical analyses, confirming the theoretical accuracy of the finite element method. Since friction and strain energy relaxation were not accurately included in the model, the finite element simulations predict deployment times up to five times shorter than those of the gravity off-loaded boom experiments. The quick deployment and violent end-of-deployment shock create boom deployment dynamics which are not seen in the experiments. 

  • 12.
    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.

  • 13.
    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

    Download full text (pdf)
    fulltext
  • 14.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Numerical and Experimental Studies of Deployment Dynamics of Space Webs and CubeSat Booms2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, experiments and simulations are performed to study the deployment dynamics of space webs and space booms, focusing on the deployment and stabilization phases of the space web and the behavior of the bi-stable tape spring booms after long-term stowage.

    The space web, Suaineadh, was launched onboard the sounding rocket REXUS-12 from the Swedish launch base Esrange in Kiruna on 19 March 2012. It served as a technology demonstrator for a space web. A reaction wheel was used to actively control the deployment and stabilization states of the 2×2 m2 space web. After ejection from the rocket, the web was deployed but entanglements occurred since the web did not start to deploy at the specified angular velocity. The deployment dynamics was reconstructed by simulations from the information recorded by inertial measurement units and cameras. Simulations show that if the web would have started to deploy at the specified angular velocity, the web would most likely have been deployed and stabilized in space by the motor, reaction wheel and controller used in the experiment. A modified control method was developed to stabilize the out-of-plane motions before or during deployment. New web arms with tape springs were proposed to avoid entanglements.

    A deployable booms assembly composed of four 1-m long bi-stable glass fiber tape springs was designed for the electromagnetically clean 3U CubeSat Small Explorer for Advanced Missions (SEAM). The deployment dynamics and reliability of the SEAM boom design after long-term stowage were tested by on-ground experiments. A simple analytical model was developed to predict the deployment dynamics and to assess the effects of the GOLS and the combined effects of friction, viscoelastic strain energy relaxation, and other factors that act to decrease the deployment force. In order to mitigate the viscoelastic effects and thus ensure self-deployment, different tape springs were designed, manufactured and tested. A numerical model was used to assess the long-term stowage effects on the deployment capability of bi-stable tape springs including the friction, nonlinear-elastic and viscoelastic effects. A finite element method was used to model a meter-class fully coiled bi-stable tape spring boom and verified by analytical models.

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    Numerical and Experimental Studies of Deployment Dynamics of Space Webs and CubeSat Booms
  • 15.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Gaborit, Mathieu
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. Le Mans Univ, CNRS, Inst Acoust Grad Sch IA GS, Lab Acoust Univ Mans LAUM,UMR 6613, Le Mans, France..
    Lundberg, Eva
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. 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), Engineering Mechanics.
    Yin, Binglun
    Zhejiang Univ, Inst Appl Mech, Hangzhou 310027, Peoples R China.;Zhejiang Univ, Ctr X Mech, Hangzhou 310027, Peoples R China..
    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.
    Dynamic behaviour of low- to high-density anisotropic cellular materials2022In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 536, article id 117137Article in journal (Refereed)
    Abstract [en]

    The dynamic behaviour of a novel anisotropic cellular micro-structural geometry derived from the basic symmetric Kelvin cell is discussed for varying relative density. The cells are arranged in a cubic array and the dynamic response is studied in a classical seismic mass setup using beam elements to represent the ligaments of the cell. The eigenfrequencies and the eigenmodes of the cellular array are computed together with forced response simulations where a proportional damping model of the Young's modulus for the cell ligaments is assumed. The frequency dependence of the damping is based on a fractional derivative representation. Using a recently developed inversion method, equivalent, homogenised solid material models of the cellular array are discussed with the associated equivalent elastic properties given in terms of the 21 elastic constants of the Hooke's tensor. For the equivalent solid material models, the eigenfrequencies and eigenmodes are computed, and forced response simulations are performed assuming the same type of proportionality in the damping as the cellular array, for the same seismic mass setup. The correlation, between the eigenfrequencies and the eigenmodes, shows an overall interesting agreement between the cellular and the equivalent solid model for the quite complex deformation shapes observed. The forced response results indicate that the equivalent solid modelling accurately represents the global dynamics of the anisotropic cellular array, but needs to be further refined when local shearing deformation within the individual cells starts to be dominating.

  • 16.
    Mao, Huina
    et al.
    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.
    Gaborit, Mathieu
    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. Laboratoire d’Acoustique de l’Université du Mans (LAUM), UMR 6613, Institut d’Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, France.
    Rumpler, Romain
    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.
    Göransson, Peter
    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.
    Vibro-acoustic behaviour of low- to high-density anisotropic cellular foams2020In: PROCEEDINGS OF INTERNATIONAL CONFERENCE ON NOISE AND VIBRATION ENGINEERING (ISMA2020) / INTERNATIONAL CONFERENCE ON UNCERTAINTY IN STRUCTURAL DYNAMICS (USD2020) / [ed] Desmet, W Pluymers, B Moens, D Vandemaele, S, KATHOLIEKE UNIV LEUVEN, DEPT WERKTUIGKUNDE , 2020, p. 451-461Conference paper (Refereed)
    Abstract [en]

    The paper discusses the vibro-acoustic behaviour of a recently proposed novel anisotropic cellular foam geometry derived from the basic symmetric Kelvin cell geometry. The associated equivalent elastic material properties are estimated based on a recently developed inversion method, in terms of the 21 elastic constants of the Hooke's tensor. The dynamic behaviour of the cellular material configuration and its homogeneous model by applying the equivalent material properties are studied under arbitrary excitation. The correlation between the vibro-acoustic behaviour, foam density, and material anisotropy is studied based on finite element simulations. High correlations of eigenfrequency and eigenmode shapes between the target cellular foam model and the equivalent solid model are found. A set of empirical relations are proposed, linking the micro-structure in low to high relative density for the anisotropic cellular geometries investigated. Potential applications in vibro-acoustic of the proposed anisotropic foam are discussed

  • 17.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Ganga, Pier Luigi
    Kayser Italia.
    Ghiozzi, Michele
    Kayser Italia.
    Ivchenko, Nickolay
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Deployment of Bistable Self-Deployable Tape Spring Booms Using a Gravity Offloading System2017In: Journal of Aerospace Engineering, ISSN 0893-1321, E-ISSN 1943-5525, Vol. 30, no 4Article in journal (Refereed)
    Abstract [en]

    Bistable tape springs are suitable as deployable structures thanks to their high packaging ratio, self-deployment ability, low cost, light weight, and stiffness. A deployable booms assembly composed of four 1-m long bistable glass fiber tape springs was designed for the electromagnetically clean 3U CubeSat Small Explorer for Advanced Missions (SEAM). The aim of the present study was to investigate the deployment dynamics and reliability of the SEAM boom design after long-term stowage using onground experiments and simulations. A gravity offloading system (GOLS) was built and used for the onground deployment experiments. Two booms assemblies were produced and tested: a prototype and an engineering qualification model (EQM). The prototype assembly was deployed in a GOLS with small height, whereas the EQM was deployed in a GOLS with tall height to minimize the effects of the GOLS. A simple analytical model was developed to predict the deployment dynamics and to assess the effects of the GOLS and the combined effects of friction, viscoelastic relaxation, and other factors that act to decrease the deployment force. Experiments and simulations of the deployment dynamics indicate significant viscoelastic energy relaxation phenomena, which depend on the coiled radius and stowage time. In combination with friction effects, these viscoelastic effects decreased the deployment speed and the end-of-deployment shock vibrations. 

  • 18.
    Mao, Huina
    et al.
    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), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Gaborit, Mathieu
    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.
    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.
    Kennedy, John
    Trinity College Dublin, Ireland.
    O'Connor, Daragh
    Trinity College, Dublin.
    Trimble, Daniel
    Trinity College Dublin, Ireland.
    Rice, Henry
    Trinity College Dublin, Ireland.
    Twist, tilt and stretch: From isometric Kelvin cells to anisotropic cellular materials2020In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 193, article id 108855Article in journal (Refereed)
    Abstract [en]

    Simple geometric distortions applied to the isometric Kelvin cell structures, (the tetrakaidecahedron), are shown to result in equivalent materials with anisotropic Hooke's tensors. The equivalent material models are estimated using a recently published inversion method where the 21 independent elastic constants of the Hooke's tensor are identified. In these cell geometries, some of the faces of the Kelvin cell have been twisted and/or tilted. Numerical experiments suggest that the equivalent material models of the distorted cells exhibit variations in compression, shearing, shear-compression and shear-shear coupling moduli, which are shown to be continuous functions of the degree of twist and tilt applied. When twist and tilt are combined, it is demonstrated that full anisotropy in the elastic properties may be generated. A rotational symmetry without symmetry planes, but having either a tetragonal or a monoclinic elastic symmetry is discussed. Four cell geometries, one isometric and three distorted, were manufactured using masked stereolithography 3D printing technology and measured in a laboratory compression set-up. Results from numerical simulations are compared to the experimental in terms of the compressive modulus.

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    fulltext
  • 19.
    Mao, Huina
    et al.
    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), 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.
    3D tunable anisotropic metamaterial for low-frequency vibration absorption2021In: Proceeding of Resource Efficient Vehicles 2021, 2021Conference paper (Other academic)
    Abstract [en]

    In the well-known conflict between design space and performance requirements e.g. in termsof noise and vibration insulation, the emergence of new materials exhibiting exceptional insula-tion properties for a reduced weight or volume increase has received much attention in the lastdecade. Metamaterials with artificially designed architectures are increasingly considered as newfunctional materials with unusual properties. This paper presents a group of novel 3D latticemetamaterials for low-frequency vibration absorption. The novel lightweight cellular microstruc-tures for vibro-acoustic metamaterials are designed by modification of the Kelvin cell. Interestinganisotropic material properties are generated by controlling the geometries, e.g., high-stiffness,auxetic, and strong compression-torsional coupling properties. The interesting meta-propertiesenable to tune the cellular resonators of the structures at a low-frequency range. Previous researchis mostly focused on metamaterials for vibration absorption along only one or two directions. Inthis paper, wide-band high sound absorption properties of energy transfer coupling in all threedirections are achieved by tunning the frequency-dependent meta-structures in controlling the ge-ometry and material properties. Additive manufacturing technologies are used for making the 3Dcomplex tunable metamaterials.

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    fulltext
  • 20.
    Mao, Huina
    et al.
    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), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, 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), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    A note on the linear deformations close to the boundaries of a cellular material2021In: Mechanics research communications, ISSN 0093-6413, E-ISSN 1873-3972, Vol. 111, article id 103657Article in journal (Refereed)
    Abstract [en]

    Previously reported measurements of uniaxial compression of cellular acoustic materials have shown an intriguing loss of stiffness in the regions close to the boundaries. The present contribution attempts to further investigate if these effects may be modelled by assuming a local alteration of the microstructure in these regions close to the boundaries resulting from cutting a block of material into smaller samples. Assuming that fewer struts contribute locally to the mechanical behaviour, implies a reduced equivalent porosity, or relative density, in the boundary region. The approach explored here consists in randomly removing a portion of the struts constituting the microstructure of the cells because of damage incurred in the cutting process. The analysis is performed using a linear elastic deformation behaviour at the boundary of cellular acoustic materials. For the modelling of the microstructure, the Kelvin cell geometry is chosen. Applying the assumption that struts are damaged in the process of cutting a block of material into smaller samples, as an explanation for the observed high-strain boundary regions, it is shown that the experimental observations may be qualitatively reproduced. It is also shown that the equivalent density in the boundary regions may be estimated from the ratio of the boundary compressive modulus to that of the interior region of the sample. Through the presented results, the approximation errors in compression stiffness measurements performed for a real material may be estimated. Although providing a viable explanation of the experimentally observed behaviour of the boundary regions, it should be understood that the proposed approach primarily offers a simple, accurate equivalent description of this phenomenon.

  • 21.
    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.

  • 22.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Rumpler, Romain
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Göransson, Peter
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    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
  • 23.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Shipsha, Anton
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Design and analysis of laminates for self-deployment of viscoelastic bi-stable tape springs after long-term stowageManuscript (preprint) (Other (popular science, discussion, etc.))
    Abstract [en]

    Bi-stable tape springs are ultra-thin fiber-reinforced polymers composites, which could self-deploy through releasing stored strain energy. Strain energy relaxation is observed after long-term stowage of bi-stable tape springs due to viscoelastic effects and the tape springs might lose their self-deployment abilities. In order to mitigate the viscoelastic effects and thus ensure self-deployment, different tape springs were designed, manufactured and tested. Deployment experiments show that a 4-layer, [-45/0/90/45], plain weave glass fiber tape spring has ahigh capability to mitigate the strain energy relaxation effects to ensure self-deployment after long-term stowage in a coiled configuration. The two inner layers increase the deployment force and the outer layers are used to generate the bi-stability. The presented 4-layer tape spring can self-deploy after more than 6 months of stowage at room temperature. A numerical model was used to assess the long-term stowage effects on the deployment capability of bi-stable tape springs. The experiments and modeling results show that the viscoelastic strain energy relaxationstarts after only a few minutes after coiling. The relaxation shear stiffness decreases as the shear strain increases and is further reduced by strain energy relaxation when a constant shear strain is loaded. The numerical model and experiments could be applied in design to predict the deployment force of other types of tape springs with viscoelastic and friction effects included.

  • 24.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Shipsha, Anton
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Design and Analysis of Laminates for Self-Deployment of Viscoelastic Bistable Tape Springs after Long-Term Stowage2017In: Journal of applied mechanics, ISSN 0021-8936, E-ISSN 1528-9036, Vol. 84, no 7, article id 071004Article in journal (Refereed)
    Abstract [en]

    Bistable tape springs are ultrathin fiber-reinforced polymer composites, which could self-deploy through releasing stored strain energy. Strain energy relaxation is observed after long-term stowage of bistable tape springs due to viscoelastic effects and the tape springs might lose their self-deployment abilities. In order to mitigate the viscoelastic effects and thus ensure self-deployment, different tape springs were designed, manufactured, and tested. Deployment experiments show that a four-layer, [â '45/0/90/45], plain weave glass fiber tape spring has a high capability to mitigate the strain energy relaxation effects to ensure self-deployment after long-term stowage in a coiled configuration. The two inner layers increase the deployment force and the outer layers are used to generate the bistability. The presented four-layer tape spring can self-deploy after more than six months of stowage at room temperature. A numerical model was used to assess the long-term stowage effects on the deployment capability of bistable tape springs. The experiments and modeling results show that the viscoelastic strain energy relaxation starts after only a few minutes after coiling. The relaxation shear stiffness decreases as the shear strain increases and is further reduced by strain energy relaxation when a constant shear strain is applied. The numerical model and experiments could be applied in design to predict the deployment force of other types of tape springs with viscoelastic and friction effects included.

  • 25.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Sinn, T.
    Vasile, M.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Simulation and control of a space web deployed by centrifugal forces in a sounding rocket experiment2016In: AIAA Modeling and Simulation Technologies Conference, 2016, American Institute of Aeronautics and Astronautics Inc, AIAA , 2016Conference paper (Refereed)
    Abstract [en]

    A deployable space web is a flexible structure that can act as a lightweight platform for construction of large structures in space. In order to save space and energy for small deployable structures, a one-step deployment method was a possible choice for future web deployment without complicated extending mechanisms. The aim of the Suaineadh experiment was to deploy and stabilize a space web by centrifugal forces and act as a test bed of the one-step deployment. Suaineadh, a 2 × 2 m2 space web, was ejected from the nose cone of REXUS-12 sounding rocket and deployed in a micro-gravity environment. A developed control law and a reaction wheel were used to control the deployment. Results from ground tests, simulations and former sounding rocket experiments were used to design the structure, folding pattern, control parameters and the deployment. During the experiment, the web was deployed but entanglements occurred since the web did not start to deploy at the specified proper initial angular velocity. It might be due to the broken inertial measurement unit which failed to detect the required spin rate of the hub or other unknown problems. The deployment dynamics was reconstructed from the information recorded by inertial measurement units and cameras. Simulations show that if the Suaineadh space web started to deploy at the specified proper angular velocity, the web would most likely have been deployed and stabilized in space by the motor, reaction wheel and controller used in the experiment. In actual flight, out-of-plane motions were observed both in deployment and stabilization phases. In order to stabilize the out-of-plane motions and reduce the risk of entanglement observed from experiment, simulation results show that small reaction wheels could be used before or during web deployment. Tape springs could also be used as web arms to avoid entanglement.

  • 26.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Sinn, Thomas
    Vasile, Massimiliano
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Post-launch analysis of the deployment dynamics of a space web sounding rocket experiment2016In: Acta Astronautica, ISSN 0094-5765, E-ISSN 1879-2030, Vol. 127, p. 345-358Article in journal (Refereed)
    Abstract [en]

    Lightweight deployable space webs have been proposed as platforms or frames for a construction of structures in space where centrifugal forces enable deployment and stabilization. The Suaineadh project was aimed to deploy a 2 x 2 m2 space web by centrifugal forces in milli-gravity conditions and act as a test bed for the space web technology. Data from former sounding rocket experiments, ground tests and simulations were used to design the structure, the folding pattern and control parameters. A developed control law and a reaction wheel were used to control the deployment. After ejection from the rocket, the web was deployed but entanglements occurred since the web did not start to deploy at the specified angular velocity. The deployment dynamics was reconstructed from the information recorded in inertial measurement units and cameras. The nonlinear torque of the motor used to drive the reaction wheel was calculated from the results. Simulations show that if the Suaineadh started to deploy at the specified angular velocity, the web would most likely have been deployed and stabilized in space by the motor, reaction wheel and controller used in the experiment.

  • 27.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Experiments and analytical modeling for designing tape spring composites2017In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2017Conference paper (Refereed)
    Abstract [en]

    Lightweight fiber reinforced tape spring composites are proposed for deployable space structures for nanosatellites. Neutral stable carbon fiber tape springs and bi-stable glass fiber tape springs were manufactured and their self-deployabilities after stowage were experimentally tested. The viscoelastic effects of the composites used were experimentally investigated. An analysis methodology that predicts neutral stability or bi-stability in appropriately arranging fiber directions, layups and fabric properties is presented. A design method flowchart is presented to give a reference for designing neutral or bi-stable tape springs based on the experiments and the analytical model, e.g., material type, layup, fibers direction and stability parameters. The tape spring properties before and after stowage can be predicted. The analytical model shows that fabrics of high strength fibers and low shear modulus resin with layer angle ±45° are good choices for neutrally tape springs and adding inner 0°/90° layers can increase the deployment force for bi-stable tape springs. The bi-stable glass fiber tape springs that can self-deploy after more than 6 months of stowage and high strength carbon fiber neutrally tape springs were fabricated. 

  • 28.
    Mao, Huina
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    EXPERIMENTS AND ANALYTICAL MODELING FOR DESIGNING TAPE SPRING COMPOSITESManuscript (preprint) (Other (popular science, discussion, etc.))
    Abstract [en]

    Lightweight fiber reinforced tape spring composites are proposed for deployable space structures for nanosatellites. Neutral stable carbon fiber tape springs and bi-stable glass fiber tape springs were manufactured and their self-deployabilities after stowage were experimentally tested. The viscoelastic effects of the composites used were experimentally investigated. An analysis methodology that predicts neutral stability or bi-stability in appropriately arranging fiber directions, layups and fabric properties is presented. A design method flowchart is presented to give a reference for designing neutral or bi-stable tape springs based on the experiments and the analytical model, e.g., material type, layup, fibers direction andstability parameters. The tape spring properties before and after stowage can be predicted. The analytical model shows that fabrics of high strength fibers and low shear modulus resin with layer angle ±45o are good choices for neutrally tape springs and adding inner 0o/90o layers can increase the deployment force for bi-stable tape springs. The bi-stable glass fiber tape springs that can self-deploy after more than 6 months of stowage and high strength carbon fiber neutrally tape springs were fabricated.

  • 29.
    Matija, Milenovic
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics.
    Dadbakhsh, Sasan
    KTH, School of Industrial Engineering and Management (ITM), Production engineering.
    Design and Development of Damping SandwichPanels for Satellite Housing Using AdditiveManufacturing2022Conference paper (Refereed)
    Abstract [en]

    The present work investigates the performance of additively-manufactured sandwich structures with the goal of reducing the effect of vibrations on a spacecraft during launch, whilst minimizing mass. Additive manufacturing allows designers to implement custom and complex geometries, such as the sheet gyroid structures, inside sandwich panels. Accordingly, this work details the development of gyroid-based sandwich structures for damping. Several test specimens are designed, additively manufactured using ABS plastic, and their damping performances are evaluated based on both simulation and experiments. Damping values are identified using frequency response transfer functions. The results show that as theory predicts, adding more mass, through the added thickness of the gyroid reduces the amplitude of vibrations. However, on a damping-per-unit-mass basis, the experimental results are inconclusive mainly due to the measurements of vibrations in the center of the sandwich panels instead of the sides where the vibrations can be maximum. Therefore, simulations better illustrate the changes of the damping behavior at different applied frequencies. Lessons and experiences are summarized for future work, particularly in exploring the effects of varying other 3D printed composite meta-lattice sandwich structures for satellites. 

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    Design_and_Development_of_Damping_Sandwich_Panels_for_Satellite_Housing_Using_Additive_Manufacturing
  • 30. 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.

  • 31.
    Rumpler, Romain
    et al.
    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.
    Vermeil De Conchard, Antoine
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Fast frequency sweeps for unbounded media: An efficient perfectly matched layer finite element formulation2020In: EURODYN 2020: XI International Conference on Structural Dynamics: Proceedings, 2020, Vol. 2, p. 2508-2520Conference paper (Refereed)
    Abstract [en]

    Effective treatment of unbounded domains using artificial truncating boundaries are essential in numerical simulation including unbounded media, such as in the scope of exterior acoustics, sound transmission calculations,... Among these, Perfectly Matched Layers (PML) have proved to be particularly efficient and flexible, as well as relatively easy to implement using the Finite Element Method (FEM). However, an efficient handling of frequency sweeps is not trivial with such absorbing layers since the formulation inherently contains coupled space- and frequency-dependent terms. Using the FEM, this may imply generating system matrices at each step of the frequency sweep. In this contribution, an approximation is presented in order to allow for efficient frequency sweeps, for instance using Pade-based methods as extensively used by the authors in previous contributions. The performance and robustness of the proposed approximation is presented on an acoustic cases. A generic, robust way to truncate the acoustic domain efficiently is also proposed, tested on a range of test cases and for different frequency regions. It is shown that the approximation, based on a sub-interval approximation of a tuning parameter in the frequency range of interest, provides consistently very good results, close to the costly, original formulations. An a priori estimate of a robust choice for this tuning parameter is also introduced, together with a set of empirical recommendations associated with mesh size, domain size and truncation.

  • 32. Sinn, Thomas
    et al.
    McRobb, Malcolm
    Wujek, Adam
    KTH, School of Information and Communication Technology (ICT).
    Skogby, Jerker
    KTH, School of Information and Communication Technology (ICT).
    Rogberg, Fredrik
    KTH, School of Electrical Engineering (EES).
    Wang, Junyi
    KTH, School of Electrical Engineering (EES).
    Vasile, Massimiliano
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    THE EXPERIMENT THAT CAME FROM THE COLD: RESULTS FROM THE RECOVERED REXUS12 SUAINEADH SPINNING WEB EXPERIMENT2015In: EUROPEAN ROCKET AND BALLOON: PROGRAMMES AND RELATED RESEARCH, 2015, p. 449-459Conference paper (Refereed)
    Abstract [en]

    The Suaineadh experiment had the purpose to deploy a 2m x 2m web in milli gravity conditions by using the centrifugal forces acting on corner sections of a web that is spinning around a central hub. Continuous exploration of our solar system and beyond requires ever larger structures in space. But the biggest problem nowadays is the transport of these structures into space due to launch vehicle payload volume constrains. By making the space structures deployable with minimum storage properties, this constrain may be bypassed. Deployable concepts range from inflatables, foldables, electrostatic to spinning web deployment. The advantage of the web deployment is the very low storage volume and the simple deployment mechanism. These webs can act as lightweight platforms for the construction of large structures in space without the huge expense of launching heavy structures from Earth. The Suaineadh experiment was launched onboard the sounding rocket REXUS12 in March 2012. After achieving the required altidue, the Suaineadh experiment was ejected from the rocket in order to be fully free flying. A specially designed spinning wheel in the ejected section was then used to spin up the experiment until the required rate is achieved for web deployment to commence. Unfortunately during re-entry, the probe was lost and also a recovery mission in August 2012 was only able to find minor components of the experiment. After 18 month, in September 2013, the experiment was found in the wilderness of Northern Sweden. In the following months all data from the experiment could be recovered. The images and accelerometer data that has been analysed showed the deployment of the web and a very interesting three dimensional behaviour that differs greatly from on ground two dimensional prototype tests. This paper will give an overview on the recovered data and it will present the analysed results of the Suaineadh spinning web experiment.

  • 33. Yin, Binglun
    et al.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Qu, Shaoxing
    A phase-field study of the scaling law in free-standing ferroelectric thin films2015In: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 26, no 50, article id 505701Article in journal (Refereed)
    Abstract [en]

    The scaling law for ferroelectric stripe domains is investigated in free-standing BaTiO3 and PbTiO3 thin films via phase-field simulations. The results agree with the Kittel law, where the square of the domain width is found to be proportional to the thin film thickness. After being rescaled by the corresponding domain wall thickness, the generalized scaling law is also demonstrated, with the dimensionless scaling constant M estimated to be similar to 3.3 in two ferroelectric materials. Moreover, we predict the effect of the exchange constant which is incorporated in Ginzburg-Landau theory on the equilibrium domain width and the critical thickness of the ferroelectric thin films.

  • 34.
    Zea, Elias
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Rumpler, Romain
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Nygren, Johan
    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.
    Mao, Huina
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Glav, Ragnar
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Carlsson, Ulf
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Boij, Susann
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Teaching and learning practical activities in Sound and Vibration courses during the COVID-19 pandemic2021Conference paper (Other academic)
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