Search

Metamaterials have recently emerged and shown potential as lightweight and compact noise and vibration solutions. By adding or embedding resonant structures to or in a flexible host structure on a sub-wavelength scale, stop bands can be created, which enable frequency ranges of strong vibration and noise attenuation. These often periodic structures are typically analyzed using infinite periodic structure theory, based on a representative unit cell model. The stop bands in metamaterials are generally analyzed by means of dispersion curves. For complex unit cell models, however, this rapidly becomes computationally expensive. Therefore, in this work, model order reduction is applied to finite element unit cell models for stop band predictions. In view of designing metamaterials for a targeted frequency range, the reduced order modeling approach is next introduced in a design optimization routine. The results show that the reduced order models for stop band predictions enable substantial gains in metamaterial analysis and fast metamaterial design optimization. ispartof: pages:2487-2501 ispartof: Proceedings of ISMA 2020 pages:2487-2501 ispartof: International Conference on Noise and Vibration Engineering - ISMA 2020 location:Leuven, Belgium date:7 Sep - 9 Sep 2020 status: published

Resonant metamaterials are a lightweight noise insulation solution due to their tunable stop band effect. In previous works, the authors have shown how resonant metamaterials can be manufactured and fully integrated into a thermoformed twin sheet panel. This work shows an design optimisation procedure for the resonant structure of the metamaterial panel, based on its modal effective mass. Additionally, foam is added in the core of the panel, to achieve high noise insulation performance at the high-frequency range, which is deteriorated by the slits introduced to create the resonant structures. Two panels are designed, targeting single and double stop bands. Their insertion loss is experimentally evaluated, showing a pronounced noise insulation performance at the stop band targeted frequency, and no loss of noise insulation in the high-frequency range thanks to the foam addition. Therefore, this work shows that resonant metamaterials can be designed through optimisation and work in synergy with classical solutions while keeping a lightweight design. ispartof: pages:2513-2524 ispartof: Proceedings of ISMA 2020 pages:2513-2524 ispartof: International Conference on Noise and Vibration Engineering - ISMA 2020 location:Leuven - Belgium date:7 Sep - 9 Sep 2020 status: accepted

ispartof: Proceedings of ISMA2020 including USD2020 ispartof: International Conference on Noise and Vibration Engineering location:Leuven, Belgium date:7 Sep - 9 Sep 2020 status: published

Most companies do not take assembly aspects of a product into account during the early design process. This often results in designs that are optimal from a performance point of view, but are hard or impossible to assemble. This leads to numerous design changes late in the product development process, causing significant extra costs. To solve this issue, a co-optimization framework is developed that takes into account the assemblability as a constraint during the performance optimization. The presented framework is applied to minimize the mass of a gearbox with constraints on the axle stiffness and the first resonance frequency of the housing, while also respecting a set of assembly rules. The assembly rules take into account the complexity of the assembly, for instance the number of unique standard parts used and geometric properties like weight and dimensions.In each iteration, the performance of the design is evaluated with a parametrized finite element model, while a numerical assemblability score of the current design is estimated based on the assembly STP file. The obtained performance and assemblability metrics and their combination serves as a constraints and objective function for the design optimization. ispartof: pages:2753-2762 ispartof: Proceeding of ISMA2020 including USD2020 pages:2753-2762 ispartof: ISMA-USD Noise and Vibration Engineering Conference 2020 location:Leuven, Belgium (Virtual event) date:7 Sep - 9 Sep 2020 status: published

Double panel partitions with a foam core suffer from a poor sound transmission loss at the mass-spring-mass resonance frequency. This paper investigates the use of vibro-acoustic resonant metamaterials as a solution to improve the acoustic insulation performance for this vibro-acoustic problem while adding only 8% of mass to the complete double panel. To design the metamaterial, unit cell analysis is applied to calculate dispersion curves and predict the stop band behaviour, while the sound transmission loss is predicted with Heckl’s model extended with the equivalent dynamic mass of the metamaterial. The dynamic mass is obtained from the dispersion curves analysis, which allows to take into account complex and realizable resonator geometries. The designed metamaterial double panel is realized and its experimentally measured insertion loss shows a strong improvement around the mass-spring-mass resonance of the original double panel. The predicted insulation performance agrees well with the measured performance, validating the proposed method. ispartof: pages:3111-3123 ispartof: Proceedings of ISMA 2018 pages:3111-3123 ispartof: International Conference on Noise and Vibration Engineering - ISMA 2018 location:Leuven, Belgium date:17 Sep - 19 Sep 2018 status: published

In many mechanical applications, a design optimization is performed on the frequency response functions of the mechanical system. In this work, a novel model reduction technique is explored for the parametric analysis of the frequency response functions of dynamical mechanical systems. This approach entails two novel aspects. First, a super-local reduced order basis is introduced which allows models of much lower order compared to models obtained with single, frequency independent reduced order basis approaches. Secondly, a novel hyper-reduction scheme is introduced which selects a subset of the considered, discrete frequency domain and computes the corresponding interpolation matrix. During the online phase, the full frequency domain response is reconstructed by interpolating between these sampled frequency lines. The proposed approach is validated numerically on an academic mass-spring-damper system and shows promising results. ispartof: pages:2461-2468 ispartof: Proceedings of the International Conference on Noise and Vibration Engineering (ISMA2018) and the International Conference on Uncertainty in Structural Dynamics (USD2018) pages:2461-2468 ispartof: ISMA 2018 International Conference on Noise and Vibration Engineering location:Leuven, Belgium date:17 Sep - 19 Sep 2018 status: published

In order to fully exploit available computer aided engineering (CAE) models for modern mechatronic systems they need to be merged with measurement data in order to obtain reliable Digital Twins. These Digital Twins are evolving to become instrumental assets that accompany the product throughout its lifetime, enabling virtual quality assurance, virtual sensing and model-based control. However, in mechatronics, the typical CAE design models are relatively expensive physics based models which cannot be directly used throughout the entire lifecycle as Digital Twins. Model order reduction approaches for these nonlinear dynamic applications allow to reduce the computational cost sufficiently for use in a Digital Twin setting. This work gives an overview of nonlinear dynamics engineering applications in modern mechatronics products design, and demonstrates the role of (novel) MOR techniques in the design engineering process. ispartof: pages:2415-2429 ispartof: Proceedings of the International Conference on Noise and Vibration Engineering (ISMA2018) and the International Conference on Uncertainty in Structural Dynamics (USD2018) pages:2415-2429 ispartof: ISMA 2018 International Conference on Noise and Vibration Engineering location:Leuven, Belgium date:17 Sep - 19 Sep 2018 status: published

Developing an accurate product model is a crucial task for the numerical simulation of the dynamic behavior of mechanical components. In this setting, this work considers the specific case of components manufactured through a deep drawing process. Because of the large deformations involved, a thickness variation is obtained in the final manufactured component with respect to the initial blank thickness, which has to be accounted for in order to have an adequate model for numerical analysis. Furthermore, the intrinsic variability of the process and local variations of the stiffness, due to plastic hardening and residuals stresses, give rise to nominally identical components with different dynamic properties, especially at high frequencies. Two simulation frameworks are considered in this study for the product model development: the first one is based on a purely numerical approach, where the dynamic simulation is performed on a model obtained from a finite element simulation of the forming process. The second one considers a reverse engineering framework, where the product model is computed by a surface reconstruction procedure starting from laser scan measurements on the manufactured component; this reverse engineering procedure can be realized either by (i) a triangular surface reconstruction that forms the starting point to obtain a finite element mesh of the component or by (ii) fitting a smooth B-spline surface on the point cloud data that can be used directly for the analysis employing the paradigm of isogeometric analysis (IGA). The different approaches are applied to predict the dynamic behaviour of an axis-symmetric deep drawn steel cup and are validated with experimental measurements. Finally, it is shown how a model updating procedure of the stiffness can be easily implemented in the framework of IGA, which can further improve the accuracy of the product model. no ISSN ispartof: pages:3605-3615 ispartof: Proceedings of the International Conference on Noise and Vibration Engineering (ISMA) / International Conference on Uncertainty in Structural Dynamics (USD) pages:3605-3615 ispartof: International Conference on Noise and Vibration Engineering (ISMA 2018) location:Leuven, Belgium date:17 Sep - 19 Sep 2018 status: Published online

The knowledge of loads acting on machines and components is crucial in many application fields. Input estimation though is a very challenging inverse problem with which researchers have struggled over the last decades. Several issues related to ill-conditioning and ill-posedness are not sufficiently understood nor solved. This paper proposes an in-depth numerical study covering some of the aspects that can make the difference between a reliable and an unreliable force estimation. A states-input estimation algorithm for multiple force estimation is implemented as a linear augmented Kalman filter/smoother coupled with a reduced order model of a complex ill-posed mechanical structure, namely a twistbeam rear suspension. The influence of different noise levels, measurements scaling and time horizon used for the estimation is thoroughly analyzed. Finally, an observability-based optimal sensors placement strategy is implemented showing robustness improved accuracy of the estimated quantities. ispartof: pages:1741-1756 ispartof: In International Conference on Noise and Vibration Engineering (ISMA2016), pages:1741-1756 ispartof: ISMA location:Leuven date:19 Sep - 21 Sep 2016 status: published

Finite element analyses of vibro-acoustic systems are usually performed in the frequency domain, meaning that the obtained results cannot straightforwardly handle time-varying input signals. These limitations can be overcome by performing a time domain analysis of the finite element model. To reduce the calculation complexity needed for time integration a model order reduction technique is proposed. A time stable Krylov subspace reduction technique is derived for the coupled exterior vibro-acoustic problem case. The Sommerfeld radiation condition is taken into account by applying infinite elements on the boundary of the mesh. The application of time stable infinite elements leads to a potentially singular mass matrix. A method is developed that circumvents mass matrix inversion, which is based on a singular value decomposition. Combined with a special formulation of the system matrices, the proposed method is shown to preserve the stability of the full model. The resulting model order reduction procedure is applied on a numerical model of a loudspeaker. ispartof: pages:1277-1290 ispartof: Proceedings of ISMA 2016 pages:1277-1290 ispartof: ISMA 2016 location:Leuven date:19 Sep - 21 Sep 2016 status: published

Latest trends in the industry of mechanical transmissions demands for a new set of design tools, able to work beyond the assumption of the traditional analytical formulation. Recent progress in the field of model order reduction schemes finally made feasible to deal with dynamic 3D simulations of contact problems for both gears and bearing components, thus posing the base for a new frontier of simulation capabilities where different operational conditions can be analyzed. This paper aims at integrating some of these techniques into a commercial multi-domain 1D simulation software package, moving the first steps towards efficient system level analysis of typical 3D effects like micro/macro geometry modification, misaligned mounting, and perturbed loading conditions. A first proof-of-concept implementation is discussed along the paper. Furthermore, a broad set of case studies is presented, in order to showcase the main advantages of the proposed methodology, with respect to available commercial solution. ispartof: pages:1357-1370 ispartof: ISMA2016 including USD2016 pages:1357-1370 ispartof: Leuven Conference on Noise and Vibration Engineering (ISMA 2016) location:Leuven date:19 Sep - 21 Sep 2016 status: published

© Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics. All rights reserved. We propose a novel phase bound magnetic vibration absorber based on parallel combinations of magnetic springs. The corresponding design methodology is based on magnetic spring toolchain consisting of FE simulations of magnetic spring and 1D models together with system dynamics model. This approach is applied to an industrially relevant vibration reduction problem of gear meshing, specifically for wind turbine applications. In order to capture the relevant gearbox dynamic a semi-analytical Cai-Hayashi formulation of the gear stiffness is used in combination with ISO 6336 norm for spur gear capacity. We compare the modeling results to a state-of-the-art tuned mass damper approach, addressing the issues of tonalities in wind turbines. As opposed to the frequency bound vibration absorbers, the novel magnetic spring vibration absorber is order-selective, similarly to centrifugal pendulum absorbers, with the added value of a virtually infinite lifetime, no de-tuning issues, and feasible high-order vibration absorbers. ispartof: pages:4833-4845 ispartof: Proceedings of ISMA2018 International Conference on Noise and Vibration Engineering pages:4833-4845 ispartof: International Conference on Noise and Vibration Engineering location:Leuven, Belgium date:17 Sep - 19 Sep 2018 status: published