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Item type:Publication, Access status: with files , Systematic design of particle dampers for transient vertical vibrationsA multilevel design toolchain is used for the development of particle dampers for vertical transient vibrating structures. Thereby various experimental tests and numerical models are combined. The design toolchain consists of three levels. The frst level deals with the micro-mechanical behavior of single particle–particle and particle–wall impacts. The resulting coeffcient of restitution is then used on the second level. Within, the second level the properties of vertical vibrated granular matters inside a container under harmonic motion are analyzed. The resulting motion modes and energy dissipation of the granular matter strongly depend on the excitation conditions, i. e. the excitation amplitude and excitation frequency. Multiple analytical formulations for the diferent motion modes, i. e. solid-like state and collect-and-collide motion mode, are derived to describe the energy dissipation within the particle damper. These analytical descriptions are in good agreement with numerical discrete element simulations. Finally, the third level of the design toolchain deals with designing a damper for a desired structure. The analytical formulations describing the energy dissipation within the particle damper are used to optimize a particle damper confguration for a simple beam-like structure undergoing a vertical transient vibration. The efciency of the optimized particle damper dissipation is proven experimentally.Publicationtype: Journal ArticleScopus© Citations 2 94 337 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Design of robust particle dampers using inner structures and coated container wallsClassical particle dampers suffer from their non-robust damping behavior, \ie they can only be efficiently applied to a specific frequency range and amplitude range. The reason for that is that particle motion, also called motion mode, and damper efficiency show a strong correlation. By changing particle or container properties the motion modes are shifted to other excitation conditions but their efficient range is not much affected. To increase the damping performance and robustness of particle dampers, two approaches are presented here by introducing new motion modes. Therefore, the particle dampers are analyzed experimentally using a shaker setup and numerically using the discrete element method. The first design approach uses inner structures inside the particle damper, manufactured by a 3D printer. The inner structures consist of different numbers of beams, placed perpendicular to the container moving direction. They lead to a much more robust damper as the transition between the motion modes gets smoother. For the second approach, the container walls are equipped with different soft polymers. In this way a new motion mode at low excitation intensities is observed, leading to a high efficiency possibly on a large excitation intensity range. For an easy calculation of the necessary wall's Young's modulus an analytical formula based on Hertz impact theory is derived.Publicationtype: Journal Article106 416 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Workshop Numerische Methoden in der Geotechnik : 12th & 13th of September 2022 Hamburg, Germany : conference proceedings(2022-09-12); ; ; ; Numerical methods have developed into standard tools for the investigation of geotechnical struc tures. With increasing computational power, hybrid and continuum-based approaches supported by sophisticated constitutive models are becoming more and more important. The Workshop “Nu merical Methods in Geotechnics 2022”, hosted by Hamburg University of Technology (TUHH) in cooperation with the working group Numerics (AK Numerik of DGGT) and the Federal Waterways Engineering and Research Institute (Bundesanstalt für Wasserbau, BAW), brings together international scientists and experts in order to present and discuss newest findings with regard to the development of numerical methods in geotechnical engineering. These proceedings have been compiled based on the different topics presented in the framework of the workshop. They are supposed to preserve the findings for their future scientific and practical use and to share them with the geotechnical community.Publicationtype: Conference Proceedings581 4119 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Systematic design of particle dampers for horizontal vibrations with application to a lightweight manipulator(2021-10-13); ; ; Particle damping has become a favorable passive damping technique for lightweight structures, however, its complex dimensioning process hinder its wide use in technical applications. In this paper, a multilevel design tool chain is presented to enable a systematic design and dimensioning process of particle dampers. Thereby various numerical models and experimental tests are combined. This starts with investigations of the micro-mechanical behavior of single particle impacts. Continuing, with analyzing the properties of vibrated granular matters inside a container and ending with designing a damper for a desired structure. The good agreement of the models and their efficiency for the damper design and dimensioning are finally demonstrated on an elastic lightweight manipulator undergoing a horizontal, transient vibration. Using this design toolchain, a new and much more efficient damper design for low amplitude vibrations is introduced using the rolling attribute of spheres. By separating the particle damper into several layers, high damping of the elastic lightweight manipulator is achieved.Publicationtype: Journal Article76 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Toward a design methodology for particle dampers by analyzing their energy dissipationParticle dampers show a huge potential to reduce undesired vibrations in technical applications even under harsh environmental conditions. However, their energy dissipation depends on many effects on the micro- and macroscopic scale, which are not fully understood yet. This paper aims toward the development of design rules for particle dampers by looking at both scales. This shall shorten the design process for future applications. The energy dissipation and loss factor of different configurations are analyzed via the complex power for a large excitation range. Comparisons to discrete element simulations show a good qualitative agreement. These simulations give an insight into the process in the damper. For monodisperse systems, a direct correlation of the loss factor to the motion modes of the rheology behavior is shown. For well-known excitation conditions, simple design rules are derived. First investigations into polydisperse settings are made, showing a potential for a more robust damping behavior.Publicationtype: Journal ArticleScopus© Citations 27 241 310 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Experimental and numerical investigations on parameters influencing energy dissipation in particle dampers(International Center for Numerical Methods in Engineering (CIMNE), 2019-10); Particle damping has become a favorable passive damping technique for light weight structures, however, its complex dimensioning process hinder its wide use in technical applications. An experimental based model and a numerical model are developed in order to investigate the energy dissipation of the dampers regardless of the underlying structure. The experimental model consists only of the particle box with a free-free boundary condition, which is excited by a harmonie force. Via the complex power, the loss factor and the energy dissipation are obtained. A corresponding numerical discrete element model is developed. With these models, a large frequency and acceleration range is analyzed. Different filling ratios of the particle box are investigated, indicating the high potential of particle dampers for ditterent excitation ranges. First comparisons of experiments and simulations showing a good qualitative agreement, enabling the simulation as a future design tool for particle dampersPublicationtype: Conference PaperScopus© Citations 5 165 183