Design of viscous dampers targeting multiple cable modes

Weber, Felix; Feltrin, Glauco; Maślanka, Marcin; Fobo, Wolfgang; Distl, Hans

doi:10.1016/j.engstruct.2009.06.020

Cited by 49 publications

(32 citation statements)

References 2 publications

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“…By using this damper, the modal damping ratio for the intermediate modes would be higher than that of the two target modes predicted from Equations and . Similar phenomenon was reported by Weber et al when optimizing linear viscous damper for multimode cable vibration control. A formal theoretical proof of this finding is presented in the Appendix A of the present paper.…”

Section: Formulation Of Nsd Design Approach To Suppress Multimode Cabmentioning

confidence: 99%

“…The optimal damper size was obtained by minimizing the difference between the optimal gain of an idealized active actuator and the achievable gain of a practical viscous damper. Weber et al developed an analytical method for the optimization of linear viscous dampers. It could supply sufficient amount of damping to multiple modes simultaneously and also minimize the damper position.…”

Section: Introductionmentioning

confidence: 99%

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Multimode vibration control of stay cables using optimized negative stiffness damper

Javanbakht

Cheng

Ghrib

2020

Struct Control Health Monit

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Summary Due to their low inherent damping and high lateral flexibility, stay cables are prone to large amplitude vibrations governed by either a single or multiple cable modes. Among the practical measures, the installation of transverse passive dampers near the cable‐deck anchorage is a popular choice. Compared to conventional positive stiffness and zero stiffness dampers, negative stiffness damper (NSD) manifests superior performance in mitigating cable vibrations, especially in the case of long cables. In this study, a novel design approach is proposed to optimize NSD for multimode cable vibration control. Two design scenarios are considered. In the former, the damper size is optimized for a predetermined negative damper stiffness; whereas in the latter, the size and negative stiffness of the NSD are both optimized to achieve a required damping ratio for the dominant modes. The applicability of the proposed NSD optimum design approach is validated using 15 sample real stay cables. A numerical example is presented, of which a NSD is designed based on the proposed approach to optimize wind‐induced multimode vibration control of a 460‐m stay cable, and the performance is compared with that of a linear‐quadratic regulator (LQR) control. Results show that the selected NSD can effectively suppress the dominant modes and has a controlling effect comparable with an active control using LQR. In addition, it is found that when there exist more than two dominant modes in vibration, designing NSD for the lowest and the highest dominant modes would also adequately control the mid‐range modes.

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Section: Formulation Of Nsd Design Approach To Suppress Multimode Cabmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multimode vibration control of stay cables using optimized negative stiffness damper

Javanbakht

Cheng

Ghrib

2020

Struct Control Health Monit

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“…Weil die viskose Dämpferkonstante von passiven Öl-dämpfern nur auf eine Seileigenschwingung optimal abgestimmt werden kann [5,6], jedoch je nach Windbedingungen verschiedene Eigenschwingungen auftreten, muss bei passiven Öldämpfern ein Kompromiss-Design gemacht werden. Müssen typischerweise die ersten drei oder vier Seileigenschwingungen bedämpft werden [7], legt man die viskose Dämpferkonstante in etwa auf die mittlere Frequenz dieser Eigenschwingungen aus [8]. Um trotzdem genügend Bedämpfung der Eigenschwingungen mit tiefster resp.…”

Section: Einführungunclassified

“…Bewegt sich die Kolbenstange des MR-Dämpfers, weil die angeschlossene Struktur schwingt, muss das MR-Fluidum -eine Suspension aus ferromagnetischen Partikeln und Silicon-Öl -durch den Ringspalt fließen (Bild 1a [7], wird c in etwa auf eine mittlere Seilfrequenz ausgelegt [8], was zu suboptimaler Bedämpfung der Seileigenschwingen mit tieferen respektive höheren Eigenfrequenzen führt.…”

Section: Mr-dämpfer 21 Funktionsweise Des Mr-dämpfersunclassified

Schrägseilbedämpfung mit echtzeitgeregelten MR‐Dämpfern

Weber

Distl

2014

Beton und Stahlbetonbau

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Seile von weitgespannten Schrägseilbrücken sind wegen ihrer kleinen Dämpfung von 0,1 %-0,15 % anfällig für windinduzierte Schwingungen [1 bis 3]. Wie das Beispiel der Franjo-Tudjman-Brücke bei Dubrovnik, Kroatien, zeigt, können die Schwingamplituden bei Seillängen um die 300 m über 1 m betragen, wenn Schnee oder Eis das Profil der Seile verändert und so die Windanregung zusätzlich verstärkt [4]. Die herkömmliche Methode zur Vermeidung großer Seilschwingungen ist das Bedämpfen der Seile mit passiven Öldämpfern. Diese werden zwischen Seil und Brückendeck installiert, damit der Dämp-fer so gegenüber dem annähernd ruhenden Brückendeck Energie dissipieren kann. Der Abstand des Dämpfers zum unteren Seilankerkopf beträgt typischerweise 2 %-3 %, da so die Ästhetik der Brücke nicht negativ beeinflusst wird und weil größere Abstände wegen langer Dämpferabstützungen ökonomisch nicht sinnvoll sind. Weil die viskose Dämpferkonstante von passiven Öl-dämpfern nur auf eine Seileigenschwingung optimal abgestimmt werden kann [5,6] Verhalten der MR-Dämpferkraft

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“…Passive viscous dampers are widely used by optimally tuning their damper coefficients to achieve maximum damping at only one targeted mode of cable vibration and properly selecting the damper installation location [7][8][9][10][11]. However, the passive dampers may potentially lead to insufficient damping to other concerned modes without increasing the damper installation location that may undesirably affect the esthetics of the bridge [12,13], especially for very long cables. Alternative promising solution to cable vibration mitigation is semiactive control based on controllable magnetorheological (MR) dampers due to their real-time adjustable damping effect, fail-safe behavior, and superior energy dissipation over passive dampers [2,6,[14][15][16][17][18][19][20][21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Adaptive Semiactive Cable Vibration Control: A Frequency Domain Perspective

Chen

2017

Shock and Vibration

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An adaptive solution to semiactive control of cable vibration is formulated by extending the linear quadratic Gaussian (LQG) control from time domain to frequency domain. Frequency shaping is introduced via the frequency dependent weights in the cost function to address the control effectiveness and robustness. The Hilbert-Huang transform (HHT) technique is further synthesized for online tuning of the controller gain adaptively to track the cable vibration evolution, which also obviates the iterative optimal gain selection for the trade-off between control performance and energy in the conventional time domain LQG (T-LQG) control. The developed adaptive frequency-shaped LQG (AF-LQG) control is realized by collocated self-sensing magnetorheological (MR) dampers considering the nonlinear damper dynamics for force tracking control. Performance of the AF-LQG control is numerically validated on a bridge cable transversely attached with a self-sensing MR damper. The results demonstrate the adaptivity in gain tuning of the AF-LQG control to target for the dominant cable mode for vibration energy dissipation, as well as its enhanced control efficacy over the optimal passive MR damping control and the T-LQG control for different excitation modes and damper locations.

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Design of viscous dampers targeting multiple cable modes

Cited by 49 publications

References 2 publications

Multimode vibration control of stay cables using optimized negative stiffness damper

Multimode vibration control of stay cables using optimized negative stiffness damper

Schrägseilbedämpfung mit echtzeitgeregelten MR‐Dämpfern

Adaptive Semiactive Cable Vibration Control: A Frequency Domain Perspective

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