Development of a long-stroke MR damper for a building with tuned masses

Zemp, René; Llera, Juan Carlos de la; Saldias, Hernaldo; Weber, Felix

doi:10.1088/0964-1726/25/10/105006

Cited by 11 publications

(10 citation statements)

References 27 publications

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“…One is a proof-of-concept MRD with short stroke of ±0.1 m and 150 kN force capacity (MRD-S), and the other is a real prototype damper with long stroke (MRD-L) of ±1 m and 300 kN nominal force capacity. Both dampers are intended to control one of the 160 ton TMs of building PA [1,3,24]. Simulations of building PA with TMs and MRDs show that the peak design velocities for the MRD subjected to the design earthquake are in the range of 100 to 350 cm s −1 .…”

Section: Properties Of Designed and Manufactured Mrdsmentioning

confidence: 99%

“…More precisely this article focuses on the experimental characterization of the MRD-L, while the building implementation aspects are discussed elsewhere [24]. To test the MRD-L at full stroke and high velocities, an interesting kinematic amplification system was built and adapted to the 1000 kN testing rig available in our laboratory at Universidad Católica (PUC), Chile.…”

Section: Introductionmentioning

confidence: 99%

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Experimental analysis of large capacity MR dampers with short- and long-stroke

Zemp

Llera

Weber

2014

Smart Mater. Struct.

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The purpose of this article is to study and characterize experimentally two magneto-rheological dampers with short- and long-stroke, denoted hereafter as MRD-S and MRD-L. The latter was designed to improve the Earthquake performance of a 21-story reinforced concrete building equipped with two 160 ton tuned pendular masses. The MRD-L has a nominal force capacity of 300 kN and a stroke of ±1 m; the MRD-S has a nominal force capacity of 150 kN, and a stroke of ±0.1 m. The MRD-S was tested with two different magneto-rheological and one viscous fluid. Due to the presence of Eddy currents, both dampers show a time lag between current intensity and damper force as the magnetization on the damper changes in time. Experimental results from the MRD-L show a force drop-off behavior. A decrease in active-mode forces due to temperature increase is also analyzed for the MRD-S and the different fluids. Moreover, the observed increase in internal damper pressure due to energy dissipation is evaluated for the different fluids in both dampers. An analytical model to predict internal pressure increase in the damper is proposed that includes as a parameter the concentration of magnetic particles inside the fluid. Analytical dynamic pressure results are validated using the experimental tests. Finally, an extended Bingham fluid model, which considers compressibility of the fluid, is also proposed and validated using damper tests.

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Section: Properties Of Designed and Manufactured Mrdsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental analysis of large capacity MR dampers with short- and long-stroke

Zemp

Llera

Weber

2014

Smart Mater. Struct.

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“…The experimental results manifest that the proposed MR damper possesses a better dynamic performance. Zemp et al [15] presented a longstroke MR damper by effectively prolonging the MR fluid channel and applied it to a 21-story building. Zhu et al [16] developed a MR damper characterizing multiple fluid flow channels, by combining the annular and radial MR fluid flow channels, and the results reveal that the MR damper can provide a large damping force of 3.5 kN, which exhibits a good damping performance.…”

Section: Introductionmentioning

confidence: 99%

Development and Evaluation of a MR Damper With Enhanced Effective Gap Lengths

Feng

Tong

et al. 2020

IEEE Access

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Traditional magnetorheological (MR) damper featuring fixed gaps has the shortcomings of small damping force, single dynamic performance, and low adaptability. To overcome these shortcomings, a new MR damper with enhanced effective gap lengths is developed in this work, which achieves a double extension of the effective gap lengths via compactly integrating the conical fluid channels into the annular fluid channels. On the other hand, by altering the axial position of the valve spool controlled by a locking nut, the relative distance between the valve spool and piston of the MR damper is flexibly regulated; thus, the width of this adjustable gap in the conical fluid channels can be continuously adjusted. The magnetic circuit of the proposed MR damper is developed and its mechanical model is established as well to evaluate the dynamic performance. Sequentially, the finite element analysis (FEA) methodology is applied by using ANSYS/Emag software to investigate the changes of magnetic flux densities in these adjustable gaps. Moreover, a prototype is manufactured and experimental tests are conducted to verify its dynamic performance. The experimental results, under a fixed applied current, indicate that the damping force decreases with the increase of the adjustable gaps, and the maximum damping force reaches 7.2 kN at the adjustable gap of 0.6 mm. Besides, the dynamic range increases with the increase of the adjustable gap, and the dynamic range appears with a peak of 13.6. In addition, the damping force varies from 0.2 kN to 7.2 kN while the dynamic range attains 33 correspondingly by regulating the applied current and adjustable gap from 1.6 mm to 0.6 mm. From an experimental results perspective, the damping force and dynamic range can be not only effectively controlled by excitation current but also flexibly altered by regulating the width of the adjustable gaps simultaneously. Therefore, the dynamic performance of the proposed MR damper is also enhanced.

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“…By using a Bouc‐Wen model for MR damper, the Linear quadratic regulator (LQR) control algorithm and a continuous optimal control concept, the superiority of semiactive control system is demonstrated. More recently, Zemp et al attempted the development of a long‐stroke MR damper for a building with tuned masses and also addressed the practical implementation challenges. Most of the literature on SATMDs with MR damper are focused on development and non‐linear characterization of MR dampers and development of suitable control algorithms for their application in TMDs.…”

Section: Introductionmentioning

confidence: 99%

Seismic retrofit of reinforced concrete structures using magnetorheological mass driver: Evolving a design methodology

Priya

Gopalakrishnan

2019

Struct Control Health Monit

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This paper proposes a design methodology for a damping enhancement-based seismic retrofitting of a damaged reinforced concrete (RC) model frame with a mass driver (MD) and magnetorheological (MR) damper. The MR-MD is applied with preset constant current inputs and the structure + MR-MD system is subjected to harmonic and seismic base excitations. Equivalent effective damping for a biviscous MR damper is derived both from energy and secant damping considerations. The effect of yielding force of the MR damper, mass value of the secondary system, and non-linearity associated with input accelerations are discussed. The paper proposes a suboptimum frequency tuning, that is, the frequency of the secondary MR-MD is marginally lower than the optimum value, anticipating a degrading stiffness and frequency drop of the target structure, typical of materials like masonry and concrete. Experimental investigations with undertuned, overtuned, and near-optimum tuned conditions of the secondary MR-MD system are performed to highlight that operation with near optimum damping plays a significant role, particularly when MR dampers are used.Higher effective damping associated with higher preset current inputs have a tendency to be counter-productive, which is proved experimentally and analytically. Four seismic performance parameters are calculated, which showed a substantial reduction of acceleration and displacement responses on the experimental structure when the damper is operated at lower input currents. From analytical and experimental investigations, a simplified retrofit design methodology for a degraded RC superstructure is proposed and experimentally validated through incorporating a mass driver coupled with a non-linear damper. KEYWORDS design methodology, mass driver, MR damper, MR-TMD, TMD retrofit, tuned mass damper Struct Control Health Monit. 2019;26:e2353.wileyonlinelibrary.com/journal/stc

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Development of a long-stroke MR damper for a building with tuned masses

Cited by 11 publications

References 27 publications

Experimental analysis of large capacity MR dampers with short- and long-stroke

Experimental analysis of large capacity MR dampers with short- and long-stroke

Development and Evaluation of a MR Damper With Enhanced Effective Gap Lengths

Seismic retrofit of reinforced concrete structures using magnetorheological mass driver: Evolving a design methodology

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