Experimental Test and Numerical Analysis of a Structure Equipped with a Multi-Tuned Liquid Damper Subjected to Dynamic Loading

2020 ◽  
Vol 20 (07) ◽  
pp. 2050075
Author(s):  
Bui Pham Duc Tuong ◽  
Phan Duc Huynh
Keyword(s):  
Shaking Table ◽  
Tuned Liquid Damper ◽  
Lumped Mass ◽  
Tuned Liquid Dampers ◽  
Lumped Mass Method ◽  
Dynamic Loadings ◽  
Coupling Equations ◽  
Liquid Dampers ◽  
Volume Method ◽  
Simplified Calculation

Tuned liquid dampers (TLDs) have many advantages in controlling building vibrations, among which multi-tuned liquid dampers (MTLDs) appear to have better stability and effectiveness. However, the tank wall was assumed to be rigid in the past by ignoring the fluid-structure interaction (FSI) at the interface, resulting in simplified calculation for the design of the TLDs. Moreover, the fluid in the tank was considered to be separate from the structure. This paper presents two numerical methods to control the responses of the frame under the dynamic loadings: (1) the lumped mass method for quickly designing the TLDs, and (2) the finite volume method/finite element method (FVM/FEM) for analyzing the fluid and solid domains of the TLDs in a single computational 3D model. In addition, the multi-field interaction between the structure-fluid-tank walls is considered by solving the coupling equations at the interfaces. A steel frame is fitted with an MTLD and tested experimentally on a shaking table to investigate its dynamic response. Numerical results are verified with the experimental ones, which show good agreement.

Tuned Liquid Damper Experiment Using Shaking Table

2013 ◽  
Vol 421 ◽  
pp. 772-777 ◽  
Author(s):  
Ki Pyo You ◽  
Young Moon Kim ◽  
Jang Youl You
Keyword(s):  
Natural Frequency ◽  
Damping Ratio ◽  
Tall Buildings ◽  
Excitation Amplitude ◽  
Shaking Table ◽  
Tuned Liquid Damper ◽  
Tuned Liquid Dampers ◽  
Liquid Dampers ◽  
Water Tanks ◽  
Wind Induced Vibration

The present study examines the characteristics of rectangular and circular tuned liquid dampers, which control wind-induced vibration in tall buildings, according to the natural frequency. The tuned liquid dampers (TLD) were of frequencies: 0.44Hz, 0.55Hz, 0.64Hz and 0.73Hz. The tuning feature of TLD water tanks was better in circular water tanks than in rectangular water tanks. Excitation amplitude affected the damping ratio based on energy dissipation capacity. At low excitation (below 5mm) and low natural frequency (0.44Hz), circular water tanks were advantageous over rectangular water tanks. However, at high excitation (over 5mm) and high natural frequency (over 0.55Hz), rectangular water tanks were advantageous over circular water tanks.

Theoretical and Experimental Studies on Reduction for Multi-Modal Seismic Responses of High-Rise Structures by Tuned Liquid Dampers

2004 ◽  
Vol 10 (7) ◽  
pp. 1041-1056 ◽  
Author(s):  
Hong-Nan Li ◽  
Ying Jia ◽  
Su-Yan Wang
Keyword(s):  
Passive Control ◽  
Equations Of Motion ◽  
Experimental Studies ◽  
Tall Buildings ◽  
Shaking Table ◽  
Earthquake Ground Motion ◽  
Seismic Responses ◽  
High Rise ◽  
Tuned Liquid Dampers ◽  
Liquid Dampers

This paper focuses on the use of multiple tuned liquid dampers (TLDs) as passive control devices to reduce the multi-modal responses of tall buildings and high-rise structures to earthquake ground motion excitation. A model of a three-story building with one and two TLDs was installed on a shaking-table. The system was subjected to three earthquake time histories. Then, the mechanical models and the equations of motion for the systems of tall buildings and high-rise structures with TLDs are established. Here, the solution of the dynamic liquid pressure is based on the method of the volume of fluid and the seismic responses are obtained by use of the state equation. The comparisons show that theoretical results are generally in good agreement with experiments. It is observed that the approach presented in this paper has proved to be quite effective both in the numerical example and in the seismic simulating tests.

Reduced Equivalent Static Wind Loads for Tall Buildings with Tuned Liquid Dampers

2012 ◽  
Vol 226-228 ◽  
pp. 1218-1227
Author(s):  
Andrew S. Ross ◽  
Ashraf A. El Damatty ◽  
Ayman M. El Ansary
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Tall Buildings ◽  
Wind Loading ◽  
Tuned Liquid Damper ◽  
Dynamic Component ◽  
Tuned Liquid Dampers ◽  
Liquid Dampers ◽  
Equivalent Static Wind Load ◽  
Auxiliary Device

The tuned liquid damper (TLD) is a proven and an increasingly popular auxiliary device for mitigating the dynamic effects induced by wind loading on tall buildings. As buildings become taller, lighter, and more flexible, there is a greater contribution from the dynamic component. The most reliable tool for assessing the dynamic component is wind tunnel testing. A boundary layer wind tunnel is capable of accurately calculating an equivalent static wind load (ESWL) acting on a building. The current study investigates the reduction in the ESWL of a lateral-torsional coupled building with a TLD system installed. The building is sensitive to torsion in the first two vibration modes. The current investigation uses three unique multi-modal TLD systems designed specifically for a lateral-torsional coupled building. The building ESWL is evaluated with the TLD systems using measurements from tests conducted at the Boundary Layer Wind Tunnel Laboratory at Western University.

Experimental Verifications on Seismic Response Control of Tall Structures by Multiple Tuned Liquid Dampers

2004 ◽  
Author(s):  
Hong-Nan Li ◽  
Ying Jia ◽  
Su-Yan Wang
Keyword(s):  
Passive Control ◽  
Equations Of Motion ◽  
Tall Buildings ◽  
State Equation ◽  
Shaking Table ◽  
Earthquake Ground Motion ◽  
High Rise ◽  
Tuned Liquid Dampers ◽  
Tall Structures ◽  
Liquid Dampers

The focus of this paper is on the use of multiple Tuned Liquid Dampers (TLDs) as passive control devices to reduce the multi-modal responses of tall buildings and high-rise structures to earthquake ground motion excitation. A model of a 3-story building with one and two TLDs was installed on a shaking-table. The system was subjected to three earthquake time histories. Then the mechanical models and the equations of motion for the systems of tall buildings and high-rise structures with TLDs are established. Here, the solution of the dynamic liquid pressure is based on the method of the Volume of Fluid and the seismic responses are obtained by use of the state equation. The comparisons show that theoretical results are generally in good agreement with experiments. It is observed that the approach presented in this paper proved to be quite effective both in the numerical example and in the seismic simulating tests.

Linearized sloshing model for 2D tuned liquid dampers with modified bottom geometries

2014 ◽  
Vol 41 (2) ◽  
pp. 106-117 ◽  
Author(s):  
J.S. Love ◽  
M.J. Tait
Keyword(s):  
Mechanical Properties ◽  
Closed Form ◽  
Cost Savings ◽  
Mode Shapes ◽  
Tuned Liquid Damper ◽  
Flat Bottom ◽  
Tuned Liquid Dampers ◽  
Proposed Model ◽  
Sloshing Mode ◽  
Liquid Dampers

This study presents a new model for predicting the response of a two-dimensional tuned liquid damper (TLD) tank with a variable fluid depth. A simple finite element method is presented, which is used to calculate the sloshing mode shapes. From the mode shapes, the equivalent mechanical properties of the sloshing fluid are estimated. Three tanks (flat-bottom, triangular-bottom, and circular-bottom), which have closed-form expressions for their equivalent mechanical properties are used to evaluate the model. The proposed model is in agreement with the closed-form expressions. Subsequently, a parametric study is conducted on tanks with a chamfered-bottom, boxed-bottom, and ramped-bottom to assess how their properties change as the shape of the tank bottom is altered. The model provides TLD designers with greater flexibility when selecting a tank shape. Moreover, the model could be used to optimize the shape of a TLD tank to maximize its performance for a given liquid mass, allowing construction cost savings to be realized.

scholarly journals Numerical Analysis of the Dynamic Responses of Multistory Structures Equipped with Tuned Liquid Dampers Considering Fluid-Structure Interactions

2019 ◽  
Vol 13 (1) ◽  
pp. 289-300 ◽  
Author(s):  
Bui Pham Duc Tuong ◽  
Phan Duc Huynh ◽  
Tan-Trung Bui ◽  
Vasilis Sarhosis
Keyword(s):  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Dynamic Responses ◽  
Water Tank ◽  
Tank Wall ◽  
Tuned Liquid Damper ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Tuned Liquid Dampers ◽  
Liquid Dampers

Aims: The paper analyzes the effectiveness of tuned liquid damper in controlling the vibration of high rise building. The new contribution is considering the fluid-structure interaction of a water tank as a Tuned Liquid Dampers (TLD). Background: Currently, buildings are being built higher and higher, which requires TLDs to be larger as well. Therefore, the fluid pressure acting on the tank wall is more significant. In previous studies of liquid sloshing in TLDs, researchers simply ignored the effect of liquid pressure acting on the tank walls by making the assumption that the tanks are rigid. Currently, the failure of a tank because of FSI occurs regularly, so this phenomenon cannot be ignored when designing the tanks in general and TLDs in particular. Objective: To investigate the thickness of the tank wall affect to the TLD mechanism. Method: Numerical method was used for this research. Results: A TLD could be easy to design; however one could not bypass the fluid-structure interaction by assuming the tank wall is rigid. Conclusion: This kind of damper is very good to mitigate the dynamic response of structrure.

Equivalent mechanical models of tuned liquid dampers with different tank geometries

2008 ◽  
Vol 35 (10) ◽  
pp. 1088-1101 ◽  
Author(s):  
X. Deng ◽  
M. J. Tait
Keyword(s):  
Mechanical Properties ◽  
Effective Mass ◽  
Virtual Work ◽  
Damping Ratio ◽  
Tuned Liquid Damper ◽  
Equivalent Viscous Damping ◽  
Tuned Liquid Dampers ◽  
Mechanical Models ◽  
Sloshing Mode ◽  
Liquid Dampers

This paper focuses on the development of equivalent mechanical models for tuned liquid dampers (TLDs) with rectangular, vertical-cylindrical, horizontal-cylindrical, and hyperboloid (conical) tank shapes under external excitation in the transverse direction. Potential flow theory is utilized to obtain the free-surface response amplitude and the corresponding velocity of the sloshing liquid and Lagrange’s equations are used to determine the generalized properties. Morison’s equation and the virtual work method are used to estimate an equivalent viscous damping ratio based on the screen loss coefficient. The equivalent mechanical properties derived in this paper model the fundamental sloshing mode only and are restricted to small response amplitudes. Subsequently, the equivalent mechanical properties including effective mass, natural frequency, and damping ratio of the TLDs, having different tank geometries, are compared. It is found that the effective mass values for horizontal-cylindrical and hyperboloid TLDs are larger than the effective mass values for vertical-cylindrical and rectangular TLDs. The increased effective mass values for horizontal-cylindrical and hyperboloid TLDs can result in improved tuned liquid damper performance given the same total liquid mass as that of rectangular or vertical-cylindrical TLDs.

SEISMIC BEHAVIOR OF ANCHORAGE IN DIVERSE LIQUID STORAGE STEEL TANKS BY ADDED-MASS METHOD

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Kamyar Kildashti ◽  
Neda Mirzadeh
Keyword(s):  
Failure Modes ◽  
Added Mass ◽  
Lumped Mass ◽  
Liquid Storage ◽  
Lumped Mass Method ◽  
Dynamic Loadings ◽  
Steel Tanks ◽  
Cylindrical Steel Tanks ◽  
Cylindrical Steel ◽  
Structure Result

Deformation of liquid storage tanks and the interaction between fluid and structure result in a variety of possible failure mechanisms during earthquakes. Among all failure modes, base-anchor failure is this paper’s focus. Three cylindrical steel tanks with different H/D were selected to investigate dynamic loadings on the tank seismic responses. The added-mass method was used in the finite element modeling of the steel tanks and fluid, and numerical analyses were performed. The added-mass method results were compared to conventional method outcomes using two or more lumped-mass and equivalent springs for tank-liquid simulation (Housner method). It was found that the added-mass method results in greater forces on the anchors in comparison to the lumped-mass method.

scholarly journals Multipoint Wave Measurement in Tuned Liquid Damper Using Laser Doppler Vibrometer and Stepwise Rotating Galvanometer Scanner

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8211
Author(s):  
Yoon-Soo Shin ◽  
Junhee Kim
Keyword(s):  
Natural Frequency ◽  
Vibration Suppression ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Liquid Level ◽  
Tuned Liquid Damper ◽  
Tuned Liquid Dampers ◽  
Liquid Dampers ◽  
Tuning Frequency ◽  
Galvanometer Scanner

Liquid dampers, such as tuned liquid dampers (TLDs), are employed to improve serviceability by reducing wind-affected building vibrations. In order to maximize the vibration suppression efficiency of the liquid damper, the tuning frequency of the liquid damper should match the natural frequency of the building. Experimental evaluation of the tuning frequency of a liquid damper performed in a factory prior to installation in a building is a critical task to ensure correct performance, and for this, multipoint measurement of the TLD is required. In this study, a novel liquid level measurement system combining Laser Doppler Vibrometer (LDV) and a stepwise rotating galvanometer scanner was developed to observe liquid sloshing in TLD. The proposed system can measure the liquid level at multiple points simultaneously with a single laser point. In the experimental phase, the liquid damper’s natural frequency and mode shape are experimentally evaluated utilizing the developed system. The performance of the proposed system was verified by comparison with the video sensing system.

Development of a novel tuned liquid damper with floating base for converting deep tanks into effective vibration control devices

2020 ◽  
pp. 136943322095353
Author(s):  
Tanmoy Konar ◽  
Aparna (Dey) Ghosh
Keyword(s):  
Vibration Control ◽  
Structural Response ◽  
Liquid Level ◽  
Water Level Fluctuations ◽  
Tuned Liquid Damper ◽  
Water Storage Tank ◽  
Tuned Liquid Dampers ◽  
Floating Base ◽  
Tank System ◽  
Liquid Dampers

Despite the proven effectiveness of tuned liquid dampers (TLDs), readily available liquid storage tanks are rarely utilized for vibration control of laterally-excited structures, as these are deep tanks with low inherent damping. Further, the fluctuation in liquid level in these tanks also causes variation in the fundamental sloshing frequency, leading to detuning. To overcome these problems, a novel TLD with floating base (TLD-FB) is proposed, in which a constant and shallow liquid level is maintained between the free liquid surface and the floating base. The liquid above the floating base acts as a conventional shallow TLD that always remains tuned to the structural frequency. The paper demonstrates how the TLD-FB can be incorporated into a water storage tank system on an example building without disturbing its functionality and achieves structural response reduction, despite water level fluctuations in the tanks.

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