Effect of soil interaction on the performance of liquid column dampers for seismic applications

Ghosh, Aparna; Basu, Biswajit

doi:10.1002/eqe.485

Cited by 12 publications

(6 citation statements)

References 13 publications

(15 reference statements)

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“…The soil has the effect of lowering the system's modal frequencies, a fact reported in numerous studies on SSI. [1][2][3][4]9,12 The tower's first and third modes of displacement response show a reduction in frequency with reduction in soil stiffness (shear modulus). There is an even greater reduction in the second modal frequency of the tower displacement response.…”

Section: Discussionmentioning

confidence: 99%

“…5 The use of SSI in design is usually restricted to buildings in seismic zones. [6][7][8][9] However, wind turbines contain moving parts and must sustain continuous vibration-induced forces throughout their operational life. Novak and Hifnawy 10,11 showed that the response of a structure when subject to a dynamic wind loading can be affected by SSI.…”

Section: Introductionmentioning

confidence: 99%

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Foundation impedance and tower transfer functions for offshore wind turbines

Harte

Basu

2013

Proceedings of the Institution of Mechanical Engineers, Part K:

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This article investigates the dynamic interaction between a horizontal-axis wind turbine, modelled as a discrete Euler-Lagrangian system, and the soil-foundation system, modelled in a finite element framework. The model comprises a rotor blade system, a nacelle and a flexible tower connected to the soil-foundation system using a substructuring approach. The aerodynamic loading on the rotor blades is modelled using blade element momentum theory. The offshore wind turbine is founded on a monopod suction caisson foundation. The soil-foundation system is modelled using a finite element method (Plaxis 3D dynamics) and a 1D strength of materials based on wave propagation approach (cone method) for comparison. A dynamic-stiffness matrix and a static stiffness matrix formulation are used to represent the soil-foundation behaviour at the mudline. Tower displacement response transfer functions are generated using each soil-foundation model at various soil stiffness. The effects of the soil stiffness on the displacement transfer functions and the wind turbine dynamics are discussed. Results from a static stiffness formulation (with coupling) are seen to match those given by frequency-dependent models, indicating that such simplified models maybe used for analysis under certain conditions.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Foundation impedance and tower transfer functions for offshore wind turbines

Harte

Basu

2013

Proceedings of the Institution of Mechanical Engineers, Part K:

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“…x g , x 0 , φ y , and x denote, respectively, the free-field displacement of the soil, horizontal displacement, and rotation of the soil-foundation interface, and the structural relative displacement with respect to foundation in the time domain. From this decomposition, the dynamic equilibrium equations for the movement of the liquid inside the pressurized damper, the translation of the structural mass and the displacements/rotations at the base are established as proposed by Ghosh and Basu (2005). The equation of motion of the liquid column is given by…”

Section: Soil Structure Interaction With Ptlcdmentioning

confidence: 99%

“…When these interaction effects are included, it is necessary to evaluate the SSI interference in the performance of the TLCD for seismic applications. Luco (1998) and Ghosh and Basu (2005) using impedance functions that consider the three systems (soil-structure-damper), analyzed these effects. After studies such as these, in which the influence of SSI on vibration control is evidenced, Mousavi et al (2013), Farshidianfar and Soheili (2013), and Ozuygur and Gunduz (2018) applied optimization methods to define optimal parameters for the passive device connected to a structure subject to seismic action and under the influence of site conditions.…”

Section: Introductionmentioning

confidence: 99%

Effects of soil-structure interaction in seismic analysis of buildings with multiple pressurized tuned liquid column dampers

Mendes

Ribeiro

Pedroso

2019

Lat. Am. j. solids struct.

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In this paper soil-structure interaction (SSI) effects are investigated while an array of Pressurized Tuned Liquid Column Dampers (PTLCD) is employed for seismic vibration control of buildings. This device represents the most general case of a passive damper, with different reduction options to other control devices obtained by simplifying the involved parameters. Soil conditions considerably affect the control device functioning, because dynamic parameters such as natural frequency, damping factor, and natural modes depend on the soil properties. A simplified mathematical model is developed for the building with multiple degrees of freedom connected to a flexible base. For the time-domain analysis, a computational routine is developed for the linearization of the equilibrium equations of the PTLCD, as well as details for the reduction to the other types of passive dampers. Several numerical examples are selected for the analysis of the damper efficiency in reducing seismic vibration considering SSI. These simulations include Kobe earthquake data, which is applied to the model to evaluate the device performance under different scenarios. It is verified the influence of SSI in the natural frequency and structural response, which is related to the earthquake frequency components. Results confirm that the array of PTLCD's can reduce the vibration amplitudes, being more effective for soils with higher stiffness values.

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“…Specifically, the main dynamic load considered in these structures is due to the wind. Just like the random action of the wind, efforts have been applied to the dynamic analysis of structures with TLCD for the control of earthquake vibrations (Gosh and Basu, 2005;Chakraborty et al, 2012;Mendes et al, 2019;Espinoza et al, 2018). For a better performance of the damper, (Gosh and Basu, 2004;Sonmez et al, 2016) propose a different composition, in which the TLCD is connected to the primary structure using an adaptive spring.…”

Section: Introductionmentioning

confidence: 99%

A study of TLCD parameters for structural vibration mitigation

Mendes

Ghedini

Batista

et al. 2023

Lat. Am. j. solids struct.

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In this article, the efficiency of the tuned liquid column damper (TLCD) in reducing structural vibration is analyzed. The analysis by numerical methods and by analytical methods is adopted in the search for the ideal parameters for the liquid column. The equivalent linear model is considered for the U-shaped liquid column equation of motion with damping resulting from an orifice. Thus, variation of TLCD parameters for different loads is investigated. Initially, for the numerical study in conjunction with the analytical formulation, a sinusoidal forcing is adopted. Subsequently, the action of an earthquake through the recorded ground accelerations is considered in the case study. Optimal TLCD parameters are presented via response map for reducing the structure's maximum permanent response to harmonic excitation and for reducing the structure's rms response to seismic excitation with wide frequency and various amplitude. The variation of the TLCD parameters presented by the response map is directly related to the force acting on the structure. However, it is verified that regardless of the acting force, there is an ideal frequency range to tune the TLCD where the greatest reductions in the primary system response are found. It appears that reducing the aspect ratio of the liquid column makes this range narrower, making the damper more sensitive to parameter variations, as well as its performance. It is also observed that the increase in the attenuator mass ratio combined with the correct tuning and damping ratios present greater reductions in structural vibration. Also, the frequency ratio is reduced with the increase of the mass ratio, while the damping rate of the liquid column increases. From the ideal liquid column parameters determined by the parametric analysis, structural response reductions of approximately 60% were achieved.

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Effect of soil interaction on the performance of liquid column dampers for seismic applications

Cited by 12 publications

References 13 publications

Foundation impedance and tower transfer functions for offshore wind turbines

Foundation impedance and tower transfer functions for offshore wind turbines

Effects of soil-structure interaction in seismic analysis of buildings with multiple pressurized tuned liquid column dampers

A study of TLCD parameters for structural vibration mitigation

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