scholarly journals Parametric Study of Tuned Mass Dampers for Long Span Transmission Tower-Line System under Wind Loads

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Li Tian ◽  
Yujie Zeng
Keyword(s):  
Frequency Ratio ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Tuned Mass Damper ◽  
Reduction Ratio ◽  
Transmission Tower ◽  
Tuned Mass Dampers ◽  
Line System ◽  
Long Span ◽  
Mass Damper

A parametric study of tuned mass dampers for a long span transmission tower-line system under wind loads is done in this paper. A three-dimensional finite element model of transmission tower-line system is established by SAP2000 software to numerically verify the effectiveness of the tuned mass damper device. The wind load time history is simulated based on Kaimal spectrum by the harmony superposition method. The equations of motion of a system with tuned mass damper under wind load excitation are proposed, and the schematic of tuned mass damper is introduced. The effects of mass ratio, frequency ratio, damping ratio, the change of the sag of transmission line, and the robustness of TMD are investigated, respectively. Results show that(1)the change of mass ratio has a greater effect on the vibration reduction ratio than those of frequency ratio and damping ratio, and the best vibration reduction ratio of TMD is not the frequency ratio of 1;(2)the sag-span ratio has an insignificant effect on the vibration reduction ratio of transmission tower when the change of sag-span ratio is not large; and(3)the effect of ice should be considered when the robustness study of TMD is carried out.

scholarly journals Wind-induced Vibration Optimal Control for Long Span Transmission Tower-line System

2013 ◽  
Vol 7 (1) ◽  
pp. 159-163 ◽  
Author(s):  
Li Tian ◽  
Qian Wang ◽  
Qiqi Yu ◽  
Nuwen Xu
Keyword(s):  
Equations Of Motion ◽  
Three Dimensional ◽  
Time History ◽  
Tuned Mass Damper ◽  
Induced Response ◽  
Transmission Tower ◽  
Line System ◽  
Long Span ◽  
Mass Damper ◽  
Three Dimensional Finite Element

In this paper, tuned mass dampers with optimal parameters for long span transmission tower-line system are investigated. Equations of motion for a structure-TMD system are derived, and the parameters of TMD, stiffness and damping are optimized, respectively. According to a real project, three-dimensional finite element models of both transmission tower and transmission tower-line system are created and their vibration performances are analyzed using SAP2000 software, respectively. Wind load time history is simulated based on wind theory. Using numerical simulation, vibration control with optimal tuned mass damper installed in transmission tower-line system is carried out. Time history curves and the maximum responses of system without and with tuned mass damper under wind excitation are analyzed and discussed. The results show that the optimal tuned mass damper could effectively decrease the wind-induced response of long span transmission tower-line system.

Determination of optimal parameters of the tuned mass damper to reduce the torsional vibration of the shaft by using the principle of minimum kinetic energy

2018 ◽  
Vol 233 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Duy-Chinh Nguyen
Keyword(s):  
Kinetic Energy ◽  
Torsional Vibration ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Tuned Mass Damper ◽  
Optimal Parameters ◽  
Lagrangian Equations ◽  
Tuning Ratio ◽  
Mass Damper

In this paper, an analytical method is presented to determine the optimal parameters of the symmetric tuned mass damper, such as the ratio between natural frequency of tuned mass damper and shaft (tuning ratio) and the ratio of the viscous coefficient of tuned mass damper (damping ratio). The optimal parameters of tuned mass damper are applied to reduce the torsional vibration of the shaft based on consideration of the vibration duration and stability criterion. The dynamic equations of the shaft are provided via Lagrangian equations, and the optimal parameters of tuned mass damper are derived by using the principle of minimum kinetic energy. Analytical and numerical examples are implemented to verify the reliability of the proposed method. The analytical and numerical results indicate that the optimal parameters of tuned mass damper have significant effects in the torsional vibration reduction of the shaft.

scholarly journals Development of a Frequency-Adjustable Tuned Mass Damper (FATMD) for Structural Vibration Control

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Huaguo Gao ◽  
Congbao Wang ◽  
Chen Huang ◽  
Wenlong Shi ◽  
Linsheng Huo
Keyword(s):  
Damping Ratio ◽  
Tuned Mass Damper ◽  
Vertical Vibration ◽  
Structural Vibration ◽  
Kinematic Equation ◽  
Pedestrian Bridge ◽  
Long Span ◽  
Mass Damper ◽  
Excitation Frequencies ◽  
Simple Assembly

The tuned mass damper (TMD) can be applied to suppress earthquake, wind, and pedestrian- and machine-induced vibration in factory buildings or large span structures. However, the traditional TMD with a fixed frequency will not be able to perform effectively against the frequency variations in multiple hazards. This paper proposed a frequency-adjustable tuned mass damper (FATMD) to solve this limitation of current TMD. The FATMD presented in this paper is composed of a simple assembly consisting of a supported beam with a mass, in which the frequency of the FATMD is changed by adjusting the span of the beam. The kinematic equation of a single degree of freedom (SDOF) structure installed with an FATMD is established to analyze the effect of the damping ratio, mass ratio, and stiffness on the vibration damping. The fundamental frequency of the FATMD at different spans is verified by simulation and experiments. Forced vibration experiments with different excitation frequencies are also conducted to verify the performance of the FATMD. The results show that the proposed FATMD can effectively suppress the vertical vibration of structures at different excitation frequencies, including frequencies at a range higher than what a traditional TMD may not be able to suppress. Additionally, the proposed FATMD is applied to a long-span pedestrian bridge which vibrates frequently due to the walking of pedestrians, the running of escalators, and earthquakes. The numerical results indicate that the FATMD can effectively reduce the vertical vibration of the pedestrian bridge under the excitations of pedestrians, escalators, and earthquakes.

A Bidirectional Pounding Tuned Mass Damper and Its Application to Transmission Tower-Line Systems under Seismic Excitations

2019 ◽  
Vol 19 (06) ◽  
pp. 1950056 ◽  
Author(s):  
Li Tian ◽  
Kunjie Rong ◽  
Kaiming Bi ◽  
Peng Zhang
Keyword(s):  
Element Model ◽  
Tuned Mass Damper ◽  
Seismic Intensity ◽  
Design Parameters ◽  
Seismic Responses ◽  
Transmission Tower ◽  
Control Effect ◽  
Seismic Excitations ◽  
Line System ◽  
Mass Damper

Failures of transmission tower-line systems have frequently occurred during large earthquakes. It is essential to control the excessive vibrations of transmission tower-line systems to ensure their safe operation in such events. This paper numerically investigates the effectiveness of using a novel bidirectional pounding tuned mass damper (BPTMD) to control the seismic responses of transmission tower-line system when subjected to earthquake ground motions. A finite element model of a typical transmission tower-line system with BPTMD is developed using the commercial software ABAQUS, with the accuracy of the results verified against a previous study. The seismic responses of the system with and without BPTMD are calculated. For comparison, the control effect of using the conventional bidirectional tuned mass damper is also calculated and discussed. Finally, a parametric study is performed to investigate the effects of the mass ratio, seismic intensity, gap size and frequency ratio on the seismic response of the system, while optimal design parameters are obtained.

A hybrid approach for parameter optimization of multiple tuned mass dampers in reducing floor vibrations due to occupant walking: Theory and parametric studies

2017 ◽  
Vol 20 (8) ◽  
pp. 1232-1246 ◽  
Author(s):  
Ruotian Xu ◽  
Jun Chen ◽  
Xinqun Zhu
Keyword(s):  
Dynamic Properties ◽  
Damping Ratio ◽  
Hybrid Approach ◽  
Tuned Mass Damper ◽  
Dynamic Responses ◽  
Optimization Approach ◽  
Tuned Mass Dampers ◽  
Mass Damper ◽  
Floor Vibrations ◽  
Multiple Tuned Mass Dampers

This article presents a hybrid approach for determining optimal parameters of multiple tuned mass dampers to reduce the floor vibration due to human walking. The proposed approach consists of two parts. The first one is a partial mode decomposition algorithm to efficiently calculate dynamic responses of the coupled floor–multiple tuned mass damper system subjected to moving walking loads. The second one is an adaptive genetic simulated annealing method for the optimization of multiple tuned mass damper parameters. To establish optimization, certain variables must be considered. These include the mass, natural frequency, and damping ratio of each tuned mass damper in a multiple tuned mass damper system. The objective is to minimize floor responses and remove unreasonable requirements, such as uniform mass distribution and symmetric distribution of the tuned mass damper frequency. The proposed hybrid approach has successfully been applied to optimize the multiple tuned mass damper system to reduce the vibration of a long-span floor with closely spaced modes. By the hybrid approach, an extensive parametric study has been carried out. The results show that different walking load models and uncertainties in the dynamic properties of the floor and each tuned mass damper itself can affect the overall performance of the multiple tuned mass damper system. The proposed hybrid optimization approach is very effective and the resulting multiple tuned mass damper system is robust in reducing floor vibrations under various conditions.

OPTIMUM MULTIPLE TUNED MASS DAMPERS FOR BASE-EXCITED DAMPED MAIN SYSTEM

2004 ◽  
Vol 04 (04) ◽  
pp. 527-542 ◽  
Author(s):  
S. V. BAKRE ◽  
R. S. JANGID
Keyword(s):  
Damping Ratio ◽  
Tuned Mass Damper ◽  
Frequency Bandwidth ◽  
Tuned Mass Dampers ◽  
Explicit Formulas ◽  
Optimum Parameters ◽  
Main System ◽  
Mass Damper ◽  
Tuning Frequency ◽  
Multiple Tuned Mass Dampers

The optimum parameters of multiple tuned mass dampers (MTMD) for suppressing the dynamic response of a base-excited damped main system are investigated by a numerical searching technique. The criterion selected for the optimality is the minimization of the steady state displacement of the main system under harmonic base acceleration. The parameters of the MTMD that are optimized include: the damping ratio, the tuning frequency ratio and the frequency bandwidth. The optimum parameters of the MTMD system and corresponding displacement are obtained for different damping ratios of the main system and different mass ratios of the MTMD system. The explicit formulas for the optimum parameters of the MTMD (i.e. damping ratio, bandwidth and tuning frequency) are then derived using a curve-fitting scheme that can readily be used in engineering applications. The error in the proposed explicit expressions is investigated and found to be negligible. The effectiveness of the optimally designed MTMD system is also compared with that of the optimum single tuned mass damper. It is observed that the optimally designed MTMD system is more effective for vibration control than the single tuned mass damper. Further, the damping in the main system significantly influences the optimum parameters and the effectiveness of the MTMD system.

scholarly journals Study on Seismic Control of Power Transmission Tower-Line Coupled System under Multicomponent Excitations

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Li Tian ◽  
Qiqi Yu ◽  
Ruisheng Ma
Keyword(s):  
Power Transmission ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Coupled System ◽  
Time Domain Analysis ◽  
Tuned Mass Damper ◽  
Transmission Tower ◽  
Line System ◽  
Seismic Control ◽  
Mass Damper

The seismic control of power transmission tower-line coupled system subjected to multicomponent excitations is studied in this paper. The schematic of tuned mass damper is introduced, and equations of motion of a system with tuned mass damper under multi-component excitations are proposed. Three-dimensional finite tower-line system models are created based on practical engineering in studying the response of this system without and with control. The time domain analysis takes into account geometric nonlinearity due to finite deformation. The optimal design of the transmission tower-line system with tuned mass damper is obtained according to different mass ratio. The effects of wave travel, coherency loss, and different site conditions on the system without and with control are investigated, respectively.

scholarly journals Optimal parameters of tuned mass dampers for machine shaft using the maximum equivalent viscous resistance method

2020 ◽  
Vol 14 (1) ◽  
pp. 127-135 ◽  
Author(s):  
Nguyen Duy Chinh
Keyword(s):  
Torsional Vibration ◽  
Vibration Reduction ◽  
Tuned Mass Damper ◽  
Random Excitation ◽  
Viscous Resistance ◽  
Optimal Parameters ◽  
Tuned Mass Dampers ◽  
Specific Data ◽  
Resistance Method ◽  
Mass Damper

The paper analyzes and determines the optimal parameters of tuned mass damper to reduce torsional vibration for the machine shaft. The research steps are as follows. First, the optimal parameters of tuned mass damper for the shafts are given by using the maximization of equivalent viscous resistance method. Second, a numerical simulation is performed for configuration of machine shaft to validate the effectiveness of the obtained analytical results. The simulation results indicate that the proposed method significantly increases the effectiveness of torsional vibration reduction. Optimal parameters include the ratio between natural frequency of tuned mass damper and the machine shaft, the ratio of the viscous coefficient of tuned mass damper. The optimal parameters found by numerical method only apply to a machine shaft with specific data. However, the optimal parameters in this paper are found as analytic and explicit to help scientists easily apply to every machine shafts when the input parameters of the machine shaft change. Keywords: tuned mass damper; torsional vibration; optimal parameters; random excitation; equivalent viscous resistance.

Effectiveness of Location and Number of Multiple Tuned Mass Damper for Seismic Structures

2020 ◽  
Vol 9 (6) ◽  
pp. 780-783
Keyword(s):  
Seismic Response ◽  
Software Tool ◽  
Tuned Mass Damper ◽  
Structure Study ◽  
Structural Performance ◽  
Mass Ratio ◽  
Tuned Mass Dampers ◽  
Maximum Reduction ◽  
Mass Damper ◽  
Earthquake Data

Tuned mass dampers (TMD) are one of the most reliable devices to control the vibration of the structure. The optimum mass ratio required for a single tuned mass damper (STMD) is evaluated corresponding to the fundamental natural frequency of the structure. The effect of STMD and Multiple tuned mass dampers (MTMD) on a G+20 storey structure are studied to demonstrate the damper’s effectiveness in seismic application. The location and number of tuned mass dampers are studied to give best structural performance in maximum reduction of seismic response for El Centro earthquake data. The analysis results from SAP 2000 software tool shows damper weighing 2.5% of the total weight of the structure effectively reduce the response of the structure. Study shows that introduction of 4-MTMD at top storey can effectively reduce the response by 10% more in comparison to single tuned mass damper. The use of MTMD of same mass ratio that of STMD is more effective in seismic response.

scholarly journals Seismic Resistance and Parametric Study of Building under Control of Impulsive Semi-Active Mass Damper

2021 ◽  
Vol 11 (6) ◽  
pp. 2468
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Frequency Ratio ◽  
Efficiency Index ◽  
Reduction Ratio ◽  
Seismic Resistance ◽  
Control Effect ◽  
Active Mass ◽  
High Rise ◽  
Mass Damper ◽  
Active Mass Damper ◽  
External Forces

When high-rise buildings are shaken due to external forces, the facilities of the building can be damaged. A Tuned Mass Damper (TMD) can resolve this issue, but the seismic resistance of TMD is exhausted due to the detuning effect. The Impulsive Semi-Active Mass Damper (ISAMD) is proposed with fast coupling and decoupling at the active joint between the mass and structure to overcome the detuning effect. The seismic proof effects of a high-rise building with TMD and ISAMD were compared. The numerical analysis results indicate that: (1) the reduction ratio of the maximum roof displacement response and the mean square root of the displacement reduction ratio of the building with the ISAMD were higher than 30% and 60%, respectively; (2) the sensitivity of the efficiency index to the frequency ratio of the ISAMD was very low, and detuning did not occur in the building with the ISAMD; (3) to achieve stable seismic resistance of the ISAMD, its frequency ratio should be between 2 and 4; (4) the amount of displacement of the control mass block of the ISAMD can be reduced by enhancing the stiffness of the auxiliary spring of the ISAMD; and (5) the proposed ISAMD has a stable control effect, regardless of the earthquake distance.

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