Response control of a large transmission tower-line system under seismic excitations using friction dampers

2016 ◽  
Vol 20 (8) ◽  
pp. 1155-1173 ◽  
Author(s):  
Bo Chen ◽  
Shun Weng ◽  
Lunhai Zhi ◽  
Dongming Li
Keyword(s):  
Axial Stiffness ◽  
Control Force ◽  
Friction Damper ◽  
Transmission Tower ◽  
Lumped Mass ◽  
Seismic Excitations ◽  
Response Control ◽  
Line System ◽  
Strong Earthquakes ◽  
Friction Dampers

The transmission tower-line system is widely used in electric infrastructures across the world and generally possesses a small stiffness and low structural damping. The excessive vibration of a transmission tower-line system subjected to seismic excitations may induce a structural damage or failure. To avoid the excessive vibration under strong earthquakes, a large transmission tower-line system requires some measures to abate their dynamic responses. Friction damper is a solution to realize the response control of a transmission tower-line system. In this regard, the response mitigation and performance assessment on a transmission tower-line system with friction dampers under strong earthquakes are actively carried out in this study. The analytical model of a transmission line is proposed based on Hamilton’s variational statement of dynamics and Lagrange’s formulation. A two-dimensional lumped mass model of a transmission tower is developed for the dynamic analysis by simplifying the three-dimensional finite element model. The mechanical model of a friction damper is established by considering the effect of damper axial stiffness. The equations of motion and dynamic analytical method of a transmission tower-line system without/with friction dampers subjected to seismic excitations are proposed. In addition, the approach for assessing energy responses of a transmission tower-line system without/with friction dampers subjected to seismic excitations is also developed. A real transmission tower-line system is taken as an example to examine the feasibility of the proposed control approach. The parametric study is conducted to investigate the effects of damper control force, damper stiffness, earthquake intensity, and damper location. The made observations demonstrate that the implementation of friction dampers in a transmission tower-line system can substantially suppress the seismic responses with optimal damper parameters.

scholarly journals Performance Evaluation on Transmission Tower-Line System with Passive Friction Dampers Subjected to Wind Excitations

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Bo Chen ◽  
Xiang Xiao ◽  
Peng-yun Li ◽  
Wan-li Zhong
Keyword(s):  
Performance Evaluation ◽  
Axial Stiffness ◽  
Parameter Study ◽  
Fe Model ◽  
Optimal Parameters ◽  
Friction Damper ◽  
Transmission Tower ◽  
Lumped Mass ◽  
Line System ◽  
Friction Dampers

The vibration control and performance evaluation on a transmission-tower line system by using friction dampers subjected to wind excitations are carried out in this study. The three-dimensional finite element (FE) model of a transmission tower is firstly constructed. A two-dimensional lumped mass model of a transmission tower is developed for dynamic analysis. The analytical model of transmission tower-line system is proposed by taking the dynamic interaction between the tower and the transmission lines into consideration. The mechanical model of passive friction damper is presented by involving the effects of damper axial stiffness. The equation of motion of the transmission tower-line system incorporated with the friction dampers disturbed by wind excitations is established. A real transmission tower-line system is taken as an example to examine the feasibility and reliability of the proposed control approach. An extensive parameter study is carried out to find the optimal parameters of friction damper and to assess the effects of slipping force axial stiffness and hysteresis loop on control performance. The work on an example structure indicates that the application of friction dampers with optimal parameters could significantly reduce wind-induced responses of the transmission tower-line system.

Response Control of a High-Rise Television Tower under Seismic Excitations by Friction Dampers

2018 ◽  
Vol 18 (11) ◽  
pp. 1850140 ◽  
Author(s):  
Bo Chen ◽  
Deng Yang ◽  
Yue Zheng ◽  
Ke Feng ◽  
Yiqin Ouyang
Keyword(s):  
Equations Of Motion ◽  
Axial Stiffness ◽  
Seismic Responses ◽  
Seismic Excitations ◽  
Response Control ◽  
Strong Earthquakes ◽  
Friction Dampers ◽  
High Rise ◽  
Television Tower ◽  
Tower System

High-rise television towers are prone to external wind and earthquake-induced oscillations in severe environments. To avoid excessive vibration under strong earthquakes, a large television tower requires certain measures to abate its dynamic responses. Friction dampers are simple and low-cost solutions for realizing the response control of television towers. In this study, response mitigation and performance assessment are conducted on a large-scale television tower with friction dampers under strong earthquakes. A 3D finite element static model of the high-rise television tower is first established, and then a 2D lumped mass dynamic model is developed. The mechanical model for the friction dampers is presented with the axial stiffness considered. The equations of motion of the damper–tower system under seismic excitations are then determined. The control force transformation, displacement increment transformation, and numerical integration of the coupled damper–tower system’s equations of motion are defined on the basis of the two aforementioned models. Finally, the seismic responses of a high-rise television tower system constructed in China are taken as an example to investigate the validity of the proposed control approach using the friction dampers. The results demonstrate that the implementation of friction dampers with optimal parameters in a large truss tower can substantially suppress the structural seismic responses in terms of peak responses and vibrant energy.

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.

Study on Simplified Models for Coupled Transmission Tower-Line System to Seismic Excitations

2004 ◽  
Author(s):  
Hong-Nan Li ◽  
Wen-Long Shi ◽  
Guo-Xin Wang
Keyword(s):  
Transmission Lines ◽  
Computational Models ◽  
Equations Of Motion ◽  
Coupled System ◽  
Shaking Table ◽  
Analysis Method ◽  
Transmission Tower ◽  
Seismic Excitations ◽  
Line System ◽  
Out Of Plane

The simplified computational models of high-voltage transmission tower-line system under out-of-plane and in-plane vibrations are presented due to seismic excitations in this paper. The equations of motion are derived and the computer program is compiled to obtain the earthquake responses of the coupled system. To verify the rationality of the proposed approaches, the shaking-table experiments of the coupled system of transmission lines and their supporting towers are carried out and the results indicate that the errors of theoretical and testing results of systemic seismic responses are within the acceptable arrange in engineering area. Based on these studies, a simplified analysis method is proposed to make the seismic response calculation of coupled tower-conductor system faster and more effective.

scholarly journals Shaking Table Array Tests of an Ultra-High-Voltage Cup-Type Transmission Tower-Line System

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Fei Wang ◽  
Ke Du ◽  
Jingjiang Sun ◽  
Fuyun Huang ◽  
Zhenghui Xiong
Keyword(s):  
Ground Motion ◽  
Transmission Lines ◽  
Shaking Table ◽  
Transmission Tower ◽  
Acceleration Response ◽  
Lumped Mass ◽  
Line System ◽  
Transmission Towers ◽  
Tower Model ◽  
Line Coupling

Ultra-high-voltage (UHV) cup-type transmission towers supported with long-span transmission lines are unavoidably subjected to the coupling action between the towers and the transmission lines. Therefore, investigating how tower-line coupling affects UHV cup-type transmission towers is important. In this study, three shaking table array tests of an UHV cup-type transmission tower-line system were carried out to investigate the dynamic characteristics of the coupling action between the towers and transmission lines based on the following four comparative models: a single-tower model, a single-tower model with suspended lumped masses, a three-tower-two-line model, and a five-tower-four-line model. The test results demonstrated that the tower-line coupling interaction had a significant effect on the dynamic characteristics and seismic responses, as the suspended conductor line and the suspended lumped mass decreased the frequency of the transmission tower. Under longitudinal ground motion, the model with the suspended lumped mass had the lowest peak acceleration response and the largest peak displacement response. Under the same ground motion, the four models had similar peak strains in the longitudinal direction. Under transverse-the-line ground motion, the model with the suspended lumped mass had the lowest peak acceleration response and the smallest peak responses for displacement and strain in the transverse direction; therefore, this model is inappropriate for the simulation and seismic evaluation of transmission tower-line systems.

SEISMIC RESPONSE OF POWER TRANSMISSION TOWER-LINE SYSTEM UNDER MULTI-COMPONENT MULTI-SUPPORT EXCITATIONS

2012 ◽  
Vol 06 (04) ◽  
pp. 1250025 ◽  
Author(s):  
TIAN LI ◽  
LI HONGNAN ◽  
LIU GUOHUAN
Keyword(s):  
Seismic Waves ◽  
Power Transmission ◽  
Incident Angle ◽  
Ground Motions ◽  
Three Dimensional ◽  
Transmission Tower ◽  
Line System ◽  
Time Stepping ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The effect of multi-component multi-support excitations on the response of power transmission tower-line system is analyzed in this paper, using three-dimensional finite element time-stepping analysis of a transmission tower-line system based on an actual project. Multi-component multi-support earthquake input waves are generated based on the Code for Design of Seismic of Electrical Installations. Geometric non-linearity was considered in the analysis. An extensive parametric study was conducted to investigate the behavior of the transmission tower-line system under multi-component multi-support seismic excitations. The parameters include single-component multi-support ground motions, multi-component multi-support ground motions, the correlations among the three-component of multi-component multi-support ground motions, the spatial correlation of multi-component multi-support ground motions, the incident angle of multi-component multi-support seismic waves, the ratio of the peak values of the three-component of multi-component multi-support ground motions, and site condition with apparent wave velocity of multi-component multi-support ground motions.

scholarly journals Improved Reliability of Bladed Disks due to Friction Dampers

1997 ◽  
Author(s):  
Walter Sextro ◽  
Karl Popp ◽  
Ivo Wolter
Keyword(s):  
Dry Friction ◽  
Three Dimensional ◽  
Line Contact ◽  
Two Dimensional ◽  
Centrifugal Forces ◽  
Friction Damper ◽  
Blade Vibration ◽  
Friction Dampers ◽  
Bladed Disk ◽  
Bladed Disk Assembly

Friction dampers are installed underneath the blade platforms to improve the reliability. Because of centrifugal forces the dampers are pressed onto the platforms. Due to dry friction and the relative motion between blades and dampers, energy is dissipated, which results in a reduction of blade vibration amplitudes. The geometry of the contact is in many cases like a Hertzian line contact. A three-dimensional motion of the blades results in a two-dimensional motion of one contact line of the friction dampers in the contact plane. An experiment with one friction damper between two blades is used to verify the two-dimensional contact model including microslip. By optimizing the friction dampers masses, the best damping effects are obtained. Finally, different methods are shown to calculate the envelope of a three-dimensional response of a detuned bladed disk assembly (V84.3-4th-stage turbine blade) with friction dampers.

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