Analytical Study on Wind-Induced Vibration and its Control of Transmission Towers in Mountainous Area

2011 ◽  
Vol 105-107 ◽  
pp. 635-639
Author(s):  
Zheng Yi Sheng ◽  
Chun Xia ◽  
Wei Ping Xu ◽  
Peng Yun Li
Keyword(s):  
Induced Response ◽  
Mountainous Area ◽  
Superposition Method ◽  
Transmission Tower ◽  
Control Effect ◽  
Line System ◽  
Viscoelastic Dampers ◽  
Transmission Towers ◽  
Out Of Plane ◽  
Wind Induced Vibration

A method for analyzing wind-induced vibration and its control of transmission tower-line system in mountainous area is described. The method is applied to a real transmission line containing two self-supporting steel angle towers, 3 spans of conductors and ground lines together with insulators. Analyses are conducted for the out-of-plane wind direction, and the fluctuating wind load on tower-line system is simulated by harmony superposition method and davenport spectrum. The numerical results indicate that the wind-induced response and its control effect are mainly related to the stiffness of the towers, rather than the mounting height or the spans of the power lines. At the same time, viscoelastic dampers fixed on the main members can suppress the wind-induced displacement of the towers effectively.

scholarly journals Parameter Analysis on Wind-Induced Vibration of UHV Cross-Rope Suspension Tower-Line

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Xilai Li ◽  
Dengke Yu ◽  
Zhengliang Li
Keyword(s):  
Structural Design ◽  
Tensile Force ◽  
Reaction Force ◽  
Time History ◽  
Parameter Analysis ◽  
Design Parameters ◽  
Induced Response ◽  
Superposition Method ◽  
Line System ◽  
Wind Induced Vibration

This paper analyzes the influences of important structural design parameters on the wind-induced response of cross-rope suspension tower-line. A finite element model of cross-rope suspension tower-line system is established, and the dynamic time-history analysis with harmonic wave superposition method is conducted. The two important structural design parameters such as initial guy pretension and sag-span ratio of suspension-rope are studied, as well as their influences on the three wind-induced vibration responses such as tensile force on guys, the reaction force on mast supports, and the along-wind displacement of the mast top; the results show that the value of sag-span ratio of suspension-rope should not be less than 1/9 and the value of guy pretension should be less than 30% of its design bearing capacity. On this occasion, the tension in guys and compression in masts would be maintained in smaller values, which can lead to a much more reasonable structure.

scholarly journals Control of Wind-Induced Vibration of Transmission Tower-Line System by Using a Spring Pendulum

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Peng Zhang ◽  
Liang Ren ◽  
Hongnan Li ◽  
Ziguang Jia ◽  
Tao Jiang
Keyword(s):  
Internal Resonance ◽  
Power Transmission ◽  
Mode Frequency ◽  
Liaoning Province ◽  
Superposition Method ◽  
Transmission Tower ◽  
Pendulum System ◽  
Line System ◽  
Kinetic Expression ◽  
Wind Induced Vibration

The high-voltage power transmission tower-line system, which is a high flexible structure, is very susceptible to the wind-induced vibrations. This paper proposes the utilization of the internal resonance feature of the spring pendulum to reduce the wind-induced vibration of a transmission tower. The kinetic expression of the spring pendulum system is obtained through Lagrangian equation. The condition of the internal resonance is verified to beλ = 2, in whichλis the ratio of the spring mode frequency over the pendulum mode frequency. A 55 m tower in the Liaoning province is established in SAP2000 to numerically verify the effectiveness of the proposed device. The spring pendulum is modeled using Link element. The wind speed history is generated based on Kaimal spectrum using harmonic superposition method. Results show that, (1) compared with the suspended mass pendulum, the spring pendulum absorbs more energy and reduces the oscillation more effectively and (2) the vibration control performance of the proposed spring pendulum improves as the external wind load increases.

scholarly journals Collapse Analysis of a Transmission Tower-Line System Induced by Ice Shedding

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaxiang Li ◽  
Biao Wang ◽  
Jian Sun ◽  
Shuhong Wang ◽  
Xiaohong Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Transmission Lines ◽  
Progressive Collapse ◽  
Element Model ◽  
Transmission Tower ◽  
Line System ◽  
Finite Element Software ◽  
Transmission Towers ◽  
Ice Shedding ◽  
The Impact

Ice shedding causes transmission lines to vibrate violently, which induces a sharp increase in the longitudinal unbalanced tension of the lines, even resulting in the progressive collapse of transmission towers in serious cases, which is a common ice-based disaster for transmission tower-line systems. Based on the actual engineering characteristics of a 500 kV transmission line taken as the research object, a finite element model of a two-tower, three-line system is established by commercial ANSYS finite element software. In the modeling process, the uniform mode method is used to introduce the initial defects, and the collapse caused by ice shedding and its influencing parameters are systematically studied. The results show that the higher the ice-shedding height is, the greater the threat of ice shedding to the system; furthermore, the greater the span is, the shorter the insulator length and the greater the dynamic response of the line; the impact of ice shedding should be considered in the design of transmission towers.

Gust Response Factor of a Transmission Tower Under Typhoon

2020 ◽  
pp. 2150001
Author(s):  
Xing Fu ◽  
Wen-Long Du ◽  
Hong-Nan Li ◽  
Wen-Ping Xie ◽  
Kai Xiao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Field Measurements ◽  
Element Model ◽  
Structural Safety ◽  
Transmission Tower ◽  
Response Factors ◽  
Line System ◽  
Transmission Towers ◽  
Synoptic Wind ◽  
Gust Response

The gust response factors (GRFs) of transmission towers in current standards are reviewed for synoptic winds. The collapse of most transmission towers has occurred under the high-intensity wind (HIW) caused by events such as typhoons, hurricanes, and downbursts. Thus, this paper studies the GRF of a transmission tower under the typhoon. First, the definition of GRF and its extended form for the transmission towers are developed. Then the wind speed simulation of a typhoon event is introduced. Based on the structural health monitoring (SHM) system installed on tower #32, the measured GRFs under the super typhoon Mangkhut are calculated. Then the finite element model (FEM) of the transmission tower-line system is established to simulate the dynamic response to further calculate the GRFs, which agrees well with the field measurements. Both the field measurement and simulation results show that the GRFs under the typhoon are larger than those under the synoptic wind and that the recommended GRFs in the Chinese standard underestimate the peak responses. Finally, a parametric analysis is performed, which demonstrates that the turbulence intensity, wind speed, and power-law exponent all have great effects on the GRFs of transmission towers. In the HIW-prone areas, it is recommended that the characteristics of the HIW can be considered in improving the GRF values to guarantee the structural safety of transmission towers.

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.

Wind-Induced Vibration Control for Transmission System Using Steel-Lead Viscoelastic Damper

2014 ◽  
Vol 597 ◽  
pp. 376-379 ◽  
Author(s):  
Feng Lin Gan ◽  
Hai Long Jiang
Keyword(s):  
Time History ◽  
Element Model ◽  
Transmission Tower ◽  
Viscoelastic Damper ◽  
Line System ◽  
Type Steel ◽  
New Type ◽  
Auto Regressive ◽  
Working Principle ◽  
Wind Induced Vibration

For wind-induced vibration of transmission tower-line system, the vibration reduction effects are studied based on a new type steel-lead viscoelastic damper. Firstly, Calculate damped coefficient basing on the test of the new type steel-lead viscoelastic damper under slow reversed cyclic horizontal loads. Then, a finite element model of transmission tower was built by using ANSYS. And the time history samples of random fluctuating wind load is obtained with the linear auto-regressive filter law principle. Next, three installation plans of dampers on tower were proposed based on analyzing the working principle damper and the structure of tower. Finally, a wind-induced vibration transient response simulation was performed respectively for the different plans. The influences of SLVD dampers on the displacement and on the acceleration of the controlled nodes were compared. SLVD damper can reduce the top node displacement by about 37.89%. The results indicated that the SLVD damper can suppress the wind-induced vibration. And through comparison, the optimal installation scheme of SLVD dampers is 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.

Analysis on Wind-Induced Vibration Dynamic Responses of Transmission Tower-Line System

2013 ◽  
Vol 327 ◽  
pp. 284-289
Author(s):  
Xiao Guang Hu ◽  
Jing Bo Yang ◽  
Feng Li Yang
Keyword(s):  
Random Vibration ◽  
Coupling Effect ◽  
Dynamic Responses ◽  
Building Structures ◽  
Transmission Tower ◽  
Line System ◽  
Vibration Theory ◽  
Random Vibration Theory ◽  
Wind Induced Vibration ◽  
Line Coupling

Tower-line system of overhead transmission line are sensitive to wind. Therefore, dynamic effect of wind load should be taken into consideration, for instance, wind-induced vibration coefficient. There might be some errors in the calculation of the coefficient in accordance with ‘Load code for the design of building structures’, for its ignoring the irregular figure, scattered masses and coupling effect of tower-line system. Tower-line system is set up in virtual environment, with tower-line coupling considered, and research wind-induced vibration dynamic responses under Davenport wind speed spectrum. Random vibration theory was applied to calculate the coefficient. Whole tower was divided by hight, and calculated segment’s the wind-induced vibration coefficient seprately. Compare the coefficient from Load Code and random vibration theory, the latter with tower-line coupling effect and tower figure considered, is close to the actual.

scholarly journals Random Wind-induced Response Analysis of Transmission Tower-line System

2012 ◽  
Vol 16 ◽  
pp. 1813-1821 ◽  
Author(s):  
Qin Li ◽  
Yuan Junjian ◽  
Li Wei
Keyword(s):  
Induced Response ◽  
Response Analysis ◽  
Transmission Tower ◽  
Line System

Research on Calculation of Equivalent Damping Ratio of Electrical Transmission Tower-Line System with Viscoelastic Dampers

2014 ◽  
Vol 1064 ◽  
pp. 115-119
Author(s):  
Cong Zeng ◽  
Dong Xue Hao ◽  
Li Qun Hou
Keyword(s):  
Calculation Method ◽  
Strain Energy ◽  
Damping Ratio ◽  
Element Model ◽  
Transmission Tower ◽  
Electrical Transmission ◽  
Line System ◽  
Equivalent Damping ◽  
Viscoelastic Dampers ◽  
The One

Installing viscoelastic dampers on electrical transmission tower will significantly reduce the wind-induced vibration response of electrical transmission tower-line system. On the basis of the concept of strain energy method with the combination of related codes and the theories of calculation for equivalent damping,a mothed is presented which is used to estimate the additional damping of electrical transmission tower-line system with viscoelastic dampers.Through a electrical transmission tower with viscoelastic dampers, based on the formula of strain energy in design code,this paper puts forward a calculation method of equivalent damping ratio based on the concept story of transmission tower,and through finite element model the responses of transmission tower with viscoelastic dampers model and the one with additional damping ratio model were compared.The simulation results show that the calculation method of equivalent damping ratio has high precision,and the errors are less than 5% in multi engineering conditions.

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