scholarly journals Statistical Analysis of Wind-Induced Dynamic Response of Power Towers and Four-Circuit Transmission Tower-Line System

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Xiaolei Zhang ◽  
Yanzhong Ju ◽  
Fuwang Wang
Keyword(s):  
Statistical Analysis ◽  
Wind Speed ◽  
Dynamic Response ◽  
Wind Field ◽  
Coherence Function ◽  
Time History ◽  
Transmission Tower ◽  
Statistical Parameters ◽  
Line System ◽  
Axial Forces

Only one wind field model loading the transmission tower or the tower-line system was investigated in the previous studies, while the influence of two different wind field models was not considered. In addition, only one sample of the wind speed random process was used in the past numerical simulations, and the multiple dynamic response statistical analysis should be carried out. In this paper, statistical analysis of the wind-induced dynamic response of single towers and the transmission tower-line system is performed with the improved accuracy. A finite element model of the transmission tower-line system (the tower consisted of both steel tubes and angel steels) is established by ANSYS software. The analysis was performed by three statistical methods. The effects of the length of the time history and of the number of samples were investigated. The frequency histograms of samples follow the Gaussian distribution. The characteristic statistical parameters of samples were random. The displacements and the axial forces of the low tower are larger than those of the high tower. Two wind field models were applied to simulate the wind speed time history. In field 1 model, Davenport wind speed spectrum and Shiotani coherence function were applied, while in field 2 model Kaimal wind speed spectrum and Davenport coherence function were used. The results indicate that wind field 1 is calmer than wind field 2. The displacements and the axial forces of the tower-line system are less than those of single towers, which indicate damping of wind-induced vibrations by the transmission line. An extended dynamic response statistical analysis should be carried out for the transmission tower-line system.

Wind-Induced Response of UHV Guyed Single-Mast Transmission Tower-Line System

2014 ◽  
Vol 501-504 ◽  
pp. 533-537 ◽  
Author(s):  
Wen Gang Yang ◽  
Bo Wen Zhu ◽  
Zhang Qi Wang
Keyword(s):  
Time History ◽  
Element Model ◽  
Wind Loads ◽  
Induced Response ◽  
Transmission Tower ◽  
Typical Structure ◽  
Line System ◽  
Mean Values ◽  
Axial Forces ◽  
Fluctuating Wind

Ultra-high voltage guyed tower is typical structure of tall and slender, with the character of nonlinear and more sensitive to wind loads. Wind load is one of the most important control loads during design phase. A single-mast guyed tower recommended by a UHV DC transmission line was set as an example in this paper. The finite-element model of transmission tower-line system was built, based on Davenport, fluctuating wind velocity time-history was simulated, the result of wind-induced response was analyzed. The result indicates that, as for displacements of the nodes on guyed tower, the mean values of wind-induced response are greater than the displacements under the static equivalent wind loads. As for axial forces of the leg members on guyed tower, the axial forces under the static equivalent wind loads are less than the max values of wind-induced response.

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.

scholarly journals Nonlinear Seismic Behavior of Different Boundary Conditions of Transmission Line Systems under Earthquake Loading

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Li Tian ◽  
Xia Gai
Keyword(s):  
Boundary Conditions ◽  
Transmission Line ◽  
Transmission Lines ◽  
Seismic Analysis ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Earthquake Loading ◽  
Transmission Tower ◽  
Line System ◽  
Different Boundary Conditions

Nonlinear seismic behaviors of different boundary conditions of transmission line system under earthquake loading are investigated in this paper. The transmission lines are modeled by cable element accounting for the nonlinearity of the cable. For the suspension type, three towers and two span lines with spring model (Model 1) and three towers and four span lines’ model (Model 2) are established, respectively. For the tension type, three towers and two span lines’ model (Model 3) and three towers and four span lines’ model (Model 4) are created, respectively. The frequencies of the transmission towers and transmission lines of the suspension type and tension type are calculated, respectively. The responses of the suspension type and tension type are investigated using nonlinear time history analysis method, respectively. The results show that the responses of the transmission tower and transmission line of the two models of the suspension type are slightly different. However, the responses of transmission tower and transmission line of the two models of the tension type are significantly different. Therefore, in order to obtain accurate results, a reasonable model should be considered. The results could provide a reference for the seismic analysis of the transmission tower-line system.

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.

scholarly journals Characteristics of Typhoon “Fung-Wong” Near Earth Pulsation

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiujun Li ◽  
Yongguang Li ◽  
Jianting Zhou ◽  
Qian Wang ◽  
Xu Wang
Keyword(s):  
Wind Speed ◽  
Turbulence Intensity ◽  
Wind Field ◽  
Coherence Function ◽  
Intensity Attenuation ◽  
Gust Factor ◽  
Peak Factor ◽  
Mean Wind Speed ◽  
Wind Characteristic ◽  
Empirical Curve

To study the wind field characteristics near the ground pulsation in typhoon conditions, wind field conditions in the area affected by Typhoon “Fung-Wong” were monitored using wind field instruments installed in the construction building of Wenzhou University, China. Real-time wind field data were collected during typhoons. Wind characteristic parameters such as mean wind speed, wind direction angle, turbulence intensity, gust factor, peak factor, coherence function, and autocorrelation were analyzed, and the wind field characteristics during the typhoon were summarized. The results indicated that the longitudinal and lateral turbulence intensities decreased with an increase in the mean wind speed, and there was an obvious linear relationship between them. The vertical and horizontal gust factor and peak factor decreased with an increase in mean wind speed, and the trend was more obvious in the horizontal direction. There was a significant correlation between the gust factor and the peak factor. The turbulence intensity and gust factor decreased with time, and the turbulence intensity attenuation speed increased with time. The empirical curve presented by Davenport (1961) can simulate the correlation characteristics of the fluctuating wind speed components of Typhoon Fung-Wong at some measuring points. With an increase in the time difference, the dependence of the instantaneous values at the two time points gradually decreased.

scholarly journals Wind-Induced Coupling Vibration Effects of High-Voltage Transmission Tower-Line Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-34 ◽  
Author(s):  
Meng Zhang ◽  
Guifeng Zhao ◽  
Lulu Wang ◽  
Jie Li
Keyword(s):  
Wind Speed ◽  
High Voltage ◽  
Coupling Effect ◽  
Static Method ◽  
Transmission Tower ◽  
Design Code ◽  
Coupling Vibration ◽  
Line System ◽  
High Voltage Transmission ◽  
Line Coupling

A three-dimensional finite element model of a 500 kV high-voltage transmission tower-line coupling system is built using ANSYS software and verified with field-measured data. The dynamic responses of the tower-line system under different wind speeds and directions are analyzed and compared with the design code. The results indicate that wind speed plays an important role in the tower-line coupling effect. Under the low wind speed, the coupling effect is less obvious and can be neglected. With increased wind speed, the coupling effect on the responses of the tower gradually becomes prominent, possibly resulting in the risk of premature failure of the tower-line system. The designs based on the quasi-static method stipulated in the current design code are unsafe because of the ignorance of the adverse impacts of coupling vibration on the transmission towers. In practical engineering, when the quasi-static method is still used in design, the results for the design wind speed should be multiplied by the corresponding tower-line coupling effect amplifying coefficient δ.

Rain-Wind-Induced Analysis of Transmission Steel Tower

2012 ◽  
Vol 450-451 ◽  
pp. 64-67
Author(s):  
Li Qin ◽  
Wen Jing Ding
Keyword(s):  
Wind Speed ◽  
Power Spectrum ◽  
Dynamic Properties ◽  
Time History ◽  
Element Model ◽  
Transmission Tower ◽  
Vibration Period ◽  
Spectrum Simulation ◽  
History Of ◽  
Load Simulation

The paper established a finite element model of DZV674 linear tower (500 kV Shiyang - Wuyi transmission project) by ANSYS and studies its dynamic properties. Its first 10 order modes and natural vibration period are obtained. Based on the principle of Kaimal power spectrum and linear filtering method (AR) for simulation time-history of fluctuating wind speed, power spectrum simulation program of wind-speed is got by using Matlab. The rain load simulation is finished on the former simulation.The dynamic analysis of the transmission tower is calculated subject to wind load and rain-wind load.The results demonstrate that wind is the main design load in rain-wind-induced, but the effect of rain shouldn’t be neglected.

scholarly journals Dynamic Response of Self-Supported Power Transmission Tower Subjected to Wind Action

2018 ◽  
Vol 7 (4.35) ◽  
pp. 476
Author(s):  
Nur Hamizah Hamzah ◽  
Fathoni Usman ◽  
Mohd Yazee Mat Yatim
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Power Transmission ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Time History ◽  
Transmission Tower ◽  
Electrical Transmission ◽  
Structural Dynamic ◽  
Wind Action

A power transmission tower carries electrical transmission conductor at adequate distance from the ground. It must withstand all nature’s forces besides its self-weight. In structural analysis, natural frequency, mode shape and damping ratio are used to define the structural dynamic properties which relate to the basic structural features. This paper described the dynamic analysis including the modal and the time history analysis on each segment of the self-supported transmission tower to understand its dynamic responses subjected to wind action. The factors such as different height above ground, a different value of wind speed and different wind angle of attack were included in this study to see the influence of those factors towards dynamic response of the structure. The contribution of the wind towards the displacement of the structure is determined in this study by comparing the result obtained in a linear static analysis which considered the load combination without and with the presence of wind action. It was found that displacement using dynamic analysis is bigger than static linear analysis. The result illustrates that the studied factors gave a significant effect on the dynamic response of the structure and the findings indicate that dynamic analysis is vital in structural design.

Analysis of Wind-Induced Vibration Response on a Tower Consisted of Steel Tubes and Angel Steels

2013 ◽  
Vol 405-408 ◽  
pp. 763-766
Author(s):  
Yan Zhong Ju ◽  
Xiao Lei Zhang
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Time History ◽  
Wind Load ◽  
Vibration Response ◽  
Response Analysis ◽  
Transmission Tower ◽  
Steel Tubes ◽  
Static Result ◽  
Tower Structure

tower consisted of steel tubes and angel steels has equal advantages which steel tube tower has and not easy to happen some bar breeze vibration,but but the wind vibration response for such transmission tower structure research is less. In the engineering background of a tower consisted of steel tubes and angel steels , set up the finite element model for transmission towers. Using Kaimal spectrum for numerical simulation of wind velocity time history. Of 90 ° Angle of wind direction wind to dynamic response are analyzed, the results show that for the displacement, the maximum of dynamic analysis results 88% larger than the result of the average wind, 53.7% larger than standard wind load static result; For axial force, the maximum of dynamic analysis results 147% larger than average the result of the wind, 108% larger than standard wind load static result. So in view of the transmission tower structure dynamic response analysis should be more precise.

scholarly journals Seismic Response of Power Transmission Tower-Line System Subjected to Spatially Varying Ground Motions

2010 ◽  
Vol 2010 ◽  
pp. 1-20 ◽  
Author(s):  
Li Tian ◽  
Hongnan Li ◽  
Guohuan Liu
Keyword(s):  
Ground Motion ◽  
Power Transmission ◽  
Ground Motions ◽  
Time History ◽  
System Response ◽  
Transmission Tower ◽  
Line System ◽  
Wave Travel ◽  
Spatially Varying Ground Motions ◽  
Spatially Varying

The behavior of power transmission tower-line system subjected to spatially varying base excitations is studied in this paper. The transmission towers are modeled by beam elements while the transmission lines are modeled by cable elements that account for the nonlinear geometry of the cables. The real multistation data from SMART-1 are used to analyze the system response subjected to spatially varying ground motions. The seismic input waves for vertical and horizontal ground motions are also generated based on the Code for Design of Seismic of Electrical Installations. Both the incoherency of seismic waves and wave travel effects are accounted for. The nonlinear time history analytical method is used in the analysis. The effects of boundary conditions, ground motion spatial variations, the incident angle of the seismic wave, coherency loss, and wave travel on the system are investigated. The results show that the uniform ground motion at all supports of system does not provide the most critical case for the response calculations.

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