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.

Dynamic Characteristics Analysis for 1000kV UHV Steel Tubular Tower under Seismic Loading

2014 ◽  
Vol 494-495 ◽  
pp. 1815-1819
Author(s):  
Li Qiang An ◽  
Yu Chu Liu ◽  
Bing Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Transmission Lines ◽  
Seismic Loading ◽  
Element Model ◽  
Steel Tube ◽  
Seismic Loads ◽  
Transmission Tower ◽  
Finite Element Software ◽  
The Impact

In this paper, the dynamic characteristics of a 1000kV UHV steel tubular tower with double circuit transmission lines on the same tower are analyzed under seismic loading with 8 degrees fortification intensity. Firstly, the finite element model of the tower and simulation of the earthquake are built in ANSYS finite element software. The dynamic characteristics of steel tube tower under Seismic Loads, such as the time-domain curves of displacement, velocity and force of UHV steel tower under Seismic Loads are obtained. The impact of 1000kV UHV transmission tower under nonlinear vibration of simplified conductor model is studied. The results can help to understand the damage forms of UHV steel tower under earthquake, to improve the capabilities to resist earthquake loads and severe damage of environmental loads under various field conditions for UHV steel tower.

scholarly journals Effect of Unbalanced Force Loading on the Safety of Transmission Tower

2021 ◽  
Vol 898 (1) ◽  
pp. 012011
Author(s):  
Hongji Zhang
Keyword(s):  
Transmission Lines ◽  
Simulation Analysis ◽  
Practical Importance ◽  
Element Model ◽  
Transmission Tower ◽  
Maximum Displacement ◽  
Force Loading ◽  
Finite Element Software ◽  
Unbalanced Force ◽  
Transmission Towers

Abstract High-voltage transmission towers, as support points for overhead transmission lines, are often under the condition of unbalanced force loading. Transmission towers can collapse because of the unbalanced forces, leading to the power outage. Therefore, it is of practical importance to set a research on the effect of unbalanced force loading on the safety of transmission tower. In this paper, based on the prototype of 500kV transmission tower, the integral beam element model is established by ABAQUS finite element software for simulation analysis. Static load mode and unbalanced force loading were considered in this simulation model. Through the comparative analysis of the maximum displacement and stress in transmission tower, the safety of the 500kV transmission tower was analyzed. The variations of maximum displacement and Mises stress with the increasing unbalanced force were obtained. The limit of unbalanced force the 500kV transmission tower can sustain was given by comparing the simulated results.

scholarly journals Progressive Collapse Analysis of Power Transmission Tower Under Earthquake Excitation

2013 ◽  
Vol 7 (1) ◽  
pp. 164-169
Author(s):  
Li Tian ◽  
Wenming Wang ◽  
Ruisheng Ma ◽  
Lei Wang
Keyword(s):  
Finite Element ◽  
Power Transmission ◽  
Progressive Collapse ◽  
Time History ◽  
Large Earthquake ◽  
Element Model ◽  
Transmission Tower ◽  
Seismic Excitations ◽  
Earthquake Excitation ◽  
Finite Element Software

Collapses of power transmission towers had usually taken place in previous large earthquake. The collapse process of a power transmission tower under earthquake excitation is studied in this paper. Using international finite element software ABAQUS, the three-dimensional finite element model of the power transmission tower is created based on a practical engineering. Three typical seismic records are selected. The progress collapse processes of the power transmission tower under different seismic excitations are simulated using the nonlinear time history method. The collapse paths and failure positions of the power transmission tower are obtained under different seismic excitations. The results can provide reference for seismic design of power transmission tower which can prevent the collapse of the power transmission tower.

DYNAMIC RESPONSES OF TRANSMISSION TOWER-LINE SYSTEM UNDER ICE SHEDDING

2010 ◽  
Vol 10 (03) ◽  
pp. 461-481 ◽  
Author(s):  
FENGLI YANG ◽  
JINGBO YANG ◽  
JUNKE HAN ◽  
DONGJIE FU
Keyword(s):  
Transmission Lines ◽  
Element Model ◽  
Dynamic Responses ◽  
Ice Thickness ◽  
Transmission Tower ◽  
Line System ◽  
Calculated Load ◽  
Ice Shedding ◽  
Stress Ratios ◽  
Phase Conductors

Ice shedding from conductors may easily induce electrical and mechanical accidents, which cause a serious threat to the safe operation of transmission lines. In this paper, a 3D finite element model of tower-conductor-ground wire-insulator system was established in ANSYS, and the dynamic responses of ice shedding under different cases were analyzed for a transmission tower-line system. The computed jumping heights are in excellent agreement with the experimental values of a two span conductors model. Many variables were considered in the ice-shedding simulations that include tower-line coupled effect, phase combination of the ice-shedding conductors, thickness of the accreted ice, length of the ice-shedding span as well as elevation difference. Influences of all the variables on the dynamic responses of jumping heights, loads at the end of insulators and the forces of transmission tower were studied. Ice-shedding simulations of an actual 500 kV transmission line section which experience failure under ice shedding in 2008 were performed. The results show that stress ratios of members at the tower head under design ice thickness exceed the limiting values when the amount of shedding ice is large. For ice shedding at the top phase conductors, the jumping height and unbalanced tension at the end of insulator can be reduced by applying interphase spacers in triangular arrangement. The tower is in a safe state under the load of the design ice thickness. In order to prevent ice-shedding accidents, interphase spacers should be used, and the weak members at the tower head should be strengthened according to the calculated load values at the end of insulators.

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.

Analysis on Ultimate Bearing Capacity of the UHV Transmission Tower with Large Width Angle Steel

2013 ◽  
Vol 405-408 ◽  
pp. 786-789
Author(s):  
Qi Xiao ◽  
Dan Dan Tong ◽  
Ling Feng Song
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Element Model ◽  
Ultimate Bearing Capacity ◽  
Transmission Tower ◽  
Future Design ◽  
Finite Element Software ◽  
Straight Line ◽  
Large Width ◽  
Angle Steel

The dissertation taked the ZBS2 straight-line tower in the UHV line project as the object,used the finite element software ANSYS to establish finite element model and did a analysis about its dynamic characteristics. Considering width and thickness of large width angle steel,the section area of large width angle steel is larger than normal angle steel,and the application of large width angle steel can increase bearing capacity of the member.Therefore,this article taked large width angle steel to replace double combined angle steels in the main members of the tower,and calculated the ultimate bearing capacity. Analysis of comparison indicate that the ultimate bearing capacity increases by 13% when large width angle steel is used.Therefore it is feasible and advantageous that large width angle steel uses in the UHV transimission tower,and it provide a reference and basis for future design of the UHV transmission tower with large width angle steel.

Progressive Collapse of Power Transmission Tower-Line System Under Extremely Strong Earthquake Excitations

2016 ◽  
Vol 16 (07) ◽  
pp. 1550030 ◽  
Author(s):  
Li Tian ◽  
Rui-sheng Ma ◽  
Hong-nan Li ◽  
Yang Wang
Keyword(s):  
Power Transmission ◽  
Progressive Collapse ◽  
Three Dimensional ◽  
Coupled System ◽  
Element Model ◽  
Single Component ◽  
Transmission Tower ◽  
Line System ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The simulation of progressive collapse of a power transmission tower-line system subjected to extremely strong earthquakes is studied in this paper. A three-dimensional finite element model is established for the coupled system that combines three towers and four span lines based on a practical project. The birth to death technique is adopted to simulate the progressive collapse of the system by using the user subroutine VUMAT in ABAQUS. The simulation of progressive collapse of the transmission tower-line system under either single-component or multi-component earthquake excitations is conducted. The collapse path, fracture position and collapse resistant capacity of the transmission tower are investigated. The result shows that the effect of multi-component seismic excitations should be taken into account in simulation of progressive collapse of the transmission tower, since the behavior of towers under multi-component excitations is different from that of single-component excitations. In addition, incremental dynamic analysis (IDA) is carried out to verify the results obtained herein. The present result should prove useful to the seismic design of power transmission towers.

Galloping of Transmission Tower-Line System and Anti-Galloping Research

2010 ◽  
Vol 44-47 ◽  
pp. 2666-2670
Author(s):  
Li Li ◽  
Wei Jiang ◽  
Hua Jin Cao
Keyword(s):  
Element Model ◽  
Nonlinear Finite Element ◽  
Control Measures ◽  
Transmission Tower ◽  
Line System ◽  
Transmission Towers ◽  
Coupling System ◽  
Internal Forces ◽  
Nonlinear Finite Element Model ◽  
Line Coupling

A nonlinear finite element model of transmission tower-line coupling system including transmissions, towers and insulators is established based on ANSYS in this paper. The restarting technology is proposed to solve the vertical, horizontal and torsional galloping of the transmission conductors. Under the condition of different wind velocity, galloping of tower line system is performed to get amplitude of the transmissions and internal forces of the transmission towers. Based on the typical case, the galloping control measures of using interphase spacers and multi-point weighting are performed. Various layouts projects of the galloping control measures are carried out and the effective ones are attained.

Performance Evaluation of a Transmission Tower Subjected to Base Settlement

2015 ◽  
Vol 744-746 ◽  
pp. 361-365
Author(s):  
Yi Jiang Wu ◽  
Qing Dong Meng ◽  
Gan Jun Wang
Keyword(s):  
Finite Element ◽  
Structural Damage ◽  
Element Model ◽  
Structural Safety ◽  
Transmission Tower ◽  
Element Analysis ◽  
Line System ◽  
Transmission Angle ◽  
Element Approach ◽  
Internal Forces

The simulation of support settlement of a transmission angle-tower is actively carried out in this study based on the actual structural damage events. The mechanical model of the transmission angle-tower is developed based on the spatial member finite element approach. The finite element model of the transmission tower-line system is constructed by taking a real 220KV transmission tower as an example. The support settlement of the tower is analyzed and the collected information are utilized in the structural finite element analysis. The made observations indicate that the support settlement may induce large structural internal forces, which may induce potential disk to the structural safety.

The Numerical Research on the Jumping Induced by the Uniform and Non-Uniform Ice-Shedding of Transmission Lines

2014 ◽  
Vol 986-987 ◽  
pp. 611-614
Author(s):  
Yi Zhen Wei ◽  
Pan Su
Keyword(s):  
Finite Element ◽  
Transmission Lines ◽  
Element Model ◽  
Simulation Method ◽  
Dynamic Tension ◽  
Equivalent Load Method ◽  
Numerical Research ◽  
Ice Shedding ◽  
Equivalent Load ◽  
The Finite Element Model

This paper introduces several kinds of icing and ice-off simulation method: the equivalent load method, quality method, Támás model method and cell death method. With a large span cross section as an example, using finite element method, established the finite element model of single span icing wire, analyzed the non-uniform ice-off and the even ice-off,the results show that: Non-uniform ice-off dynamic tension is significantly smaller than even ice-off dynamic tension,the smallest dynamic tension is closely related to wire jump amplitude, the greater jump amplitude leads to the smaller dynamic tension,the essence of which is determined by the conductor slack.

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