Research on Dynamic Responses of a Transmission Tower under Monsoon Wind

2015 ◽  
Vol 744-746 ◽  
pp. 248-252
Author(s):  
Wen Ping Xie ◽  
Bo Chen ◽  
Peng Yun Li ◽  
Xiao Fen Gong
Keyword(s):  
Element Model ◽  
Dynamic Responses ◽  
Structural Performance ◽  
Wind Loading ◽  
Transmission Tower ◽  
Line System ◽  
Commercial Package ◽  
Structural Responses ◽  
Monsoon Wind ◽  
The Finite Element Model

The research on dynamic responses of a transmission tower under monsoon wind is actively carried out in this study. A real transmission tower-line system constructed in the southern coastal areas of China is taken as an example to investigate the structural performance subjected to monsoon wind. The finite element model of the transmission tower-line system is established with the aiding of commercial package. The equation of motion of the transmission tower-line system under monsoon wind is established. The dynamic wind loading are applied on the tower-line system to examine the structural responses.

Damage Inspection and Assessment on a Transmission Angle Tower in Coastal Areas

2013 ◽  
Vol 671-674 ◽  
pp. 650-654
Author(s):  
Peng Yun Li ◽  
Bo Chen ◽  
Yu Zhou Sun
Keyword(s):  
Structural Model ◽  
Wind Loading ◽  
Transmission Tower ◽  
Line System ◽  
Steel Material ◽  
Transmission Angle ◽  
Commercial Package ◽  
Loading Effects ◽  
Structural Responses ◽  
Element Approach

The field inspection and safety assessment of a transmission angle tower are actively carried out in this study. The field measurement and inspection are firstly introduced and then the structural model is constructed based on finite element approach with the aiding of commercial package ANSYS. The equation of motion of the transmission tower-line system is established for numerical analysis. The gravity, base settlement and dynamic wind loading are applied on the tower to examine the structural responses. The deformation and stresses distribution of the transmission angle tower are computed to explore the damage reasons. The made observations indicate that the peak stresses of some members are large than the permitted yielding stresses of steel material. The damage event is induced by coupling loading effects

Wind-Induced Responses of a Transmission Angle Tower in Coastal Areas

2014 ◽  
Vol 678 ◽  
pp. 587-590
Author(s):  
Yi Jiang Wu ◽  
Bo Chen ◽  
Gan Jun Wang ◽  
Qing Jiang Chen
Keyword(s):  
Structural Model ◽  
Wind Loading ◽  
Response Analysis ◽  
Transmission Tower ◽  
Line System ◽  
Steel Material ◽  
Transmission Angle ◽  
Commercial Package ◽  
Structural Responses ◽  
Element Approach

The dynamic response analysis of a transmission angle tower subjected to wind excitations is actively carried out in this study. The structural model is constructed based on finite element approach with the aiding of commercial package ANSYS. The equation of motion of the transmission tower-line system under wind excitations is established. The dynamic wind loading are applied on the tower-line system to examine the structural responses. The deformation and stresses distribution of the transmission angle tower are computed to explore the structural performance. The made observations indicate that the peak stresses of some members are large than the permitted yielding stresses of steel material.

scholarly journals Dynamic Responses and Vibration Control of the Transmission Tower-Line System: A State-of-the-Art Review

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Bo Chen ◽  
Wei-hua Guo ◽  
Peng-yun Li ◽  
Wen-ping Xie
Keyword(s):  
Dynamic Analysis ◽  
Vibration Control ◽  
Dynamic Responses ◽  
Analytical Models ◽  
Equivalent Model ◽  
Wind Loading ◽  
Fe Model ◽  
Transmission Tower ◽  
Tuned Mass Dampers ◽  
Line System

This paper presented an overview on the dynamic analysis and control of the transmission tower-line system in the past forty years. The challenges and future developing trends in the dynamic analysis and mitigation of the transmission tower-line system under dynamic excitations are also put forward. It also reviews the analytical models and approaches of the transmission tower, transmission lines, and transmission tower-line systems, respectively, which contain the theoretical model, finite element (FE) model and the equivalent model; shows the advances in wind responses of the transmission tower-line system, which contains the dynamic effects under common wind loading, tornado, downburst, and typhoon; and discusses the dynamic responses under earthquake and ice loads, respectively. The vibration control of the transmission tower-line system is also reviewed, which includes the magnetorheological dampers, friction dampers, tuned mass dampers, and pounding tuned mass dampers.

Dynamic Behavior of Transmission Tower-Line Systems Subjected to Insulator Breakage

2018 ◽  
Vol 18 (03) ◽  
pp. 1850036 ◽  
Author(s):  
Jia-Xiang Li ◽  
Hong-Nan Li ◽  
Xing Fu
Keyword(s):  
Parametric Analysis ◽  
Failure Process ◽  
Element Model ◽  
Dynamic Responses ◽  
Span Length ◽  
Transmission Tower ◽  
Line System ◽  
Ice Load ◽  
Dynamic Analyses ◽  
Ice Loads

Ice loads attached to a transmission tower-line system can not only increase the vertical loads on the insulators, but also cause flashover to occur more easily. Both effects can lead to an increased probability of insulator breakage. In this paper, a finite-element model of a transmission tower-line system with three towers and four span lines under the ice loads is established. Dynamic analyses of the tower-line system after insulator breakage are performed to study the dynamic responses of the system and its failure process. In addition, a parametric analysis is conducted to investigate the influence of span length and insulator length on the vibration of the system and the failure mode. The results show that a larger ice load can lead to more severe vibration of the tower-line system due to the insulator breakage. Moreover, as the span length increases, the insulator breakage can result in more serious consequences and even the cascading collapse of the transmission tower-line system. This study provides crucial reference for preventing the failure of transmission tower-line systems in heavy ice regions.

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.

Evaluation on Dynamic Responses of Transmission Lines Subjected to Wind Excitations

2015 ◽  
Vol 744-746 ◽  
pp. 82-87
Author(s):  
Peng Yun Li ◽  
Bo Chen ◽  
Wen Ping Xie ◽  
Hao Liu
Keyword(s):  
Transmission Lines ◽  
Structural Model ◽  
Dynamic Responses ◽  
Induced Response ◽  
Transmission Tower ◽  
Line System ◽  
Long Span ◽  
Commercial Package ◽  
Element Approach ◽  
Strong Winds

The evaluation on dynamic responses of transmission lines subjected to wind excitations is actively carried out in this study. A transmission tower-line system constructed in the southern coastal areas of China is taken as example to examine the wind induced response of the transmission lines. The structural model is established based on finite element approach by using commercial package. The displacement, velocity and acceleration responses of the transmission lines are computed to explore structural performance. The made observations indicate that the transmission lines vibrant substantially when subjected to strong winds. It is obvious that the dynamic responses of the ground wire are smaller than those of the wire and the responses in the long span are much larger than those in the short span.

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.

Multidisciplinary Optimization of a Car Component Under NVH and Weight Constraints Using RSM

2009 ◽  
Author(s):  
Mohammad Azadi ◽  
Shahram Azadi ◽  
Farshad Zahedi ◽  
Mahmoud Moradi
Keyword(s):  
Element Model ◽  
Multidisciplinary Optimization ◽  
Structural Performance ◽  
Performance Requirements ◽  
Surface Method ◽  
Reference Map ◽  
Model Improvement ◽  
Frequency Map ◽  
Noise Vibration ◽  
The Finite Element Model

One of the important challenges in the auto industry is to reduce the mass of the vehicle while meeting structural performance requirements for Crashworthiness, Noise, Vibration and Harshness (NVH) etc. In this paper, a multidisciplinary optimization (MDO) of a car back-bonnet is investigated by using the Response Surface Method (RSM). Firstly, a car body is fully surface modeled in CATIA and meshed in HYPERMESH software. Then, modal analysis of the finite element model is performed by NASTRAN software to find natural frequencies. Frequency map of that component is extracted and compared with a reference map to detect defects. Design of Experiments (DOE) methodologies is used for a screening of the design space and for the generation of approximation models using RSM techniques. Therefore, to optimize the model, improvement of the NVH behavior and minimization of the weight are imposed.

scholarly journals The Effect Analysis of Strain Rate on Power Transmission Tower-Line System under Seismic Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Li Tian ◽  
Wenming Wang ◽  
Hui Qian
Keyword(s):  
Strain Rate ◽  
Power Transmission ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Seismic Excitation ◽  
Transmission Tower ◽  
Base Shear ◽  
Effect Analysis ◽  
Line System

The effect analysis of strain rate on power transmission tower-line system under seismic excitation is studied in this paper. A three-dimensional finite element model of a transmission tower-line system is created based on a real project. Using theoretical analysis and numerical simulation, incremental dynamic analysis of the power transmission tower-line system is conducted to investigate the effect of strain rate on the nonlinear responses of the transmission tower and line. The results show that the effect of strain rate on the transmission tower generally decreases the maximum top displacements, but it would increase the maximum base shear forces, and thus it is necessary to consider the effect of strain rate on the seismic analysis of the transmission tower. The effect of strain rate could be ignored for the seismic analysis of the conductors and ground lines, but the responses of the ground lines considering strain rate effect are larger than those of the conductors. The results could provide a reference for the seismic design of the transmission tower-line system.

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.

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