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

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.

2016 ◽  
Vol 16 (07) ◽  
pp. 1550030 ◽  
Author(s):  
Li Tian ◽  
Rui-sheng Ma ◽  
Hong-nan Li ◽  
Yang Wang

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Li Tian ◽  
Wenming Wang ◽  
Hui Qian

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.


2013 ◽  
Vol 376 ◽  
pp. 423-427 ◽  
Author(s):  
S. Prabhakaran ◽  
S. Ramachandran

Gearing is one of the most critical components in mechanical power transmission systems.. This paper explains about the comparison of the geometry of Helical gears for two different modules by modeling and mathematical equations, load distribution at various positions of the contact line and the stress analysis of Helical gears using three-dimensional finite element method. The bending stresses were examined using three-dimensional finite element model.. These stresses of different modules obtained from the finite element analysis were compared and the considerable reduction of weight occurred was found and also the values are compared with the theoretical values. Both results agree very well. This indicates that the finite element method model is accurate.


2016 ◽  
Vol 860 ◽  
pp. 35-38
Author(s):  
Chou Chau Yuan-Fong

A plasmonic photocatalytic reactor which composed of a periodic array of core-shell silver nanoparticles (CSSNPs) photodeposited onto a Titanium Dioxide (TiO2) thin film in a multilayer rotating-disk system was numerically investigated by using three-dimensional finite element method. Results show that the proposed structure can exhibit much higher photocalytic activity in a broad range of incident angle of light that are not observed for the same counterpart without the CSSNPs on the SiO2 surface. The enhanced electric field distribution and intensity could be expanded as the inner diameter of CSSNPs and incident angle of light increased.


2018 ◽  
Vol 22 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Li Tian ◽  
Haiyang Pan ◽  
Canxing Qiu ◽  
Ruisheng Ma ◽  
Qiqi Yu

The collapse problem of transmission tower upon strong winds was well noted in past few years. This article analyses the wind-induced collapse problem of a long-span transmission tower–line system. The member buckling effect was particularly considered. In doing so, a three-dimensional finite element model of the long-span transmission tower–line system was established in ABAQUS based on a practical project. The transmission tower and line were simulated by the frame and truss elements, respectively. The nonlinear behavior of a compressive member was simulated using the Marshall model, and the nonconvergence of numerical calculation was set to be the collapse criterion. The critical wind speed, damage position, and collapse probability were obtained from a collapse analysis of the long-span transmission tower–line system under different wind attack angles. The collapse mechanism of the long-span transmission tower–line system under a wind attack angle of 45° was investigated, and an incremental dynamic analysis was performed to evaluate the collapse-resistant capacity of the transmission tower. The study reveals that the interaction between bending moment and shear deformation is critical to the collapse of transmission tower.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Li Tian ◽  
Qiqi Yu ◽  
Ruisheng Ma

The seismic control of power transmission tower-line coupled system subjected to multicomponent excitations is studied in this paper. The schematic of tuned mass damper is introduced, and equations of motion of a system with tuned mass damper under multi-component excitations are proposed. Three-dimensional finite tower-line system models are created based on practical engineering in studying the response of this system without and with control. The time domain analysis takes into account geometric nonlinearity due to finite deformation. The optimal design of the transmission tower-line system with tuned mass damper is obtained according to different mass ratio. The effects of wave travel, coherency loss, and different site conditions on the system without and with control are investigated, respectively.


2013 ◽  
Vol 302 ◽  
pp. 622-627
Author(s):  
Ji Yao ◽  
Liang Cao ◽  
Hui Min Wang ◽  
Li Jie Zhang ◽  
Liang Wu ◽  
...  

The three dimensional finite element model of a groundwater hydraulic tunnel was eatablished in this paper by FEM software ANSYS, two seismic waves of bedrock wave and EI-centro wave in similar sites were entered, and dynamic time history method was applied to compare the seismic response of the two hydraulic tunnels which were under rigid boundary conditions and viscoelastic boundary conditions respectively. The results showed that, the dynamic response of the model under rigid boundary conditions was larger than the response under viscoelastic boundary, and the viscoelastic boundary was closer to the actual situation. Under viscoelastic boundary conditions, the smaller depth of the hydraulic tunnel, the more intensive of the seismic response.


2010 ◽  
Vol 2010 ◽  
pp. 1-20 ◽  
Author(s):  
Li Tian ◽  
Hongnan Li ◽  
Guohuan Liu

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.


2013 ◽  
Vol 275-277 ◽  
pp. 229-237 ◽  
Author(s):  
Lin Hui Yang ◽  
Rong Xiao ◽  
Xian Wu Ji ◽  
Hong Nan Li ◽  
Tong Sun

Considering transmission tower-line system coupling vibration ,construct a three dimensional finite element nonlinear analysis model for 500KV Shanghai to Xuzhou transmission line project.Execute Dynamic response analysis of transmission tower-line system under broken wire impact with SAP2000.The results show that :broken wire influence on the reaction of transmission tower-line system displacement and internal force can not be ignored ;influence on the reaction of transmission tower-line system displacement and internal force caused by ground wire broken is less while that of conductor is significant,peak value of a stem internal force can be as much as 2 times initial axial force ;the more wires are broken,the vibration response of transmission tower-line system is greater, the safety degree is lower;when it comes to internal force,there is significant difference between consider broken wire load as impact load and as static load,dynamic effects cannot be ignored.


2013 ◽  
Vol 7 (1) ◽  
pp. 159-163 ◽  
Author(s):  
Li Tian ◽  
Qian Wang ◽  
Qiqi Yu ◽  
Nuwen Xu

In this paper, tuned mass dampers with optimal parameters for long span transmission tower-line system are investigated. Equations of motion for a structure-TMD system are derived, and the parameters of TMD, stiffness and damping are optimized, respectively. According to a real project, three-dimensional finite element models of both transmission tower and transmission tower-line system are created and their vibration performances are analyzed using SAP2000 software, respectively. Wind load time history is simulated based on wind theory. Using numerical simulation, vibration control with optimal tuned mass damper installed in transmission tower-line system is carried out. Time history curves and the maximum responses of system without and with tuned mass damper under wind excitation are analyzed and discussed. The results show that the optimal tuned mass damper could effectively decrease the wind-induced response of long span transmission tower-line system.


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