scholarly journals Wind-induced collapse analysis of long-span transmission tower–line system considering the member buckling effect

2018 ◽  
Vol 22 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Li Tian ◽  
Haiyang Pan ◽  
Canxing Qiu ◽  
Ruisheng Ma ◽  
Qiqi Yu
Keyword(s):  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Bending Moment ◽  
Element Model ◽  
Collapse Mechanism ◽  
Transmission Tower ◽  
Line System ◽  
Long Span ◽  
Collapse Analysis ◽  
Three Dimensional Finite Element

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.

Fragility analysis of a long-span transmission tower–line system under wind loads

2020 ◽  
Vol 23 (10) ◽  
pp. 2110-2120
Author(s):  
Li Tian ◽  
Xin Zhang ◽  
Xing Fu
Keyword(s):  
Damage Index ◽  
Element Model ◽  
Attack Angle ◽  
Fragility Analysis ◽  
Wind Loads ◽  
Collapse Mechanism ◽  
Ultimate Capacity ◽  
Transmission Tower ◽  
Line System ◽  
Long Span

Numerous transmission towers have collapsed due to experiencing strong winds; therefore, the purpose of this article is to investigate the collapse mechanism and the anti-collapse performance of a long-span transmission tower–line system. The detailed finite element model of a typical tower–line system is established in ABAQUS. A global damage index is proposed to quantitatively estimate the overall damage of the structure and define the collapse criteria. An incremental dynamic analysis is performed to obtain the collapse mechanism and the ultimate capacity of the structure. Subsequently, a fragility analysis for evaluating the anti-collapse performance is conducted due to the uncertainty of wind loads. Eventually, the influence of the wind attack angle and the length of the side spans on the fragility is discussed. The results demonstrate that the proposed global damage index is capable of quantitatively reflecting the overall damage and assessing the ultimate capacity of the structure. In addition, the uncertainty of the wind load has a significant influence on the ultimate capacity and the failure position. Furthermore, the results reveal that the wind attack angle and the length of the side spans have an apparent effect on the fragility of the structure.

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.

scholarly journals The Collapse Analysis of A Transmission Tower Under Wind Excitation

2014 ◽  
Vol 8 (1) ◽  
pp. 136-142 ◽  
Author(s):  
Li Tian ◽  
Qiqi Yu ◽  
Ruisheng Ma ◽  
Chengwu Wang
Keyword(s):  
Angle Of Attack ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Collapse Mechanism ◽  
Superposition Method ◽  
Transmission Tower ◽  
Collapse Analysis ◽  
Element Technique ◽  
Fluctuating Wind

The collapse of a transmission tower under wind action is studied in this paper. A three-dimensional finite element model of the transmission tower is established based on a real project. The birth-to-death element technique is adopted in ABAQUS/Explicit. Kaimal fluctuating wind power spectrum and the harmony superposition method are used to simulate the fluctuating wind speed time history. The dynamic behavior and the collapse mechanism of the transmission tower under three different angles of attack α = 0o, 45o and 90o are carried out, respectively. The results show that the collapse of the transmission tower at 45o angle of attack occurs easily, but it is contrary at 90o angle of attack. The fracture position of the transmission tower under wind excitation is obtained, and the initial damage of the members happens simultaneously in the main and the secondary element. The results of the collapse analysis can provide reference to the design of the transmission tower and the reinforcement of this structure to prevent the collapse of the tower.

scholarly journals Wind-induced Vibration Optimal Control for Long Span Transmission Tower-line System

2013 ◽  
Vol 7 (1) ◽  
pp. 159-163 ◽  
Author(s):  
Li Tian ◽  
Qian Wang ◽  
Qiqi Yu ◽  
Nuwen Xu
Keyword(s):  
Equations Of Motion ◽  
Three Dimensional ◽  
Time History ◽  
Tuned Mass Damper ◽  
Induced Response ◽  
Transmission Tower ◽  
Line System ◽  
Long Span ◽  
Mass Damper ◽  
Three Dimensional Finite Element

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.

scholarly journals Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

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
Keyword(s):  
Seismic Waves ◽  
Power Transmission ◽  
Incident Angle ◽  
Ground Motions ◽  
Three Dimensional ◽  
Transmission Tower ◽  
Line System ◽  
Time Stepping ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

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.

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.

Propagation of Buckles in Sandwich Pipes Under External Pressure

2005 ◽  
Author(s):  
I. P. Pasqualino ◽  
M. I. Lourenc¸o ◽  
T. A. Netto
Keyword(s):  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
External Pressure ◽  
Core Material ◽  
Small Scale ◽  
Ongoing Research ◽  
Scale Models ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Sandwich pipes have been considered feasible conceptions for ultra deepwater pipelines, since they are capable to work at low temperatures and withstand high hydrostatic pressures. Sandwich pipelines are composed by inner and outer metallic pipes and a suitable core material which must provide high compression strength and good thermal insulation. The aim of this ongoing research is to study the quasi-static propagation of buckles in sandwich pipes. In this paper, a three-dimensional finite element model considering material and geometric nonlinear behavior is presented. The mesh discretization is determined through a detailed mesh sensitivity analysis. Some experiments with small scale models combining aluminum pipes and polypropylene as core material were carried out to calibrate the numerical model. The propagation pressure is evaluated under different bonding conditions between pipe layers.

Sign in / Sign up

Export Citation Format

Share Document