Effects of Different Initial Imperfections including Residual Stress on the Compressive Bearing Capacity of Steel Angles in Towers

2012 ◽  
Vol 252 ◽  
pp. 167-171
Author(s):  
Bin Rong Zhu ◽  
Jing Bo Yang ◽  
Qing Hua Li

Angles are extensively used in latticed transmission tower. Initial imperfections have a significant impact on the compressive instability and failure of angle components. To study the impact of different initial imperfections on the compressive bearing capacity, general-purpose finite element software ANSYS is used. With shell element SHELL181, selecting angle L200×20 of the slenderness ratio of 20, 40, 60, 80, 100 and 120, the bearing performance analysis with initial imperfections is conducted, including initial bending, section defects, initial eccentricity, residual stress, and a combination of imperfections. At the same time, for the angle components of the optimal slenderness ratio of 40 and slenderness ratio of 80, under the single influence of initial bending, section defects and residual stress, how the size of the value of the imperfections affects the bearing performance is investigated.

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaxiang Li ◽  
Biao Wang ◽  
Jian Sun ◽  
Shuhong Wang ◽  
Xiaohong Zhang ◽  
...  

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.


2011 ◽  
Vol 243-249 ◽  
pp. 294-297
Author(s):  
Rui Tao Zhu

Utilizing general finite element software ANSYS, the finite element computing model of the steel spatial tubular joint is built, which is used to analyze the mechanical properties under dead loads through changing its design parameters. According to the obtained and compared consequences, the different design parameters including stiffening ring thickness, cross-shaped ribbed plate thickness and stiffening ring length exert different influence on ultimate bearing capacity of the steel spatial tubular joint. Specifically, the ultimate bearing capacity under dead loads is affected by setting stiffening ring and changing cross-shaped ribbed plate thickness significantly. In contrast, if the thickness and length of stiffening ring are changed, the impact is insignificant. The results and conclusion can provide reference which is useful to optimize the design of steel spatial tubular joint in such category.


2013 ◽  
Vol 457-458 ◽  
pp. 1517-1522
Author(s):  
Wen Li ◽  
Hai Nan Yan ◽  
Peng Wang ◽  
Xiao Gang Chen ◽  
Li Na Yao

According to the basic idea of the finite element method, using the finite element software ANSYS to establish the finite element model of the reinforcement FRP pipe concrete under axial compression, introducing the unit selection in the process of building model ,based on the principle of meshing boundary conditions and constitutive relations selected; The significant degree of the model verified by compare with the test results. Analyzed by finite element reinforcement ratio, concrete strength and other factors on the mechanical properties of concrete under axial compression reinforcement FRP pipe, the analysis of the results shows: The increase of reinforcement ratio to improve the point load of the specimens and improve the composite column ultimate bearing capacity, but the reinforcement ratio increase will reduce the binding effect of the FRP pipe; The whole component be improved the strength of concrete can improve the ultimate bearing capacity, but it reduces the mechanical properties of the specimens.


2019 ◽  
Vol 136 ◽  
pp. 04039
Author(s):  
Chufan Xue ◽  
Dehong Wang ◽  
Yong Tang ◽  
Guorong Chen ◽  
Yongchang Lin ◽  
...  

Aluminum conductor composite core has many technical advantages such as high tensile strength, light weight, low sag, large current carrying capacity. In order to study the influence of the broken of aluminum conductor composite core on the transmission tower, tower-line model was built by using the finite element software ANSYS/LS-DYNA, and the deformation of joints and stress of bar were analyzed. The impact load and the impact coefficient of the representative bars of the transmission tower are calculated. The results show that the impact acting on the tower is the most serious in the place of the conductor suspension point, the connection of upper and lower crank arms, the tower neck.


2013 ◽  
Vol 405-408 ◽  
pp. 786-789
Author(s):  
Qi Xiao ◽  
Dan Dan Tong ◽  
Ling Feng Song

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.


2014 ◽  
Vol 494-495 ◽  
pp. 1815-1819
Author(s):  
Li Qiang An ◽  
Yu Chu Liu ◽  
Bing Zhang

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.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6494
Author(s):  
Mingfei Li ◽  
Mingtao Wu ◽  
Nan Guo ◽  
Lidan Mei ◽  
Yan Zhao

An anchorage device is an integral part of the prestressed Glulam beams. Therefore, its rationality and practicability have significant effects on the mechanical performance of the prestressed beams. To investigate the impact of the anchorage devices on the bearing capacity and stiffness of the prestressed beams, this paper compared and analyzed four kinds of anchors in detail through the finite element software. The results showed that when the initial mid-span deflection was 5 mm, 10 mm, and 15 mm, the bearing capacity of prestressed beams with four anchorage devices was 80.37–177.24%, 93.56–182.51%, and 95.62–194.60% higher than that of ordinary Glulam beam, respectively. When the initial mid-span top prestresses were 1 MPa, 1.5 MPa, and 2 MPa, the bearing capacity of prestressed beams with four anchorage devices was 101.71–172.57%, 105.85–175.88%, and 109.64–180.87% higher than that of ordinary Glulam beam, respectively. In addition, based on the simulation results, the prestressed beam with the external anchorage had the highest bearing capacity and stiffness. The deformation capacity of the beam with boot anchorage was the largest. The stress distribution of the beam installed under beam anchorage was the most uniform, and the beam with slotted anchorage was easy to cause stress concentration at the notch. Finally, based on the outstanding performance of the external anchorage, it was selected to carry out one experiment, and the experimental result showed that the simulation could predict the damage model and load–deflection relationship of the prestressed beams well.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5273
Author(s):  
Chun-Bao Li ◽  
Gao-Jie Li ◽  
Ran-Gang Yu ◽  
Jing Li ◽  
Xiao-Song Ma

Types of tapered piles are widely applied in tank foundation consolidation, but their inherent deficiencies in design and construction limit their further promotion. Vortex compression pile is a novel nodular pile. Compared with the traditional equal-section pile, vortex compression nodular pile is featured by stronger bearing capacity and slighter settlement. In this paper, the model test results showed that vortex compression nodular pile can greatly improve the bearing capacity and reduce the settlement. Through the finite element software ABAQUS analysis the bearing characteristics of equal-section pile foundation and vortex-compression nodular pile foundation were compared. The three-dimensional solid model was established by ABAQUS finite element software. The impact of cushion modulus, cushion thickness, vertical load, pile modulus, soil modulus around the pile on the bearing capacity of the vortex-compression nodular pile foundation were studied.


2014 ◽  
Vol 651-653 ◽  
pp. 34-37 ◽  
Author(s):  
Chen Hu ◽  
Hou Jun Qi ◽  
Xing Hui Zhang ◽  
Zhi Gang Che ◽  
Shu Ying Zhang

This paper, using the finite element software ABAQUS, establishes the model of laser shock peening (LSP) of TC4 titanium alloy, and analyzes the influence of different parameters on the residual stress of TC4 titanium alloy and plastic deformation. The results show that LSP can make the surface of TC4 titanium alloy have large compressive stress and plastic deformation, hardness and prolong the fatigue life of materials. Laser energy and the impact frequency are the main factor of surface residual stress effects. The multi-point LSP can perform processing enhanced in surface area, and form residual compressive stress on the surface of the material and in a certain depth.


2022 ◽  
Vol 2148 (1) ◽  
pp. 012052
Author(s):  
Ruizong Lin ◽  
Benzhao Fu ◽  
Xinmin Yu ◽  
Hui Ma ◽  
Zeyan Wu ◽  
...  

Abstract As an important part of power grid equipment, transmission towers are in direct contact with the external environment for a long time. As a coastal city in China, Fujian has been affected by marine environment and industrial pollution for a long time, which directly affects the safety of transmission towers in long-term service. In order to explore the changes of the ultimate bearing capacity of the tower structure after corrosion, this paper uses finite element software to analyse the mechanical properties of the tower structure during long-term service, and finds that the 45° wind direction is the control condition, and the overall stiffness of the tower decreases with the growth of corrosion time, and the increment of tower top displacement reaches 7% at 12 years of corrosion. The corrosion-sensitive members of the tower were clearly identified, and their stress ratios increased from 0.78, 0.79, and 0.83 to 0.97, 0.98, and 0.99, respectively, at 12 years of corrosion.


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