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1
ȘLAPAC, Mariana. "Constituent elements of the Kilia stone fortress." Arta 31, no. 1 (September 2022): 5–14. http://dx.doi.org/10.52603/arta.2022.31-1.01.
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Among the constituent elements of the Kilia stone fortress, which guarded the eponymous Danube portcity from the end of the XV century to the end of the XVIII century, there were the entrance gates (First Great Gates, Second Great Gates, Small Gates, Greek Gates, Guild Gates, Water Gates, etc.), the towers (Arsenal Tower, Agha Tower, Armory Tower, Commander Tower, Lighthouse Tower, Bloody Tower, Prison Tower, Tower of Gedik Akhmet Pasha, Maiden Tower, Moor Tower, Elephant Tower, Wool Tower, Mountain Tower, Millet Tower, Red Tower, Flat Tower, Cracked Tower, Biscuit Tower, etc.), courtyards (“civil courtyard”, “middle courtyard”, “garrison courtyard”, “commander courtyard” or “citadel courtyard”), curtains, artillery terraces, defensive ditches, as well as internal auxiliary buildings (residential houses, barracks, a cult object, a bathhouse, etc.). The gates were located in towers or stone curtains. The towers adjoined the walls (corner and intermediate) or advanced towards the enemy. Movable machicoulis or hoardings were used as vertical flanking elements. In the Kilia stone fortress there were hollow towers and “half-towers”. Depending on the shape of the plan, the towers could be square, rectangular, round, polygonal, D-shaped and with a complex plan ones.
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Gao, Shan, and Sheliang Wang. "Progressive Collapse Analysis of Latticed Telecommunication Towers under Wind Loads." Advances in Civil Engineering 2018 (2018): 1–13. http://dx.doi.org/10.1155/2018/3293506.
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As the antenna-supporting structures, latticed telecommunication steel towers are considered as critical members of telecommunication infrastructures. It is necessary to perform progressive collapse analysis of lattice telecommunication towers under wind loads. The present study conducts a nonlinear dynamic analysis on 50 m high typical standard latticed telecommunication tripole tower and angle tower by alternative load path method. The finite element models for two towers subjected to design wind loads are developed by ABAQUS. The analysis results show that, for 50 m high standard tripole tower, the member failure in the first three tower sections from tower top would not trigger the collapse of the tower. From the fourth tower section to tower bottom, the member failure at certain wind direction may cause a collapse. For 50 m high standard angle tower, the single member failure in any tower section would not cause the collapse of the tower. A dynamic sensitivity index is proposed to identify the most unfavorable wind direction for tripole tower and angle tower. A progressive collapse fragile curve based on collapse probability of telecommunication tower under wind loads is proposed to assess the anticollapse performance of the towers.
3
Jing, Wu, Han Junke, Ye Fang, Qi Wenyan, Yu Jinshan, Wei Peng, and Xing Haijun. "Structural Optimization and Experimental Research of High-rise Guyed Tower." E3S Web of Conferences 245 (2021): 02006. http://dx.doi.org/10.1051/e3sconf/202124502006.
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In this paper, the structural optimization of high-rise guyed tower is carried out for the guyed wire and tower column schemes. The schemes are compared from the four guyed wires and eight guyed wires, the width of the tower column, the uniform cross-section tower column and the variable cross-section tower column, etc. And the single-column tower with eight guyed wires and variable cross-section is recommended for the high-rise guyed tower. Through the full-scale test study of the high-rise guyed tower, the safety of the high-rise guyed tower structural optimization and the feasibility of engineering application are verified. According to the technical and economic analysis of traditional self-supporting towers and high-rise guyed towers recommended in this paper, it can be seen that the weight and total cost of the high-rise guyed towers are 75.3% and 88.5% of the traditional self-supporting towers respectively, demonstrating the technical and economic advantages of the high-rise guyed towers. The advantages and disadvantages of high-rise guyed towers and self-supporting towers are summarized for reference in engineering design.
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Yan, Xiang Mei. "Dynamic Characteristics Analysis of Two Adjacent Transmission Towers." Advanced Materials Research 446-449 (January 2012): 833–36. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.833.
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Dynamic analysis models of two adjacent transmission towers, two adjacent corner towers and the correspond single-tower are established, its dynamic characteristics are analyzed and compared. The results showed that: Dynamic characteristics of two adjacent transmission towers are close, but the towers connected with the corner tower changes much. Compared with the single-tower, its dynamic characteristics have changed regardless of corner tower or straight line transmission towers. It is also shown that suspended cables not only have mass effects, but have coupled stiffness effects applied to towers on transverse direction and longitudinal direction.
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Li, Jianan, Yu Li, Haonan Jiang, and Quanhua Zhao. "Hierarchical Transmission Tower Detection from High-Resolution SAR Image." Remote Sensing 14, no. 3 (January 27, 2022): 625. http://dx.doi.org/10.3390/rs14030625.
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The small scale of transmission towers and the environmental diversity around their situations make their detection in Synthetic Aperture Radar (SAR) images a challenging task. This paper presents a new hierarchical detection algorithm for transmission towers. First, Signal-to-Clutter Ratios (SCRs) of pixels are calculated. Afterwards, a SCR threshold is set. Since transmission towers possess strong scattering characteristics, pixels with SCRs above the threshold are considered as potential transmission tower pixels. Second, spatial densities of potential transmission tower pixels are calculated. According to the aggregation characteristics of transmission tower pixels, some potential transmission tower pixels with small spatial densities are removed. The remained potential transmission tower pixels are considered as candidate transmission tower pixels. The candidate transmission tower pixels are grouped by the nearest neighbour scheme such that in each group the distance between pixels is under a given threshold. Thus, each of the groups is viewed as a quasi-transmission tower. Convex-hulls of quasi-transmission towers are built, and then Minimum Bounding Rectangle (MBR) for each convex-hull is generated. According to the rectangle aspect ratios of MBRs, the real transmission towers are extracted. C-band HH-polarization GaoFen-3 (GF-3) amplitude images are used for experiments and four of the most popular transmission tower detection algorithms are selected as comparing algorithms to validate the proposed algorithms. The detection performance of transmission towers is evaluated with detection rate and quality factor. Experimental results verify that the proposed algorithm can efficiently and accurately detect transmission towers while maintaining the transmission tower geometry to a certain extent, which indicates that the proposed algorithm is efficient and promising.
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Bradney, Anthony. "The Tower." Amicus Curiae 2, no. 3 (June 16, 2021): 352–70. http://dx.doi.org/10.14296/ac.v2i3.5303.
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The image of the tower is a potent symbol in many cultures. In the ‘Epilogue’ in Blackstone’s Tower, Twining referred to the Eiffel Tower with respect to his book. This article will instead look at the Tower of Babel, the concept of the ivory tower and the tower in which Montaigne composed his essays. It will ask what lessons universities and their law schools can learn from reflecting on these mythical and real towers.
Keywords: Tower of Babel; Montaigne’s Tower; ivory tower.
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Zhelnin, Maxim, Anastasiia Kostina, Oleg Plekhov, Artem Zaitsev, and Dmitriy Olkhovskiy. "Numerical Simulation on Temperature and Moisture Fields Around Cooling Towers Used in Mine Ventilation System." Fluids 7, no. 10 (September 28, 2022): 317. http://dx.doi.org/10.3390/fluids7100317.
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For heat rejection, small air-cooling towers are widely used in mine ventilation systems. However, the thermal efficiency of the cooling towers can be significantly affected by their geometrical arrangement and crosswind conditions. In certain ambient conditions, heated air coming from an exit of one tower can flow to intakes of other towers, which leads to a reduction in the thermal efficiency of the entire ventilation system. The aim of this study was to investigate the influence of crosswind speed and tower spacing on the temperature and moisture content of intakes of cooling towers. For this purpose, a three-dimensional CFD model of the non-isothermal turbulent flow of moist air around cooling towers is proposed. The model is based on the Reynolds-averaged Navier–Stokes equations with a standard turbulence model which are supplemented by heat transfer and moisture transport equations. The investigation of the effects of the crosswind speed and the tower spacing was carried out for two cooling towers by multiparametric numerical simulation using the CFD model. It was shown that the upstream tower protects the downstream one from the effect of the crosswind. The increase in the crosswind speed causes a rise in temperature and moisture content at the intakes of the downstream tower. The increase in the tower spacing, in general, contributes to a decrease in air temperature at the intakes of the downstream tower. However, at low crosswind speed, the heat transfer at the intakes can rise with the tower spacing due to a reduction in the protection possibilities of the upstream tower. Results of the numerical simulation of airflow around three cooling towers indicated that the increase in the number of cooling towers contributes to a rise in temperature and moisture content at the intakes.
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Wang, Zhisong, Fei Yang, Yujie Wang, and Zhiyuan Fang. "Study on Wind Loads of Different Height Transmission Towers under Downbursts with Different Parameters." Buildings 12, no. 2 (February 8, 2022): 193. http://dx.doi.org/10.3390/buildings12020193.
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Disaster investigation results have shown that most wind-induced damage to transmission towers is related to downbursts. To clarify the effects of downbursts’ parameters on transmission towers with different heights, studies were conducted on five transmission towers with different diameters under static and moving downburst wind conditions. As a comparison, the responses of the towers under normal wind conditions were studied. The results showed that the effect of downbursts on the response of the transmission tower increased with the distance between the downburst center and the tower (r) when r < 1.0 Djet (Djet is the jet diameter of downburst) and then decreased when r > 1.0 Djet. The effects of jet diameter on the response of transmission towers with different tower heights were similar. As the jet diameter increased, the response of the tower continued growing until it reached a peak value and then steadily decreased soon thereafter. When the tower height was below 81.5 m, the wind load of the downburst on the transmission tower was significantly greater than that of the normal wind. As the tower height increased, the ratio of the transmission tower’s response under the two types of wind fields rapidly declined to about 0.91–1.01.
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Yu, Xinmin, Xiang Chen, Benzhao Fu, Yinhe Lin, Ye Xin, and Ming Xie. "Research on Type Selection of Diving Tower in 110kV Single and Double Circuit Transmission Line." E3S Web of Conferences 283 (2021): 02043. http://dx.doi.org/10.1051/e3sconf/202128302043.
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With the continuous development of EHV (UHV) transmission lines，new lines often need to drill through the built lines，so it is urgent to study the type of diving towers. Based on typical weather conditions and commonly used ground wire models, the basic type and tower type selection of 110kV single and double circuit overpass towers in high altitude areas are studied, and two single and double circuit overpass tower schemes are planned and arranged. And according to the pole tower structure design and optimization theory, the 110kV single-circuit diving tower and the 110kV dual-circuit diving tower are optimized from the structural optimization layout and the pole tower structure node optimization design. The research results show that the single-circuit diving tower adopts the wine glass tower, and the wires are arranged horizontally, and the double-circuit diving tower effectively reduces the height of the tower. The dish-shaped tower is used, and the single-circuit wires are arranged in a triangle pattern, which provides a certain practical guiding significance for the 110kV diving-across technology application.
10
Wang, Fei, Ke Du, Jingjiang Sun, Fuyun Huang, and Zhenghui Xiong. "Shaking Table Array Tests of an Ultra-High-Voltage Cup-Type Transmission Tower-Line System." Shock and Vibration 2019 (December 11, 2019): 1–20. http://dx.doi.org/10.1155/2019/2350675.
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Ultra-high-voltage (UHV) cup-type transmission towers supported with long-span transmission lines are unavoidably subjected to the coupling action between the towers and the transmission lines. Therefore, investigating how tower-line coupling affects UHV cup-type transmission towers is important. In this study, three shaking table array tests of an UHV cup-type transmission tower-line system were carried out to investigate the dynamic characteristics of the coupling action between the towers and transmission lines based on the following four comparative models: a single-tower model, a single-tower model with suspended lumped masses, a three-tower-two-line model, and a five-tower-four-line model. The test results demonstrated that the tower-line coupling interaction had a significant effect on the dynamic characteristics and seismic responses, as the suspended conductor line and the suspended lumped mass decreased the frequency of the transmission tower. Under longitudinal ground motion, the model with the suspended lumped mass had the lowest peak acceleration response and the largest peak displacement response. Under the same ground motion, the four models had similar peak strains in the longitudinal direction. Under transverse-the-line ground motion, the model with the suspended lumped mass had the lowest peak acceleration response and the smallest peak responses for displacement and strain in the transverse direction; therefore, this model is inappropriate for the simulation and seismic evaluation of transmission tower-line systems.
11
Zhao, Tengfei, Aimin Li, Hong Yan, Lei Zhang, Zhiwen Lan, Mojia Huang, and Han Wu. "Comparison of the Influence of Double-Limb Double-Plate Joint on the Stability Bearing Capacity of Triangular and Quadrilateral Transmission Tower Structures." Buildings 12, no. 6 (June 8, 2022): 784. http://dx.doi.org/10.3390/buildings12060784.
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The axial stiffness of the connection joints in a transmission tower will affect the stability bearing capacity of the tower. The axial stiffness of different forms of connection joints has different effects on the stability bearing capacities of triangular and quadrilateral lattice towers. This paper takes triangular and quadrilateral lattice towers as the comparative research objects and considers the influence of the stiffness of the single-limb, single-plate joint (SLSPJ) and double-limb, double-plate joint (DLDPJ) of the tower. Under vertical load, the vertical stability bearing capacities of triangular and quadrilateral transmission towers are studied from hte three aspects of theoretical analysis, numerical simulation and test result analysis. The influence rules of the SLSPJ and DLDPJ on the vertical stability bearing capacities of triangular and quadrilateral transmission towers are clarified. Through the energy method, considering the influence of the axial stiffness of connection joints, the calculation expressions of the vertical stability bearing capacities of triangular and quadrilateral lattice towers are derived. Through quantitative analysis, it is found that the axial stiffness of the connection joints has a more significant influence on the vertical stability bearing capacities of triangular lattice towers. The finite element models of the triangular and quadrilateral lattice towers including the SLSPJ and DLDPJ are further established. Through nonlinear finite element analysis, it is found that the DLDPJ can improve the vertical stability bearing capacity of the triangular lattice tower by 22.7% and the quadrilateral lattice tower by 14.9%. Through theoretical calculation, the expressions of the vertical stability bearing capacities of the triangular and quadrilateral lattice towers including the SLSPJ and DLDPJ are obtained. Combined with the test results of the SLSPJ and DLDPJ, it is found that the DLDPJ can improve the vertical stability bearing capacity of the triangular lattice tower by 23.4% and the quadrilateral lattice tower by 15.6%. The research results show that the DLDPJ can improve the vertical stability bearing capacities of triangular and quadrilateral lattice towers. The improvement effect of the vertical stability bearing capacity of the triangular lattice tower is 1.50∼1.52 times that of the quadrilateral lattice tower. The research results can provide a reference for the engineering popularization, application, and design of the DLDPJ in transmission towers.
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Kim, Yong Chul. "Aeroelastic and Aerodynamic Tests of Wind Turbine with Various Polygonal Towers." Applied Sciences 11, no. 24 (December 10, 2021): 11740. http://dx.doi.org/10.3390/app112411740.
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Traditionally, circular cross-section towers have been used as supporting systems of wind turbines, but weaknesses have become apparent with recent upsizing of wind turbines. Thus, polygonal cross-section towers have been proposed and used in Europe. In this study, the effects of polygonal cross-sections on the aeroelastic and aerodynamic characteristics of wind turbines were examined through a series of wind tunnel tests. Aeroelastic tests showed that a square cross-section tower showed instability vibrations, and polygonal cross-section towers showed limited vibrations for tower-only cases. However, for wind turbines with various polygonal cross-section towers, no instability vibrations were observed, and displacements increased proportionally to the square of mean wind speed. Furthermore, pressure measurements showed that local force coefficients changed largely depending on wind direction and azimuth angle. Local drag force coefficients decreased with increasing number of tower sides, approaching those of the tower-only case, and local lift force coefficients showed larger absolute values than those of the tower-only case. The maximum mean and fluctuating drag force and the maximum fluctuating lift coefficients at each height decreased with increasing number of tower sides.
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Wang, Xiang Yang, Kao Shan Dai, and Yi Chao Huang. "Field Testing of a Wind Turbine Tubular Tower and Structural Design of a Space Frame Steel Tower." Applied Mechanics and Materials 405-408 (September 2013): 1077–84. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1077.
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Wind energy industry has been growing tremendously in recent years. Tubular steel towers are currently dominant supporting structures for wind turbines. With the increase of the converter capacity, there is a great demand for higher supporting towers. However, structural vibrations in extreme wind events tend to become a major concern during tower design. To study wind turbine tower dynamics, an existing tubular steel tower was tested. Vibrational frequencies and damping ratios were identified. To avoid unexpected dynamic problems, a space frame steel tower has been proposed for supporting larger wind turbines. It is a structural system that can be assembled on-site by using prefabricated beams, columns, and brace members. A typical space frame steel tower was designed in this paper. Static loading, modal and buckling analyses of the tower were presented. It is expected to introduce engineers and designers more options for wind turbine tower design.
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Liu, Zhi-xiong, and Xiao-bo Feng. "A Real-Time Reliable Condition Assessment System for 500kV Transmission Towers Based on Stress Measurement." Mathematical Problems in Engineering 2019 (January 21, 2019): 1–8. http://dx.doi.org/10.1155/2019/3241897.
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Transmission power towers play an important role in power delivery systems. In recent years, some important results on reliability of transmission towers have been obtained based on theoretical analysis, but there are very few practical application systems of real-time condition monitoring. This paper proposes a new real-time reliable condition assessment system for 500kV transmission power towers based on stress measurement. The necessity of such systems and the architecture of the online monitoring system will first be presented. Through calculating the stress distribution condition of different components of the transmission tower under typical working conditions, those positions with relatively high failure probability in the transmission tower can be identified monitored for installing the stress sensors on them. A new method is presented for calculating the reliability index of the transmission tower structure is also developed based on the mechanical structure of the tower. In particular, the tower structure is simplified to a series system, and the Ditlevsen’s bounds is used to estimate the reliability of the tower system. Finally, a designed example for the online reliable condition assessment procedure is given using a 500kV oxytropis tower as an illustration.
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Zheng, Xiao Yan, Zhuo De Feng, and Yue Xu. "Multi-Tower Effect Analysis of Long-Span Suspension Bridge." Advanced Materials Research 163-167 (December 2010): 1940–44. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1940.
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As a new bridge system, mechanics behavior study on long-span multi-tower suspension is also very deficiency. The existence of center towers is the origin of performance difference between multi-tower suspension bridge and the traditional one. Based on the Midas/Civil platform, the paper takes a three tower suspension bridge as project reference, establishes finite element models of suspension bridge, which the main span is longer than one kilometer and towers from two to seven. Moreover, the structural property is analyzed separately, which bending moment and displacement effect of girder and tower along with the tower number changes is considered. Natural frequency differences of the model bridges are also paid attention on.
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Shelke, Miss Shraddha, and Prof Vishal Sapate. "Review on Analysis and Design of RCC Cooling Tower Using STAAD-Pro." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 2789–93. http://dx.doi.org/10.22214/ijraset.2022.42946.
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Abstract: Cooling tower is a device which converts hot water into cold water due to direct air contact. It works on the temperature difference between the air inside the tower and outside the tower. Natural draft cooling tower is one of most widely used cooling tower. Hyperbolic shape of cooling tower is usually preferred because of its strength and stability and large available area at the base due to shape. As it is very important structure in nuclear and chemical plants, it should be continuously assessed for its stability under selfweight, and lateral loads like wind load and earthquake load. Therefore, cooling towers have been analyses for wind load by assuming fixity at the shell base. The wind loads on these cooling towers have been calculated in the form of pressures by using the circumferentially distributed design wind pressure coefficients as given in IS: 11504 -1985 code along with the design wind pressures at different levels as per IS:875 (Part 3) - 1987 code. These towers with very small shell thickness are exceptional structures by their sheer size and sensitivity to horizontal loads. The present study deals with the analysis of cooling tower maximum displacement, support reactions, support moments, stresses and bending moments in plates due to seismic loading, wind loading and dead load i.e., its self-weight on a hyperbolic cooling tower is continuous function of geometry. Keywords: Cooling Tower, Wind Load, Stresses and Moments
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Melikhov, R., and A. Leonova. "Extension towers - features of the design, technical and economic assessment and typical issues." Bulletin of Science and Practice 5, no. 3 (March 15, 2019): 194–206. http://dx.doi.org/10.33619/2414-2948/40/25.
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Discusses the features of the design Exhaust towers. The design and configuration of exhaust towers, types of carrier circuits, grating diagrams, diaphragm diagrams are considered. It describes the main structural solutions of the carrier tower, the supporting scheme of the gas exhaust trunk, the factory assembly types of connections of the carrier tower belts, support units and lattice attachment points for the tower belts. Recommendations on anticorrosive protection of steel structures of towers are presented, technical and economic assessment and issues of typification are presented.
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Prasad, Malla Satya, and K. S. Srinivas. "Exigency of OSHA Standards Concerning Indian Telecom Riggers." International Journal of Electronics, Communications, and Measurement Engineering 10, no. 2 (July 2021): 33–50. http://dx.doi.org/10.4018/ijecme.2021070103.
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Telecom towers play the utmost important role in mobile communication whereas riggers (tower workers/climbers) are the backbone to erect and maintain such tower infrastructure. Work on telecom towers includes tower structure work, hoisting and de hoisting of various types of antennas, RF cable laying and connectorization. The purpose of this article is to identify gaps among stakeholders in adopting safety standards to protect telecom tower riggers in Indian telecom domain and proposed framework for establishing Occupational, Safety and Health Administration (OSHA) standards for Indian telecom tower riggers to fill the gap and create a conducive atmosphere among telecom companies and tower infrastructure providers while utilizing the services of riggers. This article tabulates basic parameters that are required to find “rigger-man-hours” on each work/activity of rigger on the telecom tower. This will enable telecom companies to forecast their regular riggers requirement as well to assess the future demand across geographical areas of the country.
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Cobbett, R. E. "A Dice Tower from Richborough." Britannia 39 (November 2008): 219–35. http://dx.doi.org/10.3815/006811308785917169.
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ABSTRACTThe dice tower, orpyrgus,an ancient device for rolling dice, was an everyday object in the Roman world, but up to now only two towers, from Germany and Egypt, have been found. In re-examining a group of bone box-casings from Richborough Roman Fort, however, the author has found that some of these casings must have belonged to such a tower. This article shows how this dice tower may have been constructed. The author also summarises the literary and artistic evidence for dice towers, and shows how the rosette decoration on this tower links it to the Roman game of Duodecim Scripta.
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Kong, Wei, Shi Guang Men, and Yun Fei Tao. "Seismic Responses of Multiple-Circuit Transmission Tower-Line System." Applied Mechanics and Materials 680 (October 2014): 399–402. http://dx.doi.org/10.4028/www.scientific.net/amm.680.399.
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Compared with normal transmission towers, the multiple-circuit tower was higher and heavier,it also had a longer crossarm. Response spectral method was taken to analysis the transmission tower-line’s response under earthquake.The results obtained from single tower and tower-line system under the earthquake were compared with each other，such as the tower members’ axial stresses and horizontal shears on supports .In addition,this paper discussed seismic load effects on the transmission tower-line system and some useful results were derived.
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Usman, Fathoni, and Nor Hazwani Nor Khalid. "Predicting remaining life of lattice steel transmission tower based on condition assessment and corrosion hazard data." E3S Web of Conferences 325 (2021): 01011. http://dx.doi.org/10.1051/e3sconf/202132501011.
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This paper presents a novel approach for predicting the remaining life of lattice steel transmission towers in Malaysia. The transmission tower components assessment grouped into ground corrosive condition, foundation condition, lattice steel body of the tower, and conductor. Significant and scientific field investigation and visual assessment evaluate the state of the tower. The corrosion hazard, which is a product of climate and air pollution data, is used. Three separated lines and 84 towers were selected with different ages of the tower in service. The Weighing Scoring Method with Analytical Hierarchy Process to impose the weighed factor was used. The survival function analysis is used to predict service life, and the tower remaining life was determined. The paper shows how to use the model to predict the remaining life of a transmission tower and how this can be used to advise maintenance planning.
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García-León, J., P. E. Collado Espejo, and F. J. Jiménez González. "NEGRO TOWER: DOCUMENTATION, CONSERVATION, AND RESTORATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W15 (August 22, 2019): 489–96. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w15-489-2019.
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<p><strong>Abstract.</strong> The Negro Tower or Arráez Tower, in El Algar (Cartagena, Spain), dates from 1585. This tower was part of an extensive network of watch and defense towers built along the coastline of Murcia between the sixteenth and seventeenth centuries. It is an inland rural tower, in visual contact with the coastal towers. Its objective was to receive and transfer warnings from onshore towers to protect the population, especially farmers. The tower is protected as a monument but is currently in a dilapidated state of conservation. Therefore, this building has been chosen as the object of an integral study, which can serve as a reliable basis for its correct conservation and restoration. Through historical analysis, light has been shed upon the evolution of the Tower from the social, cultural, and architectural points of view. The graphic documentation has been made using digital photogrammetry and a 3D laser scanner, compatible with classical topography. Based on all this information, an integral project of consolidation and volumetric recomposition of the tower has been proposed. As a result of this research, we intend to contribute to the conservation and recovery of the heritage value of the Tower, as well as the integration of the historic monument in its natural environment.</p>
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Shah, Hemal J., and Atul K. Desai. "Comparison of Seismic Response of Mono and Hybrid Structural System for Tall Windmill Tower considering Near-field and Far-field Earthquake." Disaster Advances 15, no. 8 (July 25, 2022): 35–45. http://dx.doi.org/10.25303/1508da035045.
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The windmill towers are the tall structures which are used as supporting mechanism for mounting the nacelle and rotor of windmill. These tower structures are conventionally steel structures with monopole configuration. It may be possible that these towers are installed in area of high earthquake risk and they are subjected to natural disaster like earthquake during its life span. The conventional monopole towers are not useful for very tall windmill tower in seismically active regions owing to slender effect. To reduce damages in conventional monopole tower constructed in near filed seismic regions, the new hybrid structural system which is blending of monopole and lattice configuration is proposed in present research. The mass and stiffness of structure are important parameters to resist the seismic forces, therefore in present research, new structural configuration is proposed which gives more stiffness to structure. The 125 mt high conventional monopole windmill tower is modelled in the numerical simulation and appropriate model of hybrid tower is also modelled in FE software. Both monopole and hybrid towers are subjected to natural disaster like earthquake, considering different near field and far filed Seismic excitation. Detailed dynamic analysis of both towers was carried out and response of monopole and hybrid tower was compared for parameters like displacement in time domain, baes shear in time domain and response spectra of structure. From the results obtained using numerical investigation, it is concluded that the innovative hybrid structural system is more effective in tall windmill tower and can be used efficiently to resist the natural disasters like earthquake.
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Zheng, Xiao Yan, Zhuo De Feng, Hong Jing Du, and Yue Xu. "Center Tower Stiffness Study in Multi-Tower Suspension Bridge." Advanced Materials Research 255-260 (May 2011): 1082–86. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.1082.
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The existence of center towers is the origin of performance difference between multi-tower suspension bridge and the traditional one, and longitudinal stiffness of the center tower is a decisive factor. Based on the finite element theory, the paper establishes numerical calculation model of multi-tower suspension bridge, and analyzes it’s static and dynamic performance variation by using different longitudinal flexural stiffness. Moreover, the factors that affect center tower stiffness are determined. Referring to judgment standards about usability and structure security given by existing research, the reasonable range of center tower stiffness is established. Besides, the paper tries to ascertain reasonable center tower stiffness by using the static mechanic performance of service phase as judgment standards.
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Wu, Z., H. Wang, W. Yu, J. Xi, W. Lei, and T. Tang. "3D HIGH-EFFICIENCY AND HIGH-PRECISION MODEL-DRIVEN MODELLING FOR POWER TRANSMISSION TOWER." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIV-4/W3-2020 (November 23, 2020): 421–26. http://dx.doi.org/10.5194/isprs-archives-xliv-4-w3-2020-421-2020.
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Abstract. Constructing the transmission tower from LiDAR point clouds is a fundamental step for smart grid. However, currently the transmission tower construction method relies heavily on manual editing, which is far from the practical industrial application. This paper proposes a model-driven based method to realize 3D construction of transmission tower fast and accurately. This method first generates different types of 3D tower models. Then, it calculates the direction characteristic of point clouds distribution using the obtained transmission towers point clouds. While finding the principal direction of transmission towers, the local coordinates of the transmission towers are settled. And then the key points are captured in a semi-automatically way. According to these key points, the transmission tower model that best matches the point clouds is selected using the model matching algorithm. Comparing with the existing traditional manual editing methods, the method proposed in this paper can ensure the integrity and accuracy of the reconstructed tower model using the model-driven based strategy. The proposed method makes a trade-off between manual editing and efficiency, which guarantees the quality of tower modelling. And the feasibility and practicability of the proposed method are verified by the experiments on real-world point clouds data.
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Liu, Xue Wu, Kai Quan Xia, and Yan Gao. "Experimental Study on Strengthening the Structure of Tower of Overhead Transmission Line." Applied Mechanics and Materials 105-107 (September 2011): 1069–72. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.1069.
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Serious damage and collapse of steel towers were easily induced by the ice disaster, the wind disaster and so on. After the disaster, to ensure the overhead transmission line working safely, it is necessary to strengthen the structure of the damaged tower perpetually, but there are few strengthening methods for the tower assembled by angle-shaped members at present. If an identical angle-shaped member is connected on the side of the existing angle-shaped member through bolts, the mechanical performance of the damaged tower can be improved effectively. In this paper several methods for strengthening the angle-shaped tower is proposed, and the mechanical behavior of the strengthened member of the tower is discussed experimentally, and some design suggestions for strengthening the towers are given.
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Akay, A. E. "ASSESSMENT OF THE VISIBILITY CAPABILITIES OF FOREST FIRE LOOKOUT TOWERS: THE CASE OF GEMLIK, BURSA, TURKEY." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVI-4/W5-2021 (December 23, 2021): 27–32. http://dx.doi.org/10.5194/isprs-archives-xlvi-4-w5-2021-27-2021.
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Abstract. In Turkey, there are forest areas that are sensitive to fire in the first degree, especially along the coastline in the Marmara region and the Aegean and Mediterranean regions. As a result of forest fires, which is one of the biggest environmental disasters on forest resources, approximately 10000 hectares of forest area is damaged annually. One of the important elements of combating forest fires is early detection. In order to achieve this goal, the correct positioning of fire lookout towers is of great importance. In this study, it was aimed to evaluate visibility capabilities of forest fire lookout tower in Gemlik Forestry Enterprise Chief (FEC) located in the city of Bursa. Firstly, the visibility analysis was implemented using in ArcGIS 10.4.1 to evaluate the existing fire tower in the FEC, and then considering the potential fire lookout tower in the study area, the visible areas from both existing and new tower were determined. According to the results, while 63.55% of the study area was visible from the existing tower, this ratio increased to 77.39% when the second tower was added. When only the forest areas are evaluated, the existing tower could see 71.73% of the forest areas, while the visible forest areas have increased to 83.36% when the two towers were taken into account. It has been seen that the visibility capacities of existing towers and potential towers can be evaluated effectively by using GIS-based visibility analysis.
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Li, Zheng, Tianhe Zhang, Yang Chen, and Ziqi Wang. "The Effect of Continuous Trapezoidal Straight Spoiler Plates on the Vortex-Induced Vibration of Wind Turbine Towers." Atmosphere 13, no. 3 (March 9, 2022): 447. http://dx.doi.org/10.3390/atmos13030447.
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This paper proposes a method of controlling the vortex-induced vibration (VIV) of wind turbine towers by adding continuous trapezoidal straight spoiler plates (TS) onto their outer surface: a fluid–solid coupling model was constructed to simulate the processes of Karman vortex generation and shedding on the different surfaces of an original tower (O–tower) and a tower with TS (TS–tower) with assumed and actual Re, while the VIV frequencies were also calculated and compared; the effects of the TS geometry parameters on the VIV frequency of towers were studied to investigate the recommended size; a modal analysis was carried out to research the effects of TS on the vortex-induced resonance risk of towers; and the simulation results as well as relevant research conclusions were validated by an analogical wind tunnel test.
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McAleer, J. Philip. "The So-Called Gundulf's Tower at Rochester Cathedral. A Reconsideration of its History, Date and Function." Antiquaries Journal 78 (March 1998): 111–76. http://dx.doi.org/10.1017/s0003581500500055.
Full textAbstract:
Since the early eighteenth century, on the basis of no particular evidence, the tower standing uncomfortably close to the north choir aisle at Rochester has been attributed to Bishop Gundulf, the builder of the first Romanesque cathedral church begun c.1080. Recently, it has been suggested that the tower dates to the mid-twelfth century and was erected as a bell tower. This paper assembles the documented history of the tower, speculates about its original form, and presents comparative material. Early post-Conquest towers of a possible defensive function and the few known examples of free-standing bell towers in twelfth-century England are considered in an attempt to establish a date and function for the tower. On the basis of this evidence, it may be suggested that an early post-Conquest – and pre-Gundulf – date is more likely than one in the mid-twelfth century, and that it was more probably erected for defensive purposes rather than as a bell tower.
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McAleer, J. Philip. "The So-Called Gundulf's Tower at Rochester Cathedral. A Reconsideration of its History, Date and Function." Antiquaries Journal 78 (September 1998): 111–76. http://dx.doi.org/10.1017/s0003581500044966.
Full textAbstract:
Since the early eighteenth century, on the basis of no particular evidence, the tower standing uncomfortably close to the north choir aisle at Rochester has been attributed to Bishop Gundulf, the builder of the first Romanesque cathedral church begun c.1080. Recently, it has been suggested that the tower dates to the mid-twelfth century and was erected as a bell tower. This paper assembles the documented history of the tower, speculates about its original form, and presents comparative material. Early post-Conquest towers of a possible defensive function and the few known examples of free-standing bell towers in twelfth-century England are considered in an attempt to establish a date and function for the tower. On the basis of this evidence, it may be suggested that an early post-Conquest – and pre-Gundulf – date is more likely than one in the mid-twelfth century, and that it was more probably erected for defensive purposes rather than as a bell tower.
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Fang, Chen, Zewen Wang, Haojun Tang, Yongle Li, and Zhouquan Deng. "Vortex-Induced Vibration of a Tall Bridge Tower with Four Columns and the Wake Effects on the Nearby Suspenders." International Journal of Structural Stability and Dynamics 20, no. 09 (August 2020): 2050105. http://dx.doi.org/10.1142/s0219455420501059.
Full textAbstract:
With the increasing span of suspension bridges, the towers have higher heights and have become more flexible, and so do the nearby suspenders. Not only are the towers easy to be affected by winds, but also the nearby suspenders by the wake flow of the towers. To enhance the structural stiffness, a bridge tower may be designed with more columns, but this design may lead to strong aerodynamic interference among the columns, complicating the wind-induced behaviors of the tower and nearby suspenders. In this paper, wind tunnel tests and numerical simulations were carried out to investigate the vortex-induced vibration of a tall bridge tower with four columns, and the wake effects on nearby suspenders. The results show that the displacement response at the tower top increases with the increasing wind speed. No obvious lock-in region is observed, as different cross-sections of the tower show different vortex shedding characteristics. The vortex shedding characteristics are determined mainly by the aerodynamic forces acting on the leeward columns. In the wake of the tower, the aerodynamic forces of the suspenders have the same dominant frequencies as the shedding frequencies of the vortices from the tower. The frequencies may approach the natural frequencies of the suspenders, causing possible wake-induced vibration that should be avoided for a good design.
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Zheng, Ni Na, Ying Min Li, Jing Zhao, and Zheng Lun Chen. "Seismic Design Scope of Tower Structures for UHV Transmission Lines on the Zone of Earthquake Fortification Intensity 8." Advanced Materials Research 446-449 (January 2012): 3730–35. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.3730.
Full textAbstract:
The seismic action effects of tower structures for ultra-high-voltage(UHV, upon 750KV) overhead transmission lines are much greater than those of 500KV and below, it is necessary to inspect the control load in structural design and specify the seismic design scope of tower structures for these UHV transmission lines. In this paper, the current regulations of seismic design and non-seismic design of tower structures for overhead transmission line were contrasted firstly; then, a series of typical towers including large-crossing towers and cup-towers at soft sites, on the zone of earthquake fortification intensity region of 8, were analyzed. The ratios of seismic action effects and wind load effects for characteristic value were calculated and the control load in structural design of tower structure was investigated. The results show that, although the height and the weigth of tower structures for UHV transmission lines are increasing, the control load in structural design is still the wind load on the zone of earthquake fortification intensity region of 8 and below.
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Barazandeh, Hanif. "Comparison of shortcut methods for designing of divided wall columns for separating tertiary zeotropic mixtures." LAPLAGE EM REVISTA 7, no. 3D (October 14, 2021): 458–84. http://dx.doi.org/10.24115/s2446-6220202173d1738p.458-484.
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Recently, divided wall column has been considered as one of the types of thermally coupled towers for separating multicomponent mixtures. In the structure of this tower, there is a wall that divides the tower into two parts, the Prefractionator and the Main Column. The divided wall column is thermodynamically equivalent of the Petlyuk tower. Therefore, in order to obtain the design and simulation parameters of the Petlyuk tower utilizing the available software, this tower must be divided into simpler towers. The shortcut method is employed to acquire the initial parameters. In the present research, initially, the design of divided wall column has been conducted using shortcut methods to separate three-component zeotropic mixtures. Next, the design and simulation of the divided wall column is performed employing ASPEN PLUS software and the results of the two methods are compared from various angles.
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Wang, Lai, and Ying Zhang. "Influence of Simplified Models on Seismic Response Analysis of Wind Turbine Towers." Applied Mechanics and Materials 94-96 (September 2011): 369–74. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.369.
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Abstract. The dynamic response of wind turbine tower under earthquake is analyzed by aid of the ANSYS program in this paper. To investigate the effects of simplification calculation models of blades and engines on calculation results, a blades-tower integrated finite element (FE) model and a mass-tower finite element (FE) model are established respectively. Then model analysis is discussed and the time history analysis of the system under the input of mean value earthquake record is carried out. The results show that seismic responses of a wind turbine tower are remarkable and seismic action may be the dominant factor in the design of wind turbine towers that located at a seismically active zone. Torsion effect of a tower is evident as a result of the impact of mass eccentricity. Bottom stress at the direction perpendicular to seismic waves is much bigger than that along it. It is also found that the blades-tower integrated finite element model can reflect more accurately the dynamic responses of the tower in the whole process of the earthquake and the “time-lag” effect by comparison, and these provide reliable reference to design and further research of towers.
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Lou, Jie, Jun Long Zhao, and Zhen Yu Zou. "The Research of Multi-Wave Impedance Model Based on Different Tower Structures." Applied Mechanics and Materials 740 (March 2015): 379–85. http://dx.doi.org/10.4028/www.scientific.net/amm.740.379.
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This paper mainly discusses the tower models in lightning overvoltage calculation, especially analysis the lossless and lossy models. Build the muti-wave impedance model of the most commonly used towers, which are portal tower, glass tower, cat head tower and strain tower in accordance with the reality. The simulation shows that muti-wave impedance model has a higher lightning overvoltage than simple model under the same condition. This is because the simple model ignores the influence of resistance and inductance, so the more accurate the model is, the more effective the protection will be.
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Subramani, T., and B. Prakash. "Design and Analysis of Power Transmission Monopole Using ETABS." International Journal of Engineering & Technology 7, no. 3.10 (July 15, 2018): 62. http://dx.doi.org/10.14419/ijet.v7i3.10.15631.
Full textAbstract:
Electricity consumption is day by day increase for each and every application. Transmitting the power source from production place to designation place via steel wire is followed by ancient people. In this we use heavy towers which carry minimum of 2000kw power in each line which is hanged in the towers. These towers are subjected to dynamic and static load cases. Hence in this thesis we proposed to design and analysis the power transmission towers in our places. We introduce type of tower and its configuring ratio as per Indian standard IS-802. A standard kind of transmission line tower selected as case examine is analyzed and modeled the usage of ETABSs software. Loads acting on the tower are wind load, dead load of the structure, braking load of conductor and earthquake load considered as per Indian standard. The place of tower underneath seismic and wind is region III. The wind pressure depends on the gust response component which will increase with height. Seismic and wind analysis is finished the usage of standard codes using ETABSs software program. The conduct of tower is analyzed for distinctive load mixtures. The most displacement values, shear forces and bending moments are obtained and are plotted graphically.
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Wang, Jin Wen. "Failure Characteristics of Transmission Towers Subjected to Downbursts." Applied Mechanics and Materials 226-228 (November 2012): 1161–64. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.1161.
Full textAbstract:
Downbursts are recognized as a significant threat to safety of transmission towers. The difference between downburst and boundary layer wind profiles will lead to different failure modes and regions of damage of a transmission tower. To account for differences of wind profiles and failure modes, the different design wind loads are proposed, and a novel analytical framework is formulated for checking the section wind-resistance capability. The framework is useful for checking strength of transmission towers under downbursts. It has been found that the peak values of section moments exceed the ultimate section moment capability at about a third of the tower height under downbursts, while failure occurs in the bottom panel of tower under boundary layer winds. The results are consistent with the fact that regions of damage for most collapsed high-rise transmission towers under downbursts were indeed in lower-middle height of tower.
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Kaunde, O. K. "Modeling of a Spray Assisted Natural Draft Cooling Tower." Tanzania Journal of Engineering and Technology 31, no. 1 (June 30, 2008): 118–26. http://dx.doi.org/10.52339/tjet.v31i1.423.
Full textAbstract:
Cooling towers are one of the largest heat and mass transfer devices that are in common use. A novel type of cooling tower has been proposed in which air flow rate into the tower is drawn by ejector action of sprays instead of fans as is done in conventional mechanical forced or induced draft cooling towers. This novel design offers the potential of savingthe energy cost for driving the fan. The paper presents mathematical models for momentum transfer which is the driving force causing the entrainment of air. Also the heat transfer model for co-current flow of liquid and gas in the tower has been presented. The liquid to gas ratio tend to decrease as liquid rate increases. The ratio attained in the experimentallaboratory tower was 3.3, correspondingly the Momentum transfer efficiency for the tower was 60% and was the highest. Experiments for cooling water initially at 45 o C to final water temperature 27 o C showed that the cooling tower efficiency was 54% and number of transfer unit 0.8.
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Chen, Bo, Xinxin Song, Wenbin Li, and Jingbo Wu. "Vibration Control of a Wind-Excited Transmission Tower-Line System by Shape Memory Alloy Dampers." Materials 15, no. 5 (February 27, 2022): 1790. http://dx.doi.org/10.3390/ma15051790.
Full textAbstract:
To be typical electrical power infrastructures, high-rise tower-line systems are widely constructed for power transmission. These flexible tower structures commonly possess small damping and may suffer strong vibrations during external excitations. The control approaches based on various devices have been developed to protect transmission towers against strong vibrations, damages, and even failure. However, studies on the vibrant control of wind-excited tower-line systems equipped with SMA dampers have not yet been reported. To this end, the control approach for wind-excited tower-line systems using SMA dampers is conducted. The mechanical model of the tower-line system is established using Lagrange’s equations by considering the dynamic interaction between transmission lines and towers. The vibration control method using SMA dampers for the tower-line coupled system is proposed. The control efficacy is verified in both the time domain and the frequency domain. Detailed parametric studies are conducted to examine the effects of physical parameters of SMA dampers on structural responses and hysteresis loops. In addition, the structural energy responses are computed to examine the control performance.
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Wan, Chao, Shengli Chen, Kai Lä, Dongtao Cheng, and Xueliang Liu. "Influence of Ambient Velocity on the Performance of SCAL Indirect Air-Cooled Towers." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 36, no. 3 (June 2018): 456–63. http://dx.doi.org/10.1051/jnwpu/20183630456.
Full textAbstract:
In order to explore the influence mechanisms of ambient wind speed on the performance of indirect air-cooled system, SCAL indirect air-cooled towers of a 600MW supercritical unit was taken as an example, and the corresponding calculation model was established. By the ways of CFD numerical simulation and field test, the variations along with ambient velocity of airflow field inside and outside the tower were simulated and the thermal performance of those towers under different ambient velocity was studied. The results showed that, the outlet resistance of air-cooled tower increased in pace with ambient velocity. Both temperature field inside the tower and pressure field inside and outside the tower were influenced by the ambient velocity to a large extent, while flow trajectory of flue gas inside the tower was basically similar. Moreover, the trends and changing laws of performance parameters from the level of segments and the tower were achieved. The conclusions would be of some reference significance for the optimal operation and design of indirect air-cooled system.
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Harish Sagar, M., Mehar Babu, S. S. Umesh, and D. S. Ananda. "Numerical Study on V Shaped Natural Draft Cooling Tower Supporting System." IOP Conference Series: Materials Science and Engineering 1255, no. 1 (September 1, 2022): 012007. http://dx.doi.org/10.1088/1757-899x/1255/1/012007.
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Abstract Cooling towers generally used to extract waste heat to the atmosphere from cooling water stream to a lower temperature and hence it rejects heat from water. The size of the cooling tower is large, with thin wall and complex geometry. Wind load plays a dominant role in the design of cooling tower. These cooling towers are subjected to self-weight and dynamic loads such as wind and earthquake. This paper presents the study of cooling tower of height 200m above the ground level. The Analysis of a cooling tower is done for a wind load using a finite element analysis considering V frame shell base supporting system. The analysis is performed in Commercial software STAAD PRO and the results obtained are presented in this paper.
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Singh, N. P. "Competitive Landscape of Mobile Telecommunications Tower Companies in India." International Journal of Interdisciplinary Telecommunications and Networking 2, no. 1 (January 2010): 49–81. http://dx.doi.org/10.4018/jitn.2010010104.
Full textAbstract:
With the entry of 3G and WiMAX players, the Indian mobile subscriber base is expected to reach 1110 million by the end of 2015. To meet mobile infrastructure demand, India will require approximately 350,000 to 400,000 mobile telecommunications towers in the next 7 to 8 years. Presently only 40% of mobile telecommunications towers are shared in India. The high growth of subscribers and initial cost of mobile telecommunications towers and license conditions will force mobile network operators to share infrastructure with other mobile network operators, specifically with new operators. The Indian government has allowed sharing of passive and active components of mobile telecommunication infrastructure. With the changing demand of the telecommunications infrastructure, many new telecommunications tower business entities and companies and mobile telecommunications tower business models are being explored. In this paper, the author presents the landscape of the mobile telecommunications tower industry in India, which consists of four types of companies and trends with respect to the strategies of telecommunication tower companies, especially tenancy ratio. Emerging features of the mobile telecommunication towers industry in India are also presented.
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Phonekeo, Sulisay, Nathan Mlot, Daria Monaenkova, David L. Hu, and Craig Tovey. "Fire ants perpetually rebuild sinking towers." Royal Society Open Science 4, no. 7 (July 2017): 170475. http://dx.doi.org/10.1098/rsos.170475.
Full textAbstract:
In the aftermath of a flood, fire ants, Solenopsis invicta , cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.
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Wang, Liang, Wei Lian Qu, Yan Fei Li, and Yi Fei Wang. "Dynamic Analysis of Power Transmission Tower Collapse with Wind Load." Advanced Materials Research 838-841 (November 2013): 494–97. http://dx.doi.org/10.4028/www.scientific.net/amr.838-841.494.
Full textAbstract:
Transmission tower collapses in adverse weather conditions now and than,which always accompanied thunderstorm.The simulation of transmission collapse under downburst wind load is studied. The tower is modeled as an assembly of beamcolumn elements,fournode isoparametric curved element,and prestressed pole unit simulation insulator,using bilinear restoring force model to formulate the material nonlinear.Simulated downburst wind load time history samples,apply it as external load to the established transmission tower model.Analysis of transmission tower know that transmission towers destroyed in the lower part of the body of the Tower, compressive failure modes in the beam , causing transmission tower's final collapse.
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Jayaprabakar, J. "Experimental Investigation on the Effect of Fill Materials in Cooling Towers." Applied Mechanics and Materials 766-767 (June 2015): 505–10. http://dx.doi.org/10.4028/www.scientific.net/amm.766-767.505.
Full textAbstract:
The cooling water system is the industry’s primary way of conserving water. Modern water cooling towers were invented during the industrial age to dissipate heat when natural cooling water sources were available. The origin of cooling towers made the plant site selection independent of the availability of water source. The development of new, high efficiency film fills produced from light weights, flame retarded PVC reduces the size and weight of cross flow cooling towers. Today’s cooling tower combine the latest advanced materials to achieve the optimum balancing of High corrosion resistance, product durability and cost. Based on their specific functions, cooling tower components are designed using the materials with the best combination of corrosion resistance and physical properties. In this work, the coefficient of performance is determined by using Simpson’s rule and the performance of cooling tower at various L/G ratios is evaluated. The optimum approach of the tower is calculated.
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Ji, Haiting, and Jianfeng Liu. "Operation Status Monitoring of Transmission Tower in Power System based on Data Fusion." International Journal of Circuits, Systems and Signal Processing 16 (January 14, 2022): 543–50. http://dx.doi.org/10.46300/9106.2022.16.68.
Full textAbstract:
This paper studies the application of data fusion technology in power system to solve some difficult problems in this complex energy system. A transmission tower identification and bird nest detection method based on corner, line, color and shape features is proposed. Through LSD (Line Segment Detection) and Harris corner detection method, the straight line segment and corner point in the image are extracted respectively. Combined with triangle method, the actual tilt angle of tower is measured; According to the nesting rule of birds in transmission towers, the basic unit segmentation algorithm of transmission towers is proposed, and the basic unit segmentation of transmission towers is realized by using the local maximum of the target pixel row statistical histogram. The algorithm proposed in this paper can effectively solve the problems of on-line measurement of tilt angle of transmission tower and on-line detection of bird's nest, which will lay a theoretical foundation for on-line monitoring of transmission tower status.
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Fan, Weinan, Junxiang Liu, Wenxiong Mo, Le Luan, Yong Wang, and Zhong Xu. "Research on transient response of tower-line system under wind field based on finite element simulation." Journal of Physics: Conference Series 2360, no. 1 (November 1, 2022): 012043. http://dx.doi.org/10.1088/1742-6596/2360/1/012043.
Full textAbstract:
Most of the transmission poles and towers are built in the wild, and are often subjected to various loads such as wind, rain, ice and snow, especially the collapse of the tower caused by wind disasters. In order to study the response characteristics and disaster risk of towers under the wind field, this paper takes a 110kV transmission line as an example, and builds a “three towers and two lines” model based on ANSYS. Relevant specification parameters are calculated for the tower and conductor loads in this wind field, and the wind pressure time history is generated; based on the ANSYS transient analysis, the load wind pressure time history is used to analyze the dynamic response of the tower line, and the model is obtained in the static and dynamic wind field. Under the stress and displacement results, the response characteristics were analyzed. The research results can provide reference for tower design and line disaster prevention and mitigation.
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Tian, Li, Wenming Wang, Ruisheng Ma, and Lei Wang. "Progressive Collapse Analysis of Power Transmission Tower Under Earthquake Excitation." Open Civil Engineering Journal 7, no. 1 (October 31, 2013): 164–69. http://dx.doi.org/10.2174/1874149501307010164.
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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.
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Gaile, Liga. "Analysis of Dynamic Parameters of Observation Towers in Latvia." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 8, 2015): 57. http://dx.doi.org/10.17770/etr2013vol2.847.
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The purpose of this research is to experimentally identify the performance of most of the light-weight observation towers open for public in Latvia. It analyzes the structure of towers, technical condition, dynamic parameters and dynamic response to human movement along the tower height. During the experiment there were measured and recorded the vibration accelerations of 18 observation towers’ upper platform. Further dynamic parameters were extracted using the spectral analysis. There was performed the sensitivity analysis to establish parameters that most influences the dynamic response amplitudes due to human movement. All experimentally obtained fundamental frequencies of the inspected towers are in the typical range of human walking frequencies. It is found that the main parameter that denotes the response level (acceleration amplitude) of the tower due to human movement is a tower self-weight.
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Zhang, Hongji. "Effect of Unbalanced Force Loading on the Safety of Transmission Tower." IOP Conference Series: Earth and Environmental Science 898, no. 1 (October 1, 2021): 012011. http://dx.doi.org/10.1088/1755-1315/898/1/012011.
Full textAbstract:
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.