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1
Cai, Ling, Yi Deng e Xing Jiang. "Construction Technology of Centro-Column Drum Towers of Dong Nationality". Advanced Materials Research 450-451 (gennaio 2012): 870–76. http://dx.doi.org/10.4028/www.scientific.net/amr.450-451.870.
Testo completoAbstract (sommario):
Abstract: The building structure of a Dong nationality’s drum tower is divided into two categories, namely, the tai-liang and chuan-dou hybrid structures, and the chuan-dou structure, which are from the major carpentry structure system of traditional Chinese timber structure architecture. Then, the most common “centro-column” type drum tower among the chuan-dou structure drum towers is defined and classified. The structure technology features of “single-column” and “ringed-column” drum towers, which are also those of a “centro-column” drum tower, are discussed in great detail. Through surveying and mapping, structure conversion models, such as those that “increased columns” and “reduced columns” of “ringed-column” drum towers, are studied mainly. In addition, many specific construction details that improve a drum tower’s external image, like multi-eaves, columns that are inclined inwards, as well as the honeycomb Dougong, are also studied in this paper.
2
Lingaraju, Mahesh Kumar Chitrahalli, Shwetha Kotagi Girisha, Shanthappa Bhaktanakatte Channabasappa e Manjunatha Karigowda. "A Study on Dynamic Behavior of Natural Draft Cooling Tower Considering the Effect of Soil-Structure Interaction". Civil and Environmental Engineering Reports 31, n. 4 (1 dicembre 2021): 17–32. http://dx.doi.org/10.2478/ceer-2021-0047.
Testo completoAbstract (sommario):
Abstract In this present era, the technology in advanced construction has developed to a very large extent. Some parts of the constructions are still in the improving stage which includes Cooling tower Construction. Hyperbolic cooling towers are large, thin shell reinforced concrete structures which Contribute to power generation efficiency, reliability, and to environmental protection. Cooling towers use evaporation of water to eject heat from processes such as cooling the circulating water used in oil refineries and in power plants. Nowadays in many thermal power plants, we can see the Cooling tower. So, preserving this industrial structure is an effort to save the cooling tower from dangerous earthquakes. The present-day cooling towers are exceptional structures in view of their sheer size and complexities. Present paper deals with the study of dynamic response that is modal analysis, seismic analysis of the two different cooling towers varying the H/t ratio and thicknesses with fixity at the base boundary condition, and the soil is modelled as raft for the effect of soil-structure interaction using the direct approach. In this paper, hyperbolic cooling towers are modelled using Ansys software, which is a Finite element Software. Results show that the soil-structure interaction effect significantly modifies the earthquake behavior of Hyperbolic Cooling towers.
3
Shah, Hemal J., e 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, n. 8 (25 luglio 2022): 35–45. http://dx.doi.org/10.25303/1508da035045.
Testo completoAbstract (sommario):
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.
4
Dang, Yu, Kai Cheng Huo e Fang Fang Qin. "Lateral-Torsional Coupled Seismic Response of Asymmetric Multi-Tower Base Isolated Structures with Large Floors". Advanced Materials Research 243-249 (maggio 2011): 3975–79. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.3975.
Testo completoAbstract (sommario):
The special type isolated building defined as asymmetric multi-tower base isolated structure with large floor is discussed in this paper. The rigid layers in series models are obtained and the elastic time history method is used to analyze the performance and seismic response of the structure. With the objective of studying the influence of the mass eccentricity in the towers and the asymmetric towers, coefficients of shear force, the ratios of period and the ratios of drift are discussed. The following conclusions have been attained: Torsional drift can be significant depending on the isolated layer in the asymmetric multi-tower with large floor. Comparing with the fixed base structures, this special type isolated building still can be reduced torsional response. The effect of isolation is reduced with the mass eccentricity in the towers and the asymmetric towers increases. It is concluded from the study that the multi-tower base isolated building with large floor should be symmetric and central in order to increase performance of isolation.
5
Halabian, Amir M., e M. Hesham El Naggar. "Effect of foundation flexibility on seismic response of reinforced concrete TV-towers". Canadian Journal of Civil Engineering 28, n. 3 (1 giugno 2001): 465–81. http://dx.doi.org/10.1139/l01-014.
Testo completoAbstract (sommario):
The analysis of tall reinforced concrete TV-towers is commonly simplified by assuming a fixed base and ignoring the effect of soilstructure interaction. However, the foundation flexibility affects the dynamic characteristics of tall structures and influences their dynamic behaviour. To design these towers for dynamic loading, the fundamental natural periods, base bending moment, and base shear force as the most important parameters are needed and must be evaluated properly. In the current study, a finite element formulation for the response analysis of TV-towers subjected to earthquake ground motion accounting for soilstructure interaction is presented. The effects of foundation flexibility on the dynamic behaviour of TV-towers were evaluated for two different types of foundation, shallow footing and deep foundation, and various soil profiles. A typical example for these towers is analysed and the results for a range of soil dynamic parameters are presented. It was found that the foundation flexibility increases the natural periods, alters the natural mode shapes, and decreases the base bending moment. It was also concluded that the effect of soilstructure interaction may have a large effect on the base shear of the tower and should be considered in the analysis, especially for the design of horizontal reinforcement.Key words: soilstructure interaction, TV-towers, natural period, base forces, foundation flexibility.
6
Gupta, Hritik, Aditi Chourasia, Dr Chaitanya Mishra e Dr Parikhsit Joshi. "A Review on Use of Telecommunication Tower over Host Structure". International Journal for Research in Applied Science and Engineering Technology 11, n. 10 (31 ottobre 2023): 1213–18. http://dx.doi.org/10.22214/ijraset.2023.56192.
Testo completoAbstract (sommario):
Abstract: Effective communication depends on strong towers since it has been used worldwide. The telephonic communication depends on this since it is the only way to connect different networks. It can be installed above the structure and over the ground but the failure of such structures during hazardous conditions can result in critical communication breakdowns. In this study different reviews based on the telecommunication towers installed on tall buildings worldwide has given. Usually, four-legged towers used for good communication and to transfer the load. Different reviews based on only tower analysis and remaining on the response over the host structure over which the tower rests. This literature review provides valuable visions and conclusions to identify the problems related to the telecommunication tower which has to be provided over the building and the location over which it has to be placed. From this study it has to be noted that previous studies were based on the location that was optimum for the host structure but no one used the worst case of tower placing if it will be necessary to provide at that location. From this, we came to know the conclusive outcome that aim to provide technical insights and recommendations for future research in this area
7
Katare, Shantilal. "A Review on Buildings having Telecommunication Tower at Roof". International Journal for Research in Applied Science and Engineering Technology 12, n. 2 (29 febbraio 2024): 1228–34. http://dx.doi.org/10.22214/ijraset.2024.58576.
Testo completoAbstract (sommario):
Abstract: Strong towers are relied upon for effective communication, as they have been used worldwide. Telephonic communication is dependent on this, as it is the sole means to connect different networks. They can be installed above structures and on the ground, but critical communication breakdowns can be caused by the failure of such structures during hazardous conditions. In this study, different reviews based on telecommunication towers installed on tall buildings worldwide has given in this paper. Typically, four-legged towers are used for ensuring good communication and for transferring the load. Different reviews are based on tower analysis alone and focus on the response of the host structure on which the tower rests. Valuable insights and conclusions are provided by this literature review to identify the problems associated with the placement of telecommunication towers over buildings and the locations where they need to be placed. From this study, it is to be noted that previous studies were based on the location that was optimal for the host structure, but the worst-case scenario of tower placement was not used till date if it was necessary to provide it at that location. As a result, the conclusive outcome is known to aim at providing technical insights and recommendations for future research in this area
8
Pavia, Arianna, Fabrizio Scozzese, Enrica Petrucci e Alessandro Zona. "Seismic Upgrading of a Historical Masonry Bell Tower through an Internal Dissipative Steel Structure". Buildings 11, n. 1 (9 gennaio 2021): 24. http://dx.doi.org/10.3390/buildings11010024.
Testo completoAbstract (sommario):
Masonry towers are part of a valuable architectural heritage characterizing the landscape of many historical areas. These towers are vulnerable structures that are prone to earthquake damage. Hence, the design of effective seismic upgrading interventions is an important task for preserving such architectural forms for future generations. In view of that, the objective of this study is to contribute a possible addition to the portfolio of available approaches for seismic upgrading of masonry towers. This goal was pursued by exploring an innovative structural solution that does not alter the external appearance of the tower and its static scheme under gravity loads, yet is able to increase its capacity to withstand seismic actions through added damping. Specifically, the proposed solution consists of a steel structure internal to the masonry tower that incorporates fluid viscous dampers. In order to evaluate its potentialities, a real case study was taken as a testbed structure, historic analysis as well as geometric and architectural surveys were undertaken, an initial design for the upgrading was made, and numerical simulations were performed. The obtained results, although preliminary, highlight the potentialities of the proposed structural solution for the seismic upgrading of masonry towers and might open the way to future developments and applications.
9
Pavia, Arianna, Fabrizio Scozzese, Enrica Petrucci e Alessandro Zona. "Seismic Upgrading of a Historical Masonry Bell Tower through an Internal Dissipative Steel Structure". Buildings 11, n. 1 (9 gennaio 2021): 24. http://dx.doi.org/10.3390/buildings11010024.
Testo completoAbstract (sommario):
Masonry towers are part of a valuable architectural heritage characterizing the landscape of many historical areas. These towers are vulnerable structures that are prone to earthquake damage. Hence, the design of effective seismic upgrading interventions is an important task for preserving such architectural forms for future generations. In view of that, the objective of this study is to contribute a possible addition to the portfolio of available approaches for seismic upgrading of masonry towers. This goal was pursued by exploring an innovative structural solution that does not alter the external appearance of the tower and its static scheme under gravity loads, yet is able to increase its capacity to withstand seismic actions through added damping. Specifically, the proposed solution consists of a steel structure internal to the masonry tower that incorporates fluid viscous dampers. In order to evaluate its potentialities, a real case study was taken as a testbed structure, historic analysis as well as geometric and architectural surveys were undertaken, an initial design for the upgrading was made, and numerical simulations were performed. The obtained results, although preliminary, highlight the potentialities of the proposed structural solution for the seismic upgrading of masonry towers and might open the way to future developments and applications.
10
Zheng, Ni Na, Ying Min Li, Jing Zhao e 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 (gennaio 2012): 3730–35. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.3730.
Testo completoAbstract (sommario):
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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Gain, Akash Asim. "Seismic Response Evaluation for Gate-Type Twin Tower Reinforced Concrete Frame Structure". International Journal for Research in Applied Science and Engineering Technology 12, n. 5 (31 maggio 2024): 5358–69. http://dx.doi.org/10.22214/ijraset.2024.62801.
Testo completoAbstract (sommario):
Abstract: As the population increases tremendously the horizontal space in urban areas are insufficient to construct a building so it is very essential to go for vertical construction. In this research The 11 storey gate type twin tower reinforced concrete frame building having the top three floors horizontally connected is analyzed by using finite element modeling software. By using linear static and dynamic analysis, the seismic responses are computed and compared for various models such as twin towers without any connection, twin towers with one-way connection, and a gate-type twin tower structure with the top three floors connected. It examines storey drift, displacement, and base shear in seismic zone III on medium soil. The results finds that structural responses to the gate building show both decreases and slight increases when compare to without connected buildings. So By connecting twin tower buildings, not only is an innovative architectural design achieved, but a roadway between the towers can also be provided., In addition, the horizontal space at the top floors after connecting the towers can also be used for residential, commercial, and office accommodation purposes.
12
Golikov, Alexander V., e Elena A. Mikhalchonok. "Determination of the rational constructive form of cellular communication towers". RUDN Journal of Engineering Researches 20, n. 2 (15 dicembre 2019): 163–73. http://dx.doi.org/10.22363/2312-8143-2019-20-2-163-173.
Testo completoAbstract (sommario):
The need for reliable supports for locating and maintaining the equipment of cellular opera-tors is increasing every year. The classic version of the supports are lattice towers. At present, optimization of the parameters of lattice towers, which is one of the ways to improve the efficiency of their design and construction, is of great importance. The purpose of the work is chosen definition of a rational constructive form of lattice cellular communication towers. In the work, the calculation and analysis of the tower supports of a prismatic and pyramidal form are made with varying basic geometric parameters of the structure and the ratio of parameters between them. To create basic dependencies, numerical modeling methods are used. According to the results of a critical analysis of the literature on the calculation of lattice supports of high-rise buildings, the absence of recommended optimal values of the geometric parameters of structures and the relationship between them was established. The stress-strain state of the design models of lattice towers of a prismatic and pyramidal shape was assessed with variation of the main overall geometric parameters of the structures. To achieve the goal of finding a rational structural form of lattice supports, two rationalization criteria have been tested and applied - the simultaneous fulfillment of the requirements of both limiting states and minimization of the mass of the structure. The results of the study of lattice tower supports are presented in dimensionless parameters, which can be applied by the engineer when assigning the overall dimensions of the structure at the initial design stage.
13
Paula, Unathan Kayke de, Luiz Fernando Rasuck de Carvalho, Elvys Dias Reis e Deysiane Antunes Barroso Damasceno. "Static and dynamic analysis of telecommunication towers subjected to wind". Research, Society and Development 11, n. 4 (15 marzo 2022): e18611427279. http://dx.doi.org/10.33448/rsd-v11i4.27279.
Testo completoAbstract (sommario):
The expansion of the telecommunications sector in Brazil in recent years and the consequent increase in demand for telecommunication towers open space for a discussion about the guidelines to be taken during the execution of projects of this type of structure. Because they are light and slender structures, wind loads become preponderant for the design of these towers and wind analysis is an important topic to be discussed. Thus, this work analyzes design aspects employing numerical modeling and parametric studies. The Brazilian standard NBR 6123:1988 was used to obtain the wind speed and its static and dynamic loads, to compare the responses generated by each of the methods. Then, this process was repeated following the European standard IEC 60826:2017, to compare the results between the two standards methods. A parametric study was also performed with towers of different heights to better understand the structure behavior. The tower responses were obtained using the finite element software SAP2000, in which a lattice tower model with a constant square section was developed, to which the wind loads calculated according to the aforementioned standards were applied. The results showed that each analysis method generates considerably different results, revealing that this is a point that should be very well studied during the design of telecommunication towers.
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Shimoda, Ichita. "Towers on the Earthen Foundation: New Insights by the Excavation and Boring Survey at the Bayon Temple". Heritage 4, n. 4 (29 settembre 2021): 2835–52. http://dx.doi.org/10.3390/heritage4040159.
Testo completoAbstract (sommario):
Bayon temple, built in the latter half of the 12th century, is one representative temple of the Angkor monuments. To shed light on the foundation structure of the central towers that stand on the elevated terrace, archaeological excavation and boring tests were conducted. Based on these surveys, a unique foundation structure was revealed under the central towers. It was confirmed that there is no laterite or sandstone support structure directly beneath the upper structure, and that there is only compacted soil at a thickness of approximately 16 m above the natural sedimentary soil. On the other hand, a laterite masonry 6 m thick and 7–9 m wide was confirmed from around the compacted soil. In other words, the heavy load of the central towers is supported by compacted soil that is constrained from the sides by a laterite structure. In addition, the boring surveys provided new insights into the low structural property of the backfilled soil after the past excavation survey below the central tower and the extension process of the elevated terrace supporting the central towers. Delivered information about the foundation structure and material of central towers, including soil property, water table, water contents, and bearing capacity will be valuable for the future structural assessment of this temple.
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Liu, Xue Wu, Kai Quan Xia e Yan Gao. "Experimental Study on Strengthening the Structure of Tower of Overhead Transmission Line". Applied Mechanics and Materials 105-107 (settembre 2011): 1069–72. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.1069.
Testo completoAbstract (sommario):
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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Lin, Ruizong, Benzhao Fu, Xinmin Yu, Hui Ma, Zeyan Wu e Chenqing Yang. "Bearing Capacity Analysis of Transmission Tower Structure Considering Corrosion Damage". Journal of Physics: Conference Series 2148, n. 1 (1 gennaio 2022): 012052. http://dx.doi.org/10.1088/1742-6596/2148/1/012052.
Testo completoAbstract (sommario):
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.
17
Liu, Zhi-xiong, e Xiao-bo Feng. "A Real-Time Reliable Condition Assessment System for 500kV Transmission Towers Based on Stress Measurement". Mathematical Problems in Engineering 2019 (21 gennaio 2019): 1–8. http://dx.doi.org/10.1155/2019/3241897.
Testo completoAbstract (sommario):
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.
18
Shi, Sufen. "Complicated High-Rise Structure Design of NingBo-Liansheng Commercial Plaza". Open Civil Engineering Journal 9, n. 1 (7 ottobre 2015): 799–804. http://dx.doi.org/10.2174/1874149501509010799.
Testo completoAbstract (sommario):
NingBo-Liansheng International Commercial Plaza is a twin towers with high-connection. It is a complex tall building. The frame-shear wall structure system is used. The connection body is in 21 and 22 layers. The connection system is strong connection and the two storey steel trusses are used. The north and South towers are placed by certain angle, and it designed for the adjustment of plane with layout of shear wall near two tower dynamic characteristics. For the complexity of connection system, the performance of different design goals are worked out for connecting different parts of body as well as the tower. According to the calculation results and to take measures to strengthen the connection body, the connection system can achieve the design target. It ensures the safety and reliability of the whole structure.
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Flanigen, Paul, Ella Atkins e Nadine Sarter. "Efficient Vertical Structure Correlation and Power Line Inference". Sensors 24, n. 5 (5 marzo 2024): 1686. http://dx.doi.org/10.3390/s24051686.
Testo completoAbstract (sommario):
High-resolution three-dimensional data from sensors such as LiDAR are sufficient to find power line towers and poles but do not reliably map relatively thin power lines. In addition, repeated detections of the same object can lead to confusion while data gaps ignore known obstacles. The slow or failed detection of low-salience vertical obstacles and associated wires is one of today’s leading causes of fatal helicopter accidents. This article presents a method to efficiently correlate vertical structure observations with existing databases and infer the presence of power lines. The method uses a spatial hash key which compares an observed tower location to potential existing tower locations using nested hash tables. When an observed tower is in the vicinity of an existing entry, the method correlates or distinguishes objects based on height and position. When applied to Delaware’s Digital Obstacle File, the average horizontal uncertainty decreased from 206 to 56 ft. The power line presence is inferred by automatically comparing the proportional spacing, height, and angle of tower sets based on the more accurate database. Over 87% of electrical transmission towers were correctly identified with no false negatives.
20
Farhan, Muhammad, Mohammad Reza Shah Mohammadi, José António Correia e Carlos Rebelo. "Transition piece design for an onshore hybrid wind turbine with multiaxial fatigue life estimation". Wind Engineering 42, n. 4 (11 luglio 2018): 286–303. http://dx.doi.org/10.1177/0309524x18777322.
Testo completoAbstract (sommario):
Steel tubular structures are somewhat entrenched for the wind turbine towers. Recently, steel hybrid lattice/tubular towers are being investigated as a conceivable answer for taller onshore wind turbines for which convectional steel tubular towers are less competitive. Hybrid lattice/tubular towers require a transition piece which serves as a connection between lattice and tubular part. As the transition piece is supposed to transfer all the dynamic and self-weight loads to the lattice and foundation, these structural elements present unique features and are critical components to design and ought to resist strong cyclic bending moments, shear forces, and axial loads. Well-designed transition pieces with optimized ultimate state and fatigue capacities for manufacturing contribute to the structural soundness, reliability, and practicability of new onshore wind turbines hybrid towers. This research focuses on the investigation of the transition piece for an onshore wind turbine hybrid tower. The 5-MW reference wind turbine and a hybrid lattice/tubular tower were simulated in the servo-hydro aero-elastic analysis tool (by ASHES software) from which the loads and dynamic response of the supporting structure were obtained. Cross-sectional forces at the transition piece elevation were calculated and the connection with the lattice structure is designed. The transition piece was designed by finite element model considering ultimate limit load and fatigue load, using nonlinear analysis and multiaxial fatigue for life-time prediction, respectively. Multiaxial fatigue life was calculated based on Brown–Miller and Smith–Watson–Topper methods. In comparison, Smith–Watson–Topper method comes out to be more conservative. Potential of using high-strength steel S690 was investigated.
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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 (8 agosto 2015): 57. http://dx.doi.org/10.17770/etr2013vol2.847.
Testo completoAbstract (sommario):
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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Jang, Minseo, Yunwoo Lee, Deokhee Won, Young-Jong Kang e Seungjun Kim. "Static Behaviors of a Long-span Cable-Stayed Bridge with a Floating Tower under Dead Loads". Journal of Marine Science and Engineering 8, n. 10 (20 ottobre 2020): 816. http://dx.doi.org/10.3390/jmse8100816.
Testo completoAbstract (sommario):
Owing to the structural characteristics of floating-type structures, they can be effectively applied to overcome the limitation of conventional long-span bridges in deep water. Unlike cable-supported bridges with fixed towers, floating cable-supported bridges show relatively large displacements and rotations under the same load because of floating towers; moreover, the difference in the support stiffness causes differences in the behavior of the superstructures. In addition, the risk of overturning is greater than in conventional floating offshore structures because the center of gravity of the tower is located above the buoyancy center of the floater. A floating cable-supported bridge in which the tether supports the floating main tower is directly influenced by the tether arrangement, which is very important for the stability of the entire structure. In this study, according to the inclined tether arrangement, the outer diameter of the floater, and the buoyancy vertical load ratio (BVR), the static behavioral characteristics of the long-span cable-stayed bridges with floating tower are evaluated through nonlinear finite-element analysis. When the intersection of the tension line of the tether and a pivot point of the tower coincide, the tethers can no longer resist the tower’s rotation. For this reason, a large displacement occurs to equilibrate the structure, and further increases as it approaches the specific slope, even if it is not exactly the specific tether slope. The analytical model of this study indicates that, in terms of increasing the rotational stiffness of the main tower, it is advantageous to increase the floater diameter until a BVR of 1.8 is reached and to increase the axial stiffness of the tether from a BVR of 2.0 or higher.
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Alessi, Lorenzo, José Correia e Nicholas Fantuzzi. "Initial Design Phase and Tender Designs of a Jacket Structure Converted into a Retrofitted Offshore Wind Turbine". Energies 12, n. 4 (18 febbraio 2019): 659. http://dx.doi.org/10.3390/en12040659.
Testo completoAbstract (sommario):
Jackets are the most common structures in the Adriatic Sea for extracting natural gas. These structural typologies are suitable for relative low water depths and flat sandy sea floors. Most of them have been built in the last 50 years. When the underground source finishes, these structures should be moved to another location or removed if they have reached their design life. Nevertheless, another solution might be considered: change the future working life of these platforms by involving renewable energy and transforming them into offshore wind towers. The present research proposal aims to investigate the possibility of converting actual structures for gas extraction into offshore platforms for wind turbine towers. This simplified analysis is useful for initial design phases and tender design, or generally when available information is limited. The model proposed is a new simplified tool used to study the structural analysis of the jacket structure, developed and summarized in 10 steps, firstly adopted to study the behavior of the oil and gas structure and then for the retrofitted wind tower configuration.
24
Du, Yue, Lan Jiang, Yu Xin Zhou, Qiao Rong Li, Tai Ran Wan e Zi Jun Pan. "Research on Dynamic Characteristics of Large Span Transmission Tower in Icing Environment". Advanced Materials Research 756-759 (settembre 2013): 4262–66. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.4262.
Testo completoAbstract (sommario):
The transmission tower with a big span in the freezing area is very sensitive to climate. When extreme weather approaches, the tower may collapse easily. The dynamic characteristics of transmission tower structure vary under different weather conditions. This paper, taking a 500kV long span tangent tower as the research subject, will demonstrate the dynamic characteristics of such structures when the weight of wires, the icing stiffness of tower structure and the thickness of ice are considered. The results show that icing has a great impact on the dynamic characteristics of the tower structure and it can not be neglected. When the ice is thick, the contribution of icing to the stiffness of the structure should be considered. This conclusion can provide a reference for the analysis and design of similar towers in high altitude area.
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Zhao, Bingliang, Zhigang Guo, Wei Yang e Yanling Lu. "Design of rapid erection system for transmission lines for disaster rescue". Journal of Physics: Conference Series 2557, n. 1 (1 luglio 2023): 012043. http://dx.doi.org/10.1088/1742-6596/2557/1/012043.
Testo completoAbstract (sommario):
Abstract The rapid erection system of transmission lines in disaster relief can restore the power supply in the disaster area in a very short time. It takes a long time to construct transmission lines in post-disaster relief and reconstruction. This paper designs the transmission line erection system with the idea of light quality and modularization and puts forward the dimensions and structures of auxiliary hoisting towers and overhead towers. Then, considering that the transmission line is a tall flexible structure, which is very sensitive to wind load, the finite element model of the transmission tower is established to analyze the simultaneous stress of the overhead tower and the lifting tower under extreme conditions. The study verifies the feasibility and stability of the designed transmission line rapid erection system.
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Bezlyudko, Gennadiy, Roman Solomakha, Svitlana Savluk e Anastasia Lukina. "Assessing Fatigue in Metal Support Towers in Wind Power Plants". Materials Evaluation 79, n. 3 (1 marzo 2021): 285–98. http://dx.doi.org/10.32548/2021.me-03981.
Testo completoAbstract (sommario):
This paper describes an overview assessment of the fatigue state of three identical 100 m metal support wind turbine towers in wind power plants (WPPs) that have been used for 12, 13, and 15 years. A nondestructive testing (NDT) technique, the magnetic coercive force method (CFM), was used to measure the magnetic characteristics of the metal, in particular, its coercive force. The weakest link of the structure is determined by the degree of fatigue, and its correlation with the individual characteristics of each wind turbine structure is shown. Based on the state of the structure’s weakest link, the residual service life of the wind turbine tower is predicted. Within the general aging process, each tower has its own state of metal characteristics, which individualizes the resource forecast. Through the assessment, it was determined that the amount of time worked is not a main deciding factor. Ways to improve the reliability of wind turbine towers during their manufacture are identified, as well as changes in structure design. CFM performed on the towers reveals maturing fatigue fractures and can be used to assess the holistic structure or its parts for priority maintenance based on the state of the metal.
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Nagar, Shruti. "Seismic Analysis of Twin Tower Structures". International Journal for Research in Applied Science and Engineering Technology 9, n. 10 (31 ottobre 2021): 1057–67. http://dx.doi.org/10.22214/ijraset.2021.38523.
Testo completoAbstract (sommario):
Abstract: In today's world, new concepts for skyscraper construction are required to mitigate the negative effects of seismic and wind forces. Since the world's most populous cities are experiencing land shortage, in this area tall buildings act as very important roles in modern cities. Due to the speedy increase in population and reduction in accessibility of land, vertical accommodation is obtaining a lot of preference which is resulting in vertical town development. Nowadays tall buildings rise higher and higher, with more and more complex and individual plan and elevation, such as multi-tower buildings. The multi-tower buildings refer to two or more towers connected with one large podium or conjunction parts at different levels. It is well known that the podium and conjunction parts shall be designed very carefully to meet the internal force and thedeformation between towers. Nowadays, when building multistory building, height is not the only pursuit. More unique forms are in trend to show the rich connotation and vitality of buildings. Connected twin tower structures conform to these requirements, and many connected structures in different forms have been or are being built in recent years. In present research work considering effects of influencing parameters like the height of the tower, connection with podium and depth of podium with two parallel towers (Twin-Tower). The main objective of this study is to analyze twin tower structure G+4 podium+25 floor building using linear dynamic earthquake analysis. We have considered four models with different combinations of twin tower with podium to achieve desirable results in terms of story drift, displacement and base shear under seismic forces for seismic zone IV and medium type of soil using Response Spectrum Analysis with the help of ETABS v19 software. Keyword: Twin Tower Structure, Podium, Etabs Software Packages.
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Li, Ruiqi, Liangjie Qi, Yao-Rong Dong e Hui Wang. "Nonlinear Performance of Steel Tube Tower in Ultra-High Voltage Transmission Lines under Wind Loads". Buildings 14, n. 1 (5 gennaio 2024): 140. http://dx.doi.org/10.3390/buildings14010140.
Testo completoAbstract (sommario):
As complex, statically indeterminate structures, transmission towers are subject to complex forces and are usually simplified into truss structures that only consider the effects of axial force. When the load and deformation of a tower are small, it is reasonable to carry out analysis according to the linear elasticity theory. However, the height of an ultra-high voltage (UHV) transmission tower is significantly large, meaning that the calculation result according to the current elastic analysis method often has a large deviation from the actual stress of the structure. With the influence of the bending moment at the end of the member, a numerical model is established considering the influence of geometric nonlinearity and material nonlinearity in this paper. The stress distribution characteristics and development law of UHV transmission towers in linear and nonlinear stress states are analyzed and studied. The real tower test and elastoplastic ultimate bearing capacity analysis show that the elastoplastic analysis is closer to the actual tower. The UHV steel pipe tower designed according to the linear elasticity and small deformation theory has a large safety margin under the design load, resulting in a significant waste of materials. Under the action of heavy load, the tower exhibits strong nonlinearity, and the influence of geometric and material nonlinear factors should be fully considered when designing the structural components in UHV transmission towers.
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Horr, A. M., e M. Safi. "Full Dynamic Analysis of Large Concrete Cooling Towers: Soil-Structure Interaction". International Journal of Space Structures 17, n. 4 (dicembre 2002): 301–12. http://dx.doi.org/10.1260/026635102321049565.
Testo completoAbstract (sommario):
Based on the complex spectral element method and the theory of fractional calculus, a hybrid complex damped spectral element method is developed. The new method is capable of making accurate predictions of the full dynamic behaviour of reinforced concrete cooling tower structures including soil-structure interaction effects. The dynamic soil-structure interaction of large space shell structures can be analysed using hybrid spectral-finite element method where the seismic wave propagation in the soil media has been modelled using the spectral element method. The frequency-dependent damping characteristic of soil materials can also be modelled accurately using the fractional derivative model. It is shown that the proposed method can be extended to develop a frequency domain dynamical method to analyse damped large space structures under earthquake excitation. The soil-structure dynamical solution is shown graphically, and the consistency of method is investigated. Using a computer program, the proposed formulation has been used to derive the dynamic response of a large concrete cooling tower with the soil media.
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Gkantou, Michaela, Carlos Rebelo e Charalampos Baniotopoulos. "Life Cycle Assessment of Tall Onshore Hybrid Steel Wind Turbine Towers". Energies 13, n. 15 (1 agosto 2020): 3950. http://dx.doi.org/10.3390/en13153950.
Testo completoAbstract (sommario):
Increasing needs for taller wind turbines with bigger capacities, intended for places with high wind velocities or at higher altitudes, have led to new technologies in the wind energy industry. A recently introduced structural system for onshore wind turbine towers is the hybrid steel tower. Comprehension of the environmental response of this hybrid steel structural system is warranted. Even though life cycle assessments (LCAs) for conventional wind turbine tubular towers exist, the environmental performance of this new hybrid structure has not been reported. The present paper examines the LCA of 185 m tall hybrid towers. Considerations made for the LCA procedure are meticulously described, including particular attention at the erection and transportation stage. The highest environmental impacts arise during the manufacturing stage followed by the erection stage. The tower is the component with the largest carbon emissions and energy requirements. The obtained LCA footprints of hybrid towers are also compared to the literature data on conventional towers, resulting in similar environmental impacts.
31
Mo, O., e T. Moan. "Environmental Load Effect Analysis of Guyed Towers". Journal of Energy Resources Technology 107, n. 1 (1 marzo 1985): 24–33. http://dx.doi.org/10.1115/1.3231158.
Testo completoAbstract (sommario):
A general method for dynamic load effect analysis of slender offshore structures subjected to short crested random waves, current and wind, is given. The structure is represented by a three-dimensional space frame model utilizing dash-pots and linear or nonlinear spring elements to represent guy lines and coupling between structure and foundation. The component mode synthesis formulation is adopted for reduction of the number of degrees of freedom. The hydrodynamic forces are computed by Morison’s equation, accounting for finite wave elevation, directionality, and relative fluid-structure motion. Various kinematic models for the fluid field in the splashing zone are compared. To get a reasonable representation of nonlinearities in the loading and the structural model, a Monte Carlo approach is adopted. Starting with simulated samples of the random fluid field and wind forces, time series of structural responses are found by numerical time integration utilizing the Newmark β-family of time integration operators. Numerical results for a guyed tower at 450-m water depth are presented. The statistical uncertainties associated with the stochastic time domain simulations are discussed. A significant discrepancy is found between linearized frequency domain solutions and the present nonlinear time domain formulation. The importance of an adequate representation of superharmonic responses is particularly discussed. The differences in results due to various solution methods are found to vary significantly with sea-state conditions.
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Xu, Ke Ju, Lei Yang, Da Da Wang, Chao Zhou, Shao Quan Zhang, Qing Jun Peng e Xiao Ming Rui. "Parametrical Finite Element Modeling of Overhead Transmission Line-Towers System". Applied Mechanics and Materials 313-314 (marzo 2013): 809–12. http://dx.doi.org/10.4028/www.scientific.net/amm.313-314.809.
Testo completoAbstract (sommario):
With large-scale development of ultra high-transmission network, the structure of transmission line-towers system tends to the tower higher, the cross-section of transmission lines larger and span between towers longer. As the increasing of transmission lines voltage grade, transmission line-towers system has higher requirements on static and dynamic stability. It is difficult for traditional design method to meet the demands of new transmission line-towers, not to mention shorten the design cycle, improve design quality. In this paper, we establish overhead transmission line-towers system model based on parameterized finite element method, by gradually increasing the thickness of the icing, iced load, wind load, weight, mechanical properties under the action of the load and the conductor tension. The analysis results show that the model can effectively reflect the mechanical properties of the transmission towers, and improve the quality of the design, greatly shortening the design cycle.
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Nico, Giovanni, Giuseppina Prezioso, Olimpia Masci e Serena Artese. "Dynamic Modal Identification of Telecommunication Towers Using Ground Based Radar Interferometry". Remote Sensing 12, n. 7 (9 aprile 2020): 1211. http://dx.doi.org/10.3390/rs12071211.
Testo completoAbstract (sommario):
This work presents a methodology to monitor the dynamic behaviour of tall metallic towers based on ground-based radar interferometry, and apply it to the case of telecommunication towers. Ground-based radar displacement measurements of metallic towers are acquired without installing any Corner Reflector (CR) on the structure. Each structural element of the tower is identified based on its range distance with respect to the radar. The interferometric processing of a time series of radar profiles is used to measure the vibration frequencies of each structural element and estimate the amplitude of its oscillation. A methodology is described to visualize the results and provide a useful tool for the real-time analysis of the dynamic behaviour of metallic towers.
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Ye, Hailin, Feng Zu, Chuwei Jiang, Wenjing Bai e Yaojiang Fan. "Experimental Investigation of the Coupling Effect of Jackup Offshore Platforms, Towers, and Seabed Foundations under Waves of Large Wave Height". Water 15, n. 1 (21 dicembre 2022): 24. http://dx.doi.org/10.3390/w15010024.
Testo completoAbstract (sommario):
A large number of jackup offshore platforms with towers are widely applied in ocean engineering. The dynamic response of the platforms to waves of large wave height is critical, as such waves may cause platform accidents, property damage, and casualties. Therefore, it is important to investigate the coupling effect of jackup offshore platform, towers and seabed foundations under waves of large wave height. In this study, the coupling effect of offshore platforms, tower structures, and seabed foundations under the impact of waves of large wave height was studied via a physical flume model test. The experimental results show that the impact of waves of large wave height on the platforms is significant when the wave is blocked by the platform surface as the water body gathers under the platform surface, causing a pile group effect that results in the onshore piles being subjected to larger pressures than the front ones. The combined action of wave impact and pile leg squeezing force leads to an increase in the pore pressure of the foundation bed near the pile leg, and the soil near the pile leg becomes soft, revealing the mechanism of instability of the offshore platform’s pile foundation under waves of large wave height. The acceleration of the longitudinal movement of the platform increases under waves of large wave height, and the vortex-induced vibration of the platform includes the vibration along the direction of the wave and perpendicular to it. A coupled vibration effect between the tower structure and the platform occurs under waves of large wave height, reducing the vibration of the platform itself. Furthermore, damping members are installed on the tower structure, greatly reducing the natural vibration period and the motion response of the tower structure. This study provides significant enlightenment for the design of offshore platforms with towers to protect against waves of large wave height.
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Zhao, Nan, Kai Ma, Shao Xue Tang, Bin Lei Chen e Ting Li. "Seismic Reaction Analysis on High-Rise Isolated Structure with Multi-Tower". Advanced Materials Research 217-218 (marzo 2011): 137–46. http://dx.doi.org/10.4028/www.scientific.net/amr.217-218.137.
Testo completoAbstract (sommario):
Structural reaction analysis under frequent earthquake and rare earthquake was carried out using time- history method. Every single-tower structure was chosen as an analysis modal, which can reflect real structural reaction. The results show that seismic response decreases obviously and story shear force and overturning moment are far less than that of aseismic structures. Horizontal reduction coefficient is lower under rare earthquake. Story drift is mainly centralized at isolator layer, which approaches zero on superstructure. The isolated structure shows whole translational motion. Reduction degree of seismic response for the three towers is more or less from each other.
36
Qin, Wei-feng, Jianfeng Yao, Zhibin Tu, Guohui Shen, Shice Yu e Jiming Xie. "Use of Modal Substructure Method to Improve Wind-Resistance Design of Twin Towers". Sustainability 15, n. 20 (11 ottobre 2023): 14767. http://dx.doi.org/10.3390/su152014767.
Testo completoAbstract (sommario):
To provide guidance for the wind-resistant design of super-tall twin towers, this study proposes a new method for the wind-induced response computation and wind-resistant design optimization of twin towers, named the Modal Substructure (MSS) method. The MSS method is established through theoretical deduction, which is utilized to investigate the effects of links on the structural dynamic characteristics of twin towers via parameter analysis. The results show that, in the in-phase mode, the structural link increases the generalized mass of the “linked tower” system but insignificantly affects its stiffness and damping. However, in the out-of-phase mode, the link increases the overall damping and stiffness of the “linked tower” system, with negligible effects on the inertia characteristics of the entire structure. Finally, the accuracy of the MSS method is validated using 570 m-high twin towers as a case study. It was found that although the MSS method is an approximate approach, its results exhibit good accuracy and convenience in exploring the impact of link properties on the dynamic characteristics of twin towers. Therefore, the MSS method can be effectively used to guide the wind-resistant design of linked twin towers.
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Juraszek, Janusz. "Fiber Bragg Sensors on Strain Analysis of Power Transmission Lines". Materials 13, n. 7 (27 marzo 2020): 1559. http://dx.doi.org/10.3390/ma13071559.
Testo completoAbstract (sommario):
The reliability and safety of power transmission depends first and foremost on the state of the power grid, and mainly on the state of the high-voltage power line towers. The steel structures of existing power line supports (towers) have been in use for many years. Their in-service time, the variability in structural, thermal and environmental loads, the state of foundations (displacement and degradation), the corrosion of supporting structures and lack of technical documentation are essential factors that have an impact on the operating safety of the towers. The tower state assessment used to date, consisting of finding the deviation in the supporting structure apex, is insufficient because it omits the other necessary condition, the stress criterion, which is not to exceed allowable stress values. Moreover, in difficult terrain conditions the measurement of the tower deviation is very troublesome, and for this reason it is often not performed. This paper presents a stress-and-strain analysis of the legs of 110 kV power line truss towers with a height of 32 m. They have been in use for over 70 years and are located in especially difficult geotechnical conditions—one of them is in a gravel mine on an island surrounded by water and the other stands on a steep, wet slope. Purpose-designed fiber Bragg grating (FBG) sensors were proposed for strain measurements. Real values of stresses arising in the tower legs were observed and determined over a period of one year. Validation was also carried out based on geodetic measurements of the tower apex deviation, and a residual magnetic field (RMF) analysis was performed to assess the occurrence of cracks and stress concentration zones.
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Dieterman, H. A. "Liquid-structure-foundation interaction of slender water towers". Archive of Applied Mechanics 63, n. 3 (marzo 1993): 176–88. http://dx.doi.org/10.1007/bf00794892.
Testo completo
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Semujju, Brian. "The structure of news in Community Audio Towers". Journal of African Media Studies 9, n. 2 (1 giugno 2017): 375–88. http://dx.doi.org/10.1386/jams.9.2.375_1.
Testo completo
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Chen, Xi, Binpeng Zhou, Xiaoxiao Liu e Junlong Lu. "An Investigation into the Effect of Near-Fault Ground Motion Duration Parameters on the Nonlinear Seismic Response of Intake Towers". Buildings 14, n. 3 (22 febbraio 2024): 580. http://dx.doi.org/10.3390/buildings14030580.
Testo completoAbstract (sommario):
Intake towers, essential for hydraulic hub projects, are integral to maintaining safety and efficiency, especially under seismic conditions that are prevalent near fault zones. These structures are vital for the integrity of hydraulic hubs, effective hydropower generation, and downstream safety. The duration of seismic events notably influences the towers’ structural response. In light of China’s initiative to build numerous high dams and large reservoirs, understanding the interplay between seismic duration and the intake tower response is crucial. This study, utilizing a duration-dependent composite parameter method based on seismic intensity, investigates the impact of near-fault ground motion duration effects on the response characteristics of intake towers. It analyzes the correlation between three types of six duration parameters and six duration-related composite parameters with the nonlinear seismic response of the physical model of the intake tower structure, as well as the rapid seismic response of the simplified model. This study investigates the impact of near-fault ground motion duration on intake towers, which is crucial for hydraulic hub projects, particularly in seismic-prone areas like those targeted by China’s dam construction initiative. Utilizing a duration-dependent composite parameter method, the study establishes a strong correlation between seismic duration parameters and the nonlinear response of intake towers, emphasizing the significance of uniform duration-related composite intensity parameters for characterizing near-fault seismic motion features. The findings reveal a pronounced correlation between the elasto-plastic response of intake towers and consistent duration-related composite strength parameters, offering crucial insights for optimizing structural design and enhancing seismic response assessment, particularly in the realm of large-scale dam projects.
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Skwarek, Marcin, e Jacek Hulimka. "Aerodynamic damping in the structural analysis of steel lattice towers". Budownictwo i Architektura 13, n. 3 (11 settembre 2014): 275–82. http://dx.doi.org/10.35784/bud-arch.1830.
Testo completoAbstract (sommario):
Structural analysis of lightweight freestanding structures, such as steel lattice towers, mainly consists of determining the along-wind dynamic response of the vibrating structure. These vibrations are damped not only structurally but also by the aerodynamic forces. In the Polish design practice, aerodynamic damping concept was introduced together with the rules of Eurocode standards. With respect to the lattice towers, in many cases, these rules are inaccurate, therefore the paper contains some suggestions of authors.
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Hanhoerster, Carlos Eduardo Vicente Chaves, e Luiz Carlos Mendes. "Analysis of transmission lines towers of electrical energy". Concilium 23, n. 6 (27 aprile 2023): 138–55. http://dx.doi.org/10.53660/clm-1099-23d21.
Testo completoAbstract (sommario):
Electrical energy became crucial for a fully functioning in a modern society and research for development of the electrical system and transmission methods became essential. The paper deals with analysis of transmission lines towers, involving details of the design of a transmission line tower from the beginning until the end of line construction. Modeling process of the structure is performed by Tower, an auxiliary software for structural analysis. Load tests to evaluate the structures behavior are showed. Recurring faults as wind action, cables rupture, and cascade effect, which cause damage to operation of the line are showed. Optimization methods for structural calculus are suggested. Structural reliability studies in order to improve the design as a whole and avoid future failures are also suggested.
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Gayatri, Gokul, B. Tirumala Reddy e B. Narender. "Comparative study of wind and ice loads on telecommunication towers in hilly terrain". E3S Web of Conferences 455 (2023): 02021. http://dx.doi.org/10.1051/e3sconf/202345502021.
Testo completoAbstract (sommario):
Telecommunication structures are usually defined as steel lattice towers on which they mount microwave dish antennas. These are slender, tall, highly optimised structures and the loading conditions that control their performance are extreme cold, snowfall, and strong winds. Strong winds combined with ice accumulation on the structure's members and dishes are the primary reasons of collapse. This comparative study is to investigate the effect of ice loads combined with wind load analysis of triangular tower configuration comprising of height 60m located in hilly terrain (specially dealt with cold region) having wind zones 39mps and 55mps. By referring specialized standards for analysis of lattice towers, reduction of wind load shall be considered when ice loads are accounted for analysis. Initial design is performed for full wind load of the tower configuration through space truss analysis using STAAD.Pro V22 software and same is checked with combined wind and ice loads as per appropriate standards. A comparison statement is derived on effect of ice loads on analysis of structure – leg forces, bracing forces and deflection for tower configuration considered in parametric study.
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Bruneau, Michel, Mohammed H. Magued e Robert B. Dryburgh. "Recommended guidelines for upgrading existing towers". Canadian Journal of Civil Engineering 16, n. 5 (1 ottobre 1989): 733–42. http://dx.doi.org/10.1139/l89-108.
Testo completoAbstract (sommario):
A companion paper reviewed the history of the development of the Canadian standard for towers, and demonstrated that the failure rate for guyed telecommunications towers designed to earlier editions of the CAN-CS A-S37 Standard "Antennas, Towers and Antenna-Supporting Structures" (S37) is generally unacceptably high. These towers are often reviewed for addition of new antennas, and upgrading to the strength levels of the most recent edition of the standard — as required in many cases — can be very expensive, due to the sizeable increases in strength requirements for guyed towers which have been introduced by successive revisions of S37. Clearly, there is a need to match strength requirements to the significance of the structure and the economic consequences of its failure. Uniformly high strength requirements will occasionally result in reinforcement costs that exceed the costs of the risk of failure. In answer to this, a rational approach has been used to develop a set of guidelines for the upgrading of existing towers. This methodology relies on the classification of towers in various reliability classes, having increased probabilities of failure attached, and correspondingly lower load factors for use in the analysis. Results from this research are presented herein, together with the recommended proposed guidelines. Key words: guyed towers, reliability classes, probability of failure, safety index, upgrading cost, failure rate, environmental loads, guidelines.
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Li, Mao Hua, Jing Bo Yang e Zheng Li. "Latest Developments of Materials Used in Transmission Tower Structure". Advanced Materials Research 250-253 (maggio 2011): 4038–41. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.4038.
Testo completoAbstract (sommario):
This paper discusses the status quo and development trend of transmission tower materials, points out that there will be higher requirements on the varieties and specifications of transmission tower material alongside the continuous construction of power grids. Tower materials will develop in the environmental-friendly, high-strength and conservation-oriented trend. In the future, the demand for Q420, Q460 high-strength and large-width angle steel will grow enormously; the steel tubular tower will be used in transmission lines more widely due to its excellent carrying capability; new materials like weathering cold-formed steel and composite material will be gradually used in transmission towers.
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Shelke, Miss Shraddha, e 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, n. 5 (31 maggio 2022): 2789–93. http://dx.doi.org/10.22214/ijraset.2022.42946.
Testo completoAbstract (sommario):
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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Gan, Feng Lin, e Xu Bo Jia. "Analysis of Guyed Transmission Tower Dynamic Characteristic". Applied Mechanics and Materials 597 (luglio 2014): 300–303. http://dx.doi.org/10.4028/www.scientific.net/amm.597.300.
Testo completoAbstract (sommario):
In the paper aiming at lots of 87(LM21) towers in Dongchang Hasong Transmission Line held under Changchun Extra-high voltage Bureau jurisdiction, by using ANSYS software, the nonlinear finite element model for towers is built. And numerical analysis methods is adopted. It is considered that the combined effect of stay wire and transmission tower, geometric non-linear effect and the influence of stay wire initial stress. The Dynamic Properties research about Guyed Transmission is conducted. It concluded that stay wire and tower's mode of vibrationare are relatively independent ,coordinated and the interaction of each other. Natural frequency of vibration and mode of vibration appears regularly and alternately changes with the increase of the formation order .Stay wire initial stress is main factor affecting the natural frequency of the structure and the frequency increases with the increase of stay wire initial stress.
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Horváth, Katalin. "“Can the Tower be Retained”". YBL Journal of Built Environment 2, n. 1 (1 luglio 2014): 65–78. http://dx.doi.org/10.2478/jbe-2014-0005.
Testo completoAbstract (sommario):
Abstract This paper focuses on the analysis of two towers of an industrial plant exhibiting extreme deflection during service loads under heavy wind conditions. The towers are 90 m and 35 m in height, respectively and are interconnected with structural steel operating platforms. The nuts have flown off at some bolted joints in the interconnecting steel structure due to high stress induced by deflections. The deflections measured at the structural steel towers had nearly twice the value permitted by the respective standard in the case of the 90 m high tower and approached the value permitted by the standard in the case of the 35 m high tower. The herein detailed complex study - covering the strength analysis of the towers, the analysis of wind effects, and the review of the foundations - has been elaborated in order to determine the causes and consequences of the experienced deflections at the plant as well as to conclude the eventual actions to be taken. The primary consideration for the conduction of the tests and analyses the determination of the eventual actions to be taken was to retain the towers and not to have them demolished.
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Wu, Xiaohan, Jun Wang e Jiangyong Zhou. "Seismic Performance Analysis of a Connected Multitower Structure with FPS and Viscous Damper". Shock and Vibration 2018 (8 ottobre 2018): 1–19. http://dx.doi.org/10.1155/2018/1865761.
Testo completoAbstract (sommario):
A high four-tower structure is interconnected with a long sky corridor bridge on the top floor. To reduce the earthquake responses and member forces of the towers and sky corridor bridge, a passive control strategy with a friction pendulum tuned mass damper (FPTMD) was adopted. The sky corridor bridge was as the mass of FPTMD. The connection between the towers and the sky corridor bridge was designed as flexible links, where friction pendulum bearings (FPBs) and viscous dampers were installed. Elastoplastic time-history analysis was conducted by using Perform-3D model to look into its seismic behavior under intensive seismic excitation. The optimal design of the FPTMD with varying friction coefficients and radius of friction pendulum bearing (FPB) under seismic excitations was carried out, and the seismic behavior of the structure was also investigated at the same time.Results show that, for this four-tower connected structure, the friction pendulum tuned mass damper (FPTMD) has very well effect on seismic reduction. The structure can meet the seismic resistance design requirements.
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Yu, Xinmin, Xiang Chen, Benzhao Fu, Yinhe Lin, Ye Xin e 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.
Testo completoAbstract (sommario):
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.