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1
Liu, Yue, Mingyang Gu, Xiaogang Liu, and T. Tafsirojjaman. "Life-Cycle Cost Analysis of Long-Span CFRP Cable-Stayed Bridges." Polymers 14, no. 9 (April 25, 2022): 1740. http://dx.doi.org/10.3390/polym14091740.
Повний текст джерелаАнотація:
With the advantages of high strength, light weight, high corrosion and fatigue resistance, and low relaxation, carbon-fiber-reinforced polymer (CFRP) is an excellent cable material for cable-stayed bridges. However, the relatively high unit price of CFRP compared to that of steel may hinder the large-scale application of CFRP stay cables. This paper presents the economic comparison between long-span cable-stayed bridges using CFRP cables and the corresponding steel cable-stayed bridges through life-cycle cost analysis (LCCA). Three CFRP cable-stayed bridges with a main span of 600 m, 1200 m, and 1800 m, respectively, along with their steel counterparts, were designed, and their life-cycle costs (LCCs) were calculated. The comparison of LCCs was not only between the CFRP and steel cable-stayed bridges with the same span, but also between the cable-stayed bridges with different spans. Furthermore, the different unit prices of CFRP cables and different replacement frequencies of steel cables were also investigated. The results show that the initial design and construction cost of the long-span CFRP cable-stayed bridge is higher than that of the corresponding steel cable-stayed bridge, although using CFRP cables can reduce the materials used, primarily due to the higher unit price of the CFRP cable. Despite the higher initial cost, the long-span CFRP cable-stayed bridge can still achieve lower LCC than the steel cable-stayed bridge, because it has significantly lower rehabilitation cost and user cost, as well as slightly lower vulnerability cost. Furthermore, with the increase in the main span and the decrease in the unit price of CFRP cables, the LCC advantage of the long-span CFRP cable-stayed bridge becomes more obvious.
2
Liu, Yue, Mingyang Gu, Xiaogang Liu, and T. Tafsirojjaman. "Life-Cycle Cost Analysis of Long-Span CFRP Cable-Stayed Bridges." Polymers 14, no. 9 (April 25, 2022): 1740. http://dx.doi.org/10.3390/polym14091740.
Повний текст джерелаАнотація:
With the advantages of high strength, light weight, high corrosion and fatigue resistance, and low relaxation, carbon-fiber-reinforced polymer (CFRP) is an excellent cable material for cable-stayed bridges. However, the relatively high unit price of CFRP compared to that of steel may hinder the large-scale application of CFRP stay cables. This paper presents the economic comparison between long-span cable-stayed bridges using CFRP cables and the corresponding steel cable-stayed bridges through life-cycle cost analysis (LCCA). Three CFRP cable-stayed bridges with a main span of 600 m, 1200 m, and 1800 m, respectively, along with their steel counterparts, were designed, and their life-cycle costs (LCCs) were calculated. The comparison of LCCs was not only between the CFRP and steel cable-stayed bridges with the same span, but also between the cable-stayed bridges with different spans. Furthermore, the different unit prices of CFRP cables and different replacement frequencies of steel cables were also investigated. The results show that the initial design and construction cost of the long-span CFRP cable-stayed bridge is higher than that of the corresponding steel cable-stayed bridge, although using CFRP cables can reduce the materials used, primarily due to the higher unit price of the CFRP cable. Despite the higher initial cost, the long-span CFRP cable-stayed bridge can still achieve lower LCC than the steel cable-stayed bridge, because it has significantly lower rehabilitation cost and user cost, as well as slightly lower vulnerability cost. Furthermore, with the increase in the main span and the decrease in the unit price of CFRP cables, the LCC advantage of the long-span CFRP cable-stayed bridge becomes more obvious.
3
Kuihua, Mei, Sun Shengjiang, Jin Guoqing, and Sun Yamin. "Static and Dynamic Mechanical Properties of Long-Span Cable-Stayed Bridges Using CFRP Cables." Advances in Civil Engineering 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/6198296.
Повний текст джерелаАнотація:
The elastic modulus and deadweight of carbon fiber-reinforced polymer (CFRP) cables are different from those of steel cables. Thus, the static and dynamic behaviors of cable-stayed bridges using CFRP cables are different from those of cable-stayed bridges using steel cables. The static and dynamic performances of the two kinds of bridges with a span of 1000 m were studied using the numerical method. The effects of geometric nonlinear factors on static performance of the two kinds of cable-stayed bridges were analyzed. The live load effects and temperature effects of the two cable-stayed bridges were also analyzed. The influences of design parameters, including different structural systems, the numbers of auxiliary piers, and the space arrangement types of cable, on the dynamic performance of the cable-stayed bridge using CFRP cables were also studied. Results demonstrate that sag effect of the CFRP cable is much smaller than that of steel cable. The temperature effects of CFRP cable-stayed bridge are less than those of steel cable-stayed bridge. The vertical bending natural vibration frequency of the CFRP cable-stayed bridge is generally lower than that of steel cable-stayed bridge, whereas the torsional natural vibration frequency of the former is higher than that of the latter.
4
Wang, Zhi Hao. "Experimental Study on Multi-Mode Vibration Control of a Stay Cable with a Passive Magnetorheological Damper." Applied Mechanics and Materials 361-363 (August 2013): 1402–5. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.1402.
Повний текст джерелаАнотація:
Effective vibration control technology for stay cables is extremely critical to safe operations of cable-stayed bridges. For super-long cables, passive linear damper cannot provide sufficient damping since it can be only optimum for a given mode of cable, while a long cable may vibrate with several modes. This paper focuses on multi-mode vibration control of stay cables with passive magnetorheological (MR) dampers. Firstly, a 21.6m-long model cable was designed and established in the laboratory.Then, control performance of the cable with a passive MR damper was tested. The test results show that modal damping ratios of the cable in the first four modes can be improved significantly with the MR damper. It is further demonstrated that optimal tuned passively operated MR damper can outperform the passive viscous damper.
5
Morimitsu, Takenori, and Masao Terasawa. "Long-Distance Optical Fiber Cable Installation System Using Automatic Control Puller." Journal of Robotics and Mechatronics 10, no. 3 (June 20, 1998): 229–34. http://dx.doi.org/10.20965/jrm.1998.p0229.
Повний текст джерелаАнотація:
To fully use optical fiber cable features such as low loss, small diameter, and light weight, cables are installed over the longest possible unit distance using pullers installed in intermediate manholes to distribute cable pulling force. An optical fiber cable pulling system has been developed that measures loading tension on the cable using tension sensors and automatically controls pulling speed so that tension is appropriate.
6
Stuklis, Arturs, Dmitrijs Serdjuks, and Vadims Goremikins. "Materials Consumption Decrease for Long-Span Prestressed Cable Roof." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 1 (June 16, 2015): 209. http://dx.doi.org/10.17770/etr2015vol1.231.
Повний текст джерелаАнотація:
<p class="R-AbstractKeywords"><span lang="EN-US">Limited raw materials and energy resources are actual national economy problems which can be solved by the decrease of weight, increase of span and durability of load bearing structures. The largest structural spans were achieved by application of cable structures. The roofs are one of the most widely used in practice type of cable structures. However, increased deformability and necessity of the special methods of stabilizing are significant cable roofs disadvantages. The prestressing of one or several groups of cables is one of the probable methods for stabilizing of cable roofs. According to the recommendations available in the literature, all cables of the roof must be prestressed by the equal forces. But after applying of design vertical load, values of the forces, acting in the cables of the roof, changes within the wide limits. So, using of structural materials will not be rational in this case, taking into account, that the cables cross-sections are constant because the cables cross-sections were determined basing on the maximum axial force, acting in the all cables.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">Possibility to decrease materials consumption by the changing of prestressing forces for cables of the roof was checked on the example of saddle-shaped cable roof with the rigid support contour and dimensions 60x60 m in the plan. Initial deflections of main suspension and stressing cables of the roof were equal to 7m. Suspension and stressing cables of the net were placed with the step equal to 2.828 m. Steel ropes with modulus of elasticity in 1.5∙105 MPa were considered as a material of suspension and stressing cables of the roof. Suspension and stressing cables were divided into the groups, which are differed by the prestressing forces. Amount of cables groups changes within the limits from 1 to 27. Values of prestressing forces for cables groups change within the limits from 20 to 80% from the cables breaking force. </span></p><p class="R-AbstractKeywords"><span lang="EN-US">The dependences of material consumption and maximum vertical displacements of cable roof on the amount of cables groups and prestressing forces were determined as second power polynomial equations. It was stated, that division of suspension and stressing cables on the 18 groups enables to decrease cables material consumption by 19.2%. Values of prestressing forces for suspension and stressing cables of the roof were equal to 57 and 80 %, from it load-carrying capacity, correspondingly</span><span lang="EN-US">. </span></p>
7
Kim, Y. H., J. K. Vandiver, and R. Holler. "Vortex-Induced Vibration and Drag Coefficients of Long Cables Subjected to Sheared Flows." Journal of Energy Resources Technology 108, no. 1 (March 1, 1986): 77–83. http://dx.doi.org/10.1115/1.3231245.
Повний текст джерелаАнотація:
The vortex-induced vibration response of long cables subjected to vertically sheared flow was investigated in two field experiments. In a typical experiment, a weight was hung over the side of the research vessel by a cable that was instrumented with accelerometers. A typical experiment measured the acceleration response of the cable, the current profile, the tension, and angle of inclination at the top of the cable. Total drag force was computed from the tension and angle measurements. Two braided Kevlar cables were tested at various lengths from 100 to 9,050 ft. As a result of these experiments, several important conclusions can be drawn: (i) the wave propagation along the length of the cable was damped, and therefore, under most conditions the cable behaved like an infinite string; (ii) response spectra were quite broad-band, with center frequencies determined by the flow speed in the region of the accelerometer; (iii) single mode lock-in was not observed for long cables in the sheared current profile; (iv) the average drag coefficient of long cables subjected to sheared flow was considerably lower than observed on short cables in uniform flows; (v) the r.m.s. response was higher in regions of higher current speed. A new dimensionless parameter is proposed that incorporates the properties of the cable as well as the sheared flow. This parameter is useful in establishing the likelihood that lock-in may occur, as well as in estimating the number of modes likely to respond.
8
WANG, XIN, and ZHISHEN WU. "VIBRATION CONTROL OF DIFFERENT FRP CABLES IN LONG-SPAN CABLE-STAYED BRIDGE UNDER INDIRECT EXCITATIONS." Journal of Earthquake and Tsunami 05, no. 02 (June 2011): 167–88. http://dx.doi.org/10.1142/s1793431111000991.
Повний текст джерелаАнотація:
To identify the vibration characteristics and potential vibration control of different fiber reinforced polymer (FRP) cables for long-span cable-stayed bridges, the critical resonant responses of these cables under indirect excitations including external and parametric excitations are studied in this paper. Based on theoretical equations, the primary resonant responses of different cables under indirect excitations were first calculated and compared, afterwards the influence of cable length and design stress to the resonant responses and the importance of external and parametric excitations were further studied. Analysis of results show that all of the FRP cables measuring 575 m in length possess lower resonant responses compared with steel cables, while the hybrid FRP cable with smart dampers exhibits even lower responses than the other FRP cables. Moreover, the external excitation induced resonance will become critical for some kinds of FRP cables with increasing cable length. A method on adjusting design stresses mitigates this critical resonance and benefits vibration control of FRP cables. In addition, parametric excitation plays a more important role in resonant responses for short-length cables in comparison to external excitation, whereas both parametric and external excitations are critically important for long-length cables.
9
An, Yonghui, Yue Zhong, Yanbin Tan, and Jinping Ou. "Experimental and numerical studies on a test method for damage diagnosis of stay cables." Advances in Structural Engineering 20, no. 2 (July 28, 2016): 245–56. http://dx.doi.org/10.1177/1369433216659927.
Повний текст джерелаАнотація:
To diagnose the state of stay cables, a vibration-based model-free damage diagnosis method of stay cables using the changes in natural frequencies is further proposed and validated. The structural frequency is rapidly and easily acquired; moreover, it is simple and reliable for damage diagnosis. The frequency would change after the stay cable is damaged, so the frequency change could be used as the damage index. However, the stay cables are very long in long-span cable-stayed bridges, and their frequencies are very small; the frequency change due to small damage of the stay cable would be submerged by the surrounding noise and error of parameter identification process. A temporary diagonal steel bar–based method is used to solve this issue. The steel bar is installed with one end on the stay cable close to the bottom anchor head and the other end on the bridge deck; thus, the stay cable is divided into a short part and a long part by the steel bar. The frequency of a stay cable with a given tension force increases with the decrease in its length; according to the qualitative analysis, the frequency of the short part increases dramatically, and the local frequency change of the short part due to the same damage in the whole stay cable is amplified dramatically; thus, the small damage of a stay cable can be diagnosed easily. Numerical simulations of a stay cable selected from a cable-stayed bridge and a laboratorial stay cable are used to validate the method and also give a recommended rule for design of the temporary diagonal steel bar; experimental validation has also been conducted. All the results indicate that the proposed method works very well in damage diagnosis of stay cables. The proposed method is an output-only, model-free, fast and economical damage diagnosis method for stay cables.
10
Wang, Long Fei, and Mu Yu Liu. "Effects of Stable Cable on Ultimate Load-Carrying Capacity of Long-Span Composite Girder Cable-Stayed Bridge with Three Pylons." Advanced Materials Research 163-167 (December 2010): 2337–42. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2337.
Повний текст джерелаАнотація:
On the background of a long-span composite girder cable-stayed bridge with three pylons under construction for research, this paper establishes two models of the whole bridge by considering the structural geometric nonlinearity, material nonlinearity and interface slip effect in composite girder, one has stable cables between pylons but the other hasn’t, then comparatively studies the failure loads and structural internal forces of the two models to achieve effects of stable cable on the ultimate load-carrying capacity of the cable-stayed bridge. This research shows that the stable cables can strengthen the vertical stiffness of structure and obviously increase the failure load of the bridge, and the internal forces in main girder, middle pylon and stayed cables are smaller and their distributions are more reasonable under the failure load than those in the bridge with no stable cables, so the stable cables can effectively improve the ultimate load-carrying capacity of long-span composite girder cable-stayed bridges with three pylons.
11
Wang, Yan, Dong-Hui Yang, Yu-Zheng Zhou, and Ting-Hua Yi. "Cable effective length model error-based bridge performance warning method under thermal action." Advances in Structural Engineering 25, no. 2 (October 5, 2021): 306–20. http://dx.doi.org/10.1177/13694332211048007.
Повний текст джерелаАнотація:
The cables of long-span cable-stayed bridges are subjected to substantial tension during long-term service and are more susceptible to corrosion and fatigue failure than concrete structures. Most existing structural health monitoring (SHM) systems do not have monitoring equipment to directly measure cable length, and long-term monitoring of the change in cables is less involved. The displacement response of a bridge is induced by the combination of dynamic effects (wind and highways) and quasi-static effects (temperature). In this paper, the dynamic responses were eliminated by averaging the displacement data for 10 min, and the relationship between temperature and displacement was studied. Based on the monitoring data, the distribution of the thermal field for the bridge was studied and the time variability of the tower displacement was investigated. The correlation was analyzed to study the relationship between the temperature and the tower displacements, the north tower–south tower distance and the tower–girder distances. A strong linear relationship between the temperature and quasi-static responses of the displacements was observed. The thermal expansion coefficient of the effective length of cables was proposed as a quantitative index for long-term cable monitoring. The error in the cable effective length is proposed as the warning index for performance warning research. The results show that the proposed performance warning method can monitor cables and perform warnings when the cable is damaged.
12
Wang, Yan, Dong-Hui Yang, Yu-Zheng Zhou, and Ting-Hua Yi. "Cable effective length model error-based bridge performance warning method under thermal action." Advances in Structural Engineering 25, no. 2 (October 5, 2021): 306–20. http://dx.doi.org/10.1177/13694332211048007.
Повний текст джерелаАнотація:
The cables of long-span cable-stayed bridges are subjected to substantial tension during long-term service and are more susceptible to corrosion and fatigue failure than concrete structures. Most existing structural health monitoring (SHM) systems do not have monitoring equipment to directly measure cable length, and long-term monitoring of the change in cables is less involved. The displacement response of a bridge is induced by the combination of dynamic effects (wind and highways) and quasi-static effects (temperature). In this paper, the dynamic responses were eliminated by averaging the displacement data for 10 min, and the relationship between temperature and displacement was studied. Based on the monitoring data, the distribution of the thermal field for the bridge was studied and the time variability of the tower displacement was investigated. The correlation was analyzed to study the relationship between the temperature and the tower displacements, the north tower–south tower distance and the tower–girder distances. A strong linear relationship between the temperature and quasi-static responses of the displacements was observed. The thermal expansion coefficient of the effective length of cables was proposed as a quantitative index for long-term cable monitoring. The error in the cable effective length is proposed as the warning index for performance warning research. The results show that the proposed performance warning method can monitor cables and perform warnings when the cable is damaged.
13
Yao, Chao Yi, Qian Hui Pu, and Ya Dong Yao. "Mechanical Features of Cable-Girder Anchorage for Long-Span Railway Cable-Stayed Bridge with Steel Box Girders." Applied Mechanics and Materials 587-589 (July 2014): 1391–94. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.1391.
Повний текст джерелаАнотація:
The cable-stayed bridge got rapid development in recent years. And for long-span cable-stayed bridges, the cable-girder anchorage structure is a key component in designing. The function of the cable-girder anchorage structure is to transfer the load between cables and the main girder. With the complex load transfer mechanism and stress concentration induced by large cable force, rational design of cable-girder anchorage structure is critical to long-span cable-stayed bridges. Take a certain long-span railway cable-stayed bridge in Zhejiang Province as the investigation, the load transfer mechanism and the stress distribution state was studied by finite element model. The research indicated that the design of this anchor box was rational. The stress distribution on each plate of the anchor box was relatively uniform. And the load transfer path and mechanisms of the main components of this anchor box were clear.
14
Wang, Lei, Yifan Zhang, Muhammad Saqib Ali, Guozhu Chen, Josep M. Guerrero, and Juan C. Vasquez. "High-Frequency Modeling and Filter Design for PWM Drives with Long Cables." Energies 14, no. 4 (February 22, 2021): 1155. http://dx.doi.org/10.3390/en14041155.
Повний текст джерелаАнотація:
Aiming at the problems emerging in a pulse width modulation (PWM) drive system with long cables, the accurate modeling of power cables is the premise for predicting and analyzing these relevant phenomena, and a proper filter design is the key solution to these problems. This paper proposes high-frequency cable models to represent these frequency-dependent characteristics, especially for the high-frequency resistance of cables, which is an easily overlooked factor that determines the damping of overvoltage. The proposed models can be used for accurately representing the cable characteristics in a wide frequency range, and correctly simulating the differential mode (DM) overvoltage and common mode (CM) current, including the peak value, oscillation frequency, and damping of the transient waveform. In addition, improved filter networks are proposed to suppress the DM voltage and CM current, with the merit of low losses, small volume, and excellent abilities for suppressing overvoltage. The proposed cable models and the filter design were validated in a 750 W PWM drive system with 200 m power cables.
15
Liu, Peng, Haibo Tian, and Xinzhou Qiao. "Minimum Cable Tensions and Tension Sensitivity for Long-Span Cable-Driven Camera Robots with Applications to Stability Analysis." Actuators 12, no. 1 (December 31, 2022): 17. http://dx.doi.org/10.3390/act12010017.
Повний текст джерелаАнотація:
Employing cables with strong flexibility and unidirectional restraints to operate a camera platform leads to stability issues for a camera robot with long-span cables considering the cable mass. Cable tensions, which are the constraints for the camera platform, have a critical influence on the stability of the robot. Consequently, this paper focuses on two special problems of minimum cable tension distributions (MCTDs) within the workspace and the cable tension sensitivity analysis (CTSA) for a camera robot by taking the cable mass into account, which can be used to investigate the stability of the robot. Firstly, three minimum cable tension distribution indices (MCTDIs) were proposed for the camera robot. An important matter is that the three proposed MCTDIs, which represent the weakest constraints for the camera platform, can be employed for investigating the stability of the robot. In addition, a specified minimum cable tension workspace (SMCTW) is introduced, where the minimum cable tension when the camera platform is located at arbitrary position meets the given requirement. Secondly, the CTSA model and cable tension sensitivity analysis index (CTSAI) for the camera robot were proposed with grey relational analysis method, in which the influence mechanism and influence degree of the positions of the camera platform relative to cable tensions was investigated in detail. Lastly, the reasonableness of the presented MCTDIs and the method for the CTSA with applications in the stability analysis of the camera robot were supported by performing some simulation studies.
16
Du, Xiao Ming, and Nan Li. "The Analysis of Stayed Cable Wind-Induced Vibration Morphology and Damping Measures." Applied Mechanics and Materials 501-504 (January 2014): 1174–77. http://dx.doi.org/10.4028/www.scientific.net/amm.501-504.1174.
Повний текст джерелаАнотація:
The stayed cable is the key part of the cable-stayed bridge and the main bearing section. Stay cables are prone to vibration under the loads of the rains winds, earthquakes and transportation for the long-span bridge is very flexible and the damping is small. A long time effect of cable vibration on the structure durability has become a serious problem of cable-stayed bridge in the development and operation. Wind induced vibration of stay cable shape is analyzed, and some common damping measures are expounded in the article and it provides the basis for further study in the future.
17
Wang, Hui Ping. "Calculation on Modal Damping Ratio of Stay Cable Using Nonlinear Friction Damper." Advanced Materials Research 538-541 (June 2012): 1800–1803. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.1800.
Повний текст джерелаАнотація:
Stay cables of long span cable-stayed bridges are easy to vibrate under wind or wind/rain loads owning to their very low inherent damping. To install cable dampers near to the anchorages of cable has become a common practice for cable vibration control of cable-stayed bridge structures. In this study, the behaviors of a nonlinear frictional type of damper were investigated. The equations of motion of a cable with a friction damper were derived by using a lumped mass model. Then by introducing modal transformation, the analytical solution for the motion equations was obtained. The results show that the friction damper evokes linearly decaying of free vibrations of the cable as long as the damper does not lock the cable. The modal damping ratio of cable with the friction damper is strongly amplitude dependent. Calculation of modal damping ratio can be simplified using control parameter and the maximum modal damping ratio can be obtained. A universal estimation curve is proposed that is similar to linear viscous damper. These studies could provide design basis for the vibration mitigation of stay cables using nonlinear friction.
18
Pan, Quan, Donghuang Yan, and Zhuangpeng Yi. "Form-Finding Analysis of the Rail Cable Shifting System of Long-Span Suspension Bridges." Applied Sciences 8, no. 11 (October 24, 2018): 2033. http://dx.doi.org/10.3390/app8112033.
Повний текст джерелаАнотація:
The determination of the non-loading condition of the rail cable shifting (RCS) system, which consists of the main cables, hangers, and rail cables, is the premise of girder erection for long-span suspension bridges. An analytical form-finding analysis model of the shifting system is established according to the basic assumptions of flexible cable structures. Herein, the rail cable is discretized into segmental linear cable elements and the main cable is discretized into segmental catenary elements. Moreover, the calculation and analysis equations of each member and their iterative solutions are derived by taking the elastic elongation of the sling into account. In addition, by taking the girder construction of the Aizhai suspension bridge as the engineering background, a global scale model of the RCS system is designed and manufactured. The test system and working conditions are also established. The comparison between the test results and analytical results shows the presented analytical method is correct and effective. The process is simplified in the analytical method, and the computational results and precision satisfy practical engineering requirements. In addition, the proposed method is suitable for application in the computation analysis of similar structures.
19
Bayraktar, Alemdar, Ashraf Ashour, Halil Karadeniz, Altok Kurşun, and Arif Erdiş. "Monitored structural behavior of a long span cable-stayed bridge under environmental effects." Challenge Journal of Structural Mechanics 4, no. 4 (December 5, 2018): 137. http://dx.doi.org/10.20528/cjsmec.2018.04.002.
Повний текст джерелаАнотація:
An accurate numerical analysis of the behavior of long-span cable-stayed bridges under environmental effects is a challenge because of complex, uncertain and varying environmental meteorology. This study aims to investigate in-situ experimental structural behavior of long-span steel cable-stayed bridges under environmental effects such as air temperature and wind using the monitoring data. Nissibi cable-stayed bridge with total length of 610m constructed in the city of Adıyaman, Turkey, in 2015 is chosen for this purpose. Structural behaviors of the main structural elements including deck, towers (pylons) and cables of the selected long span cable-stayed bridge under environmental effects such as air temperature and wind are investigated by using daily monitoring data. The daily variations of cable forces, cable accelerations, pylon accelerations and deck accelerations with air temperature and wind speed are compared using the hottest summer (July 31, 2015) and the coldest winter (January 1, 2016) days data.
20
Bilan, T., I. Rezvik, O. Sakhno, O. But, and S. Bogdanov. "Main Approaches to Cable Aging Management at Nuclear Power Plants in Ukraine." Nuclear and Radiation Safety, no. 4(84) (December 19, 2019): 54–62. http://dx.doi.org/10.32918/nrs.2019.4(84).07.
Повний текст джерелаАнотація:
The mechanisms of cable ageing at nuclear power plants (NPPs) mainly depending on the insulation material, as well as the damaging factors affecting cables that are determined by the operating conditions are considered in the paper. The main and additional mechanisms of aging resulting from the effects of damaging factors are provided. The paper presents the main methods of cable aging management: determining the actual service life and testing using field methods and other means. The basic principles for the arrangement of cable aging management at Ukrainian NPPs, as well as the methods used to investigate the technical condition of cables, are presented. A list of mandatory lists has been defined when performing activities on cable aging management. A methodology is described for lifetime extension of cables, and conditions for extending the service life of cables that are in service are provided. A number of methods of testing cables for aging management are considered: visual inspection of insulation and measurement of crack size, discoloration, etc.; insulation hardness test; insulation chemical analysis; electrical insulation tests; tensile strength measurement; measurement of elongation at break; measurements of dielectric loss at low frequency or sweep frequency; testing by dynamic reflectometry method; AC and DC current impedance measurements. The paper presents results of separate laboratory studies for selected 1 kV representative power cables with PVC insulation of SUNPP-1, ZNPP-1 and KhNPP-2 conducted within Ukrainian NPP long-term operation, which included a stage of laboratory examination and examination of cable samples in operating conditions. The following results were obtained: dependence of VVGng 4x6 cable lifetime on operating temperature; dependence of AVVG cable lifetime on operating temperature; dependence of AVVG (a) cable lifetime on operating temperature. There are possibilities and conditions under which the use of cables within long-term operation is permissible.
21
Jeong, Seunghoo, Young-Joo Lee, and Sung-Han Sim. "Serviceability Assessment Method of Stay Cables with Vibration Control Using First-Passage Probability." Mathematical Problems in Engineering 2019 (May 6, 2019): 1–9. http://dx.doi.org/10.1155/2019/4138279.
Повний текст джерелаАнотація:
As the construction of long-span bridges such as cable-stayed bridges increases worldwide, maintaining bridge serviceability and operability has become an important issue in civil engineering. The stay cable is a principal component of cable-stayed bridges and is generally lightly damped and intrinsically vulnerable to vibration. Excessive vibrations in stay cables can potentially cause long-term fatigue accumulation and serviceability issues. Previous studies have mainly focused on the mitigation of cable vibration within an acceptable operational level, while little attention has been paid to the quantitative assessment of serviceability enhancement provided by vibration control. This study accordingly proposed and evaluated a serviceability assessment method for stay cables equipped with vibration control. Cable serviceability failure was defined according to the range of acceptable cable responses provided in most bridge design codes. The cable serviceability failure probability was then determined by means of the first-passage problem using VanMarcke’s approximation. The proposed approach effectively allows the probability of serviceability failure to be calculated depending on the properties of any installed vibration control method. To demonstrate the proposed method, the stay cables of the Second Jindo Bridge in South Korea were evaluated and the analysis results accurately reflected cable behavior during a known wind event and show that the appropriate selection of vibration control method and properties can effectively reduce the probability of serviceability failure.
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Korotkevich, M. A., and S. N. Azarov. "The Evaluation of Impact of Cable Power Lines on the Environment." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 62, no. 5 (October 4, 2019): 422–32. http://dx.doi.org/10.21122/1029-7448-2019-62-5-422-432.
Повний текст джерелаАнотація:
The thermal impact of cable power lines and structural materials of cables on the environment has been considered. A quantitative evaluation of the thermal impact of electrical cables with cross-linked polyethylene insulation on the environment was carried out using the Elcut program. Analysis of the temperature field near the loaded cable line of 10 kV demonstrated high values of soil temperature that negatively affects its redox potential and living organisms. To evaluate the environmental impact of electrical cable materials, an approach has been developed that takes into account not only the toxicity of the materials but also their volumetric content in the cable. Cable lines with cables with traditional paper-oil insulation cause more damage to the environment than cable lines with cables, insulated with crosslinked polyethylene. The environment, in turn, also has an impact on the electrical cables: the values of long-term permissible load currents depend on the ambient temperature (when laying cables in the open air, in an earthen trench or in cable rooms). The impact of solar radiation on the thermal conditions of the electric cable is estimated. A comparative analysis of the complex environmental impact of electric cables with traditional insulation and insulation of crosslinked polyethylene demonstrated that unarmored cable with crosslinked polyethylene insulation at a voltage of 10 kV (regardless of the type of its shell) causes less damage to the environment than the same traditional cable throughout the considered temperature range on their surfaces.
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Jiang, Yamei, and Feng Lyu. "Large-Signal Stability Analysis of the Undersea Direct Current Power System for Scientific Cabled Seafloor Observatories." Applied Sciences 9, no. 15 (August 2, 2019): 3149. http://dx.doi.org/10.3390/app9153149.
Повний текст джерелаАнотація:
A large number of power electronic converters and long-distance submarine cables are an important part of the undersea direct current (DC) power system of the scientific cabled seafloor observatories (CSOs). However, the constant power load (CPL) characteristics of the converters and the distributed parameter characteristics of long-distance submarine cables greatly affect the stability of the CSO DC power system. This paper analyzes the large-signal stability of the CSO DC power system, and the equivalent circuits of long-distance submarine cables are established by theoretical analysis and computer simulation. A simplified computer simulation model and an equivalent experimental prototype model of a single-node CSO DC power system was built in the laboratory to study this issue. The mixed potential function method is used to analyze the large-signal stability of the CSO DC power system, and the large-signal stability criterion is obtained theoretically. The validity of the large-signal stability criterion is proved by simulations and experiments. The conclusion is that reducing the inductance of the submarine cable, increasing the capacitance of the submarine cable, increasing the output voltage of the shore station power feeding equipment (PFE) or reducing the power consumption of the undersea station, are beneficial to improve the large-signal stability of the CSO DC power system.
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Li, Yan, Da Gang Lv, and Hong Fei Sheng. "Fatigue Reliability Analysis of the Stay Cables of Cable-Stayed Bridge under Combined Loads of Stochastic Traffic and Wind." Key Engineering Materials 456 (December 2010): 23–35. http://dx.doi.org/10.4028/www.scientific.net/kem.456.23.
Повний текст джерелаАнотація:
The existent studies on cable stays fatigue for the serviced cable-stayed bridge generally only considered traffic or wind load action respectively. The long span cable-stayed bridges are very sensitive to wind load, so the fatigue estimation of cable stays considering traffic and wind load simultaneously is very important for the bridge safety. In the present research, taking an actual bridge as an example, based on linear cumulative damage theory, fatigue reliability of cable stays is analyzed under combined load of vehicles and wind. Firstly, based on the long-term traffic survey and wind speed data, traffic and wind load probability distribution models for the bridge are built respectively. Secondly, an intensive computational work is performed to obtain stress time history of the stay cables in the typical time block by running self-compiled Bridge-Vehicle-Wind interaction dynamic response analysis program. Thirdly, the stress result is updated in accordance with traffic growth and extreme wind speed changing in service period. The stress amplitude and frequency are attained by rain-flow cycle counting method. Finally, the fatigue damage limit state function of cable stays is proposed based on linear cumulative damage theory, and solved by Monte-Carlo method. The analysis result shows that the effect of buffeting wind load on the fatigue reliability of cable stays is significant, the influence degree increases generally in accordance with the order from short cable to long cable. The fatigue life of cable under designed safety probability reduces by the range from 2% to 63%, average 50% compared to only considering traffic load. So fatigue assessment of stay cables should take traffic and wind loads together into account. The proposed analysis framework offers a referenced fatigue assessment approach for conventional long span bridges.
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Wang, Ling Yun. "Mitigation of Wind-Rain-Induced Cable Vibration in Cable-Stayed Bridges: Measurement Error." Applied Mechanics and Materials 226-228 (November 2012): 1630–33. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.1630.
Повний текст джерелаАнотація:
Recent advances in structural and construction technologies have enabled engineers to use the cable efficiently in relatively large structures such as long span cable-stayed bridges. It appeared that many factors and phenomena can generate cable vibration. The cables usually possess low damping and are therefore prone to many vibration problems, even causing large displacement. The active control method has been introduced to control the cable vibration in the cable-stayed bridges. The active control method is an effective method to suppress cable vibrations by adjusting the cable tension which is varied with time. This approach utilizes the axial motion of cables supported by an actuator installed at the anchorage to produce a time-varying force in the cable. To synthesize the feedback control signal, the cable vibration is measured by an optical tracking sensor attached at the mid-span cable. The studies are carried out to investigate the measurement error features of the control method as a design guideline.
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Wang, Chung-Yue, Van-Son Nguyen, M. I. Syamsi, and Hao-Lin Wang. "Vibration of two in-plane simply supported bending cables interconnected by a flexible cross-link." Journal of Mechanics 38 (2022): 345–66. http://dx.doi.org/10.1093/jom/ufac026.
Повний текст джерелаАнотація:
ABSTRACT Most of the existing analytical solutions to the vibration of cable networks interconnected by cross-ties are developed based on string theory, where the effect of cable bending rigidity on cable vibration is ignored. However, the bending rigidity of cables strongly influences the natural frequencies and vibration mode shapes of short and stout cables and long cables at higher modes. Hence, this paper considers cable bending rigidity to form a closed-form solution that can be used in determining the natural frequencies and mode shapes of cable networks. The analytical solution of the cable network model with hinged-end boundary conditions is derived. It can be combined with other existing techniques to analyze the dynamic behaviors of a two-cable network with partly fixed supports. The analytical solution derived from this paper can be degenerated to the same solution without considering the cable bending rigidity in previous studies. The accuracy of this analytical solution considering cable bending rigidity is verified by finite element analysis. The effects of bending rigidity on the vibration frequencies and modes of the cable network with inclined and flexible cross-link are investigated in detail. This analytical solution can be applied to backward analysis to identify the cable tension of a two-cable network with partly fixed supports.
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Du, Hong, Da Yang Liu, Fu Wei Huang, and Jing Bo Liao. "Method of Bending Stiffness Parameter Identification of Stay Cable." Applied Mechanics and Materials 777 (July 2015): 52–58. http://dx.doi.org/10.4028/www.scientific.net/amm.777.52.
Повний текст джерелаАнотація:
In order to solve the problem of bending stiffness parameters identification of practical stay-cable, and provide bending stiffness correction for tension measurement. A method to identify cable bending stiffness parameters is proposed, and its basis theory established in paper. The method was applied to Xiazhang Sea-Crossing Bridge, the results showed that: Identification bending stiffness ratio is between 0.33 to 0.54 for relatively short cables of South Branch Bridge, and it tends to decrease with increase of cable length and force. However, the identification bending stiffness is close or equal to 0 EImax for relatively long cable of North Branch Bridge. It testified that the effect of bending stiffness for long cable tension is small in engineering.
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Liu, Gang, Mingming Fan, Pengyu Wang, and Ming Zheng. "Study on Reactive Power Compensation Strategies for Long Distance Submarine Cables Considering Electrothermal Coordination." Journal of Marine Science and Engineering 9, no. 1 (January 15, 2021): 90. http://dx.doi.org/10.3390/jmse9010090.
Повний текст джерелаАнотація:
Long-distance high voltage alternating current (AC) submarine cables are widely used to connect offshore wind farms and land power grids. However, the transmission capacity of the submarine cable is limited by the capacitive charging current. This paper analyzes the impacts of reactive power compensation in different positions on the current distribution on long-distance submarine cable transmission lines, and tests the rationality of the existing reactive power compensation schemes based on electrothermal coordination (ETC). Research shows that compensation at the sending end has obvious impacts on current distribution along the cable, and the maximum current occurs at the sending or receiving end. Moreover, the reactive power compensation at sending end will reduce the current at receiving end of the line. On the contrary, it will increase the current at sending end. Compared with the directly buried laying method of the submarine cable in the landing section, the cable trench laying method can increase the cable ampacity of the landing section and reduce the reactive power compensation capacity at the sending end. The ampacity is the current representation of the thermal limits of the cable. ETC exploits the cable ampacity to coordinate current distribution on transmission lines under existing reactive power compensation schemes, thus optimizing the reactive power compensation schemes and avoiding the bottleneck point of cable ampacity.
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Ren, Yuan, Xiang Xu, Qiao Huang, Dan-Yang Zhao, and Juan Yang. "Long-term condition evaluation for stay cable systems using dead load–induced cable forces." Advances in Structural Engineering 22, no. 7 (January 12, 2019): 1644–56. http://dx.doi.org/10.1177/1369433218824486.
Повний текст джерелаАнотація:
To ensure the safety of cable-stayed bridges, a long-term condition evaluation method has been proposed based on dead load–induced cable forces. To extract dead load–induced cable forces under random vehicle loadings, a novel approach is first developed by integrating influence lines with monitoring data. Then, based on the extracted dead load–induced cable forces, the evaluation algorithm for stay cable systems is presented. In the assessment algorithm, uniform and non-uniform characteristics are taken into account. Finally, the Third Nanjing Yangtze River Bridge, a typical large span cable-stayed bridge, is used to illustrate the effectiveness of the proposed methodology. As a result, the maximum relative error in extraction of dead load–induced cable forces accounts for 4.78% within the studied five stay cables. The precision of the extraction method is acceptable for practical applications since the relative error is less than 5%. Moreover, the bridge is continuously assessed using the dead load–induced cable forces for 5 years. Eliminating the influence of vehicle loadings, the condition of the bridge gradually degrades with time but still remains in good condition. The study not only provides a long-term condition evaluation method for stay cable systems but a dead load–induced extraction approach under random vehicle loadings, which will help bridge owners know well the condition of bridges to make appropriate maintenance decisions.
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Jeong, Seunghoo, Young-Joo Lee, Do Hyoung Shin, and Sung-Han Sim. "Automated Real-Time Assessment of Stay-Cable Serviceability Using Smart Sensors." Applied Sciences 9, no. 20 (October 22, 2019): 4469. http://dx.doi.org/10.3390/app9204469.
Повний текст джерелаАнотація:
The number of cable-stayed bridges being built worldwide has been increasing owing to the increasing demand for long-span bridges. As the stay-cable is one of critical load-carrying members of cable-stayed bridges, its maintenance has become a significant issue. The stay-cable has an inherently low damping ratio with high flexibility, which makes it vulnerable to vibrations owing to wind, rain, and traffic. Excessive vibration of the stay-cable can cause long-term fatigue problems in the stay-cable as well as the cable-stayed bridge. Therefore, civil engineers are required to carry out maintenance measures on stay-cables as a high priority. For the maintenance of the stay-cables, an automated real-time serviceability assessment system using wireless smart sensors was developed in this study. When the displacement of the cable in the mid-span exceeds either the upper or the lower bound provided in most bridge design codes, it is considered as a serviceability failure. The system developed in this study features embedded on-board processing, including the measurement of acceleration, estimation of displacement from measured acceleration, serviceability assessment, and monitoring through wireless communication. A series of laboratory tests were carried out to verify the performance of the developed system.
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Su, Yu, Yuanying Qiu, and Peng Liu. "Optimal Cable Tension Distribution of the High-Speed Redundant Driven Camera Robots Considering Cable Sag and Inertia Effects." Advances in Mechanical Engineering 6 (January 1, 2014): 729020. http://dx.doi.org/10.1155/2014/729020.
Повний текст джерелаАнотація:
Camera robots are high-speed redundantly cable-driven parallel manipulators that realize the aerial panoramic photographing. When long-span cables and high maneuverability are involved, the effects of cable sags and inertias on the dynamics must be carefully dealt with. This paper is devoted to the optimal cable tension distribution (OCTD for short) of the camera robots. Firstly, each fast varying-length cable is discretized into some nodes for computing the cable inertias. Secondly, the dynamic equation integrated with the cable inertias is set up regarding the large-span cables as catenaries. Thirdly, an iterative optimization algorithm is introduced for the cable tension distribution by using the dynamic equation and sag-to-span ratios as constraint conditions. Finally, numerical examples are presented to demonstrate the effects of cable sags and inertias on determining tensions. The results justify the convergence and effectiveness of the algorithm. In addition, the results show that it is necessary to take the cable sags and inertias into consideration for the large-span manipulators.
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Belmas, Ivan, Olena Bilous, Ganna Tantsura, and Angelina Shvachka. "The dependence of the internal electrical resistance of the cable rubber rope on the presence of a cable rupture." Mechanics and Advanced Technologies 6, no. 1 (May 31, 2022): 31–40. http://dx.doi.org/10.20535/2521-1943.2022.6.1.250801.
Повний текст джерелаАнотація:
Problems. The introduction of steel reinforced concrete coatings of structures, in our opinion, is preceded by the development of methods for monitoring the state of cable-stayed ropes - creating safe conditions for long-term operation of structures.
The aim of the study. Analytical determination of the dependence of the internal electrical resistance of a cable-stayed rubber cable rope on the presence of a cable rupture.
Methods of implementation. To control all cables, the system must provide alternate monitoring of the electrical resistances of the circuits formed by the cables, compare them with reference values, and issue a signal regarding the condition of the rope. It should be designed on the basis of the following data: the type and design of the cable-stayed rope, its length, the number and layout of the cables in the rope, the ability to access one or both of its ends, the electrical properties of the cables and rubber, the resistance values of the cables for all schemes of their determination.
Research results. Requirements for the automatic control system of the cable-stayed rubber cord rope. The regularity of the dependence of the electrical resistance of the cable-stayed rope on the burst of an arbitrary cable. Possibility of automatic control of the state of the rubber-cable cable-stayed rope.
Conclusions. The results obtained can be considered quite reliable, since the equations obtained on the basis of the fundamental provisions of electrical engineering are obtained analytically in a closed form. Experimental studies have established that the internal electrical resistance of the rope cables depends on its properties and the presence or absence of damage to the cables. The rope includes a number of cables. Any cable can be damaged.
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Tian, Wei Feng, Shui Xing Zhou, and Ayad Thabet Saeed Alghabsha. "Calculation of Cable Force for Long-Span Rib Arch Bridge Construction under Seasonal Ambient Temperature." Advanced Materials Research 378-379 (October 2011): 341–44. http://dx.doi.org/10.4028/www.scientific.net/amr.378-379.341.
Повний текст джерелаАнотація:
Calculation of cable force under seasonal ambient temperature is the key and difficult problem in the construction of long-span rib arch bridge. It affects the final cable forces and deformations of arch rib after arch closure. Unstressed state control method is introduced in the construction of Daning River Bridge; unstressed qualities of ribs and unstressed length of cables can be obtained by optimization analysis of the maximum cantilever state in construction. According to unstressed state control method, the cable forces of each segment were calculated using the forward-iteration method. These results offer the basis for construction control, and guarantee the arch rib line and cable forces to meet the design requirements, and an arch closure with high precision.
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Asgari, B., S. A. Osman, and A. Adnan. "A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges." Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/503016.
Повний текст джерелаАнотація:
Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.
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Xu, Yichao, Jian Zhang, Yufeng Zhang, and Changzhao Li. "A Novel Approach for Cable Tension Monitoring Based on Mode Shape Identification." Sensors 22, no. 24 (December 18, 2022): 9975. http://dx.doi.org/10.3390/s22249975.
Повний текст джерелаАнотація:
Estimation and monitoring of cable tension is of great significance in the structural assessment of cable-supported bridges. For short cables, the traditional cable tension identification method via frequency measurement has large errors due to the influence of complex boundaries, which affect the accuracy of estimation. A new cable tension estimation method based on mode shape identification with a multiple sensor arrangement on the cable can take the influence of boundary conditions into account and its accuracy has been verified. However, it requires more sensors compared to the traditional frequency-based method, which will significantly increase the cost of long-term monitoring in practice. Therefore, a novel approach for cable tension monitoring considering both cost and accuracy is further proposed in this study. The approach adopts multiple sensors to measure the influence of boundary conditions. Then, only a single sensor is required for long-term monitoring of the cable. In this paper, an analytical model of the cable is firstly established. The influence of boundary conditions is calculated, which ensures the accuracy of mode shape identification. Furthermore, a field experiment is carried out to verify the effectiveness of the new approach. The results have demonstrated the effectiveness and accurateness of the proposed method in long-term short cable tension monitoring.
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Kim, Jae Min, Jong Jae Lee, Sang Sup Ahn, and Jun Seong Choi. "A Vibration Exciter for Evaluating Cable Damping of a Cable-Stayed Bridge." Advances in Science and Technology 56 (September 2008): 206–11. http://dx.doi.org/10.4028/www.scientific.net/ast.56.206.
Повний текст джерелаАнотація:
It is necessary to accurately estimate the dynamic characteristics of stay cables, especially damping ratios, to design cable damper for appropriate vibration mitigation of a cable-stayed bridge in service. In this study, a vibration exciter has been developed to evaluate the cable damping of a cable-stayed bridge. The feasibility of the developed system was verified through field tests on a 100m long stay cable. The damping ratios of the stay cable were estimated based on acceleration data as well as displacement data measured by digital image processing technique. The performance of the passively operated MR dampers with the different voltage inputs were investigated by comparing the estimated damping ratios.
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Sohrabi, Sobhan, Hamid M. Daniali, and Ali Reza Fathi. "DYNAMIC MODELING OF LONG SPAN NEW MATERIAL CABLE ROBOT." Transactions of the Canadian Society for Mechanical Engineering 41, no. 4 (November 2017): 517–30. http://dx.doi.org/10.1139/tcsme-2017-1036.
Повний текст джерелаАнотація:
Cable driven parallel manipulator (CDPM) is a robotic mechanism which utilize multiple actuated cables to manipulate objects. It offers some advantages over the conventional parallel manipulators, such as higher load to weight ratio and larger workspace. These advantages are more evident if one uses composite materials for the cables of CDPM. This study aims at dynamic analysis and trajectory path planning of long-span CDPM by taking into accounts the effects of mass, curvature, flexibility and viscoelastic behavior of its new material cables. The dynamic analysis of the CDPM shows that its end effector vibrates throughout its desired trajectory which leads to an oscillatory pose error. An optimization algorithm is used here for the error suppression of the path planning problem.
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., Widodo, and Nur Hidayat. "Design And Development Of Automatic Fiber Optic Cable Roller Using Nodemcu Esp 8266 Module." BEST : Journal of Applied Electrical, Science, & Technology 4, no. 1 (March 22, 2022): 27–32. http://dx.doi.org/10.36456/best.vol4.no1.5442.
Повний текст джерелаАнотація:
ABSTRACT The process of winding fiber optic cable rolls takes a long time because it is done manually or conventionally. One of the tools in winding is a FO cable roller. This tool is designed to be able to roll fiber optic cables, but the limitations of this tool are still done manually, FO cables are rolled by hand like pedaling a bicycle on the pedals, the speed is set based on the speed of the rotation of the hand and it all depends on the human factor. Therefore, there is a need for an Automatic Fiber Optic Cable Winder Using NodeMCU ESP8266 and using Iot (Web of Things) to be more efficient and better in cable winding expositions.
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Kim, Cheol-Hwan, Byung-Wan Jo, and Jin-Taek Jun. "Application of Laser Vibrometer to the Measurement and Control of Cable Tensile Forces in Cable-Stayed Bridges." International Journal of Distributed Sensor Networks 8, no. 10 (October 1, 2012): 810682. http://dx.doi.org/10.1155/2012/810682.
Повний текст джерелаАнотація:
The tensile forces acting on the cable of long-span bridges are one of the most important factors since they reflect not only the structural stability of cables but also the overall quality of construction. Currently, indirect measurement using accelerometers attached to the surface of the cable is widely used to measure the natural frequency of cable. The frequency obtained from the accelerometer is converted to the tensile force of the cable. However, it sometimes requires many hazardous labors such as attaching the device on the surface of cable and wiring it with data logger, which could hinder the safety of workers during the erection of cables. In this study, a method using laser vibrometer is introduced to measure the tensile forces on cables at a distance. In addition, this study developed a unique postanalysis computer program that can calculate the tensile forces in real time. Compared with the values obtained from the accelerometers, the laser vibrometer system provided accurate and reliable matching.
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Choi, Youngjun, Dongmin Kim, Changhyung Lee, Duyeon Won, Jaeun Yoo, Hyungsuk Yang, and Seokho Kim. "Thermo-Hydraulic Analysis of a Tri-Axial High-Temperature Superconducting Power Cable with Respect to Installation Site Geography." Energies 13, no. 15 (July 30, 2020): 3898. http://dx.doi.org/10.3390/en13153898.
Повний текст джерелаАнотація:
Various high-temperature superconducting (HTS) power cables are being developed or are ready for commercial operation to help energy suppliers meet the growing power demand in urban areas. Recently, triaxial HTS power cables have been developed by Korea Electric Power Corporation (KEPCO) and LS Cable & System. Further, KEPCO has been planning to install a 2 km long 23 kV/60 MVA triaxial HTS power cable to connect the Munsan and Seonyu substations and increase the stability of the power grid. The HTS power cables should be cooled down to a cryogenic temperature near 77 K. A thermo-hydraulic analysis of the cooling system considering the geographical characteristics of the installation site is essential for long-distance sections. This paper describes the thermo-hydraulic analysis of the triaxial HTS power cable to determine the proper mass flow rates of subcooled liquid nitrogen that meet the operating temperature and pressure of the cable for four configurations of cooling systems: (1) a single cooling system with an external return path, (2) a dual cooling system with an external return path, (3) a single cooling system with an internal return path, and (4) a dual cooling system with internal return path. Since the flow characteristics in a corrugated cable cryostat differ significantly from those in a typical annular tube, a computational fluid dynamics (CFD) analysis was conducted to estimate the pressure drop along the cable cryostat. With the CFD analysis and given heat loads in the cable, the temperature and the pressure variations along the cable were calculated and their pros and cons were compared for each configuration of the cooling system. This thermo-hydraulic analysis will be referenced in the actual installation of the HTS power cable between the Munsan and Seonyu substations.
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Fu, Cuiwei, Xiaogang Qin, and Yu Wang. "Effects of Parameter Uncertainties on Interaction between Submarine Telecommunication Cables and Lateral Seabed Movements." Advances in Civil Engineering 2020 (August 20, 2020): 1–13. http://dx.doi.org/10.1155/2020/8824391.
Повний текст джерелаАнотація:
Submarine telecommunication cables are the physical backbone of the Internet. They are often buried shallowly beneath seabed and affected by seabed movements. Due to the long distance of cables and the complexity of submarine environment, interaction between cables and seabed movements inevitably involves various parameter uncertainties. However, effects of parameter uncertainties on submarine cable responses to seabed movements have not been fully investigated. This paper aims to address this problem using random finite element method (RFEM) that integrates finite element (FE) analysis with Monte Carlo simulation (MCS). First, deterministic FE analysis is performed to investigate cable responses to lateral seabed movements. Then MCS is implemented to study the effects of parameter uncertainties on cable responses. Statistical analysis of the MCS results is performed to prioritize the effects of parameter uncertainties on cable damage probability. Random field is also used to model spatial variability of soil parameters. Effect of the correlation length on cable damage probability is investigated. The results show that uncertainty of the anchored cable length La has the most significant effect on cable damage probability, while the effects of uncertainties in soil friction angle ϕ and effective unit weight γ′ are minor. Ignoring spatial variability of soil parameters may lead to significant misjudgment of cable damage risk.
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Sun, Dong Mei, and Jun Wen. "Researches on Reactive Compensation for Long-Distance and Highcapacity Hybrid Submarine Cable Lines." Advanced Materials Research 433-440 (January 2012): 2406–10. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.2406.
Повний текст джерелаАнотація:
In order to balance reactive power, reduce line losses, prevent excessive power frequency and switching over-voltage and adjust and control the line voltage etc. The long-distance and high voltage transmission lines are needed reactive power compensation. High voltage overhead transmission lines and high voltage submarine cable (including mixed-submarine) transmission lines are different, for example, the capacitance in the submarine cable lines is larger than in the conventional overhead lines. Therefore, the reactive power compensation on the EHV transmission lines which contains submarine cable lines is focus on the compensation of submarine cable lines. The reactive power compensation in 500 kV AC submarine cable interconnection project for Hainan power grid and Guangdong power grid[1], which is the first 500 kV long-distance and high-capacity sea trails interconnection project in China and which is just completed soon, is researched by Electro-Magnetic Transient Program——PSCAD/EMTDC (Power System Computer Aided Design/ Electro Magnetic Transient in DC System in this paper). The simulation results verifies that the role of shunt reactor which could absorb charging power and suppress the power frequency overvoltage for the long-distance and high-capacity hybrid submarine cable lines. The conclusions can offer references to suppress power frequency overvoltage and the reactive power compensation in extra high voltage transmission lines which is the mixed mode of overhead transmission lines and submarine cables.
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Zeng, Yong, Huijun Zheng, Yuhang Jiang, Jiuhong Ran, and Xuan He. "Modal Analysis of a Steel Truss Girder Cable-Stayed Bridge with Single Tower and Single Cable Plane." Applied Sciences 12, no. 15 (July 28, 2022): 7627. http://dx.doi.org/10.3390/app12157627.
Повний текст джерелаАнотація:
The dynamic characteristics of bridge structures are important in wind stability analysis, seismic design, fatigue assessment, health inspection, and maintenance of bridge structures; however, the mechanical and dynamic properties of different bridge types are different. A long-span cable-stayed bridge has the advantages of large flexibility, long natural vibration period, low natural frequency, dense spectrum, and denser modal than those of general structures. In this paper, the dynamic characteristics of a cable-stayed bridge with single pylon and single cable plane in the maximum cantilever stage and the complete bridge are analyzed. The single-tower cable-stayed bridge has some unique characteristics, such as lower cost, and a more beautiful appearance, but its torsional rigidity is lower, which increases the risk of wind damage and earthquake damage. Therefore, a finite element analysis of this bridge in the maximum cantilever state is carried out, and the influences of the main components’ rigidity, the inclination angles of the stayed cables, the supporting conditions, and the locations of the auxiliary piers are analyzed for the sustainability of this type of cable-stayed bridge. The analysis results show that a cable-stayed bridge with single pylon and single cable plane has more flexibility, and that the lateral rigidity and torsional rigidity are smaller. Structure rigidity, dip angles of the stayed cables, and positions of the auxiliary piers all have significant influences on the dynamic characteristics of cable-stayed bridges.
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Sun, Jiang Bo, Zuo Zhou Zhao, and Hong Hua Zhao. "Measuring Methods of Cable Tension in Cable-Stayed Bridges." Advanced Materials Research 295-297 (July 2011): 1230–35. http://dx.doi.org/10.4028/www.scientific.net/amr.295-297.1230.
Повний текст джерелаАнотація:
This paper presents several methods usually used for measuring cable tension in cable-stayed bridges, especially frequency vibration method. Taken two different length stay-cables under given tension forces in a real cable-stayed bridge as an example, different modeling methods in finite element methods (FEM) were used to solve their natural vibration frequencies. The results by FEM were compared with those from other available theoretical predicting method. It was found that FEM based on tightening string model is more suitable for a long stay-cable. For a short stay-cable under given tension force, beam bending stiffness can be ignored in predicting its first five natural frequencies using a hinged beam model in FEM. While the predicted lower frequency using clamped beam FEM model is more accurate and reasonable.
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Qiu, Jing, Rui Li Shen, and Huai Guang Li. "Mechanics Characteristics Study for Cable-Stayed-Suspension Bridges." Advanced Materials Research 243-249 (May 2011): 1817–25. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.1817.
Повний текст джерелаАнотація:
As a composite structure, the cable-stayed-suspension bridge is characterized by relatively new structure, great overall stiffness and long-span capacity, which has been proposed for the design of some extra long-span bridges. In order to research further into the mechanics characteristics of this type of structural system, the proposed preliminary design of a cable-stayed-suspension bridge with a main span of 1800m is analyzed by means of finite element simulation method. The advantages on overall stiffness in the cable-stayed-suspension bridge are summarized in comparison with the three-span suspension bridge and the single-span suspension bridge. Then, the reasons for the fatigue of the longest suspension cables in the cable-stayed-suspension bridge are also discussed in this paper.
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Marra, G., D. M. Fairweather, V. Kamalov, P. Gaynor, M. Cantono, S. Mulholland, B. Baptie, et al. "Optical interferometry–based array of seafloor environmental sensors using a transoceanic submarine cable." Science 376, no. 6595 (May 20, 2022): 874–79. http://dx.doi.org/10.1126/science.abo1939.
Повний текст джерелаАнотація:
Optical fiber–based sensing technology can drastically improve Earth observations by enabling the use of existing submarine communication cables as seafloor sensors. Previous interferometric and polarization-based techniques demonstrated environmental sensing over cable lengths up to 10,500 kilometers. However, measurements were limited to the integrated changes over the entire length of the cable. We demonstrate the detection of earthquakes and ocean signals on individual spans between repeaters of a 5860-kilometer-long transatlantic cable rather than the whole cable. By applying this technique to the existing undersea communication cables, which have a repeater-to-repeater span length of 45 to 90 kilometers, the largely unmonitored ocean floor could be instrumented with thousands of permanent real-time environmental sensors without changes to the underwater infrastructure.
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Zeng, Yong, Yuxiao Wang, Zhenwei Shi, Hongmei Tan, and Anbang Gu. "Experimental Study on Stability of Long-Span PC Cable-Stayed Bridge during the Construction Periods." Advances in Civil Engineering 2022 (August 9, 2022): 1–10. http://dx.doi.org/10.1155/2022/8578684.
Повний текст джерелаАнотація:
With the increasing span of cable-stayed bridges, the towers are getting higher and higher, and the stiffening beams are becoming more and more slender. The increase in span causes the axial pressure of the beams and towers to increase rapidly, and the sag effect of the cables, geometric nonlinearity, and material nonlinear effects are significantly increased. The influence of these disadvantages greatly reduces the stability of the cable-stayed bridge, and the stability of the cable-stayed bridge becomes prominent. In this paper, the finite element method is used to analyze the first kind of stability problem and the second kind of stability problem of cable-stayed bridges. On this basis, a large-span prestressed concrete (PC) cable-stayed bridge is taken as an example to analyze and compare the two types of stability problems of the bridge during the construction phase and the operation phase. Besides, the model experimental study on the stability of the bridge during the maximum double cantilever construction period was carried out. The theoretical values and the model test results are compared to verify the correctness of the calculation method and design theory, which may provide a reference for the design, construction, and scientific research of cable-stayed bridges.
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Fernández, Fernando Seijo, Marco Antonio Alvarez Vega, Aida Antuña Ramos, Fernando Fernández González, and Beatriz Lozano Aragoneses. "Lead Fractures in Deep Brain Stimulation during Long-Term Follow-Up." Parkinson's Disease 2010 (2010): 1–4. http://dx.doi.org/10.4061/2010/409356.
Повний текст джерелаАнотація:
The purpose was to determine the incidence of lead fracture in patients with DBS over a long period of time. We present a retrospective study of 208 patients who received 387 DBS electrodes. Fourteen patients had sixteen lead fractures (4% of the implanted leads) and two patients suffered from 2 lead fractures. Of all lead fractures, five patients had the connection between the leads and the extension cables located in mastoids region, ten in cervical area and one in thoracic region. The mean distance from the connection between the electrode and the extension cable and the lead fracture was 10.7 mm. The lead fracture is a common, although long-term complication in DBS surgery. In our experience, the most common site of electrode cable breakage is approximately between 9 and 13 mm from the junction between the lead and the extension cable. The most important cause of lead fracture is the rotational movement of the lead-extension cable system. If we suspect lead fracture, we must check the impedance of the electrode and to evaluate the side effects of voltage. Finally, we must conduct a radiological screening.
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Zhang, Tian, Xinjia Cui, Weiwei Guo, Yunfeng Zou, and Xuzhe Qin. "Static Wind Reliability Analysis of Long-Span Highway Cable-Stayed Bridge in Service." Applied Sciences 13, no. 2 (January 5, 2023): 749. http://dx.doi.org/10.3390/app13020749.
Повний текст джерелаАнотація:
Long-span cable-stayed bridge is a typical wind-sensitive structure because of its light weight and great flexibility. The reliability evaluation of the cable-stayed bridge under wind action becomes a key issue during bridge design and operation. In this paper, taking Xiangshan Harbor highway cable-stayed bridge in Ningbo City in China as the engineering background, ANSYS 15.0 is used to build a finite element model of this bridge to explore its aerostatic stability and influencing parameters, then the static wind reliability of this bridge is analyzed. Firstly, considering the structural nonlinearity and the nonlinearity of static wind load comprehensively, the critical wind speed of aerostatic instability of the Xiangshan Harbor cable-stayed bridge is calculated by the internal and external double iteration method. Then the influence of the initial wind attack angle, steel wire breakage rate of the stay cables, static three-component force coefficients, and cable broken position on the static wind stability of this bridge are discussed. Thus, the variation rule of the critical aerostatic instability wind speed is obtained, and the parameter that has the greatest impact on the static wind stability of the cable-stayed bridge in service is determined. Finally, considering the randomness of these key parameters, they are treated as random variables, Latin hypercube sampling (LHS) method is used to obtain samples of random variables to calculate aerostatic instability wind speed for a given sample by self-written calculation program, and on this basis, static wind reliability analysis is conducted by the checking point method, which provides strong support for the static wind risk evaluation of the existing long-span cable-stayed bridge.
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Zhong, Jintu, Quansheng Yan, Liu Mei, Xijun Ye, and Jie Wu. "Cable Interlayer Slip Damage Identification Based on the Derivatives of Eigenparameters." Sensors 18, no. 12 (December 16, 2018): 4456. http://dx.doi.org/10.3390/s18124456.
Повний текст джерелаАнотація:
Cables are the main load-bearing structural components of long-span bridges, such as suspension bridges and cable-stayed bridges. When relative slip occurs among the wires in a cable, the local bending stiffness of the cable will significantly decrease, and the cable enters a local interlayer slip damage state. The decrease in the local bending stiffness caused by the local interlayer slip damage to the cable is symmetric or approximately symmetric for multiple elements at both the fixed end and the external load position. An eigenpair sensitivity identification method is introduced in this study to identify the interlayer slip damage to the cable. First, an eigenparameter sensitivity calculation formula is deduced. Second, the cable is discretized as a mass-spring-damping structural system considering stiffness and damping, and the magnitude of the cable interlayer slip damage is simulated based on the degree of stiffness reduction. The Tikhonov regularization method is introduced to solve the damage identification equation of the inverse problem, and artificial white noise is introduced to evaluate the robustness of the method to noise. Numerical examples of stayed cables are investigated to illustrate the efficiency and accuracy of the method proposed in this study.