WorldWideScience

Sample records for bridge cables

  1. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...

  2. History of cable-stayed bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    The principle of supporting a bridge deck by inclined tension members leading to towers on either side of the span has been known for centuries. However, the real development of cable-stayed bridges did not begin before the 1950s. Since then the free span has been increased from 183 m in the Strö...

  3. Static and Dynamic Characteristics of a Long-Span Cable-Stayed Bridge with CFRP Cables

    Directory of Open Access Journals (Sweden)

    Xu Xie

    2014-06-01

    Full Text Available In this study, the scope of CFRP cables in cable-stayed bridges is studied by establishing a numerical model of a 1400-m span of the same. The mechanical properties and characteristics of CFRP stay cables and of a cable-stayed bridge with CFRP cables are here subjected to comprehensive analysis. The anomalies in the damping properties of free vibration, nonlinear parametric vibration and wind fluctuating vibration between steel cables and CFRP cables are determined. The structural stiffness, wind resistance and traffic vibration of the cable-stayed bridge with CFRP cables are also analyzed. It was found that the static performances of a cable-stayed bridge with CFRP cables and steel cables are basically the same. The natural frequencies of CFRP cables do not coincide with the major natural frequencies of the cable-stayed bridge, so the likelihood of CFRP cable-bridge coupling vibration is minuscule. For CFRP cables, the response amplitudes of both parametric vibration and wind fluctuating vibration are smaller than those of steel cables. It can be concluded from the research that the use of CFRP cables does not change the dynamic characteristics of the vehicle-bridge coupling vibration. Therefore, they can be used in long-span cable-stayed bridges with an excellent mechanical performance.

  4. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

    Koss, Holger; Frej Henningsen, Jesper; Olsen, Idar

    2013-01-01

    determination of these force coefficients require a proper simulation of the ice layer occurring under the specific climatic conditions, favouring real ice accretion over simplified artificial reproduction. The work presented in this paper was performed to study the influence of ice accretion on the aerodynamic...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

  5. Optimal Sensor Placement for Stay Cable Damage Identification of Cable-Stayed Bridge under Uncertainty

    OpenAIRE

    Li-Qun Hou; Xue-Feng Zhao; Rui-Cong Han; Chun-Cheng Liu

    2013-01-01

    Large cable-stayed bridges utilize hundreds of stay cables. Thus, placing a sensor on every stay cable of bridges for stay cable damage identification (SCDI) is costly and, in most cases, not necessary. Optimal sensor placement is a significant and critical issue for SCDI. This paper proposes the criteria for sensor quantity and location optimization for SCDI on the basis of the concept of damage identification reliability index (DIRI) under uncertainty. Random elimination (RE) algorithm and ...

  6. Seismic Passive Control of Cable-Stayed Bridges

    OpenAIRE

    Ali, Hosam-Eddin M.; Abdel-Ghaffar, Ahmed M.

    1995-01-01

    A three-dimensional modeling procedure is proposed for cable-stayed bridges with rubber, steel, and lead energy dissipation devices. The passive control technique is investigated by considering the response of bridge models with and without energy dissipation devices. The impact of various design parameters on the seismic response of current and future bridge designs is studied. Appropriate locations and properties of the passive devices can achieve better performance for cable-stayed bridges...

  7. Field application of a cable NDT system for cable-stayed bridge using MFL sensors integrated

    International Nuclear Information System (INIS)

    In this study, an automated cable non-destructive testing(NDT) system was developed to monitor the steel cables that are a core component of cable-stayed bridges. The magnetic flux leakage(MFL) method, which is suitable for ferromagnetic continuum structures and has been verified in previous studies, was applied to the cable inspection. A multi-channel MFL sensor head was fabricated using hall sensors and permanent magnets. A wheel-based cable climbing robot was fabricated to improve the accessibility to the cables, and operating software was developed to monitor the MFL-based NDT research and control the climbing robot. Remote data transmission and robot control were realized by applying wireless LAN communication. Finally, the developed element techniques were integrated into an MFL-based cable NDT system, and the field applicability of this system was verified through a field test at Seohae Bridge, which is a typical cable-stayed bridge currently in operation.

  8. Super-Bridges Suspended Over Carbon Nanotube Cables

    OpenAIRE

    Carpinteri, Alberto; Pugno, Nicola M.

    2008-01-01

    In this paper the new concept of super-bridges, i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of 3.

  9. Cable force monitoring system of cable stayed bridges using accelerometers inside mobile smart phone

    Science.gov (United States)

    Zhao, Xuefeng; Yu, Yan; Hu, Weitong; Jiao, Dong; Han, Ruicong; Mao, Xingquan; Li, Mingchu; Ou, Jinping

    2015-03-01

    Cable force is one of the most important parameters in structural health monitoring system integrated on cable stayed bridges for safety evaluation. In this paper, one kind of cable force monitoring system scheme was proposed. Accelerometers inside mobile smart phones were utilized for the acceleration monitoring of cable vibration. Firstly, comparative tests were conducted in the lab. The test results showed that the accelerometers inside smartphones can detect the cable vibration, and then the cable force can be obtained. Furthermore, there is good agreement between the monitoring results of different kinds of accelerometers. Finally, the proposed cable force monitoring system was applied on one cable strayed bridge structure, the monitoring result verified the feasibility of the monitoring system.

  10. Comparison of several innovative bridge cable surface modifications

    DEFF Research Database (Denmark)

    Kleissl, Kenneth; Georgakis, Christos T.

    Over the last two decades, several bridge cable manufacturers have introduced surface modifications on the high-density polyethylene (HDPE) sheathing that is installed for the protection of inner cable strands or wires. The modifications are based on research undertaken predominantly in Europe and......-span bridges can now produce more than 50% of the overall horizontal load on the bridge (Gimsing and Georgakis, 2012). Recently, the authors presented a comprehensive comparative study of the aerodynamic performance of these existing cable surface modifications (Kleissl and Georgakis, 2011, 2012). The...

  11. Application study on the first cable-stayed bridge with CFRP cables in China

    Directory of Open Access Journals (Sweden)

    Kuihua Mei

    2015-08-01

    Full Text Available In order to push forward the development of CFRP cable-stayed bridge and accumulate experiences, the study on the application of the first cable-stayed bridge with CFRP cables in China was carried out. The design essentials of main components of the bridge were introduced and its integral performances, including static properties, dynamic properties and seismic response were analyzed using finite element method. A new bond-type anchorage was developed and the processes of fabricating and installing CFRP cables were elaborated. Based on the results of construction simulation, a tension scheme for bridge was propound. During constructing, the stresses and displacement of girder and pylon, as well as the forces and stresses of cables, were tested. The results indicate that all sections of the bridge could meet the requirements of the ultimate bearing capacity and normal service; the performance of the anchorage is good and the stresses in each cable system are similar; the tested values accord well with the calculated values. Further, creep deformation of the resin in anchorages under service load is not obvious. All these results demonstrate that the first application of CFRP cables in the cable-stayed bridge in China is successful.

  12. Effects of ice accretion on the aerodynamics of bridge cables

    DEFF Research Database (Denmark)

    Demartino, C.; Koss, Holger; Georgakis, Christos T.;

    2015-01-01

    temperature, wind speed and yaw angle of accretion, were reproduced in a climatic wind tunnel, giving rise to different types of accretion. These were chosen such to generate the most common natural ice formations expected to produce bridge cable vibrations. A description of the geometric characteristics of......Undesirable wind induced vibrations of bridge cables can occur when atmospheric conditions are such to generate ice accretion. This paper contains the results of an extensive investigation of the effects of ice accretion due to in-cloud icing, on the aerodynamic characteristics of bridge hangers...... and stay cables. The aim of this paper is twofold; first, it was investigated the ice accretion process and the final shape of the ice accreted; then the aerodynamics of the ice accreted bridge cables was characterized, and related to the ice shape. Different climatic conditions, i.e. combinations of...

  13. Experimental Investigation of Aerodynamic Instability of Iced Bridge Cable Sections

    DEFF Research Database (Denmark)

    Koss, Holger; Lund, Mia Schou Møller

    2013-01-01

    The accretion of ice on structural bridge cables changes the aerodynamic conditions of the surface and influences hence the acting wind load process. Full-scale monitoring indicates that light precipitation at moderate low temperatures between zero and -5°C may lead to large amplitude vibrations of...... load coefficients and experimental simulation on a 1DOF elastically suspended cable section....

  14. Parametrically excited oscillation of stay cable and its control in cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    孙炳楠; 汪至刚; 高赞明; 倪一清

    2003-01-01

    This paper presents a nonlinear dynamic model for simulation and analysis of a kind of parametrically excited vibration of stay cable caused by support motion in cable-stayed bridges. The sag, inclination angle of the stay cable are considered in the model, based on which, the oscillation mechanism and dynamic response characteristics of this kind of vibration are analyzed through numerical calculation. It is noted that parametrically excited oscillation of a stay cable with certain sag, inclination angle and initial static tension force may occur in cable-stayed bridges due to deck vibration under the condition that the natural frequency of a cable approaches to about half of the first model frequency of the bridge deck system. A new vibration control system installed on the cable anchorage is proposed as a possible damping system to suppress the cable parametric oscillation. The numerical calculation results showed that with the use of this damping system, the cable oscillation due to the vibration of the deck and/or towers will be considerably reduced.

  15. Nonlinear Dynamic Reliability of Coupled Stay Cables and Bridge Tower

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nonlinear vibration can cause serious problems in long span cable-stayed bridges. When the internal resonance threshold is reached between the excitation frequency and natural frequency,large amplitudes occur in the cable. Based on the current situation of lacking corresponding constraint criteria, a model was presented for analyzing the dynamic reliability of coupling oscillation between the cable and tower in a cable-stayed bridge. First of all, in the case of cable sag, the d'Alembert principle is applied to studying the nonlinear dynamic behavior of the structure, and resonance failure interval of parametric oscillation is calculated accordingly. Then the dynamic reliability model is set up using the JC method. An application of this model has been developed for the preliminary design of one cable-stayed bridge located on Hai River in Tianjin, and time histories analysis as well as reliability indexes have been obtained. When frequency ratio between the cable and tower is approaching 1∶2, the reliability index is 0.98, indicating high failure probability. And this is consistent with theoretical derivation and experimental results in reference. This model, which is capable of computing the reliability index of resonance failure, provides theoretical basis for the establishment of corresponding rule.

  16. Optimum design of concrete cable-stayed bridges

    Science.gov (United States)

    Martins, Alberto M. B.; Simões, Luís M. C.; Negrão, João H. J. O.

    2016-05-01

    The design of cable-stayed bridges involves a significant number of design variables and design objectives. The concrete cable-stayed bridge optimization is formulated here as a multi-objective optimization problem with objectives of minimum cost, minimum deflections and minimum stresses. A numerical method is developed to obtain the optimum design of such structures. This numerical method includes: structural analysis, sensitivity analysis and optimization. The structural analysis accounts for all the relevant effects (concrete time-dependent effects, construction stages and geometrical nonlinear effects). The structural response to changes in the design variables is achieved by a discrete direct sensitivity analysis procedure, and an entropy-based approach was used for structural optimization. The features and applicability of the proposed method are demonstrated by numerical examples concerning the optimization of a real-sized concrete cable-stayed bridge.

  17. Influence of the Non-linear Effects in the Design of Viscous Dampers for Bridge Cables

    OpenAIRE

    Acar, Yalda; Jingstål, Pontus

    2014-01-01

    In this master thesis the performance of external viscous dampers attached to cables in cable-stayed bridges have been studied. A comparison has been performed between a linear and a non-linear cable model. The comparison was carried out for two bridge cables, one from the Dubrovnik Bridge and the other from the Normandie Bridge. The performance of the dampers have been measured in terms of maximum achieved damping ratio and minimum amplitude of vibration. The analysis was performed using the...

  18. Asymptotic behaviour of solutions to cable stayed bridge equations

    Czech Academy of Sciences Publication Activity Database

    Malík, Josef

    2006-01-01

    Roč. 317, - (2006), s. 146-162. ISSN 0022-247X R&D Projects: GA AV ČR(CZ) 1ET400300415 Institutional research plan: CEZ:AV0Z30860518 Keywords : cable stayed bridge * vertical and torsional oscillations * asymptotic behaviour of solutions Subject RIV: BA - General Mathematics Impact factor: 0.758, year: 2006

  19. A simplified fragility analysis of fan type cable stayed bridges

    Institute of Scientific and Technical Information of China (English)

    R. A. Khan; T. K. Datta; S. Ahmad

    2005-01-01

    A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA)procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeled as a beam supported on springs at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges .The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi - static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis,ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase for soft soil condition.

  20. Thermal Effect of the Cable-Stayed Bridge Tower

    Institute of Scientific and Technical Information of China (English)

    ZhangHai-long; LiJun; LiuChang-guo; JiangTian-hua; Weijun

    2003-01-01

    This paper studies the thermal effect of the cable-stayed bridge tower based on full time accurate measurement and finite element analysis on Xiantao Hanjiang River Highway Bridge. The measured results and the displacement variation of top tower show that the tower rotates periodically when it is exposed in sunshine. But the tower column will not decline when there is no sunshine. In spite of in winter or in summer, the period when the tower column changed smallest is from 0:00 am to 5:00 am. The time period when the tower column has maximum deviation lags behind the time when the tower column has maximum temperature difference, and this phenomenon is obvious in winter. The conclusions also have directive value in predicting the tower deformations and their directions in construction control of cable-stayed bridge, and in verifying the finite element program.

  1. Thermal Effect of the Cable-Stayed Bridge Tower

    Institute of Scientific and Technical Information of China (English)

    Zhang Hai-long; Li Jun; Liu Chang-guo; Jiang Tian-hua; Wei jun

    2003-01-01

    This paper studies the thermal effect of the cable-stayed bridge tower based on full time accurate measurement and finite element analysis on Xiantao Hanjiang River Highway Bridge. The measured results and the displacement variation of top tower show that the tower rotates periodically when it is exposed in sunshine. But the tower column will not decline when there is no sunshine. In spite of in winter or in summer, the period when the tower column changed smallest is from 0∶00 am to 5∶00 am. The time period when the tower column has maximum deviation lags behind the time when the tower column has maximum temperature difference, and this phenomenon is obvious in winter. The conclusions also have directive value in predicting the tower deformations and their directions in construction control of cable-stayed bridge, and in verifying the finite element program.

  2. Case Study on 4000 m-span Cable-stayed Suspension Bridge

    OpenAIRE

    Haijun Wang; Jiandong Wang; Hua Wei

    2014-01-01

    This study describes the case studies for a cable-stayed suspension bridges proposed over the Tsugaru Strait, Japan. Center Bridge is designed as a compound bridge of suspension bridges and cable-stayed bridges with 4000 m super-long-span. Case studies about the effects of cable-stayed bridge length, the design of sub-cable, height and stiffness of main tower, type of foundation and length of side span on displacement were carried out. With appropriate design of above parameters, the compound...

  3. Overlapping reliable control for a cable-stayed bridge benchmark

    OpenAIRE

    Bakule, Lubomir; Paulet-Crainiceanu, Fideliu; Rodellar Benedé, José; Rossell Garriga, Josep Maria

    2005-01-01

    The brief presents a reliable 1-out-2 reduced order control design strategy for a cable-stayed bridge benchmark using two overlapping subsystems and the linear quadratic Gaussian (LQG) design. Reliability with regard to controller failures is considered. Local controllers are designed for reduced order subsystems of expanded system. They are implemented and evaluated on the original overall system model. Two different sets of numerical experiments of reliable control design within 1-out-2 con...

  4. Performances of super-long span prestressed cable-stayed bridge with CFRP cables and RPC girder

    Institute of Scientific and Technical Information of China (English)

    Fang Zhi; Fan Fenghong; Ren Liang

    2013-01-01

    To discuss the applicability of advanced composite carbon fiber reinforced polymer (CFRP) and ultra-high performance concrete reactive powder concrete (RPC) in super-long span cable-stayed bridges , taking a 1 008 m cable-stayed bridge with steel girders and steel cables as an example,a new cable-stayed bridge in the same span with RPC girders and CFRP cables was designed,in which the cable’s cross section was determined by the principle of equivalent cable capacity and the girder’s cross section was determined in virtual of its stiffness, shear capacity and local stability. Based on the methods of finite element analysis,the comparative analysis of these two cable-stayed bridge schemes about static performances,dynamic performances,stability and wind resis-tance behavior were carried out. The results showed that it was feasible to form a highly efficient,durable concrete cable-stayed bridge with RPC girders and CFRP cables and made its applicable span range expand to 1 000 m long around.

  5. Preliminary design and parametric study of 1400 m partially earth-anchored cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The preliminary design and parametric study of 1400 m partially earth-anchored cable-stayed bridge are described. Static per-formance of this new type of bridge is discussed. Compared with fully self-anchored cable-stayed bridge, its advantages in fin-ished state are summarized. Based on numerical calculation, effects of several structural parameters on static performance are presented.

  6. Research development of digital maintenance and management system for long-span cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    REN Yuan; HUANG Qiao; SUN Yong-ming

    2009-01-01

    Digital cable-stayed bridge maintenance and management system (DCBMS) was developed for the need of maintenance and management of long-span cable-stayed bridges. In this paper, the major functions and theoretical application of eight modules were systematically stated with the background of Harbin Songhua River cable-stayed bridge, which include data management module, inspection and measurement module, assessment module, finite element analysis module, disease diagnosis and prediction module, maintenance module, query module and help module. By analyzing and calculating the data from manual inspection database, basic database and health monitoring subsystem, DCBMS can accomplish the functions like life prediction, disease diagnosis, comprehensive assessment, maintenance and management of bridges. Therefore, the maintenance and management of long-span cable-stayed bridges can be made digital, professional and scientific. By running this system, a real-time and specific technical guidance can be provided for the maintainers and managers of longspan cable-stayed bridges.

  7. Aerodynamic control of bridge cables through shape modification: A preliminary study

    DEFF Research Database (Denmark)

    Kleissl, Kenneth; Georgakis, Christos

    2011-01-01

    This paper examines the viability of modifying bridge cable shape and surface for the purpose of controlling wind-induced vibrations. To this end, an extensive wind-tunnel test campaign was carried out on various cable shapes about the critical Reynolds number region. Cable shapes were chosen to...

  8. Effects of bridge cable surface roughness and cross-sectional distortion on aerodynamic force coefficients

    DEFF Research Database (Denmark)

    Matteoni, G.; Georgakis, C.T.

    2012-01-01

    Theoretical and experimental investigations to date have assumed that bridge cables can be modeled as ideal circular cylinders and the associated aerodynamic coefficients are invariant with the wind angle-of-attack. On the other hand, bridge cables are normally characterized by local alterations ...

  9. Simple Program to Investigate Hysteresis Damping Effect of Cross-Ties on Cables Vibration of Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    Panagis G. Papadopoulos

    2012-01-01

    Full Text Available A short computer program, fully documented, is presented, for the step-by-step dynamic analysis of isolated cables or couples of parallel cables of a cable-stayed bridge, connected to each other and possibly with the deck of the bridge, by very thin pretensioned wires (cross-ties and subjected to variation of their axial forces due to traffic or to successive pulses of a wind drag force. A simplified SDOF model, approximating the fundamental vibration mode, is adopted for every individual cable. The geometric nonlinearity of the cables is taken into account by their geometric stiffness, whereas the material nonlinearities of the cross-ties include compressive loosening, tensile yielding, and hysteresis stress-strain loops. Seven numerical experiments are performed. Based on them, it is observed that if two interconnected parallel cables have different dynamic characteristics, for example different lengths, thus different masses, weights, and geometric stiffnesses, too, or if one of them has a small additional mass, then a single pretensioned very thin wire, connecting them to each other and possibly with the deck of the bridge, proves effective in suppressing, by its hysteresis damping, the vibrations of the cables.

  10. Identification of aeroelastic forces on bridge cables from full-scale measurements

    DEFF Research Database (Denmark)

    Acampora, Antonio; Macdonald, J.H.G.; Georgakis, Christos

    2011-01-01

    Despite much research in recent years, large amplitude vibrations of inclined cables continue to be of concern for cable-stayed bridges. Various mechanisms have been suggested for their excitation, including rain-wind excitation, dry inclined cable galloping, high reduced velocity vortex shedding...... and excitation from the deck and/or towers. Although some experiences have been done with full-scale measurements of inclined cables, many of the results available are based on wind tunnel tests and theoretical modelling. This paper presents results from full-scale measurements on the cables of the...... Øresund Bridge. The system records wind conditions and weather conditions, as well as accelerations of certain cables and a few locations on the deck and tower. Using state-of-the-art methods of output-only system identification, the vibration modes of the cables have been identified. From these modes...

  11. Optic fiber sensor-based smart bridge cable with functionality of self-sensing

    Science.gov (United States)

    He, Jianping; Zhou, Zhi; Jinping, Ou

    2013-02-01

    Bridge cables, characterized by distributed large span, serving in harsh environment and vulnerability to random damage, are the key load-sustaining components of cable-based bridges. To ensure the safety of the bridge structure, it is critical to monitor the loading conditions of these cables under lengthwise random damages. Aiming at obtaining accurate monitoring at the critical points as well as the general information of the cable force distributed along the entire cable, this paper presents a study on cable force monitoring by combining optical fiber Bragg grating (FBG) sensors and Brillouin optical time domain analysis/reflectory (BOTDA/R) sensing technique in one single optical fiber. A smart FRP-OF-FBG rebar based cable was fabricated by protruding a FRP packaged OF-FBG sensor into the bridge cable. And its sensing characteristics, stability under high stress state temperature self-compensation as well as BOTDA/R distributed data improvement by local FBG sensors have been investigated. The results show that FRP-OF-FBG rebar in the smart cable can deform consistantly along with the steel wire and the cable force obtained from the optical fiber sensors agree well with theoretical value with relative error less than ±5%. Besides, the temperature self-compensation method provides a significant cost-effective technique for the FRP-OF-FBG based cables' in situ cable force measurement. And furthermore, potential damages of the bridge cable, e.g. wire breaking and corrosion, can be characterized and symbolized by the discontinuity and fluctuation of the distributed BOTDA data thereafter accuracy improved by local FBG sensors.

  12. Comparison of various procedures for progressive collapse analysis of cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    Jian-guo CAI; Yi-xiang XU; Li-ping ZHUANG; Jian FENG; Jin ZHANG

    2012-01-01

    Alternate path (AP) method is the most widely used method for the progressive collapse analysis,and its application in frame structures has been well proved.However,the application of AP method for other structures,especially for cable-stayed structures,should be further developed.The four analytical procedures,i.e.,linear static,nonlinear static,linear dynamic,and nonlinear dynamic were firstly improved by taking into account the initial state.Then a cable-stayed structure was studied using the four improved methods.Furthermore,the losses of both one cable and two cables were discussed.The results show that for static and dynamic analyses of the cable-stayed bridges,there is large difference between the results obtained from simulations starting with either a deformed or a nondeformed configuration at the time of cable loss.The static results are conservative in the vicinity of the ruptured cable,but the dynamic effect of the cable loss in the area farther away from the loss-cable cannot be considered.Moreover,the dynamic amplification factor of 2.0 is found to be a good estimate for static analysis procedures,since linear static and linear dynamic procedures yield approximately the same maximum vertical deflection.The results of the comprehensive evaluation of the cable failure show that the tread of the progressive failure of the cable-stayed bridges decreases when the location of the failed cables is closer to the pylon.

  13. Seismic performance evaluation for super-long span cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    Ye Aijun; Wu Shouchang

    2009-01-01

    Based on the capacity/demand (C/D) analysis of bridge components, and life cycle and performance based seismic design principles, a practical approach is developed for the seismic performance evaluation of super-long span cable-stayed bridges. According to the approach, the seismic performance evaluation of the Sutong Bridge, which is a cable-stayed bridge with a main span of 1 088 m, is completed, and the practicality of the approach is validated. The earthquake resistance level for super-long span cable-stayed bridges is discussed, including the earthquake level, its corresponding structural performance and check indices. And a set of formula for capacity/demand ratio calculation of bridge components is proposed.

  14. Summarizing the Methods of Determination of Rational Completion Status of Cable-Stayed Bridges

    Institute of Scientific and Technical Information of China (English)

    Yang Jun; Shen Chengwu; Sheng Jun

    2006-01-01

    Cable-stayed bridge is a high-order hyperstatic structure. The size of cable force affects the stress of the structure greatly. The key problem to determine the rational completion status of cable-stayed bridges is how to control cable force on completion status. Surrounding this problem, domestic and foreign experts and scholars have done a lot of favorable work and obtained much achievement. On the basis of comprehensive reading domestic and foreign relative documentation, the author of this article classifies rationally the current researching achievement, comments and compares advantages and disadvantages of each method and lists two synthetic methods' detail steps and puts forward the researching emphasis of the field will deflect to synthesis several methods to determine the rational completion status of cable-stayed bridges.

  15. Recent monitoring of the Øresund Bridge: Observations of rain-wind induced cable vibrations

    DEFF Research Database (Denmark)

    Acampora, Antonio; Georgakis, Christos

    2011-01-01

    In 1999, 2m amplitude cable vibrations were observed on the Øresund Bridge. The vibrations were attributed to a change in cable shape due to sleet accretion. Subsequent monitoring of the bridge, though, revealed other vibration events due to rain-wind induced mechanisms and parametric excitation...... diameters have been observed, although the most frequent observations are of smaller amplitude and are almost always in combination with rain. In this paper, several observations are made, regarding the rain-wind induced vibrations (RWIVs) of the cables, based on a relatively brief full-scale monitoring...... dampers were installed on the longest and second longest cable pairs. Although the bridge has not suffered from any significant vibration events since the installation of the new damping systems, smaller amplitude vibrations are recorded from time to time. Peak to peak amplitudes of up to three cable...

  16. Geometrical nonlinearities on the static analysis of highly flexible steel cable-stayed bridges

    OpenAIRE

    Freire, A. M. S.; Negrão, J. H. O.; Lopes, A. V.

    2006-01-01

    An evaluation of the importance of geometrically nonlinear effects on the structural static analysis of steel cable-stayed bridges is presented. A finite element model is analyzed using linear, pseudo-linear and nonlinear methods. The pseudo-linear approach is based on the modified elastic modulus. The nonlinear analysis involves cable sag, large displacement and beam-column effects. The results confirm that both cable sag and large displacement originate the most important nonlinear effects ...

  17. Wind loads analysis at the anchorages of the Talavera de la Reina cable stayed bridge

    Directory of Open Access Journals (Sweden)

    L. Rosa

    2014-06-01

    Full Text Available This paper describes wind tunnel tests performed on wind tunnel models of the Talavera de la Reina cable stayed bridge. The work describes the aeroelastic model construction and it is focused on the evaluation and analysis of the mean and peak wind loads at the tower foundation and the cable anchorages since these data can be very useful by the bridge manufacturer as a support for the bridge design. The work is part of a complete wind tunnel study carried out to analyze the aeroelastic stability of the bridge.

  18. Comparison of the aerodynamics of bridge cables with helical fillets and a pattern-indented surface

    DEFF Research Database (Denmark)

    Kleissl, K.; Georgakis, C.T.

    In this paper, the aerodynamics of bridge cables with helical fillets and a pattern-indented surface are examined. To this end, an extensive wind-tunnel test campaign was undertaken to measure the static force coefficients about the critical Reynolds number region, with varying relative cable...

  19. Research of 1770 MPa galvanized steel wire for stay cable of domestic bridges

    Institute of Scientific and Technical Information of China (English)

    Ding Feng; Sang Chunming; Zhou Daiyi; Bai Bingdong

    2009-01-01

    This paper focuses on introducing the manufacture technology of 1 770 MPa galvanized steel wires for stay cables applied to domestic bridges. During the development practices of high strength galvanized wire for stay cables used in Sutong Bridge, Baosteel has established three key technologies based on research of manufacture technology and technical innovation. The three key technologies are: "Double Tensioning + limiter die" process, "dominant process + fine adjustment" in integrated optimization technology and "three-level control" in hot dip galvanization. With these key technologies, Baosteet has produced 1 770 MPa galvanized wires for stay cable, which has high tensile strength, low relaxation and good torsion performances.

  20. Analytical Study of Vertical and Torsional Free Vibration of Cable Supported Bridge Decks

    Science.gov (United States)

    Gorman, Daniel J.

    The superposition method is employed to obtain an analytical type solution for the free vibration of cable supported bridge decks. Each pair of vertical elastic cables is considered to impart a vertical force to the deck by means of a rigid cross-member passing transversely beneath it. Rigid knife-edge support encountered at bridge towers is handled as well. In this introductory study the deck is treated as a thin isotropic plate. Any number of support cable pairs, of any stiffness, may be handled. Inter cross-member distances are referred to as spans. Free vibration eigenvalues and mode shapes are presented for three and four span illustrative cases.

  1. Structural behavior of non-symmetrical steel cable-stayed bridges

    OpenAIRE

    Jorquera Lucerga, Juan Jose; Lozano Galant, Jose Antono; Turmo Coderque, José

    2016-01-01

    Despite of the growing number of built examples, the analysis of non-symmetrical cable-stayed bridges has not received considerable attention from the researchers. In feet, the effects of the main design parameters in the structural behavior of these bridges are not addressed in detail in the literature. To fill this gap, this paper studies the structural response of a number of non-symmetrical cable-stayed bridges. With this aim, a parametric analysis is performed to evaluate the effect of e...

  2. A Proposal for 4000m-span Cable-stayed Suspension Bridge

    Directory of Open Access Journals (Sweden)

    Haijun Wang

    2013-06-01

    Full Text Available This study proposed a compound bridge of suspension bridges and cable-stayed bridges with 4000 m super-long-span over the Tsugaru Strait, Japan. Near to the main towers, cable-stayed bridges and prestressed concrete decks are proposed. It is helpful to enhance rigidity and endure the great axial compression force. In the center of the span, suspension bridges and steel box decks are stiffened by trusses, it can reduce self-weigh and the space between girders, thus contribute to aero-elastic stability. RCFT main tower, RC shell pier and RCFT jacket foundation can enhance rigidity and reduce self-weigh. As a result, the live-dead load ratio of proposal is 0.05 and it is equivalent to 2500m-span suspension bridge.

  3. Stress and deformation state of suspension steel bridges with rigid cables

    OpenAIRE

    Grigorjeva, Tatjana

    2007-01-01

    Suspension bridges possess a number of advantages, allowing overlapping average and large spans. The basic disadvantage of suspension bridges can be considered their increased deformability, particularly under the action of non-symmetrical and local loads. Deformability depends, in general, on the kinematical character of displacements of a flexible suspension cable. Required rigidity of suspension bridges is achieved, by increasing the height, and consequently the weight of a stiffening gird...

  4. Integrated System of Structural Health Monitoring and Intelligent Management for a Cable-Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2014-01-01

    Full Text Available It is essential to construct structural health monitoring systems for large important bridges. Zhijiang Bridge is a cable-stayed bridge that was built recently over the Hangzhou Qiantang River (the largest river in Zhejiang Province. The length of Zhijiang Bridge is 478 m, which comprises an arched twin-tower space and a twin-cable plane structure. As an example, the present study describes the integrated system of structural health monitoring and intelligent management for Zhijiang Bridge, which comprises an information acquisition system, data management system, evaluation and decision-making system, and application service system. The monitoring components include the working environment of the bridge and various factors that affect bridge safety, such as the stress and strain of the main bridge structure, vibration, cable force, temperature, and wind speed. In addition, the integrated system includes a forecasting and decision-making module for real-time online evaluation, which provides warnings and makes decisions based on the monitoring information. From this, the monitoring information, evaluation results, maintenance decisions, and warning information can be input simultaneously into the bridge monitoring center and traffic emergency center to share the monitoring data, thereby facilitating evaluations and decision making using the system.

  5. Investigation of Strouhal number of iced cable model of cable-supported bridges with respect to angle of wind attack

    Czech Academy of Sciences Publication Activity Database

    Górski, P.; Pospíšil, Stanislav; Kuznetsov, Sergeii; Tatara, M.; Marušić, Ante

    Lublin: Polish Association for Wind Engineering, 2014 - (Lipecki, T.; Flaga, A.), s. 103-104 ISBN 978-83-932544-9-1. [International Symposium on Environmental Effects on Buildings and People /7./. Lublin - Krakow (PL), 20.10.2014-22.10.2014] R&D Projects: GA MŠk(CZ) LO1219; GA MPO(CZ) FR-TI3/654 Keywords : bridge cable * ice accretion * Strouhal number * angle of attack * vortex shedding frequency Subject RIV: JN - Civil Engineering

  6. Investigation of Strouhal numbers of iced cable models of cable-supported bridges with respect to angle of wind attack

    Czech Academy of Sciences Publication Activity Database

    Górski, P.; Tatara, M.; Pospíšil, Stanislav; Kuznetsov, Sergeii; Marušić, A.

    2015-01-01

    Roč. 112, 2-B (2015), s. 417-432. ISSN 1897-628X R&D Projects: GA MŠk(CZ) LO1219; GA MPO(CZ) FR-TI3/654 Keywords : bridge cable * ice accretion * Strouhal number * angle of attack * vortex shedding frequency Subject RIV: JN - Civil Engineering http://suw.biblos.pk.edu.pl/resources/i5/i6/i6/i8/i4/r56684/GorskiP_InvestigationsStrouhal.pdf

  7. Comparative Research of Extra-large-span Cable-stayed Bridge with Steel Truss Girder and Steel Box Girder

    OpenAIRE

    Tan Manjiang; Bai Zhizhou; Chen Dewei

    2015-01-01

    To research structural performance of extra-large-span cable-stayed bridge under different section forms, with the engineering background of a 800m main-span cable-stayed bridge with steel truss girder, the cable-stayed bridge with steel box girder is designed according to the current bridge regulations when two bridges are designed in an ultimate state of the carrying capacity, so the maximum stress and minimum stress of the stress envelope diagram are substantially the same. A comprehensive...

  8. Active control implementation in cable-stayed bridges for quasi-static loading patterns

    OpenAIRE

    Crusells Girona, Miquel; Aparicio Bengoechea, Ángel Carlos

    2016-01-01

    The following paper deals with active control implementation in cable-stayed bridges. Recent developments in structural active control of cable-stayed bridges are focused on the adaptability to dynamic effects produced by earthquakes or extreme winds (El Ouni et al., 2012; Pakos and Wojcicki, 2014; Domaneschi et al., 2015a,b). Nevertheless, no attention has been paid to the static or quasi-static case. As stated by Housner et al. (1996), Song et al. (2006) or Gilewski and Al Sabouni-Zawadzka ...

  9. Comparative Research of Extra-large-span Cable-stayed Bridge with Steel Truss Girder and Steel Box Girder

    Directory of Open Access Journals (Sweden)

    Tan Manjiang

    2015-01-01

    Full Text Available To research structural performance of extra-large-span cable-stayed bridge under different section forms, with the engineering background of a 800m main-span cable-stayed bridge with steel truss girder, the cable-stayed bridge with steel box girder is designed according to the current bridge regulations when two bridges are designed in an ultimate state of the carrying capacity, so the maximum stress and minimum stress of the stress envelope diagram are substantially the same. A comprehensive comparison is given to two types of bridge on the aspect of static force, natural vibration frequency, stability, economic performance and so on. Analysis results provide future reference for the large-span cable-stayed bridge to select between the steel truss girder and the steel box girder.

  10. GPS for structural health monitoring: A case study on the Basarab overpass cable-stayed bridge

    NARCIS (Netherlands)

    Lepadatu, L.; Tiberius, C.C.J.M.

    2014-01-01

    The Basarab cable-stayed bridge is a newly built structure in Bucharest, Romania, which was inaugurated in June 2011. Before the oficial opening, in order to assure its qualification for trafic, it had to pass several loading tests with convoys of trucks and trams. For this, besides a priori evaluat

  11. Geometric Nonlinear Analysis of Self-Anchored Cable-Stayed Suspension Bridges

    Directory of Open Access Journals (Sweden)

    Wang Hui-Li

    2013-01-01

    Full Text Available Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.

  12. Geometric nonlinear analysis of self-anchored cable-stayed suspension bridges.

    Science.gov (United States)

    Hui-Li, Wang; Yan-Bin, Tan; Si-Feng, Qin; Zhe, Zhang

    2013-01-01

    Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed. PMID:24282388

  13. Energy conservation research of dehumidification system for main cable anticorrosion of suspension bridge

    Institute of Scientific and Technical Information of China (English)

    Chen Ce; Fan Liangkai; Feng Zhaoxiang; Pen Guanzhong

    2011-01-01

    The necessity of the main cable anticorrosion for suspension bridge is described, and operating principles and composition of main cable dehumidification system are analyzed. An idea using the waste heat of high temperature outlet air of dehumidification system to heat up regeneration air of rotary-type dehumidifier is put forward in this paper. The concrete scheme is to install a heat exchanger on air-out pipeline of roots blower and air-in pipeline of regeneration electric heater of rotary dehumidifier. Air preheated by the heat exchanger enters regeneration electric heater of rotary-type dehumidifier. Energy conservation of main cable dehumidification system for the Yangtze River highway bridge is calculated, and the results show that energy conservation rate can reach 44 %.

  14. Aerodynamic force coefficients of plain bridge cables in wet conditions

    DEFF Research Database (Denmark)

    Matteoni, Giulia; Georgakis, Christos T.

    , tests were performed for wind velocities between 2 and 31 m/s, whilst in wet conditions tests were performed for the range of wind velocities where rain rivulet formation was found possible, i.e. between 8-18 m/s. For all of the tested relative cable-wind angles in wet conditions, a reduction in the...... drag coefficient with increasing Reynolds number, accompanied by a near-zero lift coefficient, was observed. A theoretical evaluation of the aerodynamic damping assuming quasi-steady conditions reveals that changes in drag and lift coefficient are nonetheless not sufficient to generate negative...

  15. Theoretical and experimental study on shear lag effect of partially cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    WU Gao-feng; XU Hong

    2005-01-01

    In order to resolve the traffic congestion problem, many cable-stayed bridges are designed with a large width to span ratio. This results in significant shear lag effect to cause nonuniform stress distribution along the flanges of the beam of bridge.This paper reports study on the shear lag effect of the Lanzhou Xiaoxihu Yellow River Bridge. A 3D finite element model of the bridge was developed and finite element analysis (FEA) was done to obtain the theoretical results. To evaluate the theoretical results, a scaled model was made to conduct static test in laboratory. The experiment results accorded with the results obtained by FEA. It is proved that FEA is an effective method to predict shear lag effect of bridges of this type.

  16. Numerical and Experimental Study of Free Vibration Characteristics of a Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    Zi Jianmin; Wang Yuanhan; Zhu Hongping

    2006-01-01

    The main aim of this study is to understand the dynamic behavior of a cable-stayed bridge,using both numerical and experimental analysis. A three-dimensionai finite element model for the bridge was developed for the free vibration analysis and the ambient vibration properties of the bridge were determined through field testing. The experimental and numerical results of natural frequencies and the associated mode shapes were compared, and the high accuracy between them shows that the 3D model is capable of approximately representing the dynamic behavior of the bridge and the use of ambient vibration survives in future testing of the bridge. These dynamic characteristics can be used as the basis for updating the finite element model and also for global damage detection.

  17. Optimal Damping of Stays in Cable-Stayed Bridges for In-Plane Vibrations

    DEFF Research Database (Denmark)

    Jensen, C.N.; Nielsen, S.R.K.; Sørensen, John Dalsgaard

    2002-01-01

    cable-stayed bridges are often designed as twin cables with a spacing of, say 1m. In such cases, it is suggested in the paper to suppress the mentioned in-plane types of vibrations by means of a tuned mass–damper (TMD) placed between the twin cables at their midpoints. The TMD divides the stay into four...... half-cables, and resonance may occur in each of the half-cables as well as in the entire stay. The optimal tuning of the TMD is investigated based on a mathematical model, where the motion of the support points on the pylons is considered to be the main cause of excitation. The indicated motion...... of the mentioned frequencies. The spring and the damper constants of the TMD are optimized so that the variances of the displacement of the adjacent four half-cables, the support point of the TMD and the secondary mass are minimized. At optimal design, it is shown that the variances reduce below 14% of those...

  18. Research of rigid cable suspension bridge%刚性索悬索桥研究

    Institute of Scientific and Technical Information of China (English)

    李映; 林长川

    2001-01-01

    Rigid cable suspension bridge,whose main cable and h anger are rigid,can solve some problems of normal suspension bridge such as fati gue of hanger and lower rigidity of the structure.The analysis,design and constr uction of rigid cable suspension bridge are discussed in this paper,and a practi ce of this type of bridge—The Guanghua Bridge in Changzhou,Jiangsu province are given in the paper.%刚性索悬索桥是指主缆及吊杆为刚度较大的构件组 成的悬索桥.它解决了中小跨度时常规悬索桥刚度差、吊杆易疲劳等问题.文中介绍了刚性 索悬索桥的计算分析、构造措施和施工方法,给出了工程实例——于1999年12月建成通车的 江苏常州广化桥,说明刚性索悬索桥是一种很有应用前景的桥型.

  19. Stochastic finite element analysis of long-span bridges with CFRP cables under earthquake ground motion

    Indian Academy of Sciences (India)

    Özlem Çavdar; Alemdar Bayraktar; Süleyman Adanur; Hasan Basri Başaǧa

    2010-06-01

    Stochastic seismic analysis of long-span bridges with Carbon fibre reinforced polymer (CFRP) cables are presented in this study through combination of the advantages of the perturbation based stochastic finite element method (SFEM) and Monte Carlo simulation (MCS) method. Jindo cable-stayed and Fatih Sultan Mehmet (Second Bosporus) suspension bridges are chosen as an example. Carbon fibre reinforced polymer cable (CFRP) and steel cables are used separately, in which the cable’s cross sectional area is determined by the principle equivalent axial stiffness. Geometric nonlinear effects are considered in the analysis. Uncertainties in the material are taken into account and Kocaeli earthquake in 1999 is chosen as a ground motion. The efficiency and accuracy of the proposed algorithm are validated by comparing with results of MCS method. It can be stated that using of CFRP cables in long-span bridges subjected to earthquake forces is feasible.

  20. APPLICATION OF ULTRA-HIGH PERFORMANCE CONCRETE TO PEDESTRIAN CABLE-STAYED BRIDGES

    Directory of Open Access Journals (Sweden)

    CHI-DONG LEE

    2013-06-01

    Full Text Available The use of ultra-high performance concrete (UHPC, which enables reducing the cross sectional dimension of the structures due to its high strength, is expected in the construction of the super-long span bridges. Unlike conventional concrete, UHPC experiences less variation of material properties such as creep and drying shrinkage and can reduce uncertainties in predicting time-dependent behavior over the long term. This study describes UHPC’s material characteristics and benefits when applied to super-long span bridges. A UHPC girder pedestrian cable-stayed bridge was designed and successfully constructed. The UHPC reduced the deflections in both the short and long term. The cost analysis demonstrates a highly competitive price for UHPC. This study indicates that UHPC has a strong potential for application in the super-long span bridges.

  1. Automatic construction management of inclined cable in Heira bridge; Heirahashi ni okeru syazai keburu seko kanri no jidoka

    Energy Technology Data Exchange (ETDEWEB)

    Kajiyama, K.

    1996-03-01

    First one sided PC inclined cable bridge based on precast block additional method is constructed at Heira in Japan. Measurements of main girder deflection and main tower displacement values are considered as necessary factors in construction of inclined cable bridge. Efficient and rapid tension force supervision of inclined cable in every stage of construction is required for the above mentioned purpose. Automatic management of tension of inclined cable in Heira bridge construction is considered in this investigation. Construction of measuring system, installation, tension force adjustment and its decision management process, required special characteristics of tension, calculation sheet`s process et., are explained. Following observations are noted when precast method is compared with cast in place method for Heira bridge. Construction cycle of main girder is small and cycle until end of tension for 1 block construction to last block construction is equal to 1.6/day/block. 12 figs., 1 tab.

  2. Automatic modal identification of cable-supported bridges instrumented with a long-term monitoring system

    Science.gov (United States)

    Ni, Y. Q.; Fan, K. Q.; Zheng, G.; Chan, T. H. T.; Ko, J. M.

    2003-08-01

    An automatic modal identification program is developed for continuous extraction of modal parameters of three cable-supported bridges in Hong Kong which are instrumented with a long-term monitoring system. The program employs the Complex Modal Indication Function (CMIF) algorithm to identify modal properties from continuous ambient vibration measurements in an on-line manner. By using the LabVIEW graphical programming language, the software realizes the algorithm in Virtual Instrument (VI) style. The applicability and implementation issues of the developed software are demonstrated by using one-year measurement data acquired from 67 channels of accelerometers deployed on the cable-stayed Ting Kau Bridge. With the continuously identified results, normal variability of modal vectors caused by varying environmental and operational conditions is observed. Such observation is very helpful for selection of appropriate measured modal vectors for structural health monitoring applications.

  3. Effects in service of the staggered construction of cable-stayed bridges built on temporary supports

    OpenAIRE

    Lozano Galant, Jose Antonio; Paya-Zaforteza, Ignacio; Turmo Coderque, José

    2015-01-01

    Cable-stayed bridges can be rarely built on a single construction stage and staggered construction is commonly used. The effects of this staggered construction are not only economical as they might also play an important role in the structural behaviour in service. Despite of this importance, these effects are rarely included into the definition of the structural response in service. In order to fill this gap, this paper deals with the effects in service of the staggered erection of steel cab...

  4. Nonlinear Stability Analysis of a Composite Girder Cable-Stayed Bridge with Three Pylons during Construction

    OpenAIRE

    Xiaoguang Deng; Muyu Liu

    2015-01-01

    Based on the nonlinear stability analysis method, the 3D nonlinear finite element model of a composite girder cable-stayed bridge with three pylons is established to research the effect of factors including geometric nonlinearity, material nonlinearity, static wind load, and unbalanced construction load on the structural stability during construction. Besides, the structural nonlinear stability in different construction schemes and the determination of temporary pier position are also studied...

  5. Strouhal number of bridge cables with ice accretion at low flow turbulence

    Czech Academy of Sciences Publication Activity Database

    Górski, P.; Pospíšil, Stanislav; Kuznetsov, Sergeii; Tatara, M.; Marušić, Ante

    2016-01-01

    Roč. 22, č. 2 (2016), s. 253-272. ISSN 1226-6116 R&D Projects: GA MŠk(CZ) LO1219; GA ČR(CZ) GC13-34405J; GA ČR(CZ) GA14-12892S Keywords : bridge cable * ice accretion * Strouhal number * angle of attack * vortex shedding frequency Subject RIV: JM - Building Engineering Impact factor: 0.584, year: 2014

  6. Effects of surface design on aerodynamic forces of iced bridge cables

    DEFF Research Database (Denmark)

    Koss, Holger

    2014-01-01

    determination of these force coefficients require a proper simulation of the ice layer occurring under the specific climatic conditions, favouring real ice accretion over simplified artificial reproduction. The work presented in this paper was performed to study whether the design of bridge cable surface...... influences the accretion of ice to an extent that the aerodynamic forces differ significantly amongst the designs. The experiments were conducted in a wind tunnel facility capable amongst others to simulate in-cloud icing conditions....

  7. Deck and Cable Dynamic Testing of a Single-span Bridge Using Radar Interferometry and Videometry Measurements

    Science.gov (United States)

    Piniotis, George; Gikas, Vassilis; Mpimis, Thanassis; Perakis, Harris

    2016-03-01

    This paper presents the dynamic testing of a roadway, single-span, cable-stayed bridge for a sequence of static load and ambient vibration monitoring scenarios. Deck movements were captured along both sideways of the bridge using a Digital Image Correlation (DIC) and a Ground-based Microwave Interfererometer (GBMI) system. Cable vibrations were measured at a single point location on each of the six cables using the GBMI technique. Dynamic testing involves three types of analyses; firstly, vibration analysis and modal parameter estimation (i. e., natural frequencies and modal shapes) of the deck using the combined DIC and GBMI measurements. Secondly, dynamic testing of the cables is performed through vibration analysis and experimental computation of their tension forces. Thirdly, the mechanism of cable-deck dynamic interaction is studied through their Power Spectra Density (PSD) and the Short Time Fourier Transform (STFT) analyses. Thereby, the global (deck and cable) and local (either deck or cable) bridge modes are identified, serving a concrete benchmark of the current state of the bridge for studying the evolution of its structural performance in the future. The level of synergy and complementarity between the GBMI and DIC techniques for bridge monitoring is also examined and assessed.

  8. Pushover analysis for the seismic response prediction of cable-stayed bridges under multi-directional excitation

    OpenAIRE

    Cámara Casado, Alfredo; Astiz Suárez, Miguel Angel

    2012-01-01

    Cable-stayed bridges represent nowadays key points in transport networks and their seismic behavior needs to be fully understood, even beyond the elastic range of materials. Both nonlinear dynamic (NL-RHA) and static (pushover) procedures are currently available to face this challenge, each with intrinsic advantages and disadvantages, and their applicability in the study of the nonlinear seismic behavior of cable-stayed bridges is discussed here. The seismic response of a large number of fini...

  9. Modification of the stress-state of cable-stayed bridge due to staggered erection of their superstructure

    OpenAIRE

    Lozano Galant, Jose Antono; Ruiz Ripoll, Lidia; Payá Zaforteza, Ignacio Javier; Turmo Coderque, José

    2014-01-01

    In current practice, the effects of the evolutionary erection of cable-stayed bridge superstructure are rarely included into the simulation of its tensioning process. In fact, stay forces in service are usually defined in early stages of design, when the construction process has not even been conceived in detail yet. In order to fill this gap, the effects of the evolutionary erection of cable-stayed bridge superstructure throughout the tensioning process are studied in this paper. This study ...

  10. Influence of wind angle of attack and isotropic turbulence on wind-induced vibrations of ice-accreted bridge cables

    OpenAIRE

    Pospíšil, S.; Trush, A. (Arsenii); Kuznetsov, S. (Sergeii); Kozmar, H.; Náprstek, J. (Jiří)

    2016-01-01

    Bridge-supporting cables and mast guys with high flexibility and low damping often experience vibrations with large amplitudes that may have consequently destructive effects on supported structures. Surface roughness and ice accretion are important issues, as they can considerably alter aerodynamic characteristics of bridge cables. This study describes wind-tunnel experiments on vortex-induced vibration of cylindrical section models with the deliberately adjusted natural frequency f = 5 Hz. T...

  11. Cross spectral energy method for damage assessment of the cable-stayed bridge under operational conditions

    Institute of Scientific and Technical Information of China (English)

    Yang Hezhen; Li Huajun

    2008-01-01

    The new cross spectral energy method (CSEM) is proposed for maintaining cable-stayed bridge safety by the measurable output-only vibration response.Damage assessment of real structures is limited by a series of problems such as unknown ambient excitation forces, errors introduced by system identification,incomplete dynamic measurements, etc.Thus the methodology based on cross spectral energy of each substructure member is derived to meet these challenges.The novel damage index does not require any modal or parameter identification technology.It can be calculated directly from vibration test data.In order to evaluate the efficiency of the presented methodology, a three dimensional (3D) actual cable-stayed bridge model with one or more damaged positions under operational conditions was studied.In order to testify the reliability of damage detection method, the response data was polluted by the random noise.It is proved that the proposed method can successfully localize all damage cases even in noisy data.With the help of examples, the CSEM can potentially be applied as a nondestructive evaluation technique (NDT) for on-line health monitoring of cable-stayed bridges with minimum disruption of its operations.

  12. Semi-active control of a cable-stayed bridge under multiple-support excitations

    Institute of Scientific and Technical Information of China (English)

    代泽兵; 黄金枝; 王红霞

    2004-01-01

    This paper presents a semi-active strategy for seismic protection of a benchmark cable-stayed bridge with consideration of multiple-support excitations. In this control strategy, Magnetorheological (MR) dampers are proposed as control devices, a LQG-clipped-optimal control algorithm is employed. An active control strategy, shown in previous researches to perform well at controlling the benchmark bridge when uniform earthquake motion was assumed, is also used in this study to control this benchmark bridge with consideration of multiple-support excitations. The performance of active control system is compared to that of the presented semi-active control strategy. Because the MR fluid damper is a controllable energy- dissipation device that cannot add mechanical energy to the structural system, the proposed control strategy is fail-safe in that bounded-input, bounded-output stability of the controlled structure is guaranteed. The numerical results demonstrated that the performance of the presented control design is nearly the same as that of the active control system; and that the MR dampers can effectively be used to control seismically excited cable-stayed bridges with multiple-support excitations.

  13. Effects of fundamental factors on coupled vibration of wind-rail vehicle-bridge system for long-span cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    张明金; 李永乐; 汪斌

    2016-01-01

    In a wind-vehicle-bridge (WVB) system, there are various interactions among wind, vehicle and bridge. The mechanism for coupling vibration of wind-vehicle-bridge systems is explored to demonstrate the effects of fundamental factors, such as mean wind, fluctuating wind, buffeting, rail irregularities, light rail vehicle vibration and bridge stiffness. A long cable-stayed bridge which carries light rail traffic is regarded as a numerical example. Firstly, a finite element model is built for the long cable-stayed bridge. The deck can generally be idealized as three-dimensional spine beam while cables are modeled as truss elements. Vehicles are modeled as mass-spring-damper systems. Rail irregularities and wind fluctuation are simulated in time domain by spectrum representation method. Then, aerodynamic loads on vehicle and bridge deck are measured by section model wind tunnel tests. Eight vertical and torsional flutter derivatives of bridge deck are identified by weighting ensemble least-square method. Finally, dynamic responses of the WVB system are analyzed in a series of cases. The results show that the accelerations of the vehicle are excited by the fluctuating wind and the track irregularity to a great extent. The transverse forces of wheel axles mainly depend on the track irregularity. The displacements of the bridge are predominantly determined by the mean wind and restricted by its stiffness. And the accelerations of the bridge are enlarged after adding the fluctuating wind.

  14. Impact of cross-tie design on the in-plane stiffness and local mode formation of cable networks on cable-stayed bridges

    Science.gov (United States)

    Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

    2016-02-01

    Suppressing unfavorable stay cable vibrations using cross-ties is becoming more popular on cable-stayed bridges though the mechanics of the formed cable network is yet fully understood. In practice, the main task in designing cross-ties or cable networks is to choose the cross-tie installation location, stiffness and number based on the main cable properties in the network. To have a more comprehensive picture of how to choose these design parameters to achieve higher in-plane network stiffness while minimizing the number of excited local modes, it is imperative to examine dynamic behavior of cable networks with general configurations. In the current study, an analytical model of a general cable network consisting of multiple main cables interconnected by multiple lines of transverse flexible cross-ties will be developed. A new term, defined as the local mode cluster, will be introduced to assess the severity of local mode excitation. Criteria for identifying the presence of local mode cluster will be proposed. A parametric study will be conducted to evaluate the impact of cross-tie installation location, stiffness and number on the network modal response. Results obtained from the present study will provide deeper insight into the selection of these system parameters to achieve the combined benefits of increasing network in-plane stiffness and minimizing the excitation of local modes.

  15. Investigation of Influence Factors of Wind-Induced Buffeting Response of a Six-Tower Cable-Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Zhi-Qiang Zhang

    2016-01-01

    Full Text Available This paper presents an investigation of the wind-induced buffeting responses of the Jiashao Bridge, the longest multispan cable-stayed bridge in the world. A three-dimensional finite element model for the Jiashao Bridge is established using the commercial software package ANSYS and a 3D fluctuating wind field is simulated for both bridge deck and towers. A time-domain procedure for analyzing buffeting responses of the bridge is implemented in ANSYS with the aeroelastic effect included. The characteristics of buffeting responses of the six-tower cable-stayed bridge are studied in some detail, focusing on the effects including the difference in the longitudinal stiffness between the side towers and central towers, partially longitudinal constraints between the bridge deck and part of bridge towers, self-excited aerodynamic forces, and the rigid hinge installed in the middle of the bridge deck. The analytical results can provide valuable references for wind-resistant design of multispan cable-stayed bridges in the future.

  16. Energy harvesting from electrospun piezoelectric nanofibers for structural health monitoring of a cable-stayed bridge

    Science.gov (United States)

    Maruccio, Claudio; Quaranta, Giuseppe; De Lorenzis, Laura; Monti, Giorgio

    2016-08-01

    Wireless monitoring could greatly impact the fields of structural health assessment and infrastructure asset management. A common problem to be tackled in wireless networks is the electric power supply, which is typically provided by batteries replaced periodically. A promising remedy for this issue would be to harvest ambient energy. Within this framework, the present paper proposes to harvest ambient-induced vibrations of bridge structures using a new class of piezoelectric textiles. The considered case study is an existing cable-stayed bridge located in Italy along a high-speed road that connects Rome and Naples, for which a recent monitoring campaign has allowed to record the dynamic responses of deck and cables. Vibration measurements have been first elaborated to provide a comprehensive dynamic assessment of this infrastructure. In order to enhance the electric energy that can be converted from ambient vibrations, the considered energy harvester exploits a power generator built using arrays of electrospun piezoelectric nanofibers. A finite element analysis is performed to demonstrate that such power generator is able to provide higher energy levels from recorded dynamic loading time histories than a standard piezoelectric energy harvester. Its feasibility for bridge health monitoring applications is finally discussed.

  17. Vibration control of a cable-stayed bridge using electromagnetic induction based sensor integrated MR dampers

    International Nuclear Information System (INIS)

    This paper presents a novel electromagnetic induction (EMI) system integrated in magneto rheological (MR) dampers: The added EMI system converts reciprocal motions of MR damper into electiral energy (electromotive force or emf) according to the Faraday's law of electromagnetic induction. Maximum energy dissipation algorithm (MEDA) is employed to regulate the MR dampers because it strives to simplify a complex design process by employing the Lyapunov's direct approach. The emf signal, produced from the EMI, provides the necessary measurement information (i.e., realtive velocity across the damper) for the MEDA controller. Thus, the EMI acts as a sensor in the proposed MR-EMI system. In order to evaluate the performance and robustness of the MR-EMI sensor system with the MEDA control, this study performed an extensive simulation study using the first generation benchmark cable-stayed bridge. Moreover, it compared the performance and the robustness of proposed system with those of Clipped-Optimal Control (COC) and Sliding Mode Control (SMC), which were previously studied for the benchmark cable-stayed bridge. The results show that the MR-EMI system reduced the vibrations of the bridge structure more than those of COC and SMC and show more robust performance than that of SMC. These results suggest that EMIs can be used cost-effective sensing devices for MR damper control systems without compromising the performance of them

  18. Structural behaviour and design criteria of under-deck cable-stayed bridges subjected to seismic action

    OpenAIRE

    Cámara Casado, Alfredo; Ruiz Teran, Ana M.; Stafford, Peter J.

    2012-01-01

    SUMMARY: Under-deck cable-stayed bridges are very effective structural systems for which the strong contribution of the stay cables under live loading allows for the design of very slender decks for persistent and transient loading scenarios. Their behaviour when subjected to seismic excitation is investigated herein and a set of design criteria are presented that relate to the type and arrangement of bearings, the number and configuration of struts, and the transverse distribution of stay ca...

  19. Inspection method of cable-stayed bridge using magnetic flux leakage detection: principle, sensor design, and signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Fengyu; Wang, Xingsong [Southeast University, Nanjing (China); Wu, Hongtao [Nanjing University of Aeronautics and Astronautics, Nanjing (China)

    2012-03-15

    A nondestructive testing technique based on magnetic flux leakage is presented to inspect automatically the stay cables with large diameters of a cable-stayed bridge. Using the proposed inspection method, an online nondestructive testing (NDT) modular sensor is developed. The wreath-like sensor is composed of several sensor units that embrace the cable at equal angles. Each sensor unit consists of two permanent magnets and a hall sensor to detect the magnetic flux density. The modular sensor can be installed conveniently on cables with various diameters by increasing the number of sensor units and adjusting the relative distances between adjacent sensor units. Results of the experiments performed on a man-made cable with faults prove that the proposed sensor can inspect the status signals of the inner wires of the cables. To filter the interfering signals, three processing algorithms are discussed, including the moving average method, improved detrending algorithm, and signal processing based on a digital filter. Results show that the developed NDT sensor carried by a cable inspection robot can move along the cable and monitor the state of the stay cables.

  20. Inspection method of cable-stayed bridge using magnetic flux leakage detection: principle, sensor design, and signal processing

    International Nuclear Information System (INIS)

    A nondestructive testing technique based on magnetic flux leakage is presented to inspect automatically the stay cables with large diameters of a cable-stayed bridge. Using the proposed inspection method, an online nondestructive testing (NDT) modular sensor is developed. The wreath-like sensor is composed of several sensor units that embrace the cable at equal angles. Each sensor unit consists of two permanent magnets and a hall sensor to detect the magnetic flux density. The modular sensor can be installed conveniently on cables with various diameters by increasing the number of sensor units and adjusting the relative distances between adjacent sensor units. Results of the experiments performed on a man-made cable with faults prove that the proposed sensor can inspect the status signals of the inner wires of the cables. To filter the interfering signals, three processing algorithms are discussed, including the moving average method, improved detrending algorithm, and signal processing based on a digital filter. Results show that the developed NDT sensor carried by a cable inspection robot can move along the cable and monitor the state of the stay cables

  1. Nonlinear Stability Analysis of a Composite Girder Cable-Stayed Bridge with Three Pylons during Construction

    Directory of Open Access Journals (Sweden)

    Xiaoguang Deng

    2015-01-01

    Full Text Available Based on the nonlinear stability analysis method, the 3D nonlinear finite element model of a composite girder cable-stayed bridge with three pylons is established to research the effect of factors including geometric nonlinearity, material nonlinearity, static wind load, and unbalanced construction load on the structural stability during construction. Besides, the structural nonlinear stability in different construction schemes and the determination of temporary pier position are also studied. The nonlinear stability safety factors are calculated to demonstrate the rationality and safety of construction schemes. The results show that the nonlinear stability safety factors of this bridge during construction meet the design requirement and the minimum value occurs in the maximum double cantilever stage. Besides, the nonlinear stability of the structure in the side of edge-pylon meets the design requirement in the two construction schemes. Furthermore, the temporary pier can improve the structure stability, effectively, and the actual position is reasonable. In addition, the local buckling of steel girder occurs earlier than overall instability under load in some cable tension stages. Finally, static wind load and the unbalanced construction load should be considered in the stability analysis for the adverse impact.

  2. Full-Scale Measurements and System Identification on Sutong Cable-Stayed Bridge during Typhoon Fung-Wong

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2014-01-01

    Full Text Available The structural health monitoring system (SHMS provides an effective tool to conduct full-scale measurements on existing bridges for essential research on bridge wind engineering. In July 2008, Typhoon Fung-Wong lashed China and hit Sutong cable-stayed bridge (SCB in China. During typhoon period, full-scale measurements were conducted to record the wind data and the structural vibration responses were collected by the SHMS installed on SCB. Based on the statistical method and the spectral analysis technique, the measured data are analyzed to obtain the typical parameters and characteristics. Furthermore, this paper analyzed the measured structural vibration responses and indicated the vibration characteristics of the stay cable and the deck, the relationship between structural vibrations and wind speed, the comparison of upstream and downstream cable vibrations, the effectiveness of cable dampers, and so forth. Considering the significance of damping ratio in vibration mitigation, the modal damping ratios of the SCB are identified based on the Hilbert-Huang transform (HHT combined with the random decrement technique (RDT. The analysis results can be used to validate the current dynamic characteristic analysis methods, buffeting calculation methods, and wind tunnel test results of the long-span cable-stayed bridges.

  3. Experimental Study on Shear Lag Effect of Partial Cable-Stayed Bridge and Elasto-Plastic Seismic Analysis

    Institute of Scientific and Technical Information of China (English)

    WU Gao-feng; XU Hong; CHEN Xing-chong

    2005-01-01

    The project of Xiaoxihu Yellow River Bridge in Lanzhou is chosen as partial cable-stayed bridge. To get the shear lag effect and anti-earthquake performance of the actual bridge under various loading conditions, organic glass scaled model was adopted to have an experiment and a theory research at one time. The experiment result is the basically same as the theory calculation which proves the FEA method can well calculate shear lag effect and dynamical performance. As a result, because the bridge is located in a seismic area of 8 degree, an elasto-plastic seismic checking is performed by customized FEA program in this paper.

  4. Hybrid networking sensing system for structural health monitoring of a concrete cable-stayed bridge

    Science.gov (United States)

    Torbol, Marco; Kim, Sehwan; Chien, Ting-Chou; Shinozuka, Masanobu

    2013-04-01

    The purpose of this study is the remote structural health monitoring to identify the torsional natural frequencies and mode shapes of a concrete cable-stayed bridge using a hybrid networking sensing system. The system consists of one data aggregation unit, which is daisy-chained to one or more sensing nodes. A wireless interface is used between the data aggregation units, whereas a wired interface is used between a data aggregation unit and the sensing nodes. Each sensing node is equipped with high-precision MEMS accelerometers with adjustable sampling frequency from 0.2 Hz to 1.2 kHz. The entire system was installed inside the reinforced concrete box-girder deck of Hwamyung Bridge, which is a cable stayed bridge in Busan, South Korea, to protect the system from the harsh environmental conditions. This deployment makes wireless communication a challenge due to the signal losses and the high levels of attenuation. To address these issues, the concept of hybrid networking system is introduced with the efficient local power distribution technique. The theoretical communication range of Wi-Fi is 100m. However, inside the concrete girder, the peer to peer wireless communication cannot exceed about 20m. The distance is further reduced by the line of sight between the antennas. However, the wired daisy-chained connection between sensing nodes is useful because the data aggregation unit can be placed in the optimal location for transmission. To overcome the limitation of the wireless communication range, we adopt a high-gain antenna that extends the wireless communication distance to 50m. Additional help is given by the multi-hopping data communication protocol. The 4G modem, which allows remote access to the system, is the only component exposed to the external environment.

  5. Comparison of the aerodynamics of bridge cables with helical fillets and a pattern-indented surface in normal flow

    DEFF Research Database (Denmark)

    Kleissl, Kenneth; Georgakis, Christos

    2011-01-01

    Over the last two decades, several bridge cable manufacturers have introduced surface modi-fications on the high-density polyethylene (HDPE) sheathing that is often installed for the protection of inner strands. The main goal of this is rain rivulet impedance, leading to the suppression of rain...... interest to bridge design-ers, as wind on stay planes of long bridges can now produce more than 50% of the overall horizontal load on a bridge. Nevertheless, there is no definitive aerodynamic performance comparison between the two systems. One of the problems of comparing them lies in the fact that...... different researchers, in different facilities, with varying wind-tunnel flow characteristics and performance, have developed each separately. As part of a comprehensive review of the aerodynamics of existing cable surface modifica-tions, the resulting static force coefficients obtained from wind...

  6. Long-term monitoring of a cable stayed bridge using a SCADA system

    Science.gov (United States)

    Torbol, Marco; Kim, Sehwan; Shinozuka, Masanobu

    2012-04-01

    DuraMote is a MEMS-based remote sensing system, which is developed for the NIST TIP project, Next Generation SCADA for Prevention and Mitigation of Water System Infrastructure Disaster. It is designed for supervisory control and data acquisition (SCADA) of pipe ruptures in water distribution systems. In this project, a method is developed to detect the pipe ruptures by analyzing the acceleration data gathered by DuraMote which consists of two primary components; the first, "Gopher" contains the accelerometers and are attached to the water pipe surface noninvasively, and the second, "Roocas" is placed above ground supplying the power to, and retrieving the data from the multiple Gophers, and then transmit the data through Wi-Fi to a base station. The relays support the Wi-Fi network to facilitate the transmission. A large scale bridge provides an ideal test-bet to validate the performance of such a complex monitoring system as DuraMote for its accuracy, reliability, robustness, and user friendliness. This is because a large bridge is most of the time subjected to susceptible level of ambient vibration due to passing loads, wind, etc. DuraMote can record the acceleration time history arising from the vibration making it possible to estimate the frequency values of various bridge vibration modes. These estimated frequency values are then compared with the values computed from analytical model of the bridge for the verification of the accuracy of DuraMote. It is noted that such a verification method cannot be used practically by deploying DuraMote on a water distribution network since the dynamic behavior of a pipe network, either above or underground, is too complex to model analytically for this purpose, and in addition, the network generally lacks conveniently recordable ambient vibration. In this experiment, the performance of DuraMote system was tested being installed on the Hwamyung Bridge, a 500 m long RC cable stayed bridge in Korea for long term monitoring. In

  7. Position-Controlled Data Acquisition Embedded System for Magnetic NDE of Bridge Stay Cables

    Directory of Open Access Journals (Sweden)

    Rouven Christen

    2010-12-01

    Full Text Available This work presents a custom-tailored sensing and data acquisition embedded system, designed to be integrated in a new magnetic NDE inspection device under development at Empa, a device intended for routine testing of large diameter bridge stay cables. The data acquisition (DAQ system fulfills the speed and resolution requirements of the application and is able to continuously capture and store up to 2 GB of data at a sampling rate of 27 kS/s, with 12-bit resolution. This paper describes the DAQ system in detail, including both hardware and software implementation, as well as the key design challenges nd the techniques employed to meet the specifications. Experimental results showing the performance of the system are also presented.

  8. Soil-structure interaction modeling effects on seismic response of cable-stayed bridge tower

    Science.gov (United States)

    Raheem, Shehata E. Abdel; Hayashikawa, Toshiro

    2013-12-01

    A nonlinear dynamic analysis, including soil-structure interaction, is developed to estimate the seismic response characteristics and to predict the earthquake response of cable-stayed bridge towers with spread foundation. An incremental iterative finite element technique is adopted for a more realistic dynamic analysis of nonlinear soil-foundation-superstructure interaction system under great-earthquake ground motion. Two different approaches to model soil foundation interaction are considered: nonlinear Winkler soil foundation model and linear lumped-parameter soil model. The numerical results show that the simplified lumped-parameter-model analysis provides a good prediction for the peak response, but it overestimates the acceleration response and underestimates the uplift force at the anchor between superstructure and pier. The soil bearing stress beneath the footing base is dramatically increased due to footing base uplift. The predominant contribution to the vertical response at footing base resulted from the massive foundation rocking rather than from the vertical excitation.

  9. Damage Localization of Cable-Supported Bridges Using Modal Frequency Data and Probabilistic Neural Network

    Directory of Open Access Journals (Sweden)

    X. T. Zhou

    2014-01-01

    Full Text Available This paper presents an investigation on using the probabilistic neural network (PNN for damage localization in the suspension Tsing Ma Bridge (TMB and the cable-stayed Ting Kau Bridge (TKB from simulated noisy modal data. Because the PNN approach describes measurement data in a Bayesian probabilistic framework, it is promising for structural damage detection in noisy conditions. For locating damage on the TMB deck, the main span of the TMB is divided into a number of segments, and damage to the deck members in a segment is classified as one pattern class. The characteristic ensembles (training samples for each pattern class are obtained by computing the modal frequency change ratios from a 3D finite element model (FEM when incurring damage at different members of the same segment and then corrupting the analytical results with random noise. The testing samples for damage localization are obtained in a similar way except that damage is generated at locations different from the training samples. For damage region/type identification of the TKB, a series of pattern classes are defined to depict different scenarios with damage occurring at different portions/components. Research efforts have been focused on evaluating the influence of measurement noise level on the identification accuracy.

  10. Effects of surface roughness and cross-sectional distortion on the wind-induced response of bridge cables in dry conditions

    DEFF Research Database (Denmark)

    Matteoni, G.; Georgakis, Christos T.

    2015-01-01

    , for varying Reynolds numbers and wind angles-of-attack. Using passive-dynamic wind tunnel tests, it is shown that the in-plane aerodynamic damping of a bridge cable section, and the overall dynamic response, is strongly affected by changes in the wind angle-of-attack. Using the drag and lift......Theoretical and experimental investigations to date have assumed that bridge stay cables can be modelled as ideal circular cylinders and that their aerodynamic coefficients are invariant with wind angle-of-attack. On the other hand it has been demonstrated that bridge cables are characterised by...... local alterations of their inherent surface roughness and shape. Small deviations from ideal circularity result in significant changes in the static drag and lift coefficients with Reynolds number. The present study focuses on the wind-induced response of a full-scale yawed bridge cable section model...

  11. Experimental study on using electromagnetic devices on bridge stay cables for simultaneous energy harvesting and vibration damping

    Science.gov (United States)

    Shen, Wenai; Zhu, Songye; Zhu, Hongping

    2016-06-01

    Flexible bridge stay cables are often vulnerable to problematic vibrations under dynamic excitations. However, from an energy perspective, such excessive vibrations denote a green and sustainable energy source to some electronic devices (such as semi-active dampers or wireless sensors) installed on the same cables. This paper presents an experimental study on a novel dual-function system called electromagnetic damper cum energy harvester (EMDEH). The proposed EMDEH, consisting of an electromagnetic device connected to an energy-harvesting circuit (EHC), simultaneously harvests cable vibration energy and provides sufficient damping to the cables. A fixed-duty-cycle buck–boost converter is employed as the EHC, which emulates a resistive load and provides approximately optimal damping and optimal energy harvesting efficiency when operating in discontinuous conduction mode. A 5.85 m long scaled stay cable installed with a prototype EMDEH is tested in the laboratory under a series of harmonic and random excitations. The EMDEH can achieve a control performance comparable to passive viscous dampers. An average electrical power of 31.6 and 21.51 mW is harvested under harmonic and random vibrations, respectively, corresponding to the efficiency of 16.9% and 13.8%, respectively. Moreover, this experimental study proves that optimal damping and energy harvesting can be achieved simultaneously, which answers a pending question regarding such a dual-objective optimization problem. Self-powered semi-active control systems or wireless sensor networks may be developed for bridge stay cables in the future based on the proposed concept in this study.

  12. Understanding and controlling wind-induced vibrations of bridge cables: Results from the Femern Crossing research project

    DEFF Research Database (Denmark)

    Georgakis, Christos T.; Jakobsen, J. B.; Koss, Holger;

    Following the successful completion of the Storebælt and Øresund Crossings, the Danish Ministry of Transport appointed Femern A/S to be in charge of preparation, investigations and planning in relation to the establishment of a fixed link across the Fehmarnbelt. To further investigate the causes ......, designed specifically for the testing of bridge cables. Five years after its initiation, the participants report the main results from the research project....

  13. Innovation on Energy Power Technology (23)Completion of Installation of 500kV Cable along the Large-scale Bridges

    Science.gov (United States)

    Maekawa, Yuichi

    This paper describes an outline of the Honshu-Shikoku Interconnecting Transmission Line which includes the first large-scale cable line. The most significant feature of this transmission line is the installation of 500kV cables along various types of bridges. This brought many previously unknown technical hurdles such as techniques to overcome movements and vibrations of a series of large bridges. These hurdles were cleared through various efforts and techniques by the concerned parties.

  14. Exploring damping characteristics of composite tower of cable-stayed bridges

    Indian Academy of Sciences (India)

    SHEHATA E ABDEL RAHEEM

    2016-03-01

    The damping characterization is important in making accurate predictions of the seismic response of the hybrid structures dominated by different damping mechanisms. Different damping characteristics arise from the construction of the tower with different materials: steel for the upper part; reinforced concrete for the lower main part and interaction with supporting soil. The process of modeling damping matrices and experimental verification is challenging because damping cannot be determined via static tests as mass and stiffness can be. The assumption of classical damping is not appropriate if the system to be analyzed consists of two or more parts with significantly different levels of damping. The dynamic response of structures is critically determined by the damping mechanisms, and its value is very important for the design and analysis of vibrating structures. An analytical approach that is capable of evaluating the equivalent modal damping ratio from structural components is desirable for improving seismic design. Two approaches are considered to define and investigate dynamic characteristics of a composite tower of cable-stayed bridges: The first approach makes use of a simplified approximation of two lumped masses to investigate the structure irregularity effects including damping of different material, mass ratio, frequency ratio on dynamic characteristics and modal damping. The second approach employs a detailed numerical step-by-step integration procedure.

  15. Aerodynamic coefficients of stationary dry inclined bridge cables in laminar flow

    DEFF Research Database (Denmark)

    Matteoni, Giulia; Georgakis, Christos; Ricciardelli, Francesco

    2011-01-01

    effective change in the cable cross section, and its aerodynamic properties. On the other hand, divergent, self-excited vibrations have been observed in the field also for dry, inclined stay cables, in warm temperatures. The need for reliable design guidelines for inclined stay cables has motivated...... experimental and theoretical research in the last two decades, even though a definitive understanding of the flow around inclined cables under various surface conditions has not been achieved. A comparative study on the aerodynamic coefficients of stationary inclined stay cables, under various surface...

  16. Identification of aeroelastic forces and static drag coefficients of a twin cable bridge stay from full-scale ambient vibration measurements

    DEFF Research Database (Denmark)

    Acampora, Antonio; Georgakis, Christos T.; Macdonald, J.H.G.;

    2014-01-01

    excitation from the deck and/or towers. Although there have been many observations of large cable vibrations on bridges, there are relatively few cases of direct full-scale cable vibration and wind measurements, and most research has been based on wind tunnel tests and theoretical modelling.This paper...... presents results from full-scale measurements on the special arrangement of twin cables adopted for the Øresund Bridge. The monitoring system records wind and weather conditions, as well as accelerations of certain cables and a few locations on the deck and tower. Using the Eigenvalue Realization Algorithm......-scale measurements are compared with the theoretical damping matrices based on the quasi-steady theory, using three different sets of wind tunnel measurements of static force coefficients on similar shaped twin or single cables, with good agreement. The damping terms are found to be dependent on Reynolds number...

  17. The Design and Construction of Cable Crane of Glass Channel Bridge%玻璃沟大桥缆索吊机设计与施工

    Institute of Scientific and Technical Information of China (English)

    王鸽; 肖稀; 曾建伟; 吴智宇

    2014-01-01

    以玻璃沟大桥为背景,对工作主索、起重索、锚梁、牵引索的设计进行了详细的分析计算,并介绍了吊运缆索吊机承重主索的工作原理,对高原上类似桥梁的施工具有一定的参考价值。%Based on the glass channel bridge, this paper analyzes and calculates the design of the main cable, the hoisting cable, anchor beam and cable in detail, and introduces the working principle of lifting cable crane load bearing cable, which provides a certain reference for the similar bridge construction on the plateau.

  18. Radar-based dynamic testing of the cable-suspended bridge crossing the Ebro River at Amposta, Spain

    International Nuclear Information System (INIS)

    Microwave remote sensing is the most recent experimental methodology suitable to the non-contact measurement of deflections on large structures, in static or dynamic conditions. After a brief description of the radar measurement system, the paper addresses the application of microwave remote sensing to ambient vibration testing of a cable-suspended bridge. The investigated bridge crosses the Ebro River at Amposta, Spain and consists of two steel stiffening trusses and a series of equally spaced steel floor beams; the main span is supported by inclined stay cables and two series of 8 suspension cables. The dynamic tests were performed in operational conditions, with the sensor being placed in two different positions so that the response of both the steel deck and the arrays of suspension elements was measured. The experimental investigation confirms the simplicity of use of the radar and the accuracy of the results provided by the microwave remote sensing as well as the issues often met in the clear localization of measurement points

  19. Radar-based dynamic testing of the cable-suspended bridge crossing the Ebro River at Amposta, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, Carmelo [Politecnico di Milano, Dept. of Architecture, Built environment and Construction engineering (ABC), Piazza Leonardo da Vinci 32, 20133 Milan (Italy); Luzi, Guido [Centre Tecnòlogic de Telecomunicacions de Catalunya (CTTC), Division of Geomatics, Av. Gauss, 7 E-08860 Castelldefels (Barcelona) (Spain)

    2014-05-27

    Microwave remote sensing is the most recent experimental methodology suitable to the non-contact measurement of deflections on large structures, in static or dynamic conditions. After a brief description of the radar measurement system, the paper addresses the application of microwave remote sensing to ambient vibration testing of a cable-suspended bridge. The investigated bridge crosses the Ebro River at Amposta, Spain and consists of two steel stiffening trusses and a series of equally spaced steel floor beams; the main span is supported by inclined stay cables and two series of 8 suspension cables. The dynamic tests were performed in operational conditions, with the sensor being placed in two different positions so that the response of both the steel deck and the arrays of suspension elements was measured. The experimental investigation confirms the simplicity of use of the radar and the accuracy of the results provided by the microwave remote sensing as well as the issues often met in the clear localization of measurement points.

  20. Application of a three-dimensional aeroelastic model to study the wind-induced response of bridge stay cables in unsteady wind conditions

    Science.gov (United States)

    Raeesi, Arash; Cheng, Shaohong; Ting, David S.-K.

    2016-08-01

    The possibility of bridge stay cables experiencing violent dry inclined cable galloping raises great concern in the engineering community. Numerous experimental and analytical studies have been conducted to investigate this phenomenon, most of which were in the context of steady wind past a rigid cylindrical body. Real stay cables however, are generally long and flexible. They are exposed to more "broad" range of atmospheric boundary layer type of wind velocity profile which is also unsteady and turbulent by nature. To better understand the physics underlying this type of wind-induced cable vibration and to elucidate various contributing factors, a more realistic analytical model which is capable of addressing the above elements is imperative. In the current paper, a three-dimensional aeroelastic model is proposed to study the aerodynamic response of an inclined and/or yawed slender flexible cylindrical body subjected to unsteady mean wind, with practical application to wind-induced vibrations of bridge stay cables under no precipitation condition. The non-linear aerodynamic forces derived in the present study are combined with the cable free vibration equations available in literature to obtain the equations of motion for the wind-induced vibration of stay cables, which are solved numerically by an explicit finite difference scheme. The proposed three-dimensional aeroelastic model and numerical solution technique are validated by comparing the predicted cable free vibration responses with existing data in the literature. The mechanism which triggers dry inclined cable galloping and the required conditions for its growth are explored. In addition, the impact of different initial conditions and various unsteady mean wind scenarios on this violent cable motion are investigated. Results show that the occurrence of dry inclined cable galloping is associated with an opposite-phase relation between the relative wind speed and the aerodynamic force along the direction of

  1. Monitoring and failure analysis of corroded bridge cables under fatigue loading using acoustic emission sensors.

    Science.gov (United States)

    Li, Dongsheng; Ou, Jinping; Lan, Chengming; Li, Hui

    2012-01-01

    Cables play an important role in cable-stayed systems, but are vulnerable to corrosion and fatigue damage. There is a dearth of studies on the fatigue damage evolution of corroded cable. In the present study, the acoustic emission (AE) technology is adopted to monitor the fatigue damage evolution process. First, the relationship between stress and strain is determined through a tensile test for corroded and non-corroded steel wires. Results show that the mechanical performance of corroded cables is changed considerably. The AE characteristic parameters for fatigue damage are then established. AE energy cumulative parameters can accurately describe the fatigue damage evolution of corroded cables. The failure modes in each phase as well as the type of acoustic emission source are determined based on the results of scanning electron microscopy. The waveform characteristics, damage types, and frequency distribution of the corroded cable at different damage phases are collected. Finally, the number of broken wires and breakage time of the cables are determined according to the variation in the margin index. PMID:22666009

  2. Monitoring and Failure Analysis of Corroded Bridge Cables under Fatigue Loading Using Acoustic Emission Sensors

    Directory of Open Access Journals (Sweden)

    Hui Li

    2012-03-01

    Full Text Available Cables play an important role in cable-stayed systems, but are vulnerable to corrosion and fatigue damage. There is a dearth of studies on the fatigue damage evolution of corroded cable. In the present study, the acoustic emission (AE technology is adopted to monitor the fatigue damage evolution process. First, the relationship between stress and strain is determined through a tensile test for corroded and non-corroded steel wires. Results show that the mechanical performance of corroded cables is changed considerably. The AE characteristic parameters for fatigue damage are then established. AE energy cumulative parameters can accurately describe the fatigue damage evolution of corroded cables. The failure modes in each phase as well as the type of acoustic emission source are determined based on the results of scanning electron microscopy. The waveform characteristics, damage types, and frequency distribution of the corroded cable at different damage phases are collected. Finally, the number of broken wires and breakage time of the cables are determined according to the variation in the margin index.

  3. Feasibility Study of Micro-Wind Turbines for Powering Wireless Sensors on a Cable-Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Billie F. Spencer

    2012-09-01

    Full Text Available In this study, the feasibility of using micro-wind turbines to power wireless sensors on a cable-stayed bridge is comprehensively investigated. To this end, the wind environment around a bridge onto which a turbine is installed is examined, as is the power consumption of a wireless sensor. Feasible alternators and rotors are then carefully selected to make an effective small wind generator (known as a micro-wind turbine. Using the three specially selected micro-wind turbines, a series of experiments was conducted to find the turbine best able to generate the largest amount of power. Finally, a horizontal-axis micro-wind turbine with a six-blade rotor was combined with a wireless sensor to validate experimentally its actual power-charging capability. It is demonstrated that the micro-wind turbine can generate sufficient electricity to power a wireless sensor under moderate wind conditions.

  4. Behaviors of super-long span prestressed cable-stayed bridge with CFRP cables and UHPC girder%CFRP拉索预应力超高性能混凝土斜拉桥力学性能分析

    Institute of Scientific and Technical Information of China (English)

    方志; 任亮; 凡凤红

    2012-01-01

    To discuss the applicability of carbon fiber reinforced polymer (CFRP) cables and reactive powder concrete ( RPC) in super-long span cable-stayed bridges, taking a 1 008 m cable-stayed bridge using steel girder and steel cables as example, a cable-stayed bridge with the same span using RPC (reactive powder concrete) as the girder and advanced composite material CFRP (carbon fiber reinforced polymer) as the cable was designed, in which the cable cross section was determined by the principles of equivalent cable strength and the beam cross section was determined considering the stiffness, shear capacity and local stability. Based on the method of finite element analysis, the comparative study of these two structures on their static properties, dynamic properties, stability and wind resistance were carried out. The results show that it is feasible for using RPC as the girder and CFRP as the cable so as to form a highly efficient, durable cable-stayed bridge of concrete structure and make its applicable span reach about 1 000 m long.%为了探讨碳纤维复合材料(carbon fiber reinforced polymer,CFRP)和超高性能活性粉末混凝土(reactive powder concrete,RPC)在超大跨度斜拉桥中应用的可行性,以主跨1008m的大跨度钢主梁斜拉桥设计方案为例,采用拉索的等强度原则将原桥钢索替换成CFRP索,考虑截面刚度、截面应力和局部稳定等要求,将原桥钢主梁替换成RPC主梁,拟订了一座等跨度的CFRP拉索、RPC主梁斜拉桥方案.采用有限元法分别对两种方案结构的静力特性、动力特性、稳定性能以及抗风性能等进行了分析与比较.结果表明:从结构受力性能角度而言,采用超高性能混凝土主梁和CFRP拉索构成千米级跨度混凝土斜拉桥的结构体系是可行的.

  5. Traveling Wave Resonance and Simplified Analysis Method for Long-Span Symmetrical Cable-Stayed Bridges under Seismic Traveling Wave Excitation

    OpenAIRE

    Zhong-ye Tian; Meng-lin Lou

    2014-01-01

    The seismic responses of a long-span cable-stayed bridge under uniform excitation and traveling wave excitation in the longitudinal direction are, respectively, computed. The numerical results show that the bridge’s peak seismic responses vary significantly as the apparent wave velocity decreases. Therefore, the traveling wave effect must be considered in the seismic design of long-span bridges. The bridge’s peak seismic responses do not vary monotonously with the apparent wave velocity due t...

  6. Understanding and simulating vibrations of plain bridge cables under varying meteorological conditions

    DEFF Research Database (Denmark)

    Matteoni, Giulia

    .e. drag, lift, and moment, with Reynolds number based on the relative flow velocity, with relative angle-of-attack, and relative cable-wind angle. The aerodynamic forces acting on the structure were linearized about zero structural velocities, structural rotation and about the steady component of the...

  7. Semi-active vibration control in cable-stayed bridges under the condition of random wind load

    International Nuclear Information System (INIS)

    This paper aims at an experimental study on the real-time vibration control of bridge structures using a semi-active vibration control method that has been in the spotlight recently. As structures are becoming larger and larger, structural harmful vibration caused by unspecified external forces such as earthquakes, gusts of wind, and collisions has been brought to attention as an important issue. These harmful vibrations can cause not only user anxiety but also severe structural damage or even complete failure of structures. Therefore, in view of structural safety and economical long-term maintenance, real-time control technology of the harmful structural vibration is urgently required. In this paper, a laboratory-scale model of a cable-stayed bridge was built, and a shear-type MR damper and a semi-active vibration control algorithm (Lyapunov and clipped optimal) were applied for the control of harmful vibration of the model bridge, in real time. On the basis of the test results, each semi-active control algorithm was verified quantitatively. (papers)

  8. A multiscale finite element model validation method of composite cable-stayed bridge based on Probability Box theory

    Science.gov (United States)

    Zhong, Rumian; Zong, Zhouhong; Niu, Jie; Liu, Qiqi; Zheng, Peijuan

    2016-05-01

    Modeling and simulation are routinely implemented to predict the behavior of complex structures. These tools powerfully unite theoretical foundations, numerical models and experimental data which include associated uncertainties and errors. A new methodology for multi-scale finite element (FE) model validation is proposed in this paper. The method is based on two-step updating method, a novel approach to obtain coupling parameters in the gluing sub-regions of a multi-scale FE model, and upon Probability Box (P-box) theory that can provide a lower and upper bound for the purpose of quantifying and transmitting the uncertainty of structural parameters. The structural health monitoring data of Guanhe Bridge, a composite cable-stayed bridge with large span, and Monte Carlo simulation were used to verify the proposed method. The results show satisfactory accuracy, as the overlap ratio index of each modal frequency is over 89% without the average absolute value of relative errors, and the CDF of normal distribution has a good coincidence with measured frequencies of Guanhe Bridge. The validated multiscale FE model may be further used in structural damage prognosis and safety prognosis.

  9. Dynamic Characteristic Analysis of Long Span Cable-Stayed Pipeline Bridges%大跨度斜拉管线桥的动力特性分析

    Institute of Scientific and Technical Information of China (English)

    伍小平; 胡世德; 冯启民; 黄万春

    2001-01-01

    本文结合一实际工程结构——斜拉管线桥,从动力分析模型的建立、计算结果与实测结果的比较以及与普通斜拉桥的比较等几个方面研究了这种新型结构的动力特性。结果表明:恒载初始内力对斜拉管线桥的动力特性影响很大;尽管与斜拉桥结构相似,但二者的动力特性却有很大差别%In this paper, the dynamic characteristic of a new type of structure-long span cablestayed pipeline bridge is investigated from the establishment of the dynamic analysis model,comparison between the computed results and the test results, comparision with common calbestayed bridges. The conclusion indicated that the initial internal force caused by the dead weight of the cable-stayed pipeline bridge has a great influence on the dynamic characteristics of the bridge. The dynamic characteristics of the cable-stayed pipeline bridge are different from that of the cable-stayed bridge, although having similar structural type.

  10. An application of Auto-regressive (AR) model in predicting Aeroelastic Effectsof Lekki Cable Stayed Bridge

    OpenAIRE

    Hassan Abba Musa; Dr. A. Mohammed

    2016-01-01

    In current practice, the predictive analysis of stochastic problems encompasses a variety of statistical techniques from modeling, machine, and data mining that analyse current and historical facts to make predictions about future. Therefore, this research uses an AR Model whose codes are incorporated in the MATLAB software to predict possible aero-elastic effects of Lekki Bridge based on its existing parametric data and the conditions around the bridge. It was seen that, the fluc...

  11. Anti-slip Performance of Interface between Carbon Fiber-Reinforced Plastic Main Cable and Cable Clamp for Large-Span Suspension Bridges%大跨悬索桥CFRP主缆-索夹界面抗滑移性能

    Institute of Scientific and Technical Information of China (English)

    诸葛萍; 章子华; 汪思聪; 丁勇; 强士中

    2014-01-01

    In order to solve the slip problem between main cable and clamp at saddles of large-span suspension bridges,the anti-slip performance of the interface between carbon fiber reinforced plastic (CFRP)cable and cable clamp was investigated. The frictional coefficient calculation formula of the interface was derived according to the equilibrium condition between the cable tension and the friction force on the interface. Based on this formula,the friction coefficient of the cable-clamp interface was obtained through laboratory model test using a cable composed of 19 CFRP tendons. Then,the test results of frictional coefficient were used to analyze the anti-slip performance of the main cable-clamp system of a CFRP cable suspension bridge with a main span of 3 500 m,where the CFRP tendons had a spirally indented surface. The results show that the friction coefficient of the CFRP main cable-cable clamp interface is up to 0. 331,which is higher than that of steel cable,and meet the requirement of engineering application. Therefore,when the CFRP tendons with a spirally indented surface are applied to the main cables of large-span suspension bridges,the cable-clamp interface is good enough to meet the requirement in anti-slip performance even if the cable clamps are designed in conventional shape and with an inner surface not granulated specially.%为解决大跨悬索桥碳纤维增强复合材料(CFRP)主缆鞍座处的抗滑移问题,研究了CFRP主缆-索夹界面的抗滑移性能,根据力的平衡原理推导了CFRP索股-索夹界面的摩擦因数计算式,结合模型试验和计算式,测试了19丝CFRP索股-索夹界面的摩擦因数.利用摩擦因数实测值对3500 m跨悬索桥CFRP主缆索夹处抗滑移性能进行了实桥应用分析.结果表明:压纹类CFRP丝主缆-索夹界面的摩擦因数超过钢主缆-索夹界面,达到0.331,可满足相应的应用要求;大跨悬索桥主缆采用压纹类CFRP丝时,索夹内表

  12. An application of Auto-regressive (AR model in predicting Aeroelastic Effectsof Lekki Cable Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Hassan Abba Musa

    2016-06-01

    Full Text Available In current practice, the predictive analysis of stochastic problems encompasses a variety of statistical techniques from modeling, machine, and data mining that analyse current and historical facts to make predictions about future. Therefore, this research uses an AR Model whose codes are incorporated in the MATLAB software to predict possible aero-elastic effects of Lekki Bridge based on its existing parametric data and the conditions around the bridge. It was seen that, the fluctuating components of the wind velocity as displayed by the fluctuant curve will result in the vibration of the structure, even strengthening the resonance effect of the structure. Therefore, it suggested that, the natural frequency of the bridge should be set aside far from system frequency considering direct parametric excitation of pedestrian or vehicular traffic speed.

  13. Statistical analysis of modal properties of a cable-stayed bridge through long-term structural health monitoring with wireless smart sensor networks

    Science.gov (United States)

    Asadollahi, Parisa; Li, Jian

    2016-04-01

    Understanding the dynamic behavior of complex structures such as long-span bridges requires dense deployment of sensors. Traditional wired sensor systems are generally expensive and time-consuming to install due to cabling. With wireless communication and on-board computation capabilities, wireless smart sensor networks have the advantages of being low cost, easy to deploy and maintain and therefore facilitate dense instrumentation for structural health monitoring. A long-term monitoring project was recently carried out for a cable-stayed bridge in South Korea with a dense array of 113 smart sensors, which feature the world's largest wireless smart sensor network for civil structural monitoring. This paper presents a comprehensive statistical analysis of the modal properties including natural frequencies, damping ratios and mode shapes of the monitored cable-stayed bridge. Data analyzed in this paper is composed of structural vibration signals monitored during a 12-month period under ambient excitations. The correlation between environmental temperature and the modal frequencies is also investigated. The results showed the long-term statistical structural behavior of the bridge, which serves as the basis for Bayesian statistical updating for the numerical model.

  14. Flutter derivatives of the Kao-Pin Hsi cable-supported bridge

    Czech Academy of Sciences Publication Activity Database

    Buljac, A.; Pospíšil, Stanislav; Kozmar, H.; Kuznetsov, Sergeii; Král, Radomil

    Vol. 821. Zürich: Trans Tech Publications Inc, 2016 - (Fischer, C.), s. 172-179. (Engineering Mechanics. 821). ISBN 978-3-03835-700-1. ISSN 1660-9336. [Engineering mechanics 2015 /21./. Svratka (CZ), 11.05.2015-14.05.2015] R&D Projects: GA ČR(CZ) GA15-01035S; GA MŠk(CZ) LO1219 Institutional support: RVO:68378297 Keywords : bridge-deck section * vibrations * aeroelasticity * flutter derivatives * wind-tunnel experiments Subject RIV: JM - Building Engineering

  15. Traveling Wave Resonance and Simplified Analysis Method for Long-Span Symmetrical Cable-Stayed Bridges under Seismic Traveling Wave Excitation

    Directory of Open Access Journals (Sweden)

    Zhong-ye Tian

    2014-01-01

    Full Text Available The seismic responses of a long-span cable-stayed bridge under uniform excitation and traveling wave excitation in the longitudinal direction are, respectively, computed. The numerical results show that the bridge’s peak seismic responses vary significantly as the apparent wave velocity decreases. Therefore, the traveling wave effect must be considered in the seismic design of long-span bridges. The bridge’s peak seismic responses do not vary monotonously with the apparent wave velocity due to the traveling wave resonance. A new traveling wave excitation method that can simplify the multisupport excitation process into a two-support excitation process is developed.

  16. Experimental Research on Dynamic Characteristics of Cable- stayed Bridge of Liaohe River Grand Bridge of Coastal Highway%滨海公路辽河特大桥斜拉桥动力特性试验研究

    Institute of Scientific and Technical Information of China (English)

    邓昌宁

    2012-01-01

    Taking the part of cable - stayed bridge of Liaohe River Grand Bridge of coastal highway of Liaoning province as an example, the method of utilizing ansys finite element software to make theoretical analysis on dynamic characteristics of cable - stayed bridge with double tower and double cable steel box girder is introduced, and technical points of dynamic test like field modal test ( pulsation test) of large bridge, slide down, vehicle jump, brake and so on are researched. Through the analysis and comparison of theoretical calculation value and field test result, it shows that the bridge has good dynamic behavior of structure and better wind - resistant stability. Under the effect of general vehicle load, the bridge has good character of service without stress and resonance phenomenon.%以辽宁省滨海公路辽河特大桥斜拉桥部分为例,介绍了利用ansys有限元软件进行双塔双索面钢箱梁斜拉桥动力特性理论分析的方法,研究了大型桥梁现场模态测试(脉动试验)、跑车、跳车、刹车等动态试验的技术要点,通过对理论计算值与现场测试的结果进行分析比较,表明该桥具有良好的结构动力特性,抗风稳定性较好,在常规车辆荷载的作用下,不易出现受迫共振现象,具有良好的使用性能。

  17. Study on key technology of bridge stay cable manufacturing%大桥斜拉索制造关键技术研究

    Institute of Scientific and Technical Information of China (English)

    游胜意; 张海良; 罗国强; 张德勤; 倪晓峰

    2013-01-01

    Galvanized steel wire for bridge must meet torsion value no less than 8 times,relaxation ratio no more than 2.5%,tensile strength no less than 1 670 MPa.The production process of galvanized steel wire for bridge stay cable and stay cable was introduced.Baosteel B82MnQL wire rod was chose to produce diameter 7.0 mm galvanized steel wire,zinc layer mass fraction is no less than 300 g/m2.In production process of galvanized steel wire,steel wire surface quality,straightness and heading performance were improved.The method of decreasing torsion of stay cable is as follows:to improve pulling method of stranding and extrusion process,to improve stranding corner to keep stay cable stranding pitch stability,to improve cable lapping tension.The new type stay cable sealing system is researched.The improvement measures of stay cable fatigue properties are as follows:to improve galvanized steel wire surface quality uniformity,straightness and diameter accuracy.The galvanized steel wire stay cable can meet special requirements of customers after it is tested and used.%大桥用镀锌钢丝必须同时满足扭转≥8次,松弛率≤2.5%,抗拉强度≥1 670 MPa.介绍大桥斜拉索用镀锌钢丝和斜拉索制作工艺.选用宝钢B82MnQL盘条生产φ7.0 mm镀锌钢丝,锌层面质量≥300 g/m2.镀锌钢丝生产过程中应提高钢丝表面质量、直线度及镦头性能.降低斜拉索索体扭转的方法:改进绞制与挤塑工序牵引方式;改进绞制弯道以保持斜拉索绞制节距稳定;改进索体绕包张力.对新型斜拉索密封体系进行研发.斜拉索疲劳性能改进措施:提高镀锌钢丝表面质量均匀性、直线性和直径精度.生产的镀锌钢丝斜拉索经检验和使用,能够满足用户的特殊要求.

  18. 斜拉桥索塔锚固区节段足尺模型试验与分析%Test and analysis on full scale segmental model of cable tower anchorage zone in cable stayed bridge

    Institute of Scientific and Technical Information of China (English)

    郭凡; 杨永清; 周厚斌; 刘国军

    2012-01-01

    A FEM model of the cable tower anchorage zone section in certain cable stayed bridge was built to analyze the spatial stress field,and the values obtained by spatial stress analysis and full scale model test were compared.The evaluation of the operating capability and safety of the bridge tower was brought forward.The frictional coefficient values of the U-shaped plastic corrugated pipes and the extension values of tendons were analyzed.Stress distribution and deformation under U-shaped and small radius ring prestressed tendons and cable force were investigated.Some suggestions about constitution and design were given to similar force analysis of cable tower anchorage zone as references.%对某斜拉桥索塔锚固区节段建立有限元计算模型进行空间应力分析,并与足尺模型试验得出的结果相比较,对该桥塔锚固区工作性能及安全性进行评价。测试分析U形塑料波纹管孔道摩阻系数和钢束伸长值,研究了小半径环向U形预应力束与拉索作用下的锚固区应力与变形情况,提出构造及设计上的建议,为设计与施工提供依据,也可为同类斜拉桥索塔锚固区的受力分析提供借鉴。

  19. 独塔空间缆索自锚式悬索桥动力特性研究%Study of Dynamic Characteristics of Single-Tower SelfAnchored Suspension Bridges with Spatial Cables

    Institute of Scientific and Technical Information of China (English)

    王玉田; 马宗志; 姜福香

    2011-01-01

    To study the dymamic characteristics of single-tower self-anchored suspension bridges with spatial cables, the Dagu River Shipping Channel Bridge (a self-anchored suspension bridge with spatial cables and with span arrangement (80 + 190 + 260 + 80) m) of Qingdao Bay Bridge was cited as an example, the finite element analysis software MIDAS Civil 2006 was used to establish the three-dimensional model for the whole bridge and the 10 orders of the natural vibration characteristcs of the bridge were caculated. The anlaysis of the dynamic characteristics reveals that in addition to the vibration characteristics of suspension bridges, the self-anchored suspension bridge also has the vibration characteristics of cable-stayed bridges, the global siffness of the bridge decreases to some extent as compared to that of a gound-anchored suspension bridge and the natural period of vibration of the bridge therefore becomes rather long.%为了研究独塔空间缆索自锚式悬索桥动力特性,以青岛海湾大桥大沽河航道桥[跨径(80+190+260+80)m的空间缆索自锚式悬索桥]为背景,利用MIDAS Civil 2006有限元分析软件建立全桥三维模型,计算出其前10阶自振特性.通过对其动力特性进行分析发现,该自锚式悬索桥除了具有悬索桥的振动特性之外,还有斜拉桥的振动特性;自锚式悬索桥的整体刚度相比地锚式悬索桥有所降低,因而其固有周期较长.

  20. 三塔斜拉桥设计参数分析%Analysis of Design Parameters for Three-Pylon Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    杨庸; 雷俊卿

    2016-01-01

    To study the mechanical behavior of the three‐pylon cable‐stayed bridge structure , combined with the real design cases of three‐pylon composite girder cable‐stayed bridge projects , the finite element model of three‐pylon composite girder cable‐stayed bridge was established to car‐ry out parametric study on the effect of the measures taken ,such as to superimpose stay cables , install stay cables between pylons ,improve pylon stiffness and add auxiliary piers ,and the varia‐tion law of their load bearing behaviors is concluded .The results of the calculation demonstrate that the load bearing capacity of the intermediate pylon ,main girder and stay cables can be effec‐tively improved by adding superimposed cables ,stiffening cables between pylons and auxiliary piers to side spans ,and the pier‐top horizontal displacement and the mid‐span deflection of the main girder can also be reduced .T he pier‐top displacement can be reduced by enhancing the stiff‐ness of the intermediate pylon .The increase of the stiffness of side pylons has little influence on the structure .The increase of the height of the intermediate pylon is capable of improving the in‐ternal force of the pylons ,but accelerating the pier‐top displacement .T he results of the calculation can provide reference for the design of configuratiion of three‐pylon composite girder cable‐stayed bridge structure .%为研究三塔斜拉桥结构的力学行为特征,为三塔斜拉桥设计提供参考,结合三塔结合梁斜拉桥工程设计实例,建立三塔结合梁斜拉桥的有限元模型,对斜拉索重叠布置、塔间斜拉索、提高桥塔刚度及采用辅助墩等措施进行参数分析,总结其受力行为的变化规律。计算结果显示:设置重叠索、设置塔间加劲索、边跨设置辅助墩可有效改善中塔、主梁、斜拉索受力,减少塔顶水平位移值及跨中主梁挠度值;提高中塔刚度可以减少塔顶位

  1. 大跨度斜拉桥斜拉索阻尼减振技术研究进展%Research Advancement of Damping Techniques for Stay Cables of Long Span Cable-Stayed Bridges

    Institute of Scientific and Technical Information of China (English)

    汪正兴; 王波; 柴小鹏

    2015-01-01

    T he vibration mechanism of the stay cables of long span cable‐stayed bridges is com‐plex ,the hazards of the vibration are severe and therefore ,the additional damping techniques need to be applied to suppress the vibration .In this paper ,the researches of the vibration characteristics of the stay cables and vibration suppression mechanism of the dampers applicable to the stay cables are summarized .The Scruton numbers of the longest stay cables of 34 cable‐stayed bridges are firstly collected and calculated .The calculations of the Scruton numbers are analyzed and compared to the existing theoretic analysis and wind tunnel test results ,are verified by the conclusions from the implemented projects and the target damping parameters for the vibration suppression corre‐sponding to each potential vortex‐induced vibration ,rain vibration ,parameter resonance ,internal resonance and wake galloping are determined .Then the damping action mechanism ,displacement transfer types and durability of the common dampers are respectively analyzed and compared and the applicable ranges of the different dampers are put forward .Finally ,in the two aspects of the action mechanism and test verification ,the advantages of the damping efficiency of the lever mass damper (LMD) are particularly introduced and the further research fields of the damping tech‐niques for the stay cables are pointed out .%斜拉索振动机理复杂且危害严重,需要采取附加阻尼技术抑制斜拉索的振动,对斜拉索的振动特性和阻尼器的减振机理进行研究总结。首先计算34座斜拉桥最长索的Scruton数,与已有的理论分析、风洞试验结果进行对比分析,并采用工程实践结论进行验证,确定了斜拉索可能发生的涡激振动、风雨振、参数共振和内共振、尾流驰振等各自对应的抑振目标阻尼参数;然后对常见阻尼器的阻尼作用机理、位移传递形式、耐久性分别进行对比分析

  2. Time series synthetic aperture radar interferometry over the multispan cable-stayed Rio-Antirio Bridge (central Greece): achievements and constraints

    Science.gov (United States)

    Parcharidis, Issaak; Foumelis, Michael; Benekos, George; Kourkouli, Penelope; Stamatopoulos, Constantine; Stramondo, Salvatore

    2015-01-01

    The aim of the present study is to monitor by means of multitemporal synthetic aperture radar (SAR) interferometry the stability of the fully suspended cable-stayed Rio-Antirio Bridge (RAB) as well as the ground deformation of its surrounding area. The bridge is located in a region characterized by high hazard susceptibility, therefore, the monitoring of its behavior is of significant interest to mitigate potential risks. Envisat ASAR descending and TerraSAR-X ascending acquisitions were exploited using the persistent scatterer interferometry technique covering the periods 2002 to 2010 and 2010 to 2012, respectively. For both periods, ground displacement rates ranging from -12 to +12 mm/year indicate the absence of a significant deformation source acting during the period of investigation. Of interest is the differential motion pattern between Rio and Antirio for both SAR geometries, signifying the contribution of horizontal motion components, meanwhile allowing the quantification of the relative vertical displacement rates of these regions. For the RAB infrastructure, displacement histories were obtained from TerraSAR-X data analysis only for the stable part of the bridge, namely the viaducts and the four pylons, possibly due to the oscillation of its suspended part and the uncertainty of phase measurements over the pavement. The common behavior of the pylons was confirmed with an overall subsidence between -2 and -3 mm/year. The highest rates were observed for pylons established on specific soil types and were attributed to sediment consolidation.

  3. 云桂铁路南盘江特大桥扣锚素系统施工设计%Construction Design for Fastening-Anchoring Cable System of Nanpanjiang Bridge on Yunnan-Guangxi Railway

    Institute of Scientific and Technical Information of China (English)

    樊秋林

    2013-01-01

    南盘江特大桥是云桂铁路全线的重难点控制性工程,也是世界铁路中斜拉扣挂+分环分段组合法模注拱圈混凝土最大跨度的混凝土拱桥,主桥为单跨416m上承式钢管外包混凝土拱桥.扣锚索系统主要由扣塔、扣点、扣索、锚索及锚碇系统组,扣塔由主体5号、6号交界墩、0号段及其上部钢塔组成;扣点利用Q345B钢板在劲性骨架上弦管节点位置焊接而成;扣锚索均采用7φ5 mm(φj15.24,Rby=1 860 MPa)钢绞线束;锚碇采用岩锚和桩基承台锚碇两种形式.利用此系统进行劲性骨架单节段整体斜拉扣挂悬臂拼装、斜拉扣挂+分环分段组合法模注外包混凝土,为解决高山深谷条件下大跨度钢管外包混凝土拱桥的安全快速施工提供了参考.%As a super major bridge, Nanpanjiang Bridge is an important and difficult control project on Yunnan-Guangxi Railway. With the longest span in this kind of bridges in the world, it belongs to the concrete arch bridge with casting arch ring concrete which was erected by cable-stayed fastening-hanging method plus piecewise combination method, and its main bridge is a deck type concrete-encased steel tube arch bridge with a span of 416 meters. Its fastening-anchoring cable system was made mainly from several subsystems, including the fastening tower, fastening point, fastening cable, anchoring cable and anchorage device. The fastening tower was composed of No, 5 and No. 6 border pier, No. 0 segment and upper steel tower. Q345B steel plate was welded at the tube joint of upper chord of the stiff frame and then was taken as the fastening point. Both the fastening cable and the anchoring cable were composed of 7φ5 (φj15. 24, Rby = 1 860 MPa) steel stranded wires respectively. Two anchorage methods including rock anchorage and pile cap anchorage were employed. With this system, the construction of the stiff frame by segmental cable-stayed fastening-hanging cantilever assembling method, and

  4. Construction Technique of Dragging Stay Cables with Parallel Steel Wire Strands into Anchorages for the Second Jiujiang Changjiang River Bridge%九江二桥平行钢丝斜拉索牵引入锚施工技术

    Institute of Scientific and Technical Information of China (English)

    吴小斌; 杜俊; 李东辉

    2014-01-01

    The main bridge of the Second Jiujiang Changjiang River Bridge is a two-pylon six-span asymmetrical hybrid girder cable-stayed bridge with a main span of 818 m and with double ca-ble planes .The stay cables are composed of the φ7 mm parallel steel wires ,each having a nominal tensile strength of 1 670 MPa .By the comparative analysis of the dragging construction techniques of dragging carried out by hoisters ,soft dragging ,strong dragging and a combination of the two , it was determined to drag the stay cables via a combined application of the above dragging tech -niques ,taking into consideration of the facts that the stay cables are very heavy and long and the difference between the cable forces in the central span and the side spans are great .According to the actual characteristics of the construction ,the auxiliary facilities for the stay cables installation were prepared ,including lifting portal mounted on pylon tops and the platform used to drag the ca-bles into the anchorages on the girder ,by which the problems of the insufficient hoisting capacity and the difficult installation of the dragging devices were resolved .To improve the efficiency of stay cable installation ,the short cables were installed by the steel strand elongation method ,effec-tively reducing the dragging force in the pressing anchorages in the girder and accelerating the speed of the cable′s entering into the anchorages in the girder .The long cables were dragged into the anchorages by the soft dragging and combined application of the aforementioned methods ,re-solving the difficulty of dragging the long cables into the anchorages in the girder .%九江二桥主桥为主跨818 m 的六跨不对称双塔双索面混合梁斜拉桥,斜拉索采用平行钢丝斜拉索,钢丝直径7 mm ,抗拉强度标准值1670 MPa 。通过对卷扬机牵引、软牵引、硬牵引及软硬组合牵引等牵引施工工艺的对比分析,结合该桥的斜拉索超重超长、中边跨索

  5. 大跨度斜拉桥钢箱梁非对称安装技术%Asymmetric Mounting Technology for Steel Box Girder of Large - span Cable - stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    黄中华

    2012-01-01

    介绍了辽宁滨海公路辽河特大桥斜拉桥钢箱梁非对称悬臂安装技术,通过对本桥方案箱梁非对称悬臂安装方案—边跨钢梁高支架上直接滑移就位连接、主跨钢梁逐段悬臂安装的方案可行性研究与实施,为同类型桥梁施工提供了很好的借鉴作用。%Asymmetric cantilever - type mounting technology of steel box girder of cable - stayed bridge of Li- aohe Bridge across Liaoning Coastal Highway is introduced; through the feasibility study and implementation of asymmetric cantilever - type mounting scheme of steel box girder of the bridge - scheme of direct slip in place con- nection on high bracket of side - span steel girder and section by section cantilever - type mounting of main span steel girder, a good reference is provided for the bridge construction of the same type.

  6. An Embedded FBG Strain Sensor for Bridge Cable Tension Measurement%光纤光栅的缆索锚固区索力测量传感器设计

    Institute of Scientific and Technical Information of China (English)

    刘立; 陈伟民; 章鹏; 吴俊; 刘浩

    2012-01-01

    A Fiber Bragg Grating (FBG) embedded strain sensor is put forward. This method can make sure the survival of the sensor and solve the problem of over range measurement. It is mounted into the bridge anchor zone to detect the decay strain derived from cable body. Based on the analysis of bridge cable, design requests of this sensor are known as package structure, modulus of elasticity of package which must be matched up with the anchor material. Finally, epoxy glue with micro silicon is used as the package layer. To make sure the performance of the sensor, tensile tests are conducted by tensile testing machine, the results show that the linearity of sensor is 0.999 74, and the sensitivity is 2.74 pm/N, good in repeatability. And then the sensors arc put into the cable anchor, tensile test of the cable is implemented, and the sensor is good at linearity and repeatability.%在光纤光栅传感器测量缆索索力的应用中,为了保证传感器的存活率以及解决超量程测量的问题,设计了一种桥梁缆索锚固区植入式光纤光栅应变传感器.通过对桥梁缆索特性分析,对该传感器的封装结构、封装材料的弹性模量提出设计要求,并选择环氧树脂添加微细硅粉作为传感器封装层材料.利用拉力试验机对植入式应变传感器进行力学传感器性能实验,其线性度R2为0.999 74,灵敏度为2.74 pm/N,重复性好.把植入式传感器植入缆索锚固区,进行缆索张力实验.实验数据具有良好的线性度和重复性.

  7. Maxwell Tension Supports the Water Bridge

    OpenAIRE

    Widom, A.; Srivastava, Y. N.; Swain, J.; Sivasubramanian, S.

    2008-01-01

    A cylindrical flexible cable made up of pure fluid water can be experimentally spanned across a spatial gap with cable endpoints fixed to the top edges of two glass beakers. The cable has been called a water bridge in close analogy to iron cables employed to build ordinary span bridges. A necessary condition for the construction of a water bridge is that a large electric field exists parallel to and located within the water cable. Presently, there is no accepted detailed theory which quantita...

  8. Magnetic flux leakage-based steel cable NDE and damage visualization on a cable climbing robot

    Science.gov (United States)

    Kim, Ju-Won; Lee, Changgil; Park, Seunghee; Lee, Jong Jae

    2012-04-01

    The steel cables in long span bridges such as cable-stayed bridges and suspension bridges are critical members which suspend the load of main girders and bridge floor slabs. Damage of cable members can occur in the form of crosssectional loss caused by fatigue, wear, and fracture, which can lead to structural failure due to concentrated stress in the cable. Therefore, nondestructive examination of steel cables is necessary so that the cross-sectional loss can be detected. Thus, an automated cable monitoring system using a suitable NDE technique and a cable climbing robot is proposed. In this study, an MFL (Magnetic Flux Leakage- based inspection system was applied to monitor the condition of cables. This inspection system measures magnetic flux to detect the local faults (LF) of steel cable. To verify the feasibility of the proposed damage detection technique, an 8-channel MFL sensor head prototype was designed and fabricated. A steel cable bunch specimen with several types of damage was fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. To interpret the condition of the steel cable, magnetic flux signals were used to determine the locations of the flaws and the level of damage. Measured signals from the damaged specimen were compared with thresholds set for objective decision making. In addition, the measured magnetic flux signal was visualized into a 3D MFL map for convenient cable monitoring. Finally, the results were compared with information on actual inflicted damages to confirm the accuracy and effectiveness of the proposed cable monitoring method.

  9. Optimal design of initative horizontal bracing structure of middle tower column of southern cable stayed bridge of Xiazhang sea-crossing bridge%厦漳跨海大桥南汊斜拉桥索塔中塔柱主动横撑的设计计算

    Institute of Scientific and Technical Information of China (English)

    林寅

    2011-01-01

    本文介绍了厦漳跨海大桥南汊斜拉桥索塔施工中,为消除中塔柱倾斜塔柱根部混凝土的不良应力状态所采用的主动横撑结构的构造特点,以及考虑了施工因素的该结构的设计计算方法,确保中塔柱根部在施工过程中不开裂。该计算方法对类似工程具有一定的指导意义。%This paper intensively introduces the structural characteristics of the adoption of initiative horizontal bracing structure in order to eliminate the bad stress of concrete in the root of leaned tower column during the cable tower construction of Southern Cable Stayed Bridge of Xia Zhang Sea-crossing Bridge,as well as the structural design calculation method considering the construction factors,which can make sure that the root of leaned tower would not cracked during the construction process,and thie could be a reference for similar engineering.

  10. 76 FR 78159 - Safety Zone; Submarine Cable Installation Project; Chicago River South Branch, Chicago, IL

    Science.gov (United States)

    2011-12-16

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Submarine Cable Installation Project... the installation of submarine cables in the vicinity of the Madison Street Bridge. This temporary... the installation of submarine cables in the vicinity of the Madison Street Bridge. Entry into...

  11. Cable manufacture

    Science.gov (United States)

    Gamble, P.

    1972-01-01

    A survey is presented of flat electrical cable manufacturing, with particular reference to patented processes. The economics of manufacture based on an analysis of material and operating costs is considered for the various methods. Attention is given to the competitive advantages of the several processes and their resulting products. The historical area of flat cable manufacture is presented to give a frame of reference for the survey.

  12. Automated wireless monitoring system for cable tension using smart sensors

    Science.gov (United States)

    Sim, Sung-Han; Li, Jian; Jo, Hongki; Park, Jongwoong; Cho, Soojin; Spencer, Billie F.; Yun, Chung-Bang

    2013-04-01

    Cables are critical load carrying members of cable-stayed bridges; monitoring tension forces of the cables provides valuable information for SHM of the cable-stayed bridges. Monitoring systems for the cable tension can be efficiently realized using wireless smart sensors in conjunction with vibration-based cable tension estimation approaches. This study develops an automated cable tension monitoring system using MEMSIC's Imote2 smart sensors. An embedded data processing strategy is implemented on the Imote2-based wireless sensor network to calculate cable tensions using a vibration-based method, significantly reducing the wireless data transmission and associated power consumption. The autonomous operation of the monitoring system is achieved by AutoMonitor, a high-level coordinator application provided by the Illinois SHM Project Services Toolsuite. The monitoring system also features power harvesting enabled by solar panels attached to each sensor node and AutoMonitor for charging control. The proposed wireless system has been deployed on the Jindo Bridge, a cable-stayed bridge located in South Korea. Tension forces are autonomously monitored for 12 cables in the east, land side of the bridge, proving the validity and potential of the presented tension monitoring system for real-world applications.

  13. Critical wind velocities for several kinds of typical vehicle running on a cable-stayed bridge deck%几种典型车辆在斜拉桥桥面行驶的临界风速研究

    Institute of Scientific and Technical Information of China (English)

    马麟; 韩万水; 刘健新; 李加武

    2011-01-01

    The critical wind velocity and running velocity were studied for three kinds of typical vehicle running on a cable-stayed bridge deck under action of strong side wind. The effects of the bridge's side buffeting and the following coordinate features of the vehicle's moving equations on the vehicle side deviation relative to the bridge deck were analyzed, the calculation formulas of its relative side slipping and velocity were obtained. Based on previous studies, a wind-vehicle-bridge coupling vibration system including vehicle side deviation and driver's behavior was studied, and the corresponding simulation code was improved and tested. A cable-stayed bridge was taken as an example, critical wind velocities of three kinds of typical automobile running on the bridge deck were obtained. Results showed that the critical wind velocity is not significantly influenced by controlling objectives of driver behavior; the accident types of different vehicles are possibly different; for box-type truck, its critical wind velocity of side slipping is always lower than that of overturning; but for cars like Santana and Jia-bao, overturning accident plays a controlling role when running velocity is high, while side slipping accident does when running velocity is low.%研究强侧风作用下三种典型汽车在斜拉桥桥面行驶时的临界风速和车速.分析汽车运动方程的随动坐标特性和桥梁的侧向抖振对汽车相对桥面侧偏的影响,得到侧偏位移及速率的计算式,在以往基础上,研究了考虑车辆侧偏和驾驶员行为的风-车-桥空间耦合振动系统,完善了仿真分析程序的功能.以某斜拉桥为实例,分析三种典型车辆在桥面行使的临界风速.分析结果表明:采用控制重心还是前轮侧滑的驾驶员模型不显著影响桥面汽车临界风速的大小;不同类型汽车的事故原因可能不同,对于箱式货车,侧滑事故起控制作用,对于桑塔纳和一汽佳宝,车速高时,侧倾

  14. Influence of Pile-soil-structure Interaction on Seismic Response of Long Span Cable Stayed Bridge%桩-土-结构相互作用对大跨度斜拉桥地震响应的影响

    Institute of Scientific and Technical Information of China (English)

    段浪; 金波

    2011-01-01

    土层条件对结构在地震作用下的破坏有很大影响.本文旨在对考虑桩-土-结构动力相互作用(PSSI)对大跨度斜拉桥地震响应造成的影响进行评估.文中将桩-土相互作用理想化为采用连续分布的水平弹簧和粘滞阻尼器的Penzien模型,并用ANSYS有限元分析软件对苏通大桥整体模型进行地震响应时程分析来研究PSSI的影响.可以看出,PSSI对苏通大桥地震响应有显著影响,如果忽略PSSI效应,大部分响应将被低估.%Soil conditions have a great deal to do with damage to structures during earthquakes. This paper attempts to assess the influence of dynamic pile-soil-structure interaction (PSSI) on the seismic behavior of long span cable stayed bridge. In the present approach, the soil-pile interaction was idealized as Penzien model using continuously distributed springs and viscous dampers placed in parallel. The effects of PSSI on integral model of SUTONG Bridge were investigated by performing seismic analysis in time domain using ANSYS FEM software. It is observed that the PSSI has significant effects on the seismic response of SUTONG Bridge and a majority of responses may be underestimated if the PSSI effects are ignored.

  15. Optical Fiber Grating Sensor for Force Measurement of Anchor Cable

    Institute of Scientific and Technical Information of China (English)

    JIANG Desheng; FU Jinghua; LIU Shengchun; SUI Lingfeng; FU Rong

    2006-01-01

    The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed in the laboratory - optical fiber grating sensor for force measurement of anchor cable (OFBFMAC). No similar report about this kind of sensor has been found up to now in China and other countries. This sensor is proved to be an effective way of monitoring in processes of anchor cable installation, cable cutting, cable force regulation, etc, with the accurate and repeatable measuring results. Its successful application in the tie bar cable force safety monitoring for Wuhan Qingchuan bridge is a new exploration of optical fiber grating sensing technology in bridge tie bar monitoring system.

  16. Fatigue of threaded rods in cable anchorages due to Vortex shedding

    NARCIS (Netherlands)

    Maljaars, J.; Snijder, H.H.

    2013-01-01

    The 'Hovenring' is a bicycle roundabout flyover built as a signature bridge with a central steel pylon carrying a circular bridge deck suspended through stay-cables. Shortly after installation of the bridge, the stay-cables turned out to vibrate in the wind due to vortex shedding. These vibrations h

  17. Carbon Fiber Reinforced Polymer for Cable Structures—A Review

    Directory of Open Access Journals (Sweden)

    Yue Liu

    2015-10-01

    Full Text Available Carbon Fiber Reinforced Polymer (CFRP is an advanced composite material with the advantages of high strength, lightweight, no corrosion and excellent fatigue resistance. Therefore, unidirectional CFRP has great potential for cables and to replace steel cables in cable structures. However, CFRP is a typical orthotropic material and its strength and modulus perpendicular to the fiber direction are much lower than those in the fiber direction, which brings a challenge for anchoring CFRP cables. This paper presents an overview of application of CFRP cables in cable structures, including historical review, state of the art and prospects for the future. After introducing properties of carbon fibers, mechanical characteristics and structural forms of CFRP cables, existing CFRP cable structures in the world (all of them are cable bridges are reviewed. Especially, their CFRP cable anchorages are presented in detail. New applications for CFRP cables, i.e., cable roofs and cable facades, are also presented, including the introduction of a prototype CFRP cable roof and the conceptual design of a novel structure—CFRP Continuous Band Winding System. In addition, other challenges that impede widespread application of CFRP cable structures are briefly introduced.

  18. 双斜塔钢箱梁斜拉桥抗风性能试验研究%Experimental investigation on wind-resistant behavior of double pylon cable stayed bridge with steel box beam

    Institute of Scientific and Technical Information of China (English)

    马存明; 陈勉; 王玉柱; 高伟

    2011-01-01

    In order to evaluate wind-resistant behavior of a double pylon cable stayed bridge with steel box beam, dynamic response characteristics of the bridge were analyzed. The aerostatic force coefficient, the critical wind velocity of vibration and vortex-induced vibration response were measured using the combined method of numerical analysis and wind tunnel test, to assess wind-resistant behavior of the bridge. The results showed that the aerodynamic and flutter stability characteristics were good, but there were two obvious vertical vortex-induced resonance regions, and the peak excursion was much larger than the allowable value. Therefore, the bridge needs an aerodynamic shape optimization to reduce or control vortex-induced vibration. By comparing a variety of optimization solutions given by vortex-induced vibration experiments, the most optimized measure for vortex-induced vibration control was to add a fair water fin of 1m wide and 30° incline to the bottom slab.%为了评价某拟建大跨度双斜塔钢箱梁斜拉桥的抗风安全性能,通过数值分析与风洞试验相结合的方法研究其结构动力特性,测定静力三分力系数、颤振临界风速和涡激振动响应,据此分析评估该桥的抗风性能.结果表明,该桥具有较好的气动和颤振稳定性,但存在两个明显的竖向涡激共振区,且最大振幅远超过规定容许值.因此,该桥需要通过气动外形优化,以减小或控制涡激振动.经多种主梁涡激振动性能优化方案对比试验得出其最优措施为轨道内侧增加一条宽1m、与底板夹角成30°的导流板.

  19. Cable Stability

    CERN Document Server

    Bottura, L

    2014-01-01

    Superconductor stability is at the core of the design of any successful cable and magnet application. This chapter reviews the initial understanding of the stability mechanism, and reviews matters of importance for stability such as the nature and magnitude of the perturbation spectrum and the cooling mechanisms. Various stability strategies are studied, providing criteria that depend on the desired design and operating conditions.

  20. 不同体系斜拉桥车桥耦合共振效应研究%Vehicle-bridge coupled vibration of different types of cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    王凌波; 马印平; 蒋培文; 周勇军; 任伟

    2015-01-01

    共振是桥梁结构应当避免的一种现象,风、人群、地震等外荷载均与桥梁结构产生过共振现象从而造成严重后果,文章对不同体系斜拉桥车桥耦合共振效应进行研究,提出了车流作用下的斜拉桥车桥共振效应判定方法,对漂浮体系、半漂浮体系等斜拉桥进行了共振效应的可能性与判定条件分析,并给出了相关算例。结果表明:等间距车流对桥梁的激扰频率主要由相邻车辆时间间隔决定,漂浮体系斜拉桥由于基频较低,在等间距车流作用下存在车桥共振的可能性,其余体系斜拉桥车桥共振概率极低;建议漂浮体系斜拉桥运营时可在桥面各车道纵向不同位置分别设置减速标志,将车流“打乱”,减小共振概率。%Resonance is a phenomenon that should be avoided in bridge structures .T here are numerous cases of bridge resonance caused by wind , pedestrian and earthquake , leading to serious conse‐quences .In this paper ,the response of vehicle‐bridge coupled vibration of different types of cable‐stayed bridges is analyzed and the judging method under traffic flow is presented .T hen the possibility and criterion of the response of the resonance of floating system and half floating system are analyzed . The related numerical example is also given .The results show that the interval time between the vehi‐cles is the main influence factor of the excitation frequency under the condition of the equally spaced traffic flow .Cable‐stayed bridge of floating system has the relatively high possibility to cause vehicle bridge resonance for the reason of the low basic frequency under the equally spaced traffic flow ,com‐paring to the other types of cable‐stayed bridges .An appropriate way to reduce the possibility of the resonance is to set up the traffic signs of deceleration at different longitudinal positions .

  1. On Determining Instability Conditions for Stay Cables Subjected to Parametric Resonance

    OpenAIRE

    Leon, Armando; Ahlin, Kjell; Kao-Walter, Sharon

    2009-01-01

    Parametric Resonance Vibration in cables of cable-stayed bridges is mainly studied when the excitation frequency is close to or twice the cable natural frequency. It is, however, important to consider other cases for this frequency relationship, since among other factors, cable-parametric resonance vibrations are strongly depending on the displacement amplitude at the cable supports. Consequently, the present research work is focused on determining, by experimental and numerical analysis, the...

  2. The Research of Application of the Looped Prestressed Tendons with Large Tonnage and Small Radius in the Anchorage Zone of Cable-stayed Bridge Tower%大吨位小半径环向预应力在斜拉桥索塔锚固区中的应用研究

    Institute of Scientific and Technical Information of China (English)

    陈建阳; 徐国平; 刘丽; 朱正群

    2001-01-01

    Nowadays the large tonnage and small radius annular prestress system are applied in the anchorage region of large span cable-stayed bridge construction in our country. The application of this system has been a breakthrough of the Design Specification of Highway Bridge and Culvert. In this article, the application of this system applied in the anchorage region of cable-stayed bridge tower has been probed in close connection with the full-scale model test of the anchorage zone of the Wuhan Junshan Changjiang River Bridge.%目前我国大跨径斜拉桥索塔锚固区开始采用大吨位小半径环向预应力体系,该体系突破了现行《公路桥涵设计规范》的规定。结合武汉军山长江公路大桥索塔锚固区足尺模型试验及张拉工艺模型试验对该预应力体系在斜拉桥索塔锚固区中的应用作了深入的探讨。

  3. Long-term monitoring FBG-based cable load sensor

    Science.gov (United States)

    Zhang, Zhichun; Zhou, Zhi; Wang, Chuan; Ou, Jinping

    2006-03-01

    Stay cables are the main load-bearing components of stayed-cable bridges. The cables stress status is an important factor to the stayed-cable bridge structure safety evaluation. So it's very important not only to the bridge construction, but also to the long-term safety evaluation for the bridge structure in-service. The accurate measurement for cable load depends on an effective sensor, especially to meet the long time durability and measurement demand. FBG, for its great advantage of corrosion resistance, absolute measurement, high accuracy, electro-magnetic resistance, quasi-distribution sensing, absolute measurement and so on, is the most promising sensor, which can cater for the cable force monitoring. In this paper, a load sensor has been developed, which is made up of a bushing elastic supporting body, 4 FBGs uniformly-spaced attached outside of the bushing supporting body, and a temperature compensation FBG for other four FBGs, moreover a cover for protection of FBGs. Firstly, the sensor measuring principle is analyzed, and relationship equation of FBG wavelength shifts and extrinsic load has also been gotten. And then the sensor calibration experiments of a steel cable stretching test with the FBG load sensor and a reference electric pressure sensor is finished, and the results shows excellent linearity of extrinsic load and FBG wavelength shifts, and good repeatability, which indicates that such kind of FBG-based load sensor is suitable for load measurement, especially for long-term, real time monitoring of stay-cables.

  4. Universal Cable Brackets

    Science.gov (United States)

    Vanvalkenburgh, C.

    1985-01-01

    Concept allows routing easily changed. No custom hardware required in concept. Instead, standard brackets cut to length and installed at selected locations along cable route. If cable route is changed, brackets simply moved to new locations. Concept for "universal" cable brackets make it easy to route electrical cable around and through virtually any structure.

  5. 考虑土-结构相互作用的大跨度斜拉桥长周期地震反应分析%Analysis of Long-period Seismic Response of Long-span Cable-stayed Bridge Considering Soil-structure Interaction

    Institute of Scientific and Technical Information of China (English)

    段浪; 赵荣欣

    2012-01-01

    为分析处于软土地基上的大跨度斜拉桥在长周期地震动下的反应,通过ANSYS有限元软件和SHAKE土层地震反应分析程序等辅助软件,基于Penzien模型建立了某大跨度斜拉桥的整体有限元模型.选取一条长周期地震波和一条普通地震波比较分析了自由场地的地震反应,并在此基础上对考虑土一结构相互作用的斜拉桥地震响应进行了研究.结果表明,长周期地震动对软弱土层产生的不利影响要远远大于普通地震动,部分土层产生液化并丧失承载能力,同时,软土地基上的大跨度斜拉桥对长周期地震动十分敏感,结构的地震响应要明显大于普通地震动作用下的响应.%In order to analyze the long-period seismic response of long-span cable-stayed bridge on soft foundation, an integral finite element model of a long-span cable-stayed bridge based on Penzien model was built by using some assistant softwares just like ANSYS software and SHAKE soil stratum seismic response analysis program. The seismic response of free field was comparatively analyzed by choosing a long-period seismic wave and a normal seismic wave. Based on this, the seismic response of cable-stayed bridge in consideration of soil-structure interaction was investigated. It is observed that (1 ) the adverse effect of long-period seismic ground motion on soft foundation is far more greater than that of normal seismic ground motion, and certain soil layer was liquefied and lost bearing capacity; (2) the long-span cable-stayed bridge on soft foundation is quite sensitive to long-period seismic ground motion, and the seismic response of the structure to this seismic ground motion is much greater than that to normal seismic ground motion.

  6. Design Specifications for a Novel Climatic Wind Tunnel for the Testing of Structural Cables

    DEFF Research Database (Denmark)

    Georgakis, Christos; Koss, Holger; Ricciardelli, Francesco

    2009-01-01

    The newly proposed Femern fixed link between Denmark and Germany will push the limits in engineering design. The selection of a cable-stayed or suspension bridge will lead to one of the longest bridges of its type in the world. The challenges of designing a bridge are many and the prospects of...... cable vibrations already preoccupy both the owners and designers. In this connection, the Danish owners/operators Femern Bælt A/S, together with Storebælt A/S, are funding a collaborative research project to examine the ways of reducing the risk of cable vibrations on a bridge solution. A novel climatic...

  7. Experimental Research on Stress Behavior of Stud Shear Connector in Tower Anchorage Area of Cable-stayed Bridge%斜拉桥锚固区栓钉剪力键力学特性研究

    Institute of Scientific and Technical Information of China (English)

    吴秀发; 张小亭

    2014-01-01

    针对栓钉剪力键用于斜拉桥索塔锚固区连接部位时的应力应变特性,以中部横梁均匀加载为思路,建立局部试验模型,以栓钉剪力键的极限承载力为依据,设计加载方案,通过试验获取栓钉的应变随荷载变化的基本特征,并分析了破坏机理。结果表明:中部加载使模型两侧剪力键受力均匀,设计更为合理;栓钉剪力键的剪应力以加载梁为中心向两侧逐渐降低;高度方向,第7排栓钉受力最大,长度方向,单钉根部受到的剪力最大,应作为控制截面;破坏时,栓钉弯曲变形,根部发生45°剪切破坏,混凝土局部产生裂缝或压碎破坏。%This article mainly studied the stud shear connector for anchorage zone of pylon cable-stayed bridge connecting parts when subject to stress-strain characteristics.Taking central uniform load for ideas established local test model.Loading program was designed which based on the ultimate bearing ca-pacity of stud shear connector.It has acquired the basic characteristics of stud strain with load variation and analyzed the failure mechanism.The results showed that:The model adopts central loaded design is more reasonable because it makes shear connector force uniform on both sides of the model.The shear stress of stud shear connector decreased gradually from the center to both ends of the load beam.In the height direction,the 7th rows of pegs subject the maximum shear stress.In the longitudinal direction,sin-gle nail roots subject the maximum shear stress.It should be used as the control section.When the stud destruction,the stud bending deformation occurs,peg roots shear failure in direction of 45 °,the partial concrete will produce cracks or be crushed.

  8. Modeling and Experiments of Spray System for Cable Painting Robot

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jia-liang; Lü Tian-sheng; LI Bei-zhi

    2008-01-01

    Many cable-stayed bridges have been built in the world in the past decades,and cable-stayed structures have been adopted in many large constructions.The cable painting robot is safe and economically efficient for stay cable maintenance.In order to satisfy the need for spraying cables in hiigh attitude,an automatic cable spray system for cable painting robots is presented in this paper.Using the βdistribution,paint thickness distribution on a cylinder surface is modeled.The spray gun's number,angle and movement are analyzed to get coat evenness.Then a robotic spray system engineering prototype has been developed,which includes a cable electric running climbing base,a spray cover,four airless spray guns and a pressurized paint container.Experiments indicate that four airless spray guns can guarantee good coat quality for general stay cables.The field tests have been successfully conducted on Nanpu Bridge,Shanghai.

  9. 基于多尺度模型修正的结合梁斜拉桥损伤识别方法%Damage identification method of composite cable-stayed bridge based on multi-scale model updating

    Institute of Scientific and Technical Information of China (English)

    钟儒勉; 宗周红; 秦中远; 郑沛娟

    2014-01-01

    The damage identification method based on a multi-scale finite element (FE)model up-dating for a composite cable-stayed bridge is presented with respect to the Guanhe Bridge.First, based on ambient vibration testing and the two-stage response surface method,the FE model upda-ting is conducted,and the updated model is chosen as the undamaged state.Secondly,a multi-scale FE model updating method is used to diagnose the structural damage at different positions and in dif-ferent degrees,and the sensitivity of damage indices including model curvature index (MCI)and modal strain energy index (MSEI)on different structure scale units is discussed.The analysis results show that without considering noise effects,the MCI and MSEI are sensitive to minimal damage (1%)of small scale units,and the locations of cracking damages can be identified,but they are in-sensitive to the big scale units;considering noise effects,the anti-noise ability of the small scale units is better than that of the big scale units in the damage identification,and the anti-noise ability of MSEI is superior to that of the MCI.The results support the idea that the proposed damage identi-fication method based on the multi-scale finite element model updating has great potential in the dam-age identification of practical engineering structures,and it lays a solid foundation for the damage prognosis (DP)of large span structures.%以灌河大桥为工程背景,提出了基于多尺度有限元模型修正的结合梁斜拉桥损伤识别方法。首先基于现场环境振动试验结果和两阶段响应面方法对初始多尺度模型进行修正,并将修正后模型定为原始未损伤状态;进而,利用多尺度模型修正方法对结构不同部位不同程度的损伤进行识别,并探讨了模态曲率损伤指标和单元模态应变能损伤指标对不同结构尺度损伤的敏感性。分析结果表明:在不考虑噪声干扰情况下,模态曲率和单元模态应变能指标

  10. 承台结构形式变化对大跨斜拉桥抗震性能的影响分析%Effects of Pile-cap Structure Form on Seismic Performance of Long-span Cable-stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    邓育林; 雷凡; 何雄君

    2013-01-01

    以一座大跨斜拉桥为工程背景,基于sap2000有限元软件,建立了考虑群桩-土动力相互作用的三维有限元模型,分别计算了分离式承台与哑铃型承台两种承台形式下大跨斜拉桥的振动特性与地震响应,探讨了主塔基础承台形式对大跨斜拉桥抗震性能的影响.分析结果表明:主塔基础承台形式的变化对结构纵桥向抗震性能的影响不大,而对结构横桥向抗震性能影响较大;对于本桥而言,主塔基础承台形式采用分离式承台时对主塔结构的抗震性能有利,而采用哑铃型承台时对主塔基础的抗震性能有利,因此,应综合考虑并予以选择承台形式.%In combination with a long-span cable-stayed bridge,based on sap2000 program,the threedimensional finite element mode which can consider pile-soil dynamic interaction was developed.Vibration characteristics and seismic response of the long span cable stayed bridge using separation type pile-cap or dumbbell type pile-cap were analyzed.And effects of main-tower's pile-cap structure form on seismic performance of the long-span cable-stayed bridge was discussed.The conclusion of the study shows that the change of main-tower's pile-cap structure form has little influence on the longitudinal seismic response,but has significant influence on the transverse seismic response.For this bridge,when using the separation type pile-cap,the transverse seismic response of the bottom of the pylon will be reduced obviously,but when using the dumbbell type pile-cap,the seismic capacity demand ratio of pile foundation will be improved and so it is of benefit to seismic performance of the bridge foundation.Therefore,it should be taken comprehensive consideration to choose the suitable form of main-tower's pile-cap structure.

  11. Superconducting ac cable

    International Nuclear Information System (INIS)

    The components of a superconducting 110 kV ac cable for power ratings >= 2000 MVA have been developed. The cable design especially considered was of the semiflexible type, with a rigid cryogenic envelope and flexible hollow coaxial cable cores pulled into the former. The cable core consists of spirally wound Nb-Al composite wires and a HDPE-tape wrapped electrical insulation. A 35 m long single phase test cable with full load terminations for 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of our cable design. (orig.)

  12. UtilityTelecom_CABLE2005

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT Cable System dataset (CABLE2005) includes lines depicting the extent of Vermont's cable system as of 12/31/2005. Numerous cable companies provide service in...

  13. UtilityTelecom_CABLE2007

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT Cable System dataset (CABLE2007) includes lines depicting the extent of Vermont's cable system as of 12/31/2007. Numerous cable companies provide service in...

  14. A wireless smart sensor network for automated monitoring of cable tension

    International Nuclear Information System (INIS)

    As cables are primary load carrying members in cable-stayed bridges, monitoring the tension forces of the cables provides valuable information regarding structural soundness. Incorporating wireless smart sensors with vibration-based tension estimation methods provides an efficient means of autonomous long-term monitoring of cable tensions. This study develops a wireless cable tension monitoring system using MEMSIC’s Imote2 smart sensors. The monitoring system features autonomous operation, sustainable energy harvesting and power consumption, and remote access using the internet. To obtain the tension force, an in-network data processing strategy associated with the vibration-based tension estimation method is implemented on the Imote2-based sensor network, significantly reducing the wireless data transmission and the power consumption. The proposed monitoring system has been deployed and validated on the Jindo Bridge, a cable-stayed bridge located in South Korea. (paper)

  15. A wireless smart sensor network for automated monitoring of cable tension

    Science.gov (United States)

    Sim, Sung-Han; Li, Jian; Jo, Hongki; Park, Jong-Woong; Cho, Soojin; Spencer, Billie F., Jr.; Jung, Hyung-Jo

    2014-02-01

    As cables are primary load carrying members in cable-stayed bridges, monitoring the tension forces of the cables provides valuable information regarding structural soundness. Incorporating wireless smart sensors with vibration-based tension estimation methods provides an efficient means of autonomous long-term monitoring of cable tensions. This study develops a wireless cable tension monitoring system using MEMSIC’s Imote2 smart sensors. The monitoring system features autonomous operation, sustainable energy harvesting and power consumption, and remote access using the internet. To obtain the tension force, an in-network data processing strategy associated with the vibration-based tension estimation method is implemented on the Imote2-based sensor network, significantly reducing the wireless data transmission and the power consumption. The proposed monitoring system has been deployed and validated on the Jindo Bridge, a cable-stayed bridge located in South Korea.

  16. Cable-fault locator

    Science.gov (United States)

    Cason, R. L.; Mcstay, J. J.; Heymann, A. P., Sr.

    1979-01-01

    Inexpensive system automatically indicates location of short-circuited section of power cable. Monitor does not require that cable be disconnected from its power source or that test signals be applied. Instead, ground-current sensors are installed in manholes or at other selected locations along cable run. When fault occurs, sensors transmit information about fault location to control center. Repair crew can be sent to location and cable can be returned to service with minimum of downtime.

  17. Cable Television: Franchising Considerations.

    Science.gov (United States)

    Baer, Walter S.; And Others

    This volume is a comprehensive reference guide to cable television technology and issues of planning, franchising, and regulating a cable system. It is intended for local government officials and citizens concerned with the development of cable television systems in their communities, as well as for college and university classes in…

  18. Modeling vibration response and damping of cables and cabled structures

    Science.gov (United States)

    Spak, Kaitlin S.; Agnes, Gregory S.; Inman, Daniel J.

    2015-02-01

    In an effort to model the vibration response of cabled structures, the distributed transfer function method is developed to model cables and a simple cabled structure. The model includes shear effects, tension, and hysteretic damping for modeling of helical stranded cables, and includes a method for modeling cable attachment points using both linear and rotational damping and stiffness. The damped cable model shows agreement with experimental data for four types of stranded cables, and the damped cabled beam model shows agreement with experimental data for the cables attached to a beam structure, as well as improvement over the distributed mass method for cabled structure modeling.

  19. Research on Damage Identification for the Girders of Cable-stayed Bridges Based on Particle Swarm Optimization-support Vector Machine(PSO-SVM)%基于粒子群优化支持向量机的斜拉桥主梁损伤识别研究

    Institute of Scientific and Technical Information of China (English)

    赵世英; 李延强

    2015-01-01

    A new method of damage detection based on particle swarm optimization-support vector machine (PSO-SVM) is proposed in this paper in order to identify the girder damage of the cable-stayed bridge more ac-curately.The best kernel parameters for support vector machine(SVM) are obtained by particle swarm optimiza-tion(PSO) and the testing model of SVM is established.Taking the most sensitivity cable tension indexes as in-puts of SVM for both training and testing, damage locations of the main girder for cable-stayed bridge are indica-ted by the outputs of SVM.A numerical example for a test model of a single-tower cable-stayed bridge is provid-ed to verify the feasibility of the method.It is shown that the automatic optimization of the parameters for SVM can be realized by PSO algorithm and different kinds of damage of the girder for cable-stayed bridge can be de-tected and the identification efficiency is high.%为了能够更加准确地判断结构损伤位置和程度,本文提出了基于粒子群优化支持向量机(PSO-SVM)方法对斜拉桥主梁进行损伤识别的新方法。该方法以最敏感索张力指标作为损伤识别指标,利用粒子群(PSO)算法寻找支持向量机(SVM)最优参数,建立 SVM 预测模型,以不同位置、不同损伤程度下最敏感索的张力指标作为 SVM 的训练和测试输入,由 SVM 的输出确定损伤位置。通过对实验室的模型斜拉桥的主梁损伤进行了仿真验证,结果表明:采用 PSO 算法很好地解决了采用 SVM 方法进行损伤识别时的参数选择随机性难题,实现了对 SVM 模型参数的自动优化,基于 PSO-SVM 的损伤识别方法对斜拉桥主梁不同程度的损伤均有很高的识别率。

  20. Magnetic Flux Leakage Sensing-Based Steel Cable NDE Technique

    Directory of Open Access Journals (Sweden)

    Seunghee Park

    2014-01-01

    Full Text Available Nondestructive evaluation (NDE of steel cables in long span bridges is necessary to prevent structural failure. Thus, an automated cable monitoring system is proposed that uses a suitable NDE technique and a cable-climbing robot. A magnetic flux leakage- (MFL- based inspection system was applied to monitor the condition of cables. This inspection system measures magnetic flux to detect the local faults (LF of steel cable. To verify the feasibility of the proposed damage detection technique, an 8-channel MFL sensor head prototype was designed and fabricated. A steel cable bunch specimen with several types of damage was fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. To interpret the condition of the steel cable, magnetic flux signals were used to determine the locations of the flaws and the levels of damage. Measured signals from the damaged specimen were compared with thresholds that were set for objective decision-making. In addition, the measured magnetic flux signals were visualized as a 3D MFL map for intuitive cable monitoring. Finally, the results were compared with information on actual inflicted damages, to confirm the accuracy and effectiveness of the proposed cable monitoring method.

  1. Probabilistic Modeling and Risk Assessment of Cable Icing

    DEFF Research Database (Denmark)

    Roldsgaard, Joan Hee

    structural risk assessments together with the Bayesian pre-posterior decision analysis and builds upon the quantification of Value of Information (VoI). The consequences are evaluated for different outputs of the probabilistic model to provide a basis for prioritizing risk management decision alternatives...... both in relation to ice induced vibrations to assess the fatigue life and in relation to decision making in risk management of bridges exposed to icing. First a basic and preliminary framework for the assessment of cumulative bridge cable fatigue damage due to wind-induced vibrations is presented. The...... on bridge cables is used as a tool to support engineering decision making and risk management of cable structures with respect to icing events. These events may lead to human life safety issues, functional disruptions and associated economic consequences. Here emphasis is placed on the value of early...

  2. Development of Murray Loop Bridge for High Induced Voltage

    Science.gov (United States)

    Isono, Shigeki; Kawasaki, Katsutoshi; Kobayashi, Shin-Ichi; Ishihara, Hayato; Chiyajo, Kiyonobu

    In the case of the cable fault that ground fault resistance is less than 10MΩ, Murray Loop Bridge is excellent as a fault locator in location accuracy and the convenience. But, when the induction of several hundred V is taken from the single core cable which adjoins it, a fault location with the high voltage Murray Loop Bridge becomes difficult. Therefore, we developed Murray Loop Bridge, which could be applied even when the induced voltage of several hundred V occurs in the measurement cable. The evaluation of the fault location accuracy was done with the developed prototype by the actual line and the training equipment.

  3. Cable fault locator research

    Science.gov (United States)

    Cole, C. A.; Honey, S. K.; Petro, J. P.; Phillips, A. C.

    1982-07-01

    Cable fault location and the construction of four field test units are discussed. Swept frequency sounding of mine cables with RF signals was the technique most thoroughly investigated. The swept frequency technique is supplemented with a form of moving target indication to provide a method for locating the position of a technician along a cable and relative to a suspected fault. Separate, more limited investigations involved high voltage time domain reflectometry and acoustical probing of mine cables. Particular areas of research included microprocessor-based control of the swept frequency system, a microprocessor based fast Fourier transform for spectral analysis, and RF synthesizers.

  4. Electrical power cable engineering

    CERN Document Server

    Thue, William A

    2011-01-01

    Fully updated, Electrical Power Cable Engineering, Third Edition again concentrates on the remarkably complex design, application, and preparation methods required to terminate and splice cables. This latest addition to the CRC Press Power Engineering series covers cutting-edge methods for design, manufacture, installation, operation, and maintenance of reliable power cable systems. It is based largely on feedback from experienced university lecturers who have taught courses on these very concepts.The book emphasizes methods to optimize vital design and installation of power cables used in the

  5. Application of Microwave Remote Sensing to Dynamic Testing of Stay-Cables

    Directory of Open Access Journals (Sweden)

    Carmelo Gentile

    2009-12-01

    Full Text Available Recent advances in radar techniques and systems have favoured the development of microwave interferometers, suitable for the non-contact vibration monitoring of large structures. The paper addresses the application of microwave remote sensing to the measurement of the vibration response in the stay-cables of cable-stayed bridges. The reliability and accuracy of the proposed technique were investigated by comparing the natural frequencies (and the cable tensions predicted from natural frequencies identified from radar data and the corresponding quantities obtained using more conventional techniques. The investigation, carried out on the cables of two different cable-stayed bridges, clearly highlights: (a the accuracy of the results provided by the microwave remote sensing; (b the simplicity of use of the radar technique (especially when compared with conventional approaches and its effectiveness to simultaneously measuring the dynamic response of all the stay-cables of an array.

  6. 桥梁半平行钢丝索对称断丝的力学特性分析%Mechanical Properties Analysis of Semi Parallel Wire Cables for Bridges with Symmetric Wire Breaks

    Institute of Scientific and Technical Information of China (English)

    彭崇梅; 张启伟; 李元兵

    2013-01-01

    Strands model or parallel model based on the assumption of parallel wire is helpless to semi parallel wire cable for its helical characteristics and complex structure.Based on the theory of Love's curved bar, the mechanical model for multilayered semi parallel wire cables with symmetric wire breaks is updated with a consideration of the effects of the Poisson's ratio and contact deflection between wires, inter-wire contact force and friction.Axial force distribution of wires, magnification factors of axial force and axial stiffness of the cable are discussed by numerical calculation.Numerical examples show that the contact deformation aggravates axial force nonuniform distribution of wires and that the axial stiffness of cables falls much after the wire breaks.%桥梁用半平行钢丝索由于外层钢丝的螺旋外形和本身构造的特殊性,不能直接应用基于平行钢丝假定的并联模型或钢绞线模型进行力学分析.基于Love曲杆理论,考虑泊松效应、钢丝间接触变形以及钢丝间的接触力和摩擦力的影响,对多层半平行钢丝索的对称断丝模型进行了修正,通过数值计算讨论了拉索截面钢丝拉力分布规律、钢丝拉力增长系数和拉索轴向刚度及其影响因素.计算表明,考虑接触变形后,截面内钢丝拉力分布不均匀,拉索轴向刚度较单根钢丝有较大幅度的下降.

  7. UtilityTelecom_CABLE2013

    Data.gov (United States)

    Vermont Center for Geographic Information — The VT Cable dataset (CABLE2013) includes lines depicting the extent of Vermont's cable modem broadband system as of 6/30/2013 in addition to those companies who do...

  8. Cable tracking system proposal

    International Nuclear Information System (INIS)

    The Experimental Facilities Division requires a labeling system to identify and catalog the instrumentation, control, and computer cables that will run throughout the building. Tom Sheridan from the MIS Group has already made some general suggestions about the information that could be included in an Oracle-based Cable Tracking System (E-mail text distributed by Gary Gunderson on the 27th of August). Glenn Decker's LS Note No. 191 is also relevant to the subject since it addresses name assignment rules for the storage ring devices. The intent of this note is to recommend a mechanism for tracking wires/cables, with enough specifics, to which all groups in the Division would adhere when pulling cables. Because most cables will run between various beamline devices, hutch safety components, and equipment racks, any method of tracking cables is related to the Equipment Tracking System. That system has been developed by the APS Project personnel and is described in the APS Project Equipment Tracking System Guidelines (DRAFT). It can be adopted to XFD's needs. Two essential features of the Cable Tracking System are: 1) Each cable shell have a unique Identifier, and 2) Cable label must contain information that is helpful during troubleshooting in the field. The Identifier is an alphanumeric string of characters that will originate in the Oraclebased Cable Tracking System. It is not necessary for the identifier to carry a lot of intelligence its primary purpose is simply to provide a link to the database. Bar-coding the Identifier would make it easy to combine cable information with the Equipment Tracking System

  9. Cable Diagnostic Focused Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hartlein, R.A.; Hampton, R.N.

    2010-12-30

    This report summarizes an extensive effort made to understand how to effectively use the various diagnostic technologies to establish the condition of medium voltage underground cable circuits. These circuits make up an extensive portion of the electric delivery infrastructure in the United States. Much of this infrastructure is old and experiencing unacceptable failure rates. By deploying efficient diagnostic testing programs, electric utilities can replace or repair circuits that are about to fail, providing an optimal approach to improving electric system reliability. This is an intrinsically complex topic. Underground cable systems are not homogeneous. Cable circuits often contain multiple branches with different cable designs and a range of insulation materials. In addition, each insulation material ages differently as a function of time, temperature and operating environment. To complicate matters further, there are a wide variety of diagnostic technologies available for assessing the condition of cable circuits with a diversity of claims about the effectiveness of each approach. As a result, the benefits of deploying cable diagnostic testing programs have been difficult to establish, leading many utilities to avoid the their use altogether. This project was designed to help address these issues. The information provided is the result of a collaborative effort between Georgia Tech NEETRAC staff, Georgia Tech academic faculty, electric utility industry participants, as well as cable system diagnostic testing service providers and test equipment providers. Report topics include: •How cable systems age and fail, •The various technologies available for detecting potential failure sites, •The advantages and disadvantages of different diagnostic technologies, •Different approaches for utilities to employ cable system diagnostics. The primary deliverables of this project are this report, a Cable Diagnostic Handbook (a subset of this report) and an online

  10. COPPER CABLE RECYCLING TECHNOLOGY

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  11. Super and Combinatorial Harmonic Response of Flexible Elastic Cables with Small Sag

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    2002-01-01

    The paper deals with the analysis of cables in stayed bridges and TV-towers, where the excitation is caused by harmonically varying in-plane motions of the upper support point with the amplitude ;. Such cables are characterized by a sag-to-chord-length ratio below 0·02, which means that the lowest...

  12. Bridge? What's a Bridge?

    Science.gov (United States)

    Gutsche, George

    1996-01-01

    Considers the metaphor of the "bridge" as it applies to Russian-language courses at the university level. The article examines broader curricular issues of technology, innovation, and outside pressures on language teaching. (22 references) (CK)

  13. Railroad Bridges

    Data.gov (United States)

    Department of Homeland Security — Bridges-Rail in the United States According to The National Bridge Inspection Standards published in the Code of Federal Regulations (23 CFR 650.3), a bridge isA...

  14. Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment

    OpenAIRE

    Jacob, Bernard; Ieng, Sio Song; SCHMIDT, Franziska

    2012-01-01

    Bridge weigh-in-motion uses an instrumented bridge as a scale to weigh vehicles. Several types of bridges may be used, if being sensitive to wheel or axle loads. Here some strains of steel orthotropic deck bridges are measured by extensometers and analyzed by software, to calculate axle loads and gross vehicle weights. Between 2009 and 2011, several large scale tests were done on the Millau viaduct (France), the tallest cable stayed bridge in the world. These tests showed that the system meet...

  15. Preliminary evaluation of two new cable surface innovations

    DEFF Research Database (Denmark)

    Burlina, Celeste; Georgakis, Christos T.; Larsen, S.V.; Egger, Phillipp

    2015-01-01

    In this paper, the aerodynamic performance of two innovative bridge cable surfaces with concave fillets are examined and compared with traditional helical fillets. To this end, an extensive wind-tunnel test campaign was undertaken to measure the aerodynamic static force coefficients up to a...

  16. Infiniband Based Cable Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Minich, Makia [ORNL

    2007-07-01

    As Infiniband continues to be more broadly adopted in High Performance Computing (HPC) and datacenter applications, one major challenge still plagues implementation: cabling. With the transition to DDR (double data rate) from SDR (single datarate), currently available Infiniband implementations such as standard CX4/IB4x style copper cables severely constrain system design (10m maximum length for DDR copper cables, thermal management due to poor airflow, etc.). This paper will examine some of the options available and compare performance with the newly released Intel Connects Cables. In addition, we will take a glance at Intel's dual-core and quad-core systems to see if core counts have noticeable effect on expected IO patterns.

  17. 三维体系斜拉索桥张拉施工技术应用%Application of Three-dimension System Cable-stayed Bridge Stretching Construction Technology

    Institute of Scientific and Technical Information of China (English)

    赵文艺; 薛长迁; 刘斌

    2009-01-01

    该文以天津市新三条石桥为例,介绍了三维斜拉索体系的分级对称张拉工艺及施工操作要点,可供类似工程参考.%Taking Tianjin Xinsantiao Stone Bridge as an example, the article introduces the grade symmetrical stretching technology and the construction operating gist, which can provide the reference for the similar projects.

  18. Magnet cable manufacturing

    International Nuclear Information System (INIS)

    The superconducting magnets used in the construction of particle accelerators are mostly built from flat, multistrand cables with rectangular or keystoned cross sections. The superconducting strands are mostly circular but a design of a cable made of preflattened wires was proposed a few years ago under the name of Berkeley flat; such cable shows some interesting characteristics. Another design consists of a few smaller precabled wires (e.g. 6 around 1). This configuration allows smaller filaments and a better transposition of the current elements. The Superconducting Super Collider project involves the largest amount of superconducting cable ever envisaged for a single machine. Furthermore, the design calls for exceptional accuracy and improved characteristics of the cable. A part of the SSC research and development program is focused on these important questions. In this paper we emphasize the difference between the conventional cabling and wires with superconducting. A new concept for the tooling will be introduced as well as the necessary characteristics of a specialized cabler. 5 figs

  19. Active control of vibrations in pedestrian bridges

    OpenAIRE

    Álvaro Cunha; Carlos Moutinho

    1999-01-01

    This paper, apart from making a brief general reference to vibration problems in pedestrian bridges, as well as to the form of modelling of dynamic pedestrian loads, presents the use of a predictive control strategy for the numerical simulation of the dynamic response of actively controlled structures of this type. The consideration of this control strategy permitted the development of a computational model, which was applied to the study of a pedestrian cable-stayed bridge, in order to show ...

  20. Pyrotechnic-actuated cable release

    Science.gov (United States)

    Hanson, R. W.

    1968-01-01

    Remote, unattended means has been designed and reduced to practice that retains and then releases an attached load by means of a restrained cable. The cable is released by an electrical impulse on signal.

  1. Actin Filament Cables in Drosophila Nurse Cells Are Composed of Modules That Slide Passively Past One Another during Dumping

    OpenAIRE

    Guild, Gregory M.; Connelly, Patricia S.; Shaw, Michael K.; Tilney, Lewis G.

    1997-01-01

    At a late stage in Drosophila oogenesis, nurse cells rapidly expel their cytoplasm into the oocyte via intracellular bridges by a process called nurse cell dumping. Before dumping, numerous cables composed of actin filaments appear in the cytoplasm and extend inward from the plasma membrane toward the nucleus. This actin cage prevents the nucleus, which becomes highly lobed, from physically blocking the intracellular bridges during dumping. Each cable is composed of a linear series of modules...

  2. Non-linear stochastic response of a shallow cable

    DEFF Research Database (Denmark)

    Larsen, Jesper Winther; Nielsen, Søren R.K.

    2004-01-01

    The paper considers the stochastic response of geometrical non-linear shallow cables. Large rain-wind induced cable oscillations with non-linear interactions have been observed in many large cable stayed bridges during the last decades. The response of the cable is investigated for a reduced two-...... the chord wise component of the support point motion relative to a safe domain determined from the harmonic analysis of the problem.......-degrees-of-freedom system with one modal coordinate for the in-plane displacement and one for the out-of-plane displacement. At first harmonic varying chord elongation at excitation frequencies close to the corresponding eigenfrequencies of the cable is considered in order to identify stable modes of vibration. Depending....... Next, the chord elongation is modelled as a narrow-banded Gaussian stochastic process, and it is shown that all the indicated harmonic solutions now become instable with probability one. Instead, the cable jumps randomly back and forth between the two in-plane and the whirling mode of vibration. A...

  3. Application of Improved Hierarchic Genetic Algorithm to Damage Detection of the Main Girder for Cable-stayed Bridge%改进分层遗传算法在斜拉桥主梁损伤识别中的应用

    Institute of Scientific and Technical Information of China (English)

    李延强; 张阳

    2014-01-01

    标准遗传算法在解决像斜拉桥这类复杂结构的损伤识别问题时会出现提前收敛,即所谓“早熟”的现象。为了避免此现象的发生,提高损伤识别的效率与精度,提出一种基于改进分层遗传算法的斜拉桥主梁损伤识别方法。采用索力变化作为优化目标函数,将3种具有不同遗传算子的标准遗传算法与变量微调和灾变策略相结合,形成了一种具有灾变特性的分层遗传算法,以实验室独塔斜拉桥模型作为研究对象进行了数值仿真,结果表明:改进的分层遗传算法成功的避免了标准遗传算法“早熟”现象的发生,能快速有效的完成斜拉桥主梁各种损伤的识别;同时对此方法进行抗噪性分析发现,该方法具有良好的抗噪能力。%In the process of damage identification for high‐order nonlinear structure such as cable‐stayed bridges by the standard genetic algorithm ,premature convergence would appear .In order to avoid this ,an improved hierarchic genetic algorithm was proposed . The cable force change was used to establish the optimization function and threetypes of standard genetic algorithm were combined with variable fine‐tuning and hierarchic strategy .To establish a hierarchical genetic algorithm with catastrophe characteristics A single‐tower cable‐stayed bridge model was used in the numerical simulation and the result showed that the probability of premature convergence was reduced in the improved hierarchic genetic algorithm and and the cable‐stayed bridge damage was identified effectively .The anti‐noise performance was better .

  4. High Temperature Superconducting Underground Cable

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Roger, A.

    2010-02-28

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the world’s first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  5. The Danish Superconducting Cable Project

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    1997-01-01

    The design and construction of a superconducting cable is described. The cable has a room temperature dielectric design with the cryostat placed inside the electrical insulation.BSCCO 2223 superconducting tapes wound in helix form around a former are used as the cable conductor. Results from...

  6. High Temperature Superconducting Underground Cable

    International Nuclear Information System (INIS)

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the worlds first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  7. Cable Television Information.

    Science.gov (United States)

    New York State Education Dept. , Albany. Bureau of Mass Communications.

    Cable television for the State of New York is discussed in detail with relation to: (1) the regents of the University of the State of New York, (2) legislation, (3) planning and proposals for franchises, (4) the Federal Communications Commission, (5) access rules, (6) a list of companies and those serving schools, and (7) federal/state/local…

  8. Using satellites to monitor Severn Bridge structure, UK

    OpenAIRE

    Roberts, GW; Brown, CJ; Tang, X; Ogundipe, O

    2015-01-01

    The Severn Bridge is a large UK suspension bridge. In 2010, a series of field surveys was commissioned to monitor the magnitude and frequencies of the bridge’s movements, through attaching nine dual-frequency survey grade global navigation satellite system receivers on the bridge and two reference satellite receivers adjacent to the structure. The satellite antenna locations and configuration allow the movements of the north cable to be analysed at four locations, as well as the differential ...

  9. Running Safety of Trains under Vessel-Bridge Collision

    OpenAIRE

    Yongle Li; Jiangtao Deng; Bin Wang; Chuanjin Yu

    2015-01-01

    To optimize the sensor placement of the health monitoring system, the dynamic behavior of the train-bridge system subjected to vessel-collision should be studied in detail firstly. This study thus focuses on the characteristics of a train-bridge system under vessel-bridge collision. The process of the vessel-bridge collision is simulated numerically with a reliable finite element model (FEM). The dynamic responses of a single car and a train crossing a cable-stayed bridge are calculated. It i...

  10. Excitation of Arch and Suspension Bridges by Subwires

    Directory of Open Access Journals (Sweden)

    Noriaki Hiwatashi

    1993-01-01

    Full Text Available A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force generator.

  11. Excitation of Arch and Suspension Bridges by Subwires

    OpenAIRE

    Noriaki Hiwatashi; Yoji Mizuta; Yutaka Ishihara; Itio Hirai

    1993-01-01

    A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force ...

  12. Internal coaxial cable seal system

    Science.gov (United States)

    Hall, David R.; Sneddon, Cameron; Dahlgren, Scott Steven; Briscoe, Michael A.

    2006-07-25

    The invention is a seal system for a coaxial cable and is placed within the coaxial cable and its constituent components. A series of seal stacks including load ring components and elastomeric rings are placed on load bearing members within the coaxial cable sealing the annular space between the coaxial cable and an electrical contact passing there through. The coaxial cable is disposed within drilling components to transmit electrical signals between drilling components within a drill string. The seal system can be used in a variety of downhole components, such as sections of pipe in a drill string, drill collars, heavy weight drill pipe, and jars.

  13. Trial of prestressed concrete cable testing by sonic integrity tester

    International Nuclear Information System (INIS)

    Highway road network of Japan is in good condition. Those roads were constructed as social infrastructures. But some damages were occurred and propagated in concrete structure which passed more than 20 years after construction. As for the damages load caring capacity of bridge was decreased due to fatigue of increasing traffics and bridge vibration. Recently many troubles happened in PC structure as cut off of the main cables by corrosion and flying the non-grouting PC-bar to roadside. Some case can be checked by hammering testing method and X-ray photo cut or not and condition of cement grouting. But another case has not checking method. Now we are testing for the PC cables by sonic integrity tester which is modified from FPDS(Foundation Pile Diagnosis System). We report in this paper on this result and scope of the future of this method.

  14. Myocardial Bridging.

    Science.gov (United States)

    Yuan, Shi-Min

    2016-02-01

    Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results. PMID:27074276

  15. Myocardial Bridging

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2016-02-01

    Full Text Available Abstract Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

  16. Analysis and test research on mechanical performance for steel-concrete composite anchor structure of cable- stayed bridge pylon%斜拉桥索塔钢混组合锚固结构力学性能分析和试验研究

    Institute of Scientific and Technical Information of China (English)

    俞先林; 张奇志

    2009-01-01

    采用自平衡式加载反力架对苏通大桥索塔钢混组合锚固结构进行足尺模型试验,观测模型的应力、裂缝分布和变形情况.采用ANSYS有限元软件对模型进行数值分析.试验和分析结果表明:索孔出口面上方的混凝土表面最易出现裂缝;钢混结合面表现为弯剪共同作用的特性,顶推荷载水平分力主要由钢锚箱结构承担,混凝土亦承担一小部分,竖向分力可全部由剪力钉传递给混凝土承受;单节段模型的有限元计算结果比多节段模型的计算结果偏大,用单节段模型试验结果代表实桥受力状况偏于安全.%Full-scale model test on steel-concrete composite anchor structure for pylon of sutong bridge was done by a self-balanced loading reaction frame to observe the stress,crack distribution and deformation of the model. Also numerical simulation was conducted by the finite element software ANSYS. The results of analysis and test show that cracks most easily occur on concrete surface at upperpart of cable anchor duct export. The steel-concrete contacting surface undertakes mutual action of bending moment and shear. Most horizontal component of pushing load is balanced by steel anchor box and only a small part by concrete,while vertical component of pushing load is all transferred to concrete by shear studs. Since numerical simulation data from single segment model test is larger than that from multi-segmental model test,it's conservative to adopt single segment mode test data instead of actual bridge stress status.

  17. EIGENFREQUENCY ANALYSIS OF CABLE STRUCTURES WITH INCLINED CABLES

    Institute of Scientific and Technical Information of China (English)

    William Paulsen; Greg Slayton

    2006-01-01

    The approximate eigenfrequencies for the in-plane vibrations of a cable structure consisting of inclined cables, together with point masses at various points were computed. It was discovered that the classical transfer matrix method was inadequate for this task, and hence the larger exterior matrices were used to determine the eigenfrequency equation. Then predictions of the dynamics of the general cable structure based on the asymptotic estimates of the exterior matrices were made.

  18. Nonlinear Dynamical Analysis for the Cable Excited with Parametric and Forced Excitation

    Directory of Open Access Journals (Sweden)

    C. Z. Qian

    2014-01-01

    Full Text Available Considering the deck vibration effect on the cable in cable-stayed bridge, using nonlinear structure dynamics theory, the nonlinear dynamical equation for the stayed cable excited with deck vibration is proposed. Research shows that the vertical vibration of the deck has a combined parametric and forced excitation effect on the cable when the angle of the cable is taken into consideration. Using multiscale method, the 1/2 principle parametric resonance is studied and the bifurcation equation is obtained. Despite the parameters analysis, the bifurcation characters of the dynamical system are studied. At last, by means of numerical method and software MATHMATIC, the effect rules of system parameters to the dynamical behavior of the system are studied, and some useful conclusions are obtained.

  19. Advanced aerostatic analysis of long-span suspension bridges

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the wind speed spatial non-uniformity all increase consequently, which may have unnegligible influence on the aerostatic behavior of long-span suspension bridges. In this work, a method of advanced aerostatic analysis is presented firstly by considering the geometric nonlinearity, the nonlinear wind-structures and wind speed spatial non-uniformity. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic behavior of the bridge are investigated analytically. The results showed that these factors all have important influence on the aerostatic behavior, and should be considered in the aerostatic analysis of long and particularly super long-span suspension bridges.

  20. Vibration characteristics and damage detection in a suspension bridge

    Science.gov (United States)

    Wickramasinghe, Wasanthi R.; Thambiratnam, David P.; Chan, Tommy H. T.; Nguyen, Theanh

    2016-08-01

    Suspension bridges are flexible and vibration sensitive structures that exhibit complex and multi-modal vibration. Due to this, the usual vibration based methods could face a challenge when used for damage detection in these structures. This paper develops and applies a mode shape component specific damage index (DI) to detect and locate damage in a suspension bridge with pre-tensioned cables. This is important as suspension bridges are large structures and damage in them during their long service lives could easily go un-noticed. The capability of the proposed vibration based DI is demonstrated through its application to detect and locate single and multiple damages with varied locations and severity in the cables of the suspension bridge. The outcome of this research will enhance the safety and performance of these bridges which play an important role in the transport network.

  1. Cable networks, services, and management

    CERN Document Server

    2015-01-01

    Cable Networks, Services, and Management is the first book to cover cable networks, services, and their management, in-depth, for network operators, engineers, researchers, and students. Thirteen experts in various fields have contributed their knowledge of network architectures and services, Operations, Administration, Maintenance, Provisioning, Troubleshooting (OAMPT) for residential and business services, cloud, Software Defined Networks (SDN), as well as virtualization concepts and their applications as part of the future directions of cable networks. The book begins by introducing architecture and services for Data Over Cable Service Interface Specification (DOCSIS) 3.0/ 3.1, Converged Cable Access Platform (CCAP), Content Distribution Networks (CDN, IP TV, and Packet Cable and Wi-Fi for Residential Services. Topics that are discussed in proceeding chapters include: operational systems and management architectures, service orders, provisioning, fault manageme t, performance management, billing systems a...

  2. 14 CFR 23.689 - Cable systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cable systems. 23.689 Section 23.689... Systems § 23.689 Cable systems. (a) Each cable, cable fitting, turnbuckle, splice, and pulley used must... primary control systems; (2) Each cable system must be designed so that there will be no hazardous...

  3. Cable Bacteria in Freshwater Sediments

    OpenAIRE

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the fre...

  4. Electromagnetic transients in power cables

    CERN Document Server

    da Silva, Filipe Faria

    2013-01-01

    From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,

  5. Power applications for superconducting cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Hansen, Steen; Jørgensen, Preben; Lomholt, Karin; Mikkelsen, Søren D.; Okholm, Jan; Salvin, Sven; Østergaard, Jacob

    2000-01-01

    High temperature superconducting (HTS) cables for use in electric ac power systems are under development around the world today. There are two main constructions under development: the room temperature dielectric design and the cryogenic dielectric design. However, theoretical studies have shown...... that the insertion of these cables in the network is not without problems. The network stability requirements may impose severe constraints on the actual obtainable length of superconducting cables. Load flow considerations show that it may be difficult to use these high current cables to their full...

  6. LOCA testing of damaged cables

    International Nuclear Information System (INIS)

    Experiments were conducted to assess the effects of dielectric withstand voltage testing of cables and to assess the survivability of aged and damaged cables under loss-of-coolant accident (LOCA) conditions. High potential testing at 240 Vdc/mil on undamaged cables suggested that no damage was incurred on the selected cables. During aging and LOCA testing, Okonite ethylene propylene rubber cables with a bonded jacket experienced unexpected failures. The failures appear to be primarily related to the level of thermal aging. For Brand Rex crosslinked polyolefin cables, the results suggest that 8 mils of insulation remaining should give the cables a high probability of surviving accident exposure following aging. The voltage levels necessary to detect when 8 mils of insulation remain are expected to be roughly 40 kVdc. This voltage level would almost certainly be unacceptable to a utility for use as a damage assessment tool. Although two Rockbestos silicone rubber cables failed during the accident test, the induced wall thickness did not seem to be the major cause of the failures. It appears likely that under less stressful thermal aging conditions, the cables would survive accident testing with as little as 4 mils or less of insulation remaining

  7. Superconducting flat tape cable magnet

    Energy Technology Data Exchange (ETDEWEB)

    Takayasu, Makoto

    2015-08-11

    A method for winding a coil magnet with the stacked tape cables, and a coil so wound. The winding process is controlled and various shape coils can be wound by twisting about the longitudinal axis of the cable and bending following the easy bend direction during winding, so that sharp local bending can be obtained by adjusting the twist pitch. Stack-tape cable is twisted while being wound, instead of being twisted in a straight configuration and then wound. In certain embodiments, the straight length should be half of the cable twist-pitch or a multiple of it.

  8. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2015-01-01

    the technology was used. We also study other important components and details in the Pearl-Chain Bridge concept and review the effects of different types of loads. A theoretical case study of a circular 30 m span Pearl-Chain Bridge is presented showing the influence of a number of parameters: The......A Pearl-Chain Bridge is a closed-spandrel arch bridge consisting of a number of straight pre-fabricated so called Super-Light Deck elements put together in an arch shape by post-tensioning cables. Several Pearl-Chain arches can be positioned adjacent to each other by a crane to achieve a bridge of...... number of post-tensioning cables, the rise to span ratio, the height of the filling, and the height of the Super-Light Decks. We find that Pearl-Chain Bridges can be adjusted to resist specific moment loads by changing the normal force in the arch cross section by altering the above parameters. It is...

  9. Thermal Load in Large-Scale Bridges: A State-of-the-Art Review

    OpenAIRE

    Guang-Dong Zhou; Ting-Hua Yi

    2013-01-01

    Thermal load is an important factor that must be taken into account during the procedure of bridge design and structural condition evaluation especially for those statically indeterminate bridges and cable-supported bridges. This paper presents an overview of current research and development activities in the field of thermal load in bridge, in which emphasis is placed on the thermal load models established by numerical analysis and field measurement. The theoretical formulations and boundary...

  10. A strange bridge by Leonardo

    CERN Document Server

    Huylebrouck, Dirk

    2013-01-01

    On folio 855 recto of the Codex Atlanticus, Leonardo da Vinci drew three 'easily movable' bridges, but one of them is enigmatic: all 'replicas' in Leonardo museums and exhibitions come as a surprise, to say the least, to any engineer or architect whose attention is drawn to it. This is the case for models in Amboise (France), Chicago and Portland (USA), Florence (Italy) and for the one of the traveling exhibition by the Australian company 'Grande Exhibitions' that already visited 40 major cities in the world. All 'replicas' of the bridge model attributed to Leonardo have pillars standing on the deck of the bridge, while the deck is suspended by cables attached on these pillars. At first sight this problem does not catch the attention of the observer, as the bridge seems to be a mixed form of a beam and a suspension bridge, but it was not overlooked by my colleague architect-engineer Dr. Laurens Luyten (Gent, Belgium). Yet, after a TV-interview in Brussels so much pressure was exerted by some of the museum col...

  11. Cable tray fire tests

    International Nuclear Information System (INIS)

    Funds were authorized by the Nuclear Regulatory Commission to provide data needed for confirmation of the suitability of current design standards and regulatory guides for fire protection and control in water reactor power plants. The activities of this program through August 1978 are summarized. A survey of industry to determine current design practices and a screening test to select two cable constructions which were used in small scale and full scale testing are described. Both small and full scale tests to assess the adequacy of fire retardant coatings and full scale tests on fire shields to determine their effectiveness are outlined

  12. Construction and control technology of the main bridge superstructure of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Hong; Luo Chenbin; Zhang Yongtao; You Xinpeng

    2009-01-01

    The Sutong Yangtze River Bridge (short as Sutong Bridge) is now the largest span cable-stayed bridge in the world. The construction of the superstructure of the middle bridge covered several stages including erection of the big block girders for the side span, assistant span and tower area, erection of standard girders and closure of the middle span. The big block girders were hoisted by a floating crane, and the standard girders were hoisted by a double crane system on the deck. The pushing assistant method was adopted for the middle span closure construction. Furthermore, key technologies and innovative methods used in the processes of girder erection and cable assemblage in all stages were expatiated systematically. An all-stage self- adaptive geometry control method was used in the construction process. By accurately controlling the unstressed dimensions and shape of all structural components in each step, and realization that the control system and the controlled system adapt to each other, the goal was to make control of the final line shape and inner force of the bridge structure achievable. Two solutions, including GPS based and total station based dynamic geometry monitoring systems, were used to resolve the measure problem under the wide-range of wind-induced vibrations in the long cantilever state. Finally, research on the wind-induced vibration of the superstructure during the construction period was executed. Buffeting response analysis to the longest single and double cantilever states were carried out. The analysis and evaluation of wind resistance safety of the main girders under the longest single cantilever state was made, and corresponding wind resistance measures were suggested. The as-built geometric error and cable force error were controlled in a required design range, and this whole technological achievement can be a benchmark for construction of other large span cable-stayed bridges in the future.

  13. Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way....

  14. Snap loads and torsional oscillations of the original Tacoma Narrows Bridge

    Science.gov (United States)

    Plaut, R. H.

    2008-01-01

    In 1940, the original Tacoma Narrows Bridge was completed on June 10 and opened to traffic on July 1. On November 7, the deck collapsed. Before that day, significant vertical oscillations had occurred, but no torsion. The bridge as built was stable with respect to torsional motion under the winds of November 7 and previous winds with higher speeds. However, snap loads in the diagonal ties attached to the north midspan cable band helped to loosen the band, and the frictional resistance between the band and the north suspension cable passing through it was overcome. The cable began to slip through the band. For this new structural system, with longitudinal motion of the north cable, the wind speed was higher than the critical speed for torsional flutter, and torsional motion was initiated. Approximately 700 cycles of torsional oscillations occurred during the hour prior to the collapse. In the present study, the snap loads on the cable band are discussed first. Then a continuum model of the central span (deck, cables, and hangers) is formulated. The longitudinal motions of the cables are included, so that the slippage can be incorporated. Known information from the observed steady-state torsional motion is utilized with assumed forms of the vertical cable displacements, and the governing equations provide the horizontal cable displacements, the dynamic tensions in the cables, the vertical and torsional motions of the deck, and the resultant lift force and pitching moment (including damping) acting on the deck during its final hour.

  15. Programmevaluierung Bridge

    OpenAIRE

    Warta, Katharina; Good, Barbara; Geyer, Anton

    2009-01-01

    BRIDGE is an initiative funded by the Ministry for Transport, Innovation and Technology (BMVIT) that aims to close the “funding gap” between basic and applied research in stand-alone projects with the primary objective of jointly developing the potential of basic and applied research. BRIDGE acts as an  umbrella structure under which the Austrian Science Fund (FWF) and the  Austrian Research Promotion Agency (FFG) coordinate two thematically open funding programmes: The ...

  16. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus;

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  17. Electromagnetic Transients in Power Cables

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth

    For more than a century, overhead lines have been the most commonly used technology for transmitting electrical energy at all voltage levels, especially on the highest levels. However, in recent years, an increase in both the number and length of HVAC cables in the transmission networks...... concerning HVAC cables. An important topic that is not covered in this book is measurements protocols/ methods. The protocols used when performing measurements on a cable depend on what is to be measured, the available equipment and accessibility. Readers interested in the topic are referred to search...... of the method. The chapter continues by analysing the frequency-spectrums of cable-based networks which have lower resonance frequencies than usual because of the larger capacitance of the cables. At the same time, a technique that may help save time when plotting the frequency spectrum of a network is proposed...

  18. Length of a Hanging Cable

    Directory of Open Access Journals (Sweden)

    Eric Costello

    2011-01-01

    Full Text Available The shape of a cable hanging under its own weight and uniform horizontal tension between two power poles is a catenary. The catenary is a curve which has an equation defined by a hyperbolic cosine function and a scaling factor. The scaling factor for power cables hanging under their own weight is equal to the horizontal tension on the cable divided by the weight of the cable. Both of these values are unknown for this problem. Newton's method was used to approximate the scaling factor and the arc length function to determine the length of the cable. A script was written using the Python programming language in order to quickly perform several iterations of Newton's method to get a good approximation for the scaling factor.

  19. National Bridge Inventory (NBI) Bridges

    Data.gov (United States)

    Department of Homeland Security — The NBI is a collection of information (database) describing the more than 600,000 of the Nation's bridges located on public roads, including Interstate Highways,...

  20. Cable Aerodynamic Control

    DEFF Research Database (Denmark)

    Kleissl, Kenneth

    categorization of the different control technics together with an identification of two key mechanisms for reduction of the design drag force. During this project extensive experimental work examining the aerodynamics of the currently used cable surface modifications together with new innovative proposals have...... drag force due to the high intensity of streamwise vorticity, whereas the helical fillets resulted in a more gradual flow transition because of the spanwise variation. During yawed flow conditions, the asymmetrical appearance of the helical solution was found to induce a significant lift force with a...... were tested. While a proper discrete helical arrangement of Cylindrical Vortex Generators resulted in a superior drag performance, only systems applying "mini-strakes" were capable of complete rivulet suppression. When the strakes was positioned in a staggered helical arrangement, the innovative system...

  1. Cable Bacteria in Freshwater Sediments.

    Science.gov (United States)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  2. Overlapping reliable control for a cable-stayed bridge benchmark

    Czech Academy of Sciences Publication Activity Database

    Bakule, Lubomír; Paulet-Crainiceanu, F.; Rodellar, J.; Rossell, J. M.

    2005-01-01

    Roč. 13, č. 4 (2005), s. 663-669. ISSN 1063-6536 R&D Projects: GA AV ČR IAA2075304 Institutional research plan: CEZ:AV0Z10750506 Keywords : decentralized control * reliable control * overlapping Subject RIV: BC - Control Systems Theory Impact factor: 1.027, year: 2005

  3. Shape modification of bridge cables for aerodynamic vibration control

    DEFF Research Database (Denmark)

    Kleissl, Kenneth; Georgakis, Christos

    2010-01-01

    found to eliminate the risk of dry inclined galloping, with a reduction in lift fluctuations. Nevertheless, the particular cylinder is at risk of “drag crisis” instability. Finally, turbulent flow is shown to introduce a significant amount of aerodynamic damping by proving a more stable lift force over...... and faceted cylinders are found to suffer from either dry inclined galloping, ”drag crisis” or Den Hartog galloping, the shrouded cylinder is found to be completely stable for all wind angles of attack, albeit with a slight increase in drag at traditional design wind velocities. The wavy cylinder is...

  4. Preliminary probabilistic prediction of ice/snow accretion on stay cables based on meteorological variables

    DEFF Research Database (Denmark)

    Roldsgaard, Joan Hee; Kiremidjian, A.; Georgakis, Christos T.; Faber, Michael Havbro

    The scope of the present paper is to present a framework for assessment of the probability of occurrence of ice/snow accretion on bridge cables. The framework utilizes Bayesian Probabilistic Networks and the methodology is illustrated with an example of the cable-stayed Øresund Bridge. The case...... study focuses on the ice/snow accretion due to the in-cloud icing or precipitation icing mechanisms and includes probabilistic assessments of the meteorological variables influencing the ice/snow accretion on the stay cables. Different probability distribution functions are utilized for the...... representation of the meteorological variables and evaluated both by goodness-of-fit test and qualitatively. Conditional probability curves are developed to predict the amount of ice accretion given a set of meteorological conditions using the Gaussian Kernel Smoothing method. The fitted probability distribution...

  5. Building Bridges

    DEFF Research Database (Denmark)

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...... in the Media”, “Audience Interactivity and Participation”, “The Role of Media and ICT Use for Evolving Social Relationships” and “Audience Transformations and Social Integration”. Building Bridges is the result of an ongoing dialogue between the Action and non-academic stakeholders in the field of audience...

  6. On the cable expansion formula

    OpenAIRE

    Liu, Qihou

    2008-01-01

    In this paper, a generalized version of Morton's formula is proved. Using this formula, one can write down the colored Jones polynomials of cabling of an knot in terms of the colored Jones polynomials of the original knot.

  7. Probabilistic Approach to Fatigue Assessment for Stay Cables

    DEFF Research Database (Denmark)

    Baussaron, Julien; Sørensen, John Dalsgaard; Toft, Henrik Stensgaard;

    2013-01-01

    into account main sources of variability in fatigue prediction for stay cables in cable stayed bridges. The first step of this methodology is to model the variability of each parameter. Loading is one of the most important sources of variability. Another important source of variability is the fatigue strength......In structures submitted to repeated variable loads, initiation and growth of cracks in the material are one of the most common causes of the deterioration of structures, especially in combination with corrosion. Under variable amplitude and repeated loads, some local cracks initiate on critical...... of the material. Probabilistic Wöhler curves are fitted using available data, and used to represent the variability of material fatigue behaviour. Finally, the reliability is assessed using Monte Carlo simulations....

  8. Determination of aerodynamic damping and force coefficients of filleted twin cables in dry conditions through passive-dynamic wind tunnel tests

    DEFF Research Database (Denmark)

    Mattiello, E.; Eriksen, M. B.; Georgakis, Christos T.

    Moderate amplitude vibrations continue to be reported on the Øresund Bridge cables, although fitted with fillets and dampers. To further investigate the aerodynamics of the bridge’s twin-cable arrangement, 1:2.3 scale passive-dynamic wind tunnel tests of the cables were performed at the DTU....../FORCE Technology Climatic Wind Tunnel facility. The measured aerodynamic damping of the twin-cable arrangement in dry conditions was compared to the values obtained from full-scale monitoring and from an analytical model using static force coefficients. The comparison revealed broad agreement in the investigated...

  9. Research on the video detection device in the invisible part of stay cable anchorage system

    Science.gov (United States)

    Cai, Lin; Deng, Nianchun; Xiao, Zexin

    2012-11-01

    The cables in anchorage zone of cable-stayed bridge are hidden within the embedded pipe, which leads to the difficulty for detecting the damage of the cables with visual inspection. We have built a detection device based on high-resolution video capture, realized the distance observing of invisible segment of stay cable and damage detection of outer surface of cable in the small volume. The system mainly consists of optical stents and precision mechanical support device, optical imaging system, lighting source, drived motor control and IP camera video capture system. The principal innovations of the device are ⑴A set of telescope objectives with three different focal lengths are designed and used in different distances of the monitors by means of converter. ⑵Lens system is far separated with lighting system, so that the imaging optical path could effectively avoid the harsh environment which would be in the invisible part of cables. The practice shows that the device not only can collect the clear surveillance video images of outer surface of cable effectively, but also has a broad application prospect in security warning of prestressed structures.

  10. An energy harvesting system using the wind-induced vibration of a stay cable for powering a wireless sensor node

    International Nuclear Information System (INIS)

    This paper proposes an electromagnetic energy harvesting system, which utilizes the wind-induced vibration of a stay cable, and investigates its feasibility for powering a wireless sensor node on the cable through numerical simulations as well as experimental tests. To this end, the ambient acceleration responses of a stay cable installed in an in-service cable-stayed bridge are measured, and then they are used as input excitations in cases of both numerical simulations and experimental tests to evaluate the performance of the proposed energy harvesting system. The results of the feasibility test demonstrate that the proposed system generates sufficient electricity for operation of a wireless sensor node attached on the cable under the moderate wind conditions

  11. Finite element simulations of low-mass readout cables for the CBM Silicon Tracking System using RAPHAEL

    Science.gov (United States)

    Singla, M.; Chatterji, S.; Müller, W. F. J.; Kleipa, V.; Heuser, J. M.

    2014-01-01

    The first three-dimensional simulation study of thin multi-line readout cables using finite element simulation tool RAPHAEL is being reported. The application is the Silicon Tracking System (STS) of the fixed-target heavy-ion experiment Compressed Baryonic Matter (CBM), under design at the forthcoming accelerator center FAIR in Germany. RAPHAEL has been used to design low-mass analog readout cables with minimum possible Equivalent Noise Charge (ENC). Various trace geometries and trace materials have been explored in detail for this optimization study. These cables will bridge the distance between the microstrip detectors and the signal processing electronics placed at the periphery of the silicon tracking stations. SPICE modeling has been implemented in Sentaurus Device to study the transmission loss (dB loss) in cables and simulation has been validated with measurements. An optimized design having minimum possible ENC, material budget and transmission loss for the readout cables has been proposed.

  12. Parametric Vibration and Vibration Reduction of Cables in Cable-stayed Space Latticed Structure

    Institute of Scientific and Technical Information of China (English)

    BAO Yan; ZHOU Dai; LIU Jie

    2008-01-01

    Mechanical model and vibration equation of a cable in cable-stayed sparse latticed structure (CSLS) under external axial excitation were founded. Determination of the mass lumps and natural frequencies supplied by the space latticed structure (SLS) was analyzed. Multiple scales method (MSM) was introduced to analyze the characteristics of cable's parametric vibration, and the precise time-integration method (PTIM) was used to solve vibration equation. The vibration behavior of a cable is closely relative to the frequency ratio of the cable and SLS. The cable's parametric vibration caused by the external axial excitation easily occurs if the frequency ratio of the cable and SLS is in a certain range, and the cable's vibration amplitude varies greatly even if the initial disturbance supplied by SLS changes a little. Furthermore, the mechanical model and vibration equation of the composite cable system consisting of main cables and assistant cables were studied. The parametric analysis such as the pre-tension level and arrangement of the assistant cables was carried out. Due to the assistant cables, the single-cable vibration mode can be transferred to the global vibration mode, and the stiffness and damping of the cable system are enhanced. The natural frequencies of the composite cable system with the curve line arrangement of assistant cables are higher than those with the straight-line arrangement and the former is more effective than the latter on the cable's vibration suppression.

  13. Stone bridges

    Czech Academy of Sciences Publication Activity Database

    Drdácký, Miloš; Slížková, Zuzana

    Prague : Institute of theoretical and applied mechanics AS CR, v.v.i, 2011 - (Drdácký, M.; Binda, L.; Hennen, I.; Kőpp, C.; Lanza, L.), s. 122-129 ISBN 978-80-86246-37-6 Grant ostatní: evropská komise(XE) CHEF-SSPI-044251 Institutional research plan: CEZ:AV0Z20710524 Keywords : flood * stone bridge * cultural heritage Subject RIV: AL - Art, Architecture, Cultural Heritage

  14. Flat conductor cable design, manufacture, and installation

    Science.gov (United States)

    Angele, W.; Hankins, J. D.

    1973-01-01

    Pertinent information for hardware selection, design, manufacture, and quality control necessary for flat conductor cable interconnecting harness application is presented. Comparisons are made between round wire cable and flat conductor cable. The flat conductor cable interconnecting harness systems show major cost, weight, and space savings, plus increased system performance and reliability. The design application section includes electrical characteristics, harness design and development, and a full treatise on EMC considerations. Manufacturing and quality control sections pertain primarily to the developed conductor-contact connector system and special flat conductor cable to round wire cable transitions.

  15. Optical Measurement of Cable and String Vibration

    Directory of Open Access Journals (Sweden)

    Y. Achkire

    1998-01-01

    Full Text Available This paper describes a non contacting measurement technique for the transverse vibration of small cables and strings using an analog position sensing detector. On the one hand, the sensor is used to monitor the cable vibrations of a small scale mock-up of a cable structure in order to validate the nonlinear cable dynamics model. On the other hand, the optical sensor is used to evaluate the performance of an active tendon control algorithm with guaranteed stability properties. It is demonstrated experimentally, that a force feedback control law based on a collocated force sensor measuring the tension in the cable is feasible and provides active damping in the cable.

  16. Health monitoring of Binzhou Yellow River highway bridge using fiber Bragg gratings

    Science.gov (United States)

    Ou, Jinping; Zhao, Xuefeng; Li, Hui; Zhou, Zhi; Zhang, Zhichun; Wang, Chuan

    2005-05-01

    Binzhou yellow river Highway Bridge with 300 meter span and 768 meter length is located in the Shandong province of China and is the first cable stayed bridge with three towers along the yellow river, one of the biggest rivers in China. In order to monitoring the strain and temperature of the bridge and evaluate the health condition, one fiber Bragg grating sensing network consists of about one hundred and thirty FBG sensors mounted in 31 monitoring sections respectively, had been built during three years time. Signal cables of sensors were led to central control room located near the main tower. One four-channel FBG interrogator was used to read the wavelengths from all the sensors, associated with four computer-controlled optic switches connected to each channel. One program was written to control the interrogator and optic switches simultaneously, and ensure signal input precisely. The progress of the monitoring can be controlled through the internet. The sensors embedded were mainly used to monitor the strain and temperature of the steel cable and reinforced concrete beam. PE jacket opening embedding technique of steel cable had been developed to embed FBG sensors safely, and ensure the reliability of the steel cable opened at the same time. Data obtained during the load test can show the strain and temperature status of elements were in good condition. The data obtained via internet since the bridge's opening to traffic shown the bridge under various load such as traffic load, wind load were in good condition.

  17. Full Model Wind Tunnel Study on the Xia-Zhang Bridge Under Operation Stage

    Directory of Open Access Journals (Sweden)

    Ayad T. Saeed

    2010-01-01

    Full Text Available Problem statement: Long-span cable-stayed bridges under service and particular construction conditions are very susceptible to wind action due to their great flexibility, so the aerodynamic stability is becoming a major concern in the design and construction phrases. Cable-stayed bridges may exhibit wind-induced vibration phenomena such as flutter, buffeting and vortex oscillation under wind excitation. The study concentrated on the issues concerning the aerodynamic response of Xia-Zhang cable-stayed Bridge to make it safe and stable under wind action. Although there have been accumulating experience in the building of cable-stayed bridges and research on wind-resistant stability in Chinese Mainland, most of the research focuses on inland cable-stayed bridges or littoral ones of mid-length, but not on littoral ones whose main span is over 600 m. Therefore, wind-resistant performance research of north branch bridge of Xia-Zhang cross-sea Bridges is very necessary and important for its wind-resistant stability, safety and applicability in the operation condition. Approach: This study mainly presented the wind tunnel test program of the Xia-Zhang Bridge aeroelastic full model, including test method, test contents, test results and so on. Results: The test results contained Root Mean Square (RMS of accelerations and displacements as well as average values of displacements. Conclusion: The conclusions were as follows: (a In the uniform flow field, under the condition of entire bridge without rail may vibration divergence occur when α = 3°, V>122 m sec-1. (b No vortex-induced vibration with extreme amplitudes or static collapsing was detected in all the testing conditions. (c In the turbulent flow field, there were very obvious buffeting phenomena. Responses to turbulence are quite intense.

  18. Online Cable Tester and Rerouter

    Science.gov (United States)

    Lewis, Mark; Medelius, Pedro

    2012-01-01

    Hardware and algorithms have been developed to transfer electrical power and data connectivity safely, efficiently, and automatically from an identified damaged/defective wire in a cable to an alternate wire path. The combination of online cable testing capabilities, along with intelligent signal rerouting algorithms, allows the user to overcome the inherent difficulty of maintaining system integrity and configuration control, while autonomously rerouting signals and functions without introducing new failure modes. The incorporation of this capability will increase the reliability of systems by ensuring system availability during operations.

  19. Equalization of data transmission cable

    Science.gov (United States)

    Zobrist, G. W.

    1975-01-01

    The paper describes an equalization approach utilizing a simple RLC network which can obtain a maximum slope of -12dB/octave for reshaping the frequency characteristics of a data transmission cable, so that data may be generated and detected at the receiver. An experimental procedure for determining equalizer design specifications using distortion analysis is presented. It was found that for lengths of 16 PEV-L cable of up to 5 miles and data transmission rates of up to 1 Mbs, the equalization scheme proposed here is sufficient for generation of the data with acceptable error rates.

  20. Development of the communication cable suspending robot. Automation of cable suspending works; Tsushin cable tsurika robot no kaihatsu. Cable tsurika sagyo no jidoka

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, T. [Kansai Electaric Power Co. Inc., Osaka (Japan)

    2000-04-01

    The automatic communication cable suspending robot was developed. For disuse of dangerous stringers and improvement of suspending workability, adoption of the new mechanical high-speed labor-saving cable laying method was decided regardless of current communication cable laying methods. This robot can deal with automatic removal works of existing cable hangers which has been thought to be extremely difficult, and thus integration works of many cables by a cable hanger in cable additional installation work. For easy handling of the robot, the robot body is composed of 6 separated parts such as driving part, power source part, cable draw-in part, hanger attaching part, hanger removing part and hanger recovering part according to each function. For avoiding troubles with telephone lines and CATV lines in city areas, the size and mass of the robot were considered enough. After this, some verification tests on the robot effectiveness including performance test, workability test on dummy poles, and field test are scheduled. (NEDO)

  1. North American Submarine Cable Association (NASCA) Submarine Cables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data show the locations of in-service and out-of-service submarine cables that are owned by members of NASCA and located in U.S. territorial waters. More...

  2. 47 CFR 76.640 - Support for unidirectional digital cable products on digital cable systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Support for unidirectional digital cable products on digital cable systems. 76.640 Section 76.640 Telecommunication FEDERAL COMMUNICATIONS... Standards § 76.640 Support for unidirectional digital cable products on digital cable systems. (a)...

  3. Improvements in electric cable gland seals

    International Nuclear Information System (INIS)

    An electric cable gland seal has a deformable sealing member which is penetrated by cables arranged in annular spaced array, the sealing member being disposed between two spreader plates which when urged together by springs compress and deform the sealing member into sealing contact with the cables, a distributor which holds the cables in the spaced array, and a cylindrical body adapted for sealing about an opening in the wall of a vessel. (UK)

  4. Anti-slip security assessment between main cable and saddle of the middle pylon under extreme vehicle loads

    Institute of Scientific and Technical Information of China (English)

    Cui Jia; Ruan Xin; Zhou Xiaoyi

    2011-01-01

    The traffic condition of Taizhou Yangtze River Bridge is obtained to a certain extent, according to the traffic investigation nearby Taizhou Bridge. The statistical characteristics of the traffic conditions are acquired by statistical analysis. Simulation of the extreme vehicle loads and the sensitive analysis of load parameters are carried out based on these data complemented, which would guide the determination of the frictional coefficient between the main cables and the saddle.

  5. In-plane Auto-Parametric Vibration of Inclined Cables under Random Transverse Excitation

    Institute of Scientific and Technical Information of China (English)

    WANG Bo; ZHANG Hai-long; XU Feng; GUO Cui-cui

    2008-01-01

    In-plane auto-parametric stochastic vibration of inclined cables subjected to Gaussian white noise in transverse bridge orientation is investigated. Based on Newton's laws of motion and Galerkin's modal truncation principle, the influences of geometry nonlinearity induced by sag and large displacement of cables and the initial equilibrium state are taken into account. Meanwhile, the three-dimensional non-linear differential equations of inclined cables for coupling vibration are deduced, equivalent stochastic linearization method is applied to derive the 1A-dimensional first-order nonlinear differential equations of state vectors, and the Runge-Kutta integration method is utilized to obtain the root mean square (RMS) response. Results show that when the transverse random excitation imposed on the stayed cable exceeds a critical value, the in-plane transverse vibration of the cable are excited due to the auto-parametric nonlinear coupling, and the critical value of random excitation increases with the damping ratio. In this motion, the cable response possesses non-stationary characteristics, even though the loading keeps stationary.

  6. Ambient Modal Testing of the Vestvej Bridge using Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune; Rytter, A.

    1998-01-01

    This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the...

  7. Ambient Modal Testing of the Vestvej Bridge using Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune; Rytter, A.

    This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the...

  8. 47 CFR 32.2422 - Underground cable.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Underground cable. 32.2422 Section 32.2422... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2422 Underground cable. (a) This account shall include the original cost of underground cable installed in conduit and...

  9. Your Personal Genie in the Cable.

    Science.gov (United States)

    Schlafly, Hubert J.

    The technology necessary for the use of cable television (TV) has been invented; it simply must be put to use. By the 1970's, cable TV should be commonplace in this country. Its rapid growth was caused in part by its appearance at a time of explosive expansion of related technologies like data theory and computer design. The coaxial cable system…

  10. EMP coupling to multiconductor shielded cables

    International Nuclear Information System (INIS)

    A method is presented for calculating EMP coupling to multiconductor shielded cables by electromagnetic pulse. The induced voltage of inner conductor of the SYV-50-7 cable and SYVZ-9 cable placed on the ground are computed. The computed results agree with those measured

  11. Using Cable Television for Library Data Transmission.

    Science.gov (United States)

    Whitaker, Douglas A.

    1985-01-01

    Discusses information gained from a test of cable data circuits on a Geac bibliographic control system at the Wayne Oakland Library Federation (WOLF) (Michigan). Highlights include an introduction to cable, hardware profile, the WOLF experience, and key questions that will affect the future use of cable for data transmission. (EJS)

  12. Simplified Analytical Method for Optimized Initial Shape Analysis of Self-Anchored Suspension Bridges and Its Verification

    Directory of Open Access Journals (Sweden)

    Myung-Rag Jung

    2015-01-01

    Full Text Available A simplified analytical method providing accurate unstrained lengths of all structural elements is proposed to find the optimized initial state of self-anchored suspension bridges under dead loads. For this, equilibrium equations of the main girder and the main cable system are derived and solved by evaluating the self-weights of cable members using unstrained cable lengths and iteratively updating both the horizontal tension component and the vertical profile of the main cable. Furthermore, to demonstrate the validity of the simplified analytical method, the unstrained element length method (ULM is applied to suspension bridge models based on the unstressed lengths of both cable and frame members calculated from the analytical method. Through numerical examples, it is demonstrated that the proposed analytical method can indeed provide an optimized initial solution by showing that both the simplified method and the nonlinear FE procedure lead to practically identical initial configurations with only localized small bending moment distributions.

  13. 我国桥梁结构分析%Analysis on domestic bridge structure

    Institute of Scientific and Technical Information of China (English)

    苏国天

    2012-01-01

    This article introduces various bridge structures including plate,type bridge, beam-type bridge, cable-stayed bridge, and suspension bridge and so on, respectively illustrates the characteristics, advantages and structure of bridge structures, and points out the future bridge development trend of "the longer, the larger, the softer", which will be taken bridge aesthetics and environment protection into consideration.%针对国内板式桥、梁式桥、斜拉桥、悬索桥等多种桥梁结构进行了介绍,分别阐述了各种桥梁结构的特点、优点及结构组成,指出未来桥梁发展趋势是"更长、更大、更柔",并更加注重桥梁美学及环境保护。

  14. ALOHA Cabled Observatory: Early Results

    Science.gov (United States)

    Howe, B. M.; Lukas, R.; Duennebier, F. K.

    2011-12-01

    The ALOHA Cabled Observatory (ACO) was installed 6 June 2011, extending power, network communications and timing to a seafloor node and instruments at 4726 m water depth 100 km north of Oahu. The system was installed using ROV Jason operated from the R/V Kilo Moana. Station ALOHA is the field site of the Hawaii Ocean Time-series (HOT) program that has investigated temporal dynamics in biology, physics, and chemistry since 1988. HOT conducts near monthly ship-based sampling and makes continuous observations from moored instruments to document and study climate and ecosystem variability over semi-diurnal to decadal time scales. The cabled observatory system will provide the infrastructure for continuous, interactive ocean sampling enabling new measurements as well as a new mode of ocean observing that integrates ship and cabled observations. The ACO is a prototypical example of a deep observatory system that uses a retired first-generation fiber-optic telecommunications cable. Sensors provide live video, sound from local and distant sources, and measure currents, pressure, temperature, and salinity. Preliminary results will be presented and discussed.

  15. 300 Area signal cable study

    International Nuclear Information System (INIS)

    This report was prepared to discuss the alternatives available for removing the 300 Area overhead signal cable system. This system, installed in 1969, has been used for various monitoring and communication signaling needs throughout the 300 Area. Over the years this cabling system has deteriorated, has been continually reconfigured, and has been poorly documented to the point of nonreliability. The first step was to look at the systems utilizing the overhead signal cable that are still required for operation. Of the ten systems that once operated via the signal cable, only five are still required; the civil defense evacuation alarms, the public address (PA) system, the criticality alarms, the Pacific Northwest Laboratory Facilities Management Control System (FMCS), and the 384 annunciator panel. Of these five, the criticality alarms and the FMCS have been dealt with under other proposals. Therefore, this study focused on the alternatives available for the remaining three systems (evacuation alarms, PA system, and 384 panel) plus the accountability aid phones. Once the systems to be discussed were determined, then three alternatives for providing the signaling pathway were examined for each system: (1) re-wire using underground communication ducts, (2) use the Integrated Voice/Data Telecommunications System (IVDTS) already installed and operated by US West, and (3) use radio control. Each alternative was developed with an estimated cost, advantages, and disadvantages. Finally, a recommendation was provided for the best alternative for each system

  16. Advanced method for cable aging evaluation

    International Nuclear Information System (INIS)

    The project of 'Assessment of Cable Aging for Nuclear Power Plants' started in FY2002. Until the end of FY2006, approximately 80% of the planned aging data has been acquired by the cable aging evaluation tests. The LOCA tests for nine kinds of cables were also conducted using the simultaneous aging specimens. Based on these results, the outlines of 'Guidelines for environmental qualification test for cables (Draft)' were developed. And a tentative assessment for seven kinds of cables was made using data acquired until present according to the outlines of guidelines. (author)

  17. Aeolic vibration of aerial electricity transmission cables

    Science.gov (United States)

    Avila, A.; Rodriguez-Vera, Ramon; Rayas, Juan A.; Barrientos, Bernardino

    2005-02-01

    A feasibility study for amplitude and frequency vibration measurement in aerial electricity transmission cable has been made. This study was carried out incorporating a fringe projection method for the experimental part and horizontal taut string model for theoretical one. However, this kind of model ignores some inherent properties such as cable sag and cable inclination. Then, this work reports advances on aeolic vibration considering real cables. Catenary and sag are considered in our theoretical model in such a way that an optical theodolite for measuring has been used. Preliminary measurements of the catenary as well as numerical simulation of a sagged cable vibration are given.

  18. Offshore Cable Installation - Lillgrund. Lillgrund Pilot Project

    Energy Technology Data Exchange (ETDEWEB)

    Unosson, Oscar (Vattenfall Vindkraft AB, Stockholm (Sweden))

    2009-01-15

    This report describes the installation method and the experiences gained during the installation of the submarine cables for the offshore wind farm at Lillgrund. The wind farm consists of 48 wind turbines and is expected to produce 0.33 TWh annually. Different aspects of the installation, such as techniques, co-operation between the installation teams, weather conditions and regulatory and environmental issues are described in this report. In addition, recommendations and guidelines are provided, which hopefully can be utilised in future offshore wind projects. The trenches, in which the submarine cables were laid, were excavated weeks before the cable laying. This installation technique proved to be successful for the laying of the inter array cables. The export cable, however, was laid into position with difficulty. The main reason why the laying of the export cable proved more challenging was due to practical difficulties connected with the barge entrusted with the cable laying, Nautilus Maxi. The barge ran aground a number of times and it had difficulties with the thrusters, which made it impossible to manoeuvre. When laying the inter array cables, the method specification was closely followed, and the laying of the cables was executed successfully. The knowledge and experience gained from the offshore cable installation in Lillgrund is essential when writing technical specifications for new wind plant projects. It is recommended to avoid offshore cable installation work in winter seasons. That will lower the chances of dealing with bad weather and, in turn, will reduce the risks

  19. Aerodynamics of bridge hangers in smooth and turbulent flow and implications on aeroelastic stability

    DEFF Research Database (Denmark)

    Demartino, Cristoforo; Ricciardelli, Francesco; Georgakis, Christos T.

    2015-01-01

    an extruded High Density PolyEthylene (HDPE) circular sheath [1]. In the last 20 years, several bridge cable manufacturers have introduced surface modifications on HDPE sheath in order to reduce the drag and to ensure the aerodynamic stability in all climatic conditions. In the case of plain HDPE...... sheaths, although manufacturers put in place all efforts to obtain smooth, perfectly circular sections, superficial irregularities such as roughness, labeling and ovalling make the aerodynamic behaviour deviate from that of perfect circular cylinder. The imperfections are the result of the manufacturing......The aerodynamics of circular cylinders featuring geometric imperfections, such as bridge cables, has received much attention in recent years due to the recognition that such imperfections can be the cause of large amplitude vibrations. Bridge cables are usually made of strands or wires protected by...

  20. Self-healing cable apparatus and methods

    Science.gov (United States)

    Huston, Dryver (Inventor); Esser, Brian (Inventor)

    2007-01-01

    Self-healing cable apparatus and methods are disclosed. The cable has a central core surrounded by an adaptive cover that can extend over the entire length of the cable or just one or more portions of the cable. The adaptive cover includes a protective layer having an initial damage resistance, and a reactive layer. When the cable is subjected to a localized damaging force, the reactive layer responds by creating a corresponding localized self-healed region. The self-healed region provides the cable with enhanced damage resistance as compared to the cable's initial damage resistance. Embodiments of the invention utilize conventional epoxies or foaming materials in the reactive layer that are released to form the self-healed region when the damaging force reaches the reactive layer.

  1. Power applications for superconducting cables in Denmark

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Østergaard, Jacob; Olsen, S. Krüger

    1999-01-01

    In Denmark a growing concern for environmental protection has lead to wishes that the open country is kept free of overhead lines as far as possible. New lines under 100 kV and existing 60/50 kV lines should be established as underground cables. Superconducting cables represent an interesting...... alternative to conventional cables, as they are able to transmit two or more times the energy than a conventional cable. HTS cables with a room temperature dielectric design are especially interesting as a target for replacing overhead lines. Superconducting cables in the overall network are of interest in...... cases such as transmission of energy into cities and through areas of special interest. The planned large groups of windmills in Denmark generating up to 2000 MVA or more both on dry land and off-shore will be an obvious case for the application of superconducting AC or DC cables. These opportunities...

  2. Gjoea power cable; a green solution

    Energy Technology Data Exchange (ETDEWEB)

    Dretvik, Svein-Egil

    2010-07-01

    An alternative to today's power generation offshore using either gas or diesel, is alternating current (AC) electric power cable from shore. The power from shore through the AC cable gives high savings for the environment. The cable replaces 4 gas turbines with a total CO2 disposal of 240 00 tonnes each year which represents the disposal of 100 000 cars. ABB was awarded the contract which includes engineering, fabrication and installation of the power cable from Mongstad to the Gjoea platform which will be the longest AC cable in the world with a total length of 100 km. The presentation will include system design, qualification of dynamic power cable, cable fabrication experiences, testing at fabrication yard and installation aspects. (Author)

  3. Electrical testing of generator station cables

    International Nuclear Information System (INIS)

    Tests have been performed at a decommissioned nuclear plant to assess the ability of electrical diagnostic tests to determine the remaining life of cable insulation. Power and control cables with either SBR or PVC insulation were tested. These materials are typical of cables in plants built before 1960. Insulation resistance, capacitance, dissipation factor and partial discharge activity were not correlated to the dc breakdown voltage of the cables, which is taken as a measure of insulation condition. Thus it is uncertain if such tests can be used to predict remaining life, especially if historical data has not been collected. All the cables had very high dc breakdown voltages, which was consistent with the generally good physical condition of the cables. Based on this limited study, it seems that hipot tests may be the only convenient electrical method currently available to assure the condition of cables in a generating station undergoing life extension. However more work is needed to determine suitable hipot test voltages

  4. Modeling Magnetic Fields from a DC Power Cable Buried Beneath San Francisco Bay Based on Empirical Measurements.

    Science.gov (United States)

    Kavet, Robert; Wyman, Megan T; Klimley, A Peter

    2016-01-01

    The Trans Bay Cable (TBC) is a ±200-kilovolt (kV), 400 MW 85-km long High Voltage Direct Current (DC) buried transmission line linking Pittsburg, CA with San Francisco, CA (SF) beneath the San Francisco Estuary. The TBC runs parallel to the migratory route of various marine species, including green sturgeon, Chinook salmon, and steelhead trout. In July and August 2014, an extensive series of magnetic field measurements were taken using a pair of submerged Geometrics magnetometers towed behind a survey vessel in four locations in the San Francisco estuary along profiles that cross the cable's path; these included the San Francisco-Oakland Bay Bridge (BB), the Richmond-San Rafael Bridge (RSR), the Benicia-Martinez Bridge (Ben) and an area in San Pablo Bay (SP) in which a bridge is not present. In this paper, we apply basic formulas that ideally describe the magnetic field from a DC cable summed vectorially with the background geomagnetic field (in the absence of other sources that would perturb the ambient field) to derive characteristics of the cable that are otherwise not immediately observable. Magnetic field profiles from measurements taken along 170 survey lines were inspected visually for evidence of a distinct pattern representing the presence of the cable. Many profiles were dominated by field distortions unrelated to the cable caused by bridge structures or other submerged objects, and the cable's contribution to the field was not detectable. BB, with 40 of the survey lines, did not yield usable data for these reasons. The unrelated anomalies could be up to 100 times greater than those from the cable. In total, discernible magnetic field profiles measured from 76 survey lines were regressed against the equations, representing eight days of measurement. The modeled field anomalies due to the cable (the difference between the maximum and minimum field along the survey line at the cable crossing) were virtually identical to the measured values. The modeling

  5. Modeling Magnetic Fields from a DC Power Cable Buried Beneath San Francisco Bay Based on Empirical Measurements.

    Directory of Open Access Journals (Sweden)

    Robert Kavet

    Full Text Available The Trans Bay Cable (TBC is a ±200-kilovolt (kV, 400 MW 85-km long High Voltage Direct Current (DC buried transmission line linking Pittsburg, CA with San Francisco, CA (SF beneath the San Francisco Estuary. The TBC runs parallel to the migratory route of various marine species, including green sturgeon, Chinook salmon, and steelhead trout. In July and August 2014, an extensive series of magnetic field measurements were taken using a pair of submerged Geometrics magnetometers towed behind a survey vessel in four locations in the San Francisco estuary along profiles that cross the cable's path; these included the San Francisco-Oakland Bay Bridge (BB, the Richmond-San Rafael Bridge (RSR, the Benicia-Martinez Bridge (Ben and an area in San Pablo Bay (SP in which a bridge is not present. In this paper, we apply basic formulas that ideally describe the magnetic field from a DC cable summed vectorially with the background geomagnetic field (in the absence of other sources that would perturb the ambient field to derive characteristics of the cable that are otherwise not immediately observable. Magnetic field profiles from measurements taken along 170 survey lines were inspected visually for evidence of a distinct pattern representing the presence of the cable. Many profiles were dominated by field distortions unrelated to the cable caused by bridge structures or other submerged objects, and the cable's contribution to the field was not detectable. BB, with 40 of the survey lines, did not yield usable data for these reasons. The unrelated anomalies could be up to 100 times greater than those from the cable. In total, discernible magnetic field profiles measured from 76 survey lines were regressed against the equations, representing eight days of measurement. The modeled field anomalies due to the cable (the difference between the maximum and minimum field along the survey line at the cable crossing were virtually identical to the measured values. The

  6. 大连长山大桥主桥合拢段施工方案%Construction Program of the Main Bridge Closure Section of Dalian Changshan Bridge

    Institute of Scientific and Technical Information of China (English)

    潘宇

    2015-01-01

    The main bridge of Changshan Bridge is twin towers and double cable planes three-span prestressed concrete extradosed cable-stayed bridge, whose main span is 260m, so it has the largest span in the same type of bridge. The main beam uses the prestressed concrete single box three rooms streamlined flat box girder. This paper briefly introduces the construction of main beam closure section.%长山大桥工程主桥为双塔双索面三跨预应力混凝土矮塔斜拉桥,主跨260m,为国内同类型桥梁最大跨径。主梁采用预应力混凝土单箱三室流线型扁平箱梁。文章就主梁合拢段施工作简要介绍。

  7. Study on the effects of cable sliding motion on the seismic response of cable tray

    International Nuclear Information System (INIS)

    In various industrial plants such as thermal power plants, nuclear power plants or chemical plants, many cable trays are generally used for supporting cables by which control signals will be transmitted. Cable trays are generally made by thin steel plates both sides of which are folded in the vertical direction, while cables are simply placed on the tray. Thus, cables begin to slides when the response acceleration of trays exceeds some amount of value. Consequently, seismic responses of cable tray will also depend on the occurrence of sliding motion of cables. Therefore, cable trays are seen as highly nonlinear structural systems. In this study, seismic responses of the cable tray are investigated analytically considering the cable sliding motions. A cable tray is modeled by a two-degree-of-freedom system. Response acceleration and displacement of the tray and the cable are evaluated for seismic inputs. It is confirmed that the sliding motion of the cable has very large influences on the seismic responses of the cable tray. (author)

  8. Field Application of Cable Tension Estimation Technique Using the h-SI Method

    Directory of Open Access Journals (Sweden)

    Myung-Hyun Noh

    2015-01-01

    Full Text Available This paper investigates field applicability of a new system identification technique of estimating tensile force for a cable of long span bridges. The newly proposed h-SI method using the combination of the sensitivity updating algorithm and the advanced hybrid microgenetic algorithm can allow not only avoiding the trap of local minimum at initial searching stage but also finding the optimal solution in terms of better numerical efficiency than existing methods. First, this paper overviews the procedure of tension estimation through a theoretical formulation. Secondly, the validity of the proposed technique is numerically examined using a set of dynamic data obtained from benchmark numerical samples considering the effect of sag extensibility and bending stiffness of a sag-cable system. Finally, the feasibility of the proposed method is investigated through actual field data extracted from a cable-stayed Seohae Bridge. The test results show that the existing methods require precise initial data in advance but the proposed method is not affected by such initial information. In particular, the proposed method can improve accuracy and convergence rate toward final values. Consequently, the proposed method can be more effective than existing methods in terms of characterizing the tensile force variation for cable structures.

  9. Variation of Strouhal number on iced cable in sub-transitional range

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Stanislav; Górski, P.; Kuznetsov, Sergeii; Tatara, M.; Marušić, A.

    Prague: Institute of theoretical and applied mechanics, Academy of Sciences of the Czech Republic, v. v. i., 2015 - (Náprstek, J.; Fischer, C.), s. 238-239 ISBN 978-80-86246-42-0. ISSN 1805-8248. [Engineering mechanics 2015 /21./. Svratka (CZ), 11.05.2015-14.05.2015] Institutional support: RVO:68378297 Keywords : bridge cable * ice accretion * Strouhal number * angle of attack * vortex shedding frequency Subject RIV: JM - Building Engineering

  10. Reduce Nb3Sn Strand Deformation when Fabricating High Jc Rutherford Cables

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Xuan Peng

    2012-12-17

    During Phase I, our efforts were to reduce subelements deformation when fabricating Nb3Sn Rutherford cables. Our first focus is on 217-sublement tube type strand. We successfully made a few billets in ¾” OD tube with different Cu spacing between subelements, and supplied the strands to Fermi Lab for cabling. Through the rolling test characterization, these types of strands did not have enough bonding between subelements to withstand the deformation. We saw copper cracking between subelements in the deformed strands. We scaled up the billet from ¾” OD to 1.5” OD, and made two billets. This greatly improves the bonding. There is no copper cracking in the deformed strands when we scaled up the diameter of the billets. Fermi Lab successfully made cables using one of this improved strands. In their cables, no Cu cracking and no filament bridging occurred. We also successfully made a couple of billets with hex OD and round ID subelements for 61-subelement restack. Due to the lack of bonding, we could not judge its cabling property properly. But we know through this experiment, we could keep the Nb round, once we select the proper Cu spacing.

  11. Discrete wavelet transform to improve guided-wave-based health monitoring of tendons and cables

    Science.gov (United States)

    Rizzo, Piervincenzo; Lanza di Scalea, Francesco

    2004-07-01

    Multi-wire steel strands are used in civil structures as pre-stressing tendons in prestressed concrete and as stay-cables in cable-stayed and suspension bridges. Monitoring the structural performance of these components is important to ensure the proper functioning and safety of the entire structure. Among the various NDE techniques that are under investigation for monitoring tendons and cables, the use of ultrasonic guided waves shows good promises. The main advantage of this approach is the possibility for the simultaneous monitoring of loads and detection of defects, such as corrosion and broken wires, by using the same ultrasonic setup. Load monitoring is achieved by measuring the travel time of the wave across a given length of the cable. Defect detection is achieved by measuring the reflections of the wave from the geometrical discontinuities. The new contributions of the current paper are two-fold. First, the study identifies those ultrasonic frequencies propagating with low attenuation for long-range defect detection. Second, the technique is substantially improved by implementing the Discrete Wavelet Transform (DWT) as a data post-processing tool. The data de-noising and data compression abilities of the DWT allow for greater sensitivity, larger ranges and higher monitoring speed. It is shown that the implementation of the DWT in the ultrasonic guided-wave technique becomes necessary for monitoring tendons and cables in the field.

  12. Low Friction Cryostat for HTS Power Cable of Dutch Project

    NARCIS (Netherlands)

    Chevtchenko, O.; Zuijderduin, R.; Smit, J.; Willen, D.; Lentge, H.; Thidemann, C.; Traeholt, C.

    2012-01-01

    Particulars of 6 km long HTS AC power cable for Amsterdam project are: a cable has to fit in an annulus of 160 mm, with only two cooling stations at the cable ends [1]. Application of existing solutions for HTS cables would result in excessively high coolant pressure drop in the cable, possibly affe

  13. Bridge SHM system based on fiber optical sensing technology

    Science.gov (United States)

    Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

    2015-09-01

    The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

  14. Stress and noises of steel box girders in Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Xue Tao; Chen Zhijian; Dong Xuewu

    2008-01-01

    Sutong Bridge is a cable-stayed bridge with a main span of 1 088 m.370 high-precision stress monitoring measured data show that in the process of hoisting the steel box girders,the stress of the main girders is in the fluctuant and complex state and many meteorological factors,such as sunshine radiation,temperature and wind,have important influence on the change of stress of the steel box girders.According to the real-time weather data,the stress data after the process of wavelet denoising from representative measuring points in different weather conditions is picked to estab-lish the stress response brought by meteorological factors with Layered Separation method,thereby basically eliminating the influence of meteorological factors on the stress of main girders,so that accurate and reliable stress data can be got for steel box girders adjustment and cable-tensioned construction control.

  15. Occupational Asthma in a Cable Manufacturing Company

    OpenAIRE

    Attarchi, Mirsaeed; Dehghan, Faezeh; Yazdanparast, Taraneh; Mohammadi, Saber; Golchin, Mahdie; Sadeghi, Zargham; Moafi, Masoud; Seyed Mehdi, Seyed Mohammad

    2014-01-01

    Background: During the past decade, incidence of asthma has increased, which might have been due to environmental exposures. Objectives: Considering the expansion of cable manufacturing industry in Iran, the present study was conducted to evaluate the prevalence of occupational asthma in a cable manufacturing company in Iran as well as its related factors. Patients and Methods: This study was conducted on employees of a cable manufacturing company in Yazd, Iran, in 2012. The workers were divi...

  16. Review of high voltage direct current cables

    OpenAIRE

    Chen, George; Miao, Hao; Z. Xu; A. S. Vaughan; Cao, Junzheng; Wang, Haitian

    2015-01-01

    Increased renewable energy integration and international power trades have led to the construction and development of new HVDC transmission systems. HVDC cables, in particular, play an important role in undersea power transmission and offshore renewable energy integration having lower losses and higher reliability. In this paper, the current commercial feasibility of HVDC cables and the development of different types of HVDC cables and accessories are reviewed. The non-uniform electric field ...

  17. Innovative configurations for long-span suspension bridges

    OpenAIRE

    Bartoli, G.; P. D’Asdia; S. Febo; C. Mannini; S. Noè; L. Procino

    2009-01-01

    This paper reports the results of a piece of research about long-span suspension bridges with multiple-box girder steel deck characterized by low drag coefficient and high aeroelastic stability. For this type of bridges, by increasing the span length, the contribution to the stiffness of the suspension cables becomes dominant with respect to that of the deck, so that the ratio of the frequency of the first torsional mode to the frequency of the first vertical bending mode approaches unity, wh...

  18. How do you like them cables?

    CERN Multimedia

    Sergei Malyukov

    Cabling work is not for clautrophobic people! Cables are like the blood vessels and nervous system of ATLAS. With the help of all these cables, we can power ATLAS, control the detector and read out the data. Like the human blood vessels, they penetrate inside the ATLAS volume, reaching each of its elements. The ATLAS developers started to think about design of services, cables and pipes at the very first stages of the project. The cabling project has been developing most intensively during the last five years, passing through the projection and CAD design phases, then the installation of cable trays and finally the cables. The cable installation itself took two and a half years and was done by teams of technicians from several institutes from Russia, the Czech Republic and Poland. Here are some numbers to illustrate the scale of the ATLAS cabling system. More than 25000 optical fiber channels are used for reading the information from the sub-detectors and delivering the timing signals. The total numbe...

  19. Feasibility Study on Tension Estimation Technique for Hanger Cables Using the FE Model-Based System Identification Method

    Directory of Open Access Journals (Sweden)

    Kyu-Sik Park

    2015-01-01

    Full Text Available Hanger cables in suspension bridges are partly constrained by horizontal clamps. So, existing tension estimation methods based on a single cable model are prone to higher errors as the cable gets shorter, making it more sensitive to flexural rigidity. Therefore, inverse analysis and system identification methods based on finite element models are suggested recently. In this paper, the applicability of system identification methods is investigated using the hanger cables of Gwang-An bridge. The test results show that the inverse analysis and systemic identification methods based on finite element models are more reliable than the existing string theory and linear regression method for calculating the tension in terms of natural frequency errors. However, the estimation error of tension can be varied according to the accuracy of finite element model in model based methods. In particular, the boundary conditions affect the results more profoundly when the cable gets shorter. Therefore, it is important to identify the boundary conditions through experiment if it is possible. The FE model-based tension estimation method using system identification method can take various boundary conditions into account. Also, since it is not sensitive to the number of natural frequency inputs, the availability of this system is high.

  20. Fiber reinforced polymer composites for bridge structures

    Directory of Open Access Journals (Sweden)

    Alexandra CANTORIU

    2013-12-01

    Full Text Available Rapid advances in construction materials technology have led to the emergence of new materials with special properties, aiming at safety, economy and functionality of bridges structures. A class of structural materials which was originally developed many years ago, but recently caught the attention of engineers involved in the construction of bridges is fiber reinforced polymer composites. This paper provides an overview of fiber reinforced polymer composites used in bridge structures including types, properties, applications and future trends. The results of this study have revealed that this class of materials presents outstanding properties such as high specific strength, high fatigue and environmental resistance, lightweight, stiffness, magnetic transparency, highly cost-effective, and quick assembly, but in the same time high initial costs, lack of data on long-term field performance, low fire resistance. Fiber reinforced polymer composites were widely used in construction of different bridge structures such as: deck and tower, I-beams, tendons, cable stands and proved to be materials for future in this field.

  1. Aerodynamic stability of long span suspension bridges with low torsional natural frequencies

    DEFF Research Database (Denmark)

    Andersen, Michael Styrk; Johansson, Jens; Brandt, Anders; Hansen, Svend Ole

    2016-01-01

    Classical flutter of suspended bridge decks can be avoided if the torsional frequencies are lower than the vertical. Wind tunnel tests of single boxes and twin box section models with torsional natural frequencies above and below the vertical frequency has been conducted. Flutter was avoided in all...... order to design aerodynamically stable suspension bridges with low torsional natural frequencies it is suggested to increase the mass moment of inertia and provide adequate torsional stiffness by the main cables spacing....

  2. Research on the special lifting devices for steel box girders of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Chen Ming; Wu Qihe; Luo Chengbin; Zhou Hanfa

    2009-01-01

    Sutong Bridge is a cable-stayed bridge with a steel box girder and a main span of 1 088 m. The steel box girder of main span includes five portions: back span large unit, large block of pylon, standard girder, back span closure girder and middle span closure girder. Each back span large unit is fabricated by welding several deck segments together in factory, and is erected by floating crane. As navigational clearance of the main bridge is high, the traditional truss lifting device can' t satisfy the requirement of domestic lifting cranes for this kind of lifting height and weight. Hence, a kind of lighter lifting device for the erection of back span large units was accepted for this bridge. In this paper, the design and use of this lifting device is introduced.The upper structure used lifting gantry to install the standard girder segment by cantilever method. Because the bridge's navigation clearance is high, and the girder segment is wide and heavy, the meteorology and hydrology condition of the bridge district is abominable, and the requirements of long cable girder side pull-in, structure and performance propose high request to the lifting gantry. In this paper, the design and use key point of long cable pull-in angle adjustment device integrate into lifting gantry is introduced.

  3. Local Government Uses of Cable Television.

    Science.gov (United States)

    Cable Television Information Center, Washington, DC.

    The local government cable access channel is essentially a television station completely controlled by the local government. It differs from a local broadcast television station by being able to reach only those places which are connected to the cable system, having much less programming distribution costs, and having the capacity to deliver…

  4. Assessment of sodium conductor distribution cable

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    The study assesses the barriers and incentives for using sodium conductor distribution cable. The assessment considers environmental, safety, energy conservation, electrical performance and economic factors. Along with all of these factors considered in the assessment, the sodium distribution cable system is compared to the present day alternative - an aluminum conductor system. (TFD)

  5. 21 CFR 890.1175 - Electrode cable.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrode cable. 890.1175 Section 890.1175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1175 Electrode cable....

  6. 14 CFR 25.689 - Cable systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cable systems. 25.689 Section 25.689... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.689 Cable systems. (a... smaller than 1/8 inch in diameter may be used in the aileron, elevator, or rudder systems; and (2)...

  7. Cable Television: Its Urban Context and Programming.

    Science.gov (United States)

    Warthman, Forrest

    Cable television's future in urban settings is discussed in the context of alternative media capable of serving similar markets with similar programing. In addition to cable television, other transmission networks such as the telephone network, radio and television broadcasting, microwave networks, domestic satellites, and recording media are…

  8. Optical cable fault locating using Brillouin optical time domain reflectometer and cable localized heating method

    International Nuclear Information System (INIS)

    A novel optical cable fault location method, which is based on Brillouin optical time domain reflectometer (BOTDR) and cable localized heating, is proposed and demonstrated. In the method, a BOTDR apparatus is used to measure the optical loss and strain distribution along the fiber in an optical cable, and a heating device is used to heat the cable at its certain local site. Actual experimental results make it clear that the proposed method works effectively without complicated calculation. By means of the new method, we have successfully located the optical cable fault in the 60 km optical fiber composite power cable from Shanghai to Shengshi, Zhejiang. A fault location accuracy of 1 meter was achieved. The fault location uncertainty of the new optical cable fault location method is at least one order of magnitude smaller than that of the traditional OTDR method

  9. Optical cable fault locating using Brillouin optical time domain reflectometer and cable localized heating method

    Science.gov (United States)

    Lu, Y. G.; Zhang, X. P.; Dong, Y. M.; Wang, F.; Liu, Y. H.

    2007-07-01

    A novel optical cable fault location method, which is based on Brillouin optical time domain reflectometer (BOTDR) and cable localized heating, is proposed and demonstrated. In the method, a BOTDR apparatus is used to measure the optical loss and strain distribution along the fiber in an optical cable, and a heating device is used to heat the cable at its certain local site. Actual experimental results make it clear that the proposed method works effectively without complicated calculation. By means of the new method, we have successfully located the optical cable fault in the 60 km optical fiber composite power cable from Shanghai to Shengshi, Zhejiang. A fault location accuracy of 1 meter was achieved. The fault location uncertainty of the new optical cable fault location method is at least one order of magnitude smaller than that of the traditional OTDR method.

  10. Electrohydrodynamic pumping in cable pipes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crowley, J.M.; Chato, J.C.

    1983-02-01

    Many oil-insulated electric power cables are limited by heat buildup caused in part by the low thermal conductivity of the oil. Circulation of the oil is known to reduce the cable temperature, but can lead to excessive pressure buildup on long cables when using conventional pumping methods. An alternate pumping method using distributed electric fields to avoid this pressure buildup is described. Electrohydrodynamic (EHD) pumping was studied both theoretically and experimentally for possible application in underground cable cooling. Theoretical studies included both analytical and finite-element analysis of the flow patterns driven by travelling electric fields. Experimentally, flow rates in a cable-pipe model were measured under a wide variety of operating conditions. Theory and experiment are in agreement for velocities below 10 cm/s, but higher velocities could not be reached in the experiment, due to increased electroconvection and, possibly, turbulence.

  11. Behaviour of electrical cables under fire conditions

    International Nuclear Information System (INIS)

    A Fire Probabilistic Safety Assessment - called the Fire PSA - is being carried out by the French Institute of Radiological Protection and Nuclear Safety (IPSN) to be used in the framework of the safety assessment of operating 900 MWe PWRs. The aim of this study is to evaluate the core damage conditional probability which could result from a fire. A fire can induce unavailability of safety equipment, notably damaging electrical cables introducing a significant risk contributor. The purpose of this paper is to present the electrical cable fire tests carried out by IPSN to identify the failure modes and to determine the cable damage criteria. The impact of each kind of cable failure mode and the methodology used to estimate the conditional probability of a failure mode when cable damage occurred is also discussed. (orig.)

  12. Modal identification of long-span Runyang Bridge using ambient responses recorded by SHMS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Runyang Bridge is a newly built cable-supported bridge that crosses the Yangtze River in China.The bridge is composed of one suspension bridge and one cable-stayed bridge.During the construction of the bridge,a structural health monitoring system(SHMS)was installed,which was designed by the Southeast University.Since the bridge was open to traffic,quantities of structural ambient responses have been recorded by the SHMS.And,it’s really important to extract structrural information from these records for health monitoring.This paper presents the study on modal identification of the bridge.The dynamic properites including modal frequencies,mode shapes and damping ratios are extracted from the ambient responses.Two identification methods are employed including the enhanced frequency domain decomposition and the stochastic subspace identification.The identified modal parameters from the two methods are compared.Results show that modal frequencies and mode shapes from the two methods are almost the same while the damping ratios are different.

  13. Bridge ice accretion and de- and anti-icing systems: A review

    DEFF Research Database (Denmark)

    Kleissl, Kenneth; Georgakis, Christos

    turn lead to severe financial losses. This paper presents a review of the different de- and anti-icing techniques, already developed or in development, which could be applied to bridge cables or pylons. Furthermore, the fundamentals of icing caused by freezing precipitation and in-cloud icing are...

  14. Sudden lateral asymmetry and torsional oscillations of section models of suspension bridges

    Science.gov (United States)

    Plaut, R. H.; Davis, F. M.

    2007-11-01

    Cable-supported bridges typically exhibit minimal torsional motion under traffic and wind loads. If symmetry of the bridge about the deck's centerline is suddenly lost, such as by the failure of one or more cables or hangers (suspenders), torsional motion of the deck may grow and angles of twist may become large. The initiation of the disastrous torsional oscillations of the original Tacoma Narrows Bridge involved a sudden lateral asymmetry due to loosening of a cable band at midspan. The effects of these types of events on two-degree-of-freedom and four-degree-of-freedom section models of suspension bridges are analyzed. Vertical and rotational motions of the deck, along with vertical motions of the cables, are considered. A harmonic vertical force and an aerodynamic moment proportional to angular velocity are applied to the deck. Resistance is provided by translational and rotational springs and dashpots. Flutter instability and large oscillations occur under the aerodynamic moment, which provides "negative damping." In order to model the occurrence of limit cycles, nonlinear damping of the van der Pol type is included in one case, and nonlinear stiffness of the hangers in others. The frequencies of the limit cycles are compared to the natural frequencies of the system.

  15. Design and Evaluation of Ybco Cable for the Albany Hts Cable Project

    Science.gov (United States)

    Ohya, M.; Yumura, H.; Ashibe, Y.; Ito, H.; Masuda, T.; Sato, K.

    2008-03-01

    The Albany Cable Project's aim is to develop a 350 meter long HTS cable system with a capacity of 800 A at 34.5 kV, located between two substations in the National Grid Power Company's grid. In-grid use of BSCCO HTS cable began on July 20, 2006, and successful long-term operation proceeded as planned. The cable system consists of two cables, one 320 meters long and the other 30 meters, a cable-to-cable splice in a vault, two terminations, and a cooling system. In Phase-II of the Albany project, this autumn, the 30-meter section will be replaced with YBCO cable. The test manufacturing and evaluation of YBCO cable has been carried out using SuperPower's YBCO wires in order to confirm the credibility of the cable design. No degradation of the critical current was found at any stage of manufacture. The fault-current test, involving a 1-meter sample carrying 23 kA at 38 cycles, was conducted under open-bath conditions. The temperature increases at the conductor and shield were comparable to those of the BSCCO core, and no Ic degradation was found after the fault-current test. After the design suitability was confirmed, a 30-meter YBCO cable was manufactured. The critical current of the conductor and the shield were approximately 2.6 kA and 2.4 kA, respectively, almost the same as the design values, considering the wire's Ic and the effect of the magnetic field. The AC loss of the sample cable was 0.34 W/m/phase at 800 Arms and 60 Hz. Following favorable shipping test results, the YBCO cable was shipped to the United States, and arrived at the site in June 2007.

  16. Non-cable vehicle guidance

    Energy Technology Data Exchange (ETDEWEB)

    Daugela, G.C.; Willott, A.M.; Chopiuk, R.G.; Thornton, S.E.

    1988-06-01

    The purpose is to determine the most promising driverless mine vehicle guidance systems that are not dependent on buried cables, and to plan their development. The project is presented in two phases: a preliminary study and literature review to determine whether suitable technologies exist to justify further work; and an in-depth assessment and selection of technologies for vehicle guidance. A large number of guidance elements are involved in a completely automated vehicle. The technologies that hold the best potential for development of guidance systems for mine vehicles are ultrasonics, radar, lasers, dead reckoning, and guidance algorithms. The best approach to adaptation of these technologies is on a step by step basis. Guidance modules that are complete in themselves and are designed to be integrated with other modules can provide short term benefits. Two modules are selected for development: the dragline operations monitor and automated machine control for optimized mining (AMCOM). 99 refs., 20 figs., 40 tabs.

  17. Self-healing cable for extreme environments

    Science.gov (United States)

    Huston, Dryver R. (Inventor); Tolmie, Bernard R. (Inventor)

    2009-01-01

    Self-healing cable apparatus and methods disclosed. The self-healing cable has a central core surrounded by an adaptive cover that can extend over the entire length of the self-healing cable or just one or more portions of the self-healing cable. The adaptive cover includes an axially and/or radially compressible-expandable (C/E) foam layer that maintains its properties over a wide range of environmental conditions. A tape layer surrounds the C/E layer and is applied so that it surrounds and axially and/or radially compresses the C/E layer. When the self-healing cable is subjected to a damaging force that causes a breach in the outer jacket and the tape layer, the corresponding localized axially and/or radially compressed portion of the C/E foam layer expands into the breach to form a corresponding localized self-healed region. The self-healing cable is manufacturable with present-day commercial self-healing cable manufacturing tools.

  18. Power plant practices to ensure cable operability

    International Nuclear Information System (INIS)

    This report describes the design, installation, qualification, maintenance, and testing of nuclear power plant cables with regard to continued operability. The report was initiated after questions arose concerning inadvertent abuse of cables during installation at two nuclear power plants. The extent of the damage was not clear and there was a concern as to whether cables, if damaged, would be able to function under accident conditions. This report reviews and discusses installation practices in the industry. The report also discusses currently available troubleshooting and in-situ testing techniques and provides cautions for some cases which may lead to further cable damage. Improved troubleshooting techniques currently under development are also discussed. These techniques may reduce the difficulty of testing while being able to identify cable flaws more definitively. The report finds, in general, that nuclear power plant cables have been relatively trouble-free; however, there is a need for further research and development of troubleshooting techniques which will make cable condition testing easier and more reliable. Also, recommendations for ''good'' installation practices are needed

  19. Study on the Fault Location Method for Power Cables using the Time-frequency Analysis

    Science.gov (United States)

    Kobayashi, Shin'ichi; Morimoto, Nozomi; Miyajima, Kazuhisa; Hozumi, Naohiro

    The pulse radar method is one of fault location methods for power cables. It locates the breakdown point by measuring the delay time of the echo or the discharge signal coming from the breakdown point. The equipment for the pulse radar method is more compact compared with the Murray loop bridge, and its operation is more simple because sensitive adjustments of proportion are not needed. However the signal propagating through the cable is distorted depending on the distance and frequency, leading to a poor accuracy for the location. In this report, signal processing in the time-frequency domain is proposed to solve this problem. The pulse waveforms received at two different terminals of the cable were extracted by a window function, and subsequently Fourier transformed in order to calculate the phase difference at an appropriate frequency. A special care was taken for un-wrapping the folded phase spectrum. The phase difference was interpreted as the time lag at an identical frequency. The technique was applied to the fault location for a full size XLPE cable line.

  20. Design and construction of scour protection for deep-water group pile foundation structures of two pylons in the Sutong Bridge project

    Institute of Scientific and Technical Information of China (English)

    He Ping; Guan Yijun; Zhang Xiongwen; Zhang Qun; Zhou Jianhua

    2009-01-01

    Sutong Bridge, as a world-record cable-stayed bridge with its main span exceeding 1 000 m constructed in Yangtze River estuary region in China, is located at a site with complicated hydrologic conditions and poor geotechnical conditions and therefore, scour protection will be a decisive factor for ensuring smooth and successful construction of this bridge. This paper, starting from structural description of deep-water group pile foundation, analyzes impact to the bridge safety introduced by scour and its protection and further presents different solutions of scour protection for foundation structures of this bridge.

  1. 47 CFR 32.2424 - Submarine & deep sea cable.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  2. Basic cable routing guidelines for a fast reactor plant

    International Nuclear Information System (INIS)

    In this paper the guidelines evolved for cable routing in 500 MWe Prototype Fast Breeder Reactor (PFBR) are presented. Safety related redundant system cables in a nuclear plant shall not become unavailable due to cable fire. This is ensured by proper cable routing in the plant in addition to the other general fire protection measures

  3. Cable Television 1980: Status and Prospect for Higher Education.

    Science.gov (United States)

    Baus, F., Ed.

    Baseline information for the would-be cable television educational programer is provided by two papers, one an overview of the state of the cable television industry, and the other a report on a marketing study conducted to determine consumer attitudes toward cable TV as an educational medium. In "The Promise and Reality of Cable Television,"…

  4. A unique cabling machine designed to produce rutherford-type superconducting cable for the SSC project

    International Nuclear Information System (INIS)

    Up to 25,000 Km of keystoned flat cable must be produced for the SSC project. Starting from a specification developed by Lawrence Berkeley Laboratory (LBL), a special cabling machine has been designed by Dour Metal. It has been designed to be able to run at a speed corresponding to a maximum production rate of 10 m/min. This cabling machine is the key part of the production line which consists of a precision Turkshead equipped with a variable power drive, a caterpillar, a dimensional control bench, a data acquisition system, and a take-up unit. The main features of the cabling unit to be described are a design with nearly equal path length between spool and assembling point for all the wires, and the possibility to run the machine with several over- or under-twisting ratios between cable and wires. These requirements led Dour Metal to the choice of an unconventional mechanical concept for a cabling machine

  5. Wind Resistant Design of Bridges in Japan Developments and Practices

    CERN Document Server

    Fujino, Yozo; Tanaka, Hiroshi

    2012-01-01

    For long-span bridges, wind action is a dominant factor in their safety and serviceability. A large number of long-span bridges have been built in Japan over the past 30 years, and tremendous amounts of research and technical development have been accomplished in wind resistant design. This book is a compilation of the results of active research and development. Wind resistant design standards generated in Japan are described in the first few chapters. Then comes information such as design wind speed, structural damping, wind tunnel tests, and analyses, which provide the basis of the design standards. Wind-induced vibrations and their control of girders, towers, cables, and other features are explained with examples of field measurements. Comprehensive listings of Japanese experience in vibration control are also presented. Because achieving particularly dynamic safety against wind is still not an easy task, these data and information will be valuable assets for the wind-engineering and bridge-engineering com...

  6. 大跨度公铁两用钢桁梁斜拉桥结构地震响应特征研究%Study of Structural Seismic Response Characteristics of Long Span Rail-cum-Road Steel Truss Girder Cable-Stayed Bridges

    Institute of Scientific and Technical Information of China (English)

    阮怀圣; 屈爱平; 何友娣; 苗润池; 李龙安

    2015-01-01

    大跨度公铁两用钢桁梁斜拉桥是一种技术复杂的特殊桥梁,为系统地把握该类型桥梁结构在地震作用下的动力响应规律,总结该类桥梁的总体结构特征,统计分析5座公铁两用大桥的结构动力特性值,利用有限元数值仿真方法分析不同结构抗震约束体系的地震响应特点,统计粘滞阻尼器的减震效果并解释效果差异的原因。研究表明:大跨度公铁两用斜拉桥的竖向刚度与公路斜拉桥相比有明显差异,前者的竖弯基频比后者平均高20%左右;在多种结构抗震约束体系中,具有耗能显著特点的液体粘滞阻尼器体系是一种较为理想的结构抗震支承体系;采用粘滞阻尼器后,6座大桥桥塔的弯矩减震率呈现20%左右与60%以上两种不同表现结果,该现象主要与地震动输入的长周期成分取值有关;由于剪力比弯矩的阶次低,导致桥塔剪力比弯矩的减震效果低;粘滞阻尼器对梁端位移的减震效果显著,可达到60%~80%。%T he long span rail‐cum‐road steel truss girder cable‐stayed bridge is a type of the special bridge of technical complexity . To systematically understand the structural dynamic re‐sponse law s of such type of the bridges under the action of earthquake ,the general structural char‐acteristics of the bridges were summed up and the structural dynamic characteristic values of 5 long span rail‐cum‐road steel truss girder cable‐stayed bridges were statistically analyzed .The seismic response characteristics of the different structural seismic restraint systems were analyzed ,using the finite element numerical simulation ,the damping effect of the fluid viscous dampers was statis‐tically collected and the differences of the damping effect were illustrated .The results of the analy‐sis demonstrate that the vertical stiffness of a long span rail‐cum‐road steel truss girder cable‐stayed bridge is

  7. Smart semiconductor bridge (SCB) igniter for explosives

    Science.gov (United States)

    Bickes, R. W., Jr.

    We have developed a silicon semiconductor bridge (SCB) igniter which, when driven with a low-energy current pulse, produces a plasma discharge that ignites explosive materials pressed against the bridge. Our experiments have demonstrated that SCB explosive devices function in a few tens of microseconds at one-tenth the input energy of hot-wire devices. Despite the low input energies for ignition, tests have revealed SCB devices to be explosively safe, passing electrostatic discharge (ESD) requirements and no-fire current levels. In fact, SCB devices have better no-fire characteristics than hot-wire devices, because of the intimate bridge contact with the underlying thermally conductive substrate. We have tested several different prototype explosive devices including pyrotechnic actuators, secondary explosive deflagration-to-detonation detonators and a primary explosive detonator. In addition, we have tested SCB actuators with breadboarded smart firing sets that will fire the SCB actuators only after transmission of a digital code, after a preset delay, or in a preprogrammed sequence. We have also tested an optical system that requires only a single fiber optic cable connecting the SCB device to a low power laser that both energizes the firing set and transmits a coded firing signal.

  8. Research on key technologies in design of middle pylon of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Ji Lin

    2012-01-01

    At the middle pylon of a three-pylon two-span suspension bridge, the effect of unbalanced loads on the adjacent spans may result in a series of technical bottlenecks in design, such as stability and anti-slippage between saddles and main cables. This article presents the researches conducted on structure selection and behavior characteristics of middle pylon, interaction mechanism between main cables and saddles and their anti-slippage safety performance, elastic and plastic stability analysis and safety assessment of steel middle pylon, and fatigue design load and method for steel pylon of Taizhou Bridge. According to the research results, a longitudinal inverted Y shape steel middle pylon is used in design, effectively solving many technical difficulties, and this type of pylon has become a suitable middle pylon structural form for many three-ovlon two-soan susoension bridges.

  9. Condition Monitoring of Cables Task 3 Report: Condition Monitoring Techniques for Electric Cables

    Energy Technology Data Exchange (ETDEWEB)

    Villaran, M.; Lofaro, R.; na

    2009-11-30

    For more than 20 years the NRC has sponsored research studying electric cable aging degradation, condition monitoring, and environmental qualification testing practices for electric cables used in nuclear power plants. This report summarizes several of the most effective and commonly used condition monitoring techniques available to detect damage and measure the extent of degradation in electric cable insulation. The technical basis for each technique is summarized, along with its application, trendability of test data, ease of performing the technique, advantages and limitations, and the usefulness of the test results to characterize and assess the condition of electric cables.

  10. Switching Restrikes in HVAC Cable Lines and Hybrid HVAC Cable/OHL Lines

    DEFF Research Database (Denmark)

    da Silva, Filipe Miguel Faria; Bak, Claus Leth; Balle Holst, Per

    2011-01-01

    The disconnection of HV underground cables may, if unsuccessful, originate a restrike in the circuit breaker, leading to high overvoltages, and potentially damaging the cable and near equipment. Due to the cable high capacitance and low resistance the voltage damping is slow, resulting, half a...... cycle after the disconnection, in a voltage of approximately 2 pu at the circuit breaker terminals. In case of restrike in that instant, it is theoretical possible to attain an overvoltage of 3 pu. The overvoltage can be even larger in hybrid cable-Overhead Lines (OHL), due to voltage magnifications in...

  11. Chinese Market for Fibres and Cables

    Institute of Scientific and Technical Information of China (English)

    Yuxing Zhao

    2003-01-01

    This article presents a summary of Chinese market of optical fibres and cables based on the development of the optical communications industry. Analysis shows that the market will keep growing for sometime in the future.

  12. 3-D Numerical Simulations of Twisted Stacked Tape Cables

    OpenAIRE

    Krüger, Philipp A. C.; Zermeño, Victor M. R.; Takayasu, Makoto; Grilli, Francesco

    2014-01-01

    Different magnet applications require compact high current cables. Among the proposed solutions, the Twisted Stacked Tape Cable (TSTC) is easy to manufacture and has very high tape length usage efficiency. In this kind of cables the tapes are closely packed, so that their electromagnetic interaction is very strong and determines the overall performance of the cable. Numerical models are necessary tools to precisely evaluate this interaction and to predict the cable's behavior, e.g. in terms o...

  13. Experimental Simulation of Wet-Snow Shedding from Sagged Cables

    OpenAIRE

    Fonyó, András; Kollar, László E.; Farzaneh, Masoud; Montpellier, Patrice

    2009-01-01

    The process of wet-snow shedding from overhead cables was simulated in cold-chamber experiments under different ambient conditions. The main objective of the study was to examine how cable sag influences the snow-shedding process. However, the effects of several other parameters were also considered, such as air temperature, solar radiation, snow-sleeve length, and periodic excitation of the cable. Periodic excitation was applied at the suspension point of the cable, leading to cable vibratio...

  14. High frequency characteristics of medium voltage XLPE power cables

    OpenAIRE

    Mugala, Gavita

    2005-01-01

    The response of a cable can be used to analyze the variation of the material characteristics along its length. For diagnosis of possible ageing, it is necessary to know how cable design, material properties and cable insulation ageing affects the wave propagation. A cable model has therefore been worked out based upon the high frequency properties of the cable insulation and conductor systems. The high frequency characteristics of the semi-conducting screens, new and water-tree aged cross-lin...

  15. Anomaly Detection Algorithm for Stay Cable Monitoring Data Based on Data Fusion

    Institute of Scientific and Technical Information of China (English)

    Xiaoling Liu,Qiao Huang∗; Yuan Ren

    2016-01-01

    In order to improve the accuracy and consistency of data in health monitoring system, an anomaly detection algorithm for stay cables based on data fusion is proposed. The monitoring data of Nanjing No. 3 Yangtze River Bridge is used as the basis of study. Firstly, an adaptive processing framework with feedback control is established based on the concept of data fusion. The data processing contains four steps: data specification, data cleaning, data conversion and data fusion. Data processing information offers feedback to the original data system, which further gives guidance for the sensor maintenance or replacement. Subsequently, the algorithm steps based on the continuous data distortion is investigated,which integrates the inspection data and the distribution test method. Finally, a group of cable force data is utilized as an example to verify the established framework and algorithm. Experimental results show that the proposed algorithm can achieve high detection accuracy, providing a valuable reference for other monitoring data processing.

  16. An integrated FBG sensing system for bridge health monitoring

    Science.gov (United States)

    Sun, Ru-Jiao; Sun, Zhi; Dan, Dan-Hui; Sun, Li-Min

    2006-03-01

    Thanking to its distinguishing advantages including wavelength multiplexing capability, miniature size, high sensitivity, immunity from electro-magnetic interference and etc, the fiber Bragg grating (FBG) sensing technologies are regarded as a competent candidate for the bridge long-term health monitoring. According to the shifted Bragg wavelength of the light reflected by a fiber grating, the FBG sensors can accurately measure various physical properties such as strain, temperature, displacement, acceleration and corrosion. One special advantage of the FBG sensing technology is that only one demodulation device is required to acquire various physical properties simultaneously. Compared with the bridge health monitoring system using conventional sensors, this advantage makes the quasi-distributed sensing possible and data transmission more convenient because many FBG sensors can be connected in series by a single fiber. In this paper, an integrated FBG sensing system is presented for monitoring the physical state of a real bridge, the main-navigation channel cable-stayed bridge of the Donghai Bridge. The strain variation of two selected sections in the construction stage and during the load trial test are continuously monitored. The results of this study will supply a good guidance for the use of FBG sensors on the health monitoring of real bridges. Finally, the paper present the design and fabrication of an accelerometer based on the FBG technology for structure vibration monitoring.

  17. Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottomof the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron ‘carpet’, trapping toxic hydrogen sulfide.......Animals at the bottomof the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron ‘carpet’, trapping toxic hydrogen sulfide....

  18. Cable system transients theory, modeling and simulation

    CERN Document Server

    Ametani, Akihiro; Nagaoka, Naoto

    2015-01-01

    A systematic and comprehensive introduction to electromagnetic transient in cable systems, written by the internationally renowned pioneer in this field Presents a systematic and comprehensive introduction to electromagnetic transient in cable systems Written by the internationally renowned pioneer in the field Thorough coverage of the state of the art on the topic, presented in a well-organized, logical style, from fundamentals and practical applications A companion website is available

  19. Ecology: Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.......Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  20. Generalized Gaussian Bridges

    CERN Document Server

    Sottinen, Tommi

    2012-01-01

    A generalized bridge is the law of a stochastic process that is conditioned on linear functionals of its path. We consider two types of representations of such bridges: orthogonal and canonical. In the canonical representation the filtrations and the linear spaces generated by the bridge process and the original process coincide. In the orthogonal representation the bridge is constructed from the entire path of the underlying process. The orthogonal representation is given for any continuous Gaussian process but the canonical representation is given only for so-called prediction-invertible Gaussian processes. Finally, we apply the canonical bridge representation to insider trading by interpreting the bridge from an initial enlargement of filtration point of view.

  1. Concrete bridge prioritization system

    OpenAIRE

    Kesselring, Debbie Anne

    1995-01-01

    An alternative method of prioritization for concrete bridge maintenance, repair, and rehabilitation activities is required due to the inability of the current system to manage the increasing nmnber of aging concrete bridges. The Concrete Bridge Prioritization System was proposed because of its ability to address the critical technical parameters of safety and cost benefit in prioritization of funding and work allocation. The analysis includes four parts, service life assessment, s...

  2. Environmental assessment of submarine power cables

    International Nuclear Information System (INIS)

    Extensive analyses conducted by the European Community revealed that offshore wind energy have relatively benign effects on the marine environment by comparison to other forms of electric power generation [1]. However, the materials employed in offshore wind power farms suffer major changes to be confined to the marine environment at extreme conditions: saline medium, hydrostatic pressure... which can produce an important corrosion effect. This phenomenon can affect on the one hand, to the material from the structural viewpoint and on the other hand, to the marine environment. In this sense, to better understand the environmental impacts of generating electricity from offshore wind energy, this study evaluated the life cycle assessment for some new designs of submarine power cables developed by General Cable. To achieve this goal, three approaches have been carried out: leaching tests, eco-toxicity tests and Life Cycle Assessment (LCA) methodologies. All of them are aimed to obtaining quantitative data for environmental assessment of selected submarine cables. LCA is a method used to assess environmental aspects and potential impacts of a product or activity. LCA does not include financial and social factors, which means that the results of an LCA cannot exclusively form the basis for assessment of a product's sustainability. Leaching tests results allowed to conclude that pH of seawater did not significantly changed by the presence of submarine three-core cables. Although, it was slightly higher in case of broken cable, pH values were nearly equals. Concerning to the heavy metals which could migrate to the aquatic medium, there were significant differences in both scenarios. The leaching of zinc is the major environmental concern during undersea operation of undamaged cables whereas the fully sectioned three-core cable produced the migration of significant quantities of copper and iron apart from the zinc migrated from the galvanized steel. Thus, the tar

  3. Environmental assessment of submarine power cables

    Energy Technology Data Exchange (ETDEWEB)

    Isus, Daniel; Martinez, Juan D. [Grupo General Cable Sistemas, S.A., 08560-Manlleu, Barcelona (Spain); Arteche, Amaya; Del Rio, Carmen; Madina, Virginia [Tecnalia Research and Innovation, 20009 San Sebastian (Spain)

    2011-03-15

    Extensive analyses conducted by the European Community revealed that offshore wind energy have relatively benign effects on the marine environment by comparison to other forms of electric power generation [1]. However, the materials employed in offshore wind power farms suffer major changes to be confined to the marine environment at extreme conditions: saline medium, hydrostatic pressure... which can produce an important corrosion effect. This phenomenon can affect on the one hand, to the material from the structural viewpoint and on the other hand, to the marine environment. In this sense, to better understand the environmental impacts of generating electricity from offshore wind energy, this study evaluated the life cycle assessment for some new designs of submarine power cables developed by General Cable. To achieve this goal, three approaches have been carried out: leaching tests, eco-toxicity tests and Life Cycle Assessment (LCA) methodologies. All of them are aimed to obtaining quantitative data for environmental assessment of selected submarine cables. LCA is a method used to assess environmental aspects and potential impacts of a product or activity. LCA does not include financial and social factors, which means that the results of an LCA cannot exclusively form the basis for assessment of a product's sustainability. Leaching tests results allowed to conclude that pH of seawater did not significantly changed by the presence of submarine three-core cables. Although, it was slightly higher in case of broken cable, pH values were nearly equals. Concerning to the heavy metals which could migrate to the aquatic medium, there were significant differences in both scenarios. The leaching of zinc is the major environmental concern during undersea operation of undamaged cables whereas the fully sectioned three-core cable produced the migration of significant quantities of copper and iron apart from the zinc migrated from the galvanized steel. Thus, the tar

  4. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska;

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  5. Bridging the Gap

    OpenAIRE

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska; Murdock, Karen; Schmidt, Iben Julie

    2015-01-01

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures. Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ve...

  6. Generalized cable theory for neurons in complex and heterogeneous media

    Science.gov (United States)

    Bédard, Claude; Destexhe, Alain

    2013-08-01

    Cable theory has been developed over the last decade, usually assuming that the extracellular space around membranes is a perfect resistor. However, extracellular media may display more complex electrical properties due to various phenomena, such as polarization, ionic diffusion, or capacitive effects, but their impact on cable properties is not known. In this paper, we generalize cable theory for membranes embedded in arbitrarily complex extracellular media. We outline the generalized cable equations, then consider specific cases. The simplest case is a resistive medium, in which case the equations recover the traditional cable equations. We show that for more complex media, for example, in the presence of ionic diffusion, the impact on cable properties such as voltage attenuation can be significant. We illustrate this numerically, always by comparing the generalized cable to the traditional cable. We conclude that the nature of intracellular and extracellular media may have a strong influence on cable filtering as well as on the passive integrative properties of neurons.

  7. Cable condition monitoring in a pressurized water reactor environment

    International Nuclear Information System (INIS)

    Oconee Nuclear Station is the first nuclear plant designed, engineered and constructed by Duke Power Company. Even though the accelerated aging method was available to determine the life expectancy of the cable used in the reactor building, no natural aging data was available at that time. In order to be able to verify the condition of the reactor building cable over the life of the plant, an on-going cable monitoring plan was instituted. Various types of cable were selected to be monitored, and they were installed in cable life evaluation circuits in the reactor building. At five year intervals over the life of the plant, cable samples would be removed from these cable life evaluation circuits and tested to determine the effects of the reactor building environment on the integrity of the cable. A review of the cable life evaluation circuits and the results of the evaluation program to date is presented

  8. Ship nuclear power device of cable aging management

    International Nuclear Information System (INIS)

    Cable for marine nuclear power plant continuous delivery of electrical energy. Cable is mostly in the high temperature and strong radiation and harsh working environment, and can not be replaced in the lifetime This should be the cable aging management methods through research, maintenance and repair program to provide a scientific basis. Cable aging management approach for a number of different levels of cable management at different levels, relying on computers and other modern tools, the use of information management database software maintenance of the cable through the science of aging control. Cable Aging Management including the scope of cable aging management, classification management basis and used for different levels of management supervision and implementation of means testing approach. Application of the ship that has the operational management science, both planned maintenance to improve the science, but also improves the efficiency of aging management. This management method can be extended to nuclear power plants of cable aging management. (authors)

  9. Full-scale fire experiments on vertical horizontal cable trays

    International Nuclear Information System (INIS)

    Two full-scale fire experiments on PVC cables used in nuclear power plants were carried out, one with cables in vertical position and one with cables in horizontal position. The vertical cable bundle, 3 m high, 300 mm wide and 30 mm thick, was attached to a steel cable ladder. The vertical bundle experiment was carried out in nearly free space with three walls near the cable ladder guiding air flow in order to stabilise flames. The horizontal cable experiment was carried out in a small room with five cable bundles attached to steel cable ladders. Three of the 2 m long cable bundles were located in an array, equally spaced above each other near one long side of the room and two correspondingly near the opposite long side. The vertical cable bundle was ignited with a small propane gas burner beneath the lower edge of the bundle. The horizontal cable bundles were ignited with a small propane burner beneath the lowest bundle in an array of three bundles. Rate of heat release by means of oxygen consumption calorimetry, mass change, CO2, CO and smoke production rate and gas, wall and cable surface temperatures were measured as a function of time, as well as time to sprinkler operation and failure of test voltage in cables. Additionally, the minimum rate of heat release needed to ignite the bundle was determined. This paper concentrates on describing and recording the experimental set-up and the data obtained. (orig.)

  10. Applying Diagnostics to Enhance Cable System Reliability (Cable Diagnostic Focused Initiative, Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    Hartlein, Rick [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hampton, Nigel [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Perkel, Josh [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hernandez, JC [Univ. de Los Andes, Merida (Venezuela); Elledge, Stacy [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); del Valle, Yamille [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Grimaldo, Jose [Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering; Deku, Kodzo [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

    2016-02-01

    The Cable Diagnostic Focused Initiative (CDFI) played a significant and powerful role in clarifying the concerns and understanding the benefits of performing diagnostic tests on underground power cable systems. This project focused on the medium and high voltage cable systems used in utility transmission and distribution (T&D) systems. While many of the analysis techniques and interpretations are applicable to diagnostics and cable systems outside of T&D, areas such as generating stations (nuclear, coal, wind, etc.) and other industrial environments were not the focus. Many large utilities in North America now deploy diagnostics or have changed their diagnostic testing approach as a result of this project. Previous to the CDFI, different diagnostic technology providers individually promoted their approach as the “the best” or “the only” means of detecting cable system defects.

  11. Cable support for electric poles. Support de cables pour poteau electrique

    Energy Technology Data Exchange (ETDEWEB)

    Bourrieres, P.

    1989-11-21

    The cable support according to this invention comprises a central body of insulating material upon which are mounted individual cable supports and means for connecting the central body to a pole. In this manner, a support designed to support a plurality of cables is realized in a single operation. On the other hand, the placing of the cable support is carried out by a single operation of connecting the central body to the pole, allowing provision for mounting a cable support after erecting the pole, or in additions, a quick repair by transferring the central body from the broken end fo a pole to a new pole or to the trunk of the pole for a temporary restoration of electrical service.

  12. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated...

  13. The floating water bridge

    International Nuclear Information System (INIS)

    When high voltage is applied to distilled water filled in two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed experimental analysis reveals static and dynamic structures as well as heat and mass transfer through this bridge

  14. Evaluation of cable ageing in Nuclear Power Plants; Evaluacion del envejecimiento de cables en centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Vergara, T. [Empresarios Agrupados, A. I. E. Madrid (Spain); Alonso Chicote, J. [TECNATOM, S. A. (Spain); Burnay, S. [AEA Technology (UK)

    2000-07-01

    The majority of power, control and instrumentation cables in nuclear power plants use polymers as their basic material for insulation and jacket. In many cases, these cables form part of safety-related circuits and should therefore be capable of operating correctly under both normal and accident conditions. Since polymeric materials are degraded by the long term action of the radiation and thermal environments found in the plant, it is important to be able to establish the cable condition during the plant lifetime. Nowadays there are a number of different methods to evaluate the remaining lifetime of cables. In the case of new plants, or new cables in old plants, accelerated ageing tests and predictive models can be used to establish the behaviour of the cable materials under operating conditions. There are verified techniques and considerable experience in the definition of predictive models. This type of approach is best carried out during the commissioning stage or in the early stages of operation. In older plants, particularly where there is a wide range of cable types in use, it is more appropriate to use condition monitoring methods to establish the state of degradation of cables in-plant. Over the last 10 years there have been considerable developments in methods for condition monitoring of cables and a tool-box of practical techniques are now available. There is no single technique which is suitable for all cable materials but the range of methods covers nearly all of the types currently in use, at present, the most established methods are the indented, thermal analysis (OIT, OITP and TGA) and dielectric loss measurements, All of these are either non-destructive methods or require only micro-samples of material. (Author) 15 refs.

  15. High voltage pulsed cable design: a practical example

    International Nuclear Information System (INIS)

    The design of optimum high voltage pulse cable is difficult because very little emperical data are available on performance in pulsed applications. This paper follows the design and testing of one high voltage pulse cable, 40/100 trigger cable. The design was based on an unproven theory and the impressive outcome lends support to the theory. The theory is outlined and it is shown that there exists an inductance which gives a cable of minimum size for a given maximum stress. Test results on cable manufactured according to the design are presented and compared with the test results on the cable that 40/100 replaces

  16. CSNS control cable information management system based on web

    International Nuclear Information System (INIS)

    This paper presents an approach to data modeling a great number of control devices and cables with complicated relations of CSNS (China Spallation Neutron Source). The CSNS accelerator control cable database was created using MySQL, and the control cable information management system based on Web was further built. During the development of the database, the design idea of IRMIS database was studied. and the actual situation of CSNS accelerator control cables was investigated. The control cable database model fitting the requirements was designed. This system is of great convenience to manage and maintain CSNS control devices and cables in the future. (authors)

  17. Low Friction Cryostat for HTS Power Cable of Dutch Project

    DEFF Research Database (Denmark)

    Chevtchenko, Oleg; Zuijderduin, Roy; Smit, Johan;

    2012-01-01

    affecting public acceptance of the project. In order to solve this problem, a model cryostat was developed consisting of alternating rigid and flexible sections and hydraulic tests were conducted using sub-cooled liquid nitrogen. In the 47 m-long cryostat, containing a full-size HTS cable model, measured......Particulars of 6km long HTS AC power cable for Amsterdam project are: a cable has to fit in an annulus of 160mm, with only two cooling stations at the cable ends [1]. Application of existing solutions for HTS cables would result in excessively high coolant pressure drop in the cable, possibly...

  18. Cable condition monitoring research activities at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Sandia National Laboratories is currently conducting long-term aging research on representative samples of nuclear power plant cables. The objectives of this program are to determine the suitability of these cables for extended life (beyond 40 year design basis) and to assess various cable condition monitoring techniques for predicting remaining cable life. The cables are being aged for long times at relatively mild exposure conditions with various condition monitoring techniques to be employed during the aging process. Following the aging process, the cables will be exposed to a sequential accident profile consisting of high dose rate irradiation followed by a simulated design basis loss-of-coolant accident (LOCA) steam exposure

  19. Energy losses of superconducting power transmission cables in the grid

    DEFF Research Database (Denmark)

    Østergaard, Jacob; Okholm, Jan; Lomholt, Karin;

    2001-01-01

    One of the obvious motives for development of superconducting power transmission cables is reduction of transmission losses. Loss components in superconducting cables as well as in conventional cables have been examined. These losses are used for calculating the total energy losses of conventional...... as well as superconducting cables when they are placed in the electric power transmission network. It is concluded that high load connections are necessary to obtain energy saving by the use of HTSC cables. For selected high load connections, an energy saving of 40% is expected. It is shown that the...... thermal insulation and cooling machine efficiency are the most important loss element in a superconducting cable system...

  20. NEPO cable system aging management programs

    International Nuclear Information System (INIS)

    Full text: Cable polymer aging and condition monitoring is being studied in detail under the Nuclear Energy Plant Optimization Program (NEPO) that is co-sponsored by the U.S. Department of Energy and EPRI. Significant advances in modeling of polymer aging and condition monitoring have occurred and continue to be developed. The activities include: Analysis of the linearity of the Arrhenius model to room temperature; Development of a wear-out technique for determining remaining life of cable polymers; Determination of the aging fragility point for composite EPR/CSPE insulation with respect to LOCA function; Development of visual/tactile training aids for cable assessment; Development of a totally new nuclear magnetic resonance condition monitoring technique; Assessment of existing techniques with regard to repeatability, accuracy and ease of use. Through use of highly precise oxygen consumption experiments, the linearity of the Arrhenius model is being evaluated. In these experiments, polymer is placed in vials with a known amount of oxygen and aged at much lower temperatures than is possible with standard accelerated aging techniques. aging results are possible at room temperature. The technique is being applied to commonly used insulation and jacket polymers. The wear-out technique allows highly non-linear aging behavior to be made linear. The wearout point of a polymer is determined through high-rate aging and use of a condition monitoring technique to establish the end point. Then, micro-samples of cable that have been naturally aged are subjected to high rate aging to the same end point. The ratio of the remaining high rate aging period to the total high rate aging time provides a linear indication of the remaining service time. Initial screening of nuclear plant cable systems can use visual/tactile techniques to identify cable that has aged significantly. Training aids have been developed by developing sets of specimens with accelerated aging ranging from none

  1. HTS twisted stacked-tape cable conductor

    International Nuclear Information System (INIS)

    The feasibility of high field magnet applications of the twisted stacked-tape cabling method with 2G YBCO tapes has been investigated. An analysis of torsional twist strains of a thin HTS tape has been carried out taking into account the internal shortening compressive strains accompanied with the lengthening tensile strains due to the torsional twist. The model is benchmarked against experimental tests using YBCO tapes. The critical current degradation and current distribution of a four-tape conductor was evaluated by taking account of the twist strain, the self-field and the termination resistances. The critical current degradation for the tested YBCO cables can be explained by the perpendicular self-field effect. It is shown that the critical current of a twisted stacked-tape conductor with a four-tape cable does not degrade with a twist pitch length as short as 120 mm. Current distribution among tapes and hysteresis losses are also investigated. A compact joint termination method for a 2G YBCO tape cable has been developed. The twisted stacked-tape conductor method may be an attractive means for the fabrication of highly compact, high current cables from multiple flat HTS tapes.

  2. Computer-Aided Engineering Of Cabling

    Science.gov (United States)

    Billitti, Joseph W.

    1989-01-01

    Program generates data sheets, drawings, and other information on electrical connections. DFACS program, centered around single data base, has built-in menus providing easy input of, and access to, data for all personnel involved in system, subsystem, and cabling. Enables parallel design of circuit-data sheets and drawings of harnesses. Also recombines raw information to generate automatically various project documents and drawings, including index of circuit-data sheets, list of electrical-interface circuits, lists of assemblies and equipment, cabling trees, and drawings of cabling electrical interfaces and harnesses. Purpose of program to provide engineering community with centralized data base for putting in, and gaining access to, functional definition of system as specified in terms of details of pin connections of end circuits of subsystems and instruments and data on harnessing. Primary objective to provide instantaneous single point of interchange of information, thus avoiding

  3. Distance and Cable Length Measurement System

    Science.gov (United States)

    Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

    2009-01-01

    A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

  4. Insulation systems for superconducting transmission cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    This paper describes shortly the status of superconducting transmission lines and assesses what impact the recently discovered BSCCO superconductors may have on the design of the cables.Two basically different insulation systems are discussed:1) The room temperature dielectric design, where the...... electrical insulation is placed outside both the superconducting tube and the cryostat. The superconducting tube is cooled by liquid nitrogen which is pumped through the hollow part of the tube.2) The cryogenic dielectric design, where the electrical insulation is placed inside the cryostat and thus is kept...... at temperature near 77 K.The optimal design is determined by a loss evaluation in relation to the power transfer capacity of the cable. Development work in progress on the design and construction of superconducting cables in Denmark is described as an example....

  5. Aging assessment of nuclear generating station cables

    International Nuclear Information System (INIS)

    A number of diagnostic techniques requiring small samples (e.g. shavings) for monitoring the condition of nuclear generating station cables have been identified. The cables studied were insulated with cross-linked or unmodified polyethylene, ethylene propylene rubber, butyl rubber, styrene butadiene rubber, and polyvinyl chloride. Specimens were aged at elevated temperatures, or gamma irradiated up to 120 Mrad. The degradation was assessed by conventional elongation measurements, differential scanning calorimetry (DSC), oxidation induction time, DSC oxidation induction temperature (under high oxygen pressure), infrared carbonyl absorption, density, and swelling measurements. The sensitivities of the diagnostic techniques in measuring oxidation and embrittlement were compared with the elongation results, and a criterion for monitoring the cable degradation was developed. Some results presented illustrate the use of the diagnostic techniques in monitoring degradation. 13 refs., 2 tabs., 24 figs

  6. Electrothermal Coordination in Cable Based Transmission Grids

    DEFF Research Database (Denmark)

    Olsen, Rasmus Schmidt; Holbøll, Joachim; Gudmundsdottir, Unnur Stella

    2013-01-01

    Electrothermal coordination (ETC) is introduced for cable based transmission grids. ETC is the term covering operation and planning of transmission systems based on temperature, instead of current. ETC consists of one part covering the load conditions of the system and one covering the thermal...... behavior of the components. The dynamic temperature calculations of power cables are suggested to be based on thermoelectric equivalents (TEEs). It is shown that the thermal behavior can be built into widely used load flow software, creating a strong ETC tool. ETC is, through two case scenarios, proven to...... be beneficial for both operator and system planner. It is shown how the thermal behavior can be monitored in real-time during normal dynamic load and during emergencies. In that way, ETC enables cables to be loaded above their normal rating, while maintaining high reliability of the system, which...

  7. 鸭绿江界河公路大桥主桥桥型方案比选%Comparison and Selection of Proposed Bridge Types for Main Bridge of Yalu Boundary River Highway Bridge

    Institute of Scientific and Technical Information of China (English)

    吴宏业; 于传君

    2013-01-01

    The Yalu Boundary River Highway Bridge is an important international project connecting China and DPR Korea. In the light of the actual project conditions at the bridge site, two proposed bridge types for the main bridge of the bridge were compared, i. e. a steel box girder cable-stayed bridge with double pylons and double cable planes (the span arrangement being (86 + 229 + 636 + 229 + 86) m and the pylons being the H-shape concrete structures to be cast in situ) and a steel and concrete composite girder cable-stayed bridge with double pylons and double cable planes (the span arrangement being (87 + 228 + 636 + 228 + 87) m and the pylons being the inverted Y-shape concrete structures to be cast in situ). The plane link program Doctor Bridge V3. 2. 0 was used to respectively set up the finite element models for the two bridge types, the global mechanical behavior of the two bridges at completion and operation stages were analyzed and the construction convenience, durability and economy were analyzed as well. The results of the analysis show that the structural mechanical behavior of the steel box girder cable-stayed bridge is more advantageous, the construction is more convenient, the construction time schedule is shorter and the seismic performance is better and therefore the box girder bridge having 5 spans, double pylons and double planes is finally selected.%鸭绿江界河公路大桥是连接朝鲜的跨国性重要工程,结合桥址处实际工程条件,选取双塔双索面钢箱梁斜拉桥[跨径布置为(86+229+636+229+86)m,采用现浇H形桥塔]和双塔双索面钢-混结合梁斜拉桥[跨径布置为(87+228+636+228+87)m,采用现浇倒Y形桥塔]2种桥型方案进行比选.采用平面杆系程序桥梁博士V3.2.0分别建立2种方案的有限元模型,按整体成型对桥梁成桥阶段及运营阶段进行整体受力分析,并对2种方案的施工便利性、耐久性及经济性进行对比分析.分析结果表明,钢箱梁斜拉桥结

  8. Calorimetric measurements of losses in HTS cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Veje, Niels Erling Winsløv; Rasmussen, Carsten;

    2001-01-01

    A calorimetric test rig is used to investigate various loss components in a 10 m long superconducting cable model. A calorimetric technique, based on thermocouple measurements, is used to measure the losses of the 10 m long superconducting cable model. The current dependent losses are also measured...... electrically and compared with the losses obtained with the calorimetric method. The results obtained by the two methods are consistent. Based on an I2 (current) fitting procedure, the loss, caused by the eddy current generated in the stainless steel cryostat housing, and the hysteresis loss generated in the...

  9. Bridge technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. As LANs have proliferated, new technologies and system concepts have come to the fore. One of the key issues is how to interconnect networks. One means of interconnection is to use a 'bridge'. Other competing technologies are repeaters, routers, and gateways. Bridges permit traffic isolation, connect network segments together and operate at the MAC layer. Further, because they operate at the MAC layer, they can handle a variety of protocols such as TCP/IP, SNA, and X.25. This report focuses on the specific technology of bridging two netw

  10. Configuration Synthesis for Fully Restrained 7-Cable-Driven Manipulators

    Directory of Open Access Journals (Sweden)

    Xiaoqiang Tang

    2012-10-01

    Full Text Available Cable distribution plays a vital role in Cable Driven Parallel Manipulators (CDPMs regarding tension and workspace quality, especially in fully restrained CDPMs. This paper focuses on three typical configurations of fully restrained CDPMs with 7 cables in order to introduce an approach for configuration synthesis. Firstly, the kinematic models of three types of CDPMs with 7 cables are set up. Then, in order to evaluate workspace quality, two new indices are proposed by using tensions along each cable, which are the All Cable Tension Distribution Index (ACTDI and Global Tension Distribution Index (GTDI. Next, the three types of CDPMs with 7 cables are analysed with the two indices. At the end, according to different performance requirements, the configurations of cable distribution are discussed and selected.

  11. Superscreened co-axial cables for the nuclear power industry

    International Nuclear Information System (INIS)

    This specification covers the requirements of superscreened cables. Part 1 covers general requirements and test methods. Part 2 covers data sheets setting out the electrical and mechanical requirements for each type of cable, together with engineering information. (U.K.)

  12. Fault Management of a Cold Dielectric HTS Power Transmission Cable

    International Nuclear Information System (INIS)

    High temperature superconductor (HTS) power transmission cables offer significant advantages in power density over conventional copper-based cables. As with conventional cables, HTS cables must be safe and reliable when abnormal conditions, such as local and through faults, occur in the power grid. Due to the unique characteristics of HTS power cables, the fault management of an HTS cable is different from that of a conventional cable. Issues, such as nitrogen bubble formation within lapped dielectric material, need to be addressed. This paper reviews the efforts that have been performed to study the fault conditions of a cold dielectric HTS power cable. As a result of the efforts, a fault management scheme has been developed, which provides both local and through faults system protection. Details of the fault management scheme with examples are presented

  13. Dynamic Analysis of Towed and Variable Length Cable Systems

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-xin; WANG Yan-hui; LI Xiao-ping

    2007-01-01

    Towed cable systems are frequently used in marine measurements where the length of the towed cable varies during launch and recovery. In this paper a novel method for modeling variable length cable systems is introduced based on the finite segment formulation. The variable length of the towed cable is described by changing the length of the segment near the towing point and by increasing or decreasing the number of the discrete segments of the cable. In this way, the elastic effects of the cable can be easily handled since geometry and material properties of each segment are kept constant. Experimental results show that the dynamic behavior of the towed cable is consistent between the model and the physical cable. Results show that the model provides numerical efficiency and simulation accuracy for the variable length towed system.

  14. Basic Requirements for Cables of Systems Important to NPP Safety

    International Nuclear Information System (INIS)

    In view of the need for equipment upgrades at Ukrainian nuclear power plants, the replacement of cables, as an integral part of any system, becomes important. There is no document in Ukraine that combines requirements for cables of systems important to nuclear safety. The paper systematizes the technical requirements of national regulatory documents on nuclear and radiation safety in relation to cable products. The most important requirements for selecting cables are fire safety, resistance to high temperatures, humidity and pressure, resistance to ionizing radiation, seismic resistance and electromagnetic compatibility. The use of cables in the NPP containment and safety systems imposes on them the most stringent requirements as regards nuclear and radiation safety in plant operation. The paper identifies features and operating conditions for cable lines as part of NPP safety systems and shows the general classification of cable products. Development of a regulatory document to combine requirements for cables of safety systems will facilitate their selection during upgrading.

  15. Analysis of Electrical Coupling Parameters in Superconducting Cables

    CERN Document Server

    Bottura, L; Rosso, C

    2003-01-01

    The analysis of current distribution and redistribution in superconducting cables requires the knowledge of the electric coupling among strands, and in particular the interstrand resistance and inductance values. In practice both parameters can have wide variations in cables commonly used such as Rutherford cables for accelerators or Cable-in-Conduits for fusion and SMES magnets. In this paper we describe a model of a multi-stage twisted cable with arbitrary geometry that can be used to study the range of interstrand resistances and inductances that is associated with variations of geometry. These variations can be due to cabling or compaction effects. To describe the variations from the nominal geometry we have adopted a cable model that resembles to the physical process of cabling and compaction. The inductance calculation part of the model is validated by comparison to semi-analytical results, showing excellent accuracy and execution speed.

  16. Nonlinear dynamic response of stay cables under axial harmonic excitation

    Institute of Scientific and Technical Information of China (English)

    Xu XIE; He ZHAN; Zhi-cheng ZHANG

    2008-01-01

    This paper proposes a new numerical simulation method for analyzing the parametric vibration of stay cables based on the theory of nonlinear dynamic response of structures under the asynchronous support excitation.The effects of important parameters related to parametric vibration of cables,I.e., characteristics of structure,excitation frequency,excitation amplitude,damping effect of the air and the viscous damping coefficient of the cables,were investigated by using the proposed method for the cables with significant length difference as examples.The analysis results show that nonlinear finite element method is a powerful technique in analyzing the parametric vibration of cables,the behavior of parametric vibration of the two cables with different Irvine parameters has similar properties,the amplitudes of parametric vibration of cables are related to the frequency and amplitude of harmonic support excitations and the effect of distributed viscous damping on parametric vibration of the cables is very small.

  17. Bridge Management Systems:present and future

    OpenAIRE

    Thoft-Christensen, Palle

    1997-01-01

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way.

  18. Bridging a cultural gap

    Science.gov (United States)

    Leviatan, Talma

    2008-09-01

    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes—aimed at bridging the gap between high-school mathematics and tertiary mathematics—is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a potential bridging programme, this paper aims at demonstrating that the gap can be bridged, by presenting an ongoing modular bridging programme especially designed for the diverse types of student populations in teachers training colleges. We also present here some innovative teaching and assessment methods that were judged essential for the success of these programmes—focusing mainly on the "Questionnaire Based Instruction Method". Finally we suggest directions of follow up and research.

  19. Bridged Race Population Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  20. Broadcast Service Areas, Cable, cable, Published in Not Provided, 1:600 (1in=50ft) scale, Comcast.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Broadcast Service Areas, Cable dataset, published at 1:600 (1in=50ft) scale as of Not Provided. It is described as 'cable'. Data by this publisher are often...

  1. Environmental Impact of a Submarine Cable: Case Study of the Acoustic Thermometry of Ocean Climate (ATOC)/ Pioneer Seamount Cable

    Science.gov (United States)

    Kogan, I.; Paull, C. K.; Kuhnz, L.; von Thun, S.; Burton, E.; Greene, H. G.; Barry, J. P.

    2003-12-01

    To better understand the potential impacts of the presence of cables on the seabed, a topic of interest for which little data is published or publicly available, a study of the environmental impacts of the ATOC/Pioneer Seamount cable was conducted. The 95 km long, submarine, coaxial cable extends between Pioneer Seamount and the Pillar Point Air Force Station in Half Moon Bay, California. Approximately two thirds of the cable lies within the Monterey Bay National Marine Sanctuary. The cable is permitted to NOAA- Oceanic and Atmospheric Research for transmitting data from a hydrophone array on Pioneer Seamount to shore. The cable was installed unburied on the seafloor in 1995. The cable path crosses the continental shelf, descends to a maximum depth of 1,933 m, and climbs back upslope to 998 m depth near the crest of Pioneer Seamount. A total of 42 hours of video and 152 push cores were collected in 10 stations along cable and control transects using the ROVs Ventana and Tiburon equipped with cable-tracking tools. The condition of the cable, its effect on the seafloor, and distribution of benthic megafauna and infauna were determined. Video data indicated the nature of interaction between the cable and the seafloor. Rocky nearshore areas, where wave energies are greatest, showed the clearest evidence of impact. Here, evidence of abrasion included frayed and unraveling portions of the cable's armor and vertical grooves in the rock apparently cut by the cable. The greatest incision and armor damage occurred on ledges between spans in irregular rock outcrop areas. Unlike the nearshore rocky region, neither the rocks nor the cable appeared damaged along outcrops on Pioneer Seamount. Multiple loops of slack cable added during a 1997 cable repair operation were found lying flat on the seafloor. Several sharp kinks in the cable were seen at 240 m water depths in an area subjected to intense trawling activity. Most of the cable has become buried with time in sediment

  2. 30 CFR 75.804 - Underground high-voltage cables.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground high-voltage cables. 75.804 Section... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.804 Underground high-voltage cables. (a) Underground high-voltage cables used in...

  3. 47 CFR 32.6422 - Underground cable expense.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Underground cable expense. 32.6422 Section 32.6422 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM... Underground cable expense. (a) This account shall include expenses associated with underground cable....

  4. 30 CFR 57.4057 - Underground trailing cables.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground trailing cables. 57.4057 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control § 57.4057 Underground trailing cables. Underground trailing cables shall be accepted...

  5. 47 CFR 76.111 - Cable sports blackout.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Cable sports blackout. 76.111 Section 76.111... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.111 Cable sports blackout. (a) No community unit located in whole or in part within the...

  6. Working Paper for the Revision of San Francisco's Cable Franchise.

    Science.gov (United States)

    San Francisco Public Library, CA. Video Task Force.

    Ideas are presented for the revision of San Francisco's cable franchise. The recommendations in the report are based upon national research of library and urban use of cable communications and are designed to help the city's present and future cable franchises to comply with the regulations of the Federal Communications Commission by March 31,…

  7. Estimation of Medium Voltage Cable Parameters for PD Detection

    DEFF Research Database (Denmark)

    Villefrance, Rasmus; Holbøll, Joachim T.; Henriksen, Mogens

    measured signal at the cable terminations to a specific PD-amplitude and location on the cable, the attenuation and the transmission speed of PD-pulses on the cable have to be known. Consequently, the main parameter to be determined is the complex propagation constant which consists of the attenuation and...

  8. 47 CFR 32.2426 - Intrabuilding network cable.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Intrabuilding network cable. 32.2426 Section 32... Intrabuilding network cable. (a) This account shall include the original cost of cables and wires located on the company's side of the demarcation point or standard network interface inside subscribers' buildings...

  9. 47 CFR 32.6426 - Intrabuilding network cable expense.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Intrabuilding network cable expense. 32.6426... Intrabuilding network cable expense. (a) This account shall include expenses associated with intrabuilding network cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2426(a) of...

  10. Broadband Wireline Provider Service: Cable Modem - Other; BBRI_cableOther12

    Data.gov (United States)

    University of Rhode Island Geospatial Extension Program — This dataset represents the availability of wireline broadband Internet access in Rhode Island via "Cable Modem - Other" technology. Broadband availability is...

  11. Broadband Wireline Provider Service: Cable Modem - DOCSIS 3.0; BBRI_cableDOCSIS12

    Data.gov (United States)

    University of Rhode Island Geospatial Extension Program — This dataset represents the availability of wireline broadband Internet access in Rhode Island via "Cable Modem - DOCSIS 3.0" technology. Broadband availability is...

  12. Overhead lines: materials. Guard conductors and cables; Lignes aeriennes: materiels. Conducteurs et cables de garde

    Energy Technology Data Exchange (ETDEWEB)

    Chanal, A. [Electricite de France (EDF), 75 - Paris (France). Direction de la Production et du Transport; Leveque, J.P. [Electricite de France (EDF), Reseau de Transport d' Electricite, 75 - Paris (France)

    2003-02-01

    This article presents the characteristics of bare cables for the construction of overhead lines. During the last decades, no important change has been made in the choice of conductive materials. The main materials used are: the high purity cold drawn aluminium in bi-metal aluminium-steel cables, and the 'almelec', an aluminium alloy with a reinforced traction resistance. Recently, new conductors with a higher transport capacity and a better temperature resistance have been developed. Another way of research concerns the combination of conductors and composite materials (carbon fibers) but no satisfactory solutions have been obtained so far. A more important evolution concerns the guard cables for high voltage lines which now include telecommunication circuits (optical fibers) for high flow rate transmission of numerical data. The laying out of such cables has been generalized in France in order to supply the overall territory with equivalent and satisfactory performances. (J.S.)

  13. Analysis of local influences in structural details of the bridges

    Directory of Open Access Journals (Sweden)

    Adam RUDZIK

    2015-03-01

    Full Text Available The article analyses the problems of local influences in structural details of bridges as the critical locations, whose damages or excessive force may directly affect the safety of users. These analyses are shown on selected examples. Presented is the example of local changes in the forms of proper vibrations in the node of the truss bridge that can be used in expert issues concerning the causes of damages. The second example are the changes in stresses in the stay cable anchorage element including the nonlinear material models. Models of this type can be successfully used by engineers as they allow for analysis of selected structural details without the need for detailed mapping of the entire structure, but only a selected section.

  14. Assistant pullback technique for main span closure of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Chen Ming; Luo Chengbin; Wu Qihe; Zhang Yongtao; You Xinpeng

    2009-01-01

    Sutong Bridge is a cable-stayed steel box girder bridge with a main span of 1 088 m. The erection of upper structure adopts geometry control method and requires no change to the unit's size and the structure's none-stress geometry. Before main span closure, the cantilever of girder reaches 540.8 m, the structure state is noticeably influenced by external circumstances, the main span closure face great difficulty. By abstracting the advantage of the pullback method abroad and the domestic temperature-cutting method, a new assistant pullback method have put forward and bring into practice actually. In this paper, the analysis key point of practice conditions, key parameter of practice, main measures of the method and the performance is introduced.

  15. Insulation system for high temperature superconductor cables

    Science.gov (United States)

    Michael, P. C.; Haight, A. E.; Bromberg, L.; Kano, K.

    2015-12-01

    Large-scale superconductor applications, like fusion magnets, require high-current capacity conductors to limit system inductance and peak operating voltage. Several cabling methods using high temperature superconductor (HTS) tapes are presently under development so that the unique high-field, high-current-density, high operating temperature characteristics of 2nd generation REBCO coated conductors can be utilized in next generation fusion devices. Large-scale magnets are generally epoxy impregnated to support and distribute electromagnetic stresses through the magnet volume. However, the present generation of REBCO coated conductors are prone to delamination when tensile stresses are applied to the broad surface of REBCO tapes; this can occur during epoxy cure, cooldown, or magnet energization. We present the development of an insulation system which effectively insulates HTS cabled conductors at high withstand voltage while simultaneously preventing the intrusion of the epoxy impregnant into the cable, eliminating degradation due to conductor delamination. We also describe a small-scale coil test program to demonstrate the cable insulation scheme and present preliminary test results.

  16. Modeling of Pressure Effects in HVDC Cables

    DEFF Research Database (Denmark)

    Szabo, Peter; Hassager, Ole; Strøbech, Esben

    1999-01-01

    A model is developed for the prediction of pressure effects in HVDC mass impregnatedcables as a result of temperature changes.To test the model assumptions, experiments were performed in cable like geometries.It is concluded that the model may predict the formation of gas cavities....

  17. Dynamic Loadability of Cable Based Transmission Grids

    DEFF Research Database (Denmark)

    Olsen, Rasmus Schmidt

    supervised 2 master projects, as well as 5 special courses at DTU. Furthermore I created and taught a cable course, with approximately 25 students, throughout 13 weeks during the spring of 2011. The PhD project has until now contributed with 3 journal papers and 4 conference papers. Selected papers can be...

  18. Dutch VULA consumer market services over Cable

    NARCIS (Netherlands)

    Anoniem

    2015-01-01

    KPN offers a virtual unbundled local access wholesale service over its DSL infrastructure. This offer has been accepted by the Dutch Authority Consumer Market. In the report, it is argued that for consumer market services, the Dutch cable providers can develop an equivalent wholesale service from th

  19. AC loss in superconducting tapes and cables

    NARCIS (Netherlands)

    Oomen, Marijn Pieter

    2000-01-01

    The present study discusses the AC loss in high-temperature superconductors. Superconducting materials with a relatively high critical temperature were discovered in 1986. They are presently developed for use in large-scale power-engineering devices such as power-transmission cables, transformers an

  20. Study on Impedance Characteristics of Aircraft Cables

    Directory of Open Access Journals (Sweden)

    Weilin Li

    2016-01-01

    Full Text Available Voltage decrease and power loss in distribution lines of aircraft electric power system are harmful to the normal operation of electrical equipment and may even threaten the safety of aircraft. This study investigates how the gap distance (the distance between aircraft cables and aircraft skin and voltage frequency (variable frequency power supply will be adopted for next generation aircraft will affect the impedance of aircraft cables. To be more precise, the forming mechanism of cable resistance and inductance is illustrated in detail and their changing trends with frequency and gap distance are analyzed with the help of electromagnetic theoretical analysis. An aircraft cable simulation model is built with Maxwell 2D and the simulation results are consistent with the conclusions drawn from the theoretical analysis. The changing trends of the four core parameters of interest are analyzed: resistance, inductance, reactance, and impedance. The research results can be used as reference for the applications in Variable Speed Variable Frequency (VSVF aircraft electric power system.

  1. Integral Abutment and Jointless Bridges

    OpenAIRE

    Cristian-Claudiu Comisu

    2005-01-01

    Integral bridges, or integral abutment and jointless bridges, as they are more commonly known in the USA, are constructed without any movement joints between spans or between spans and abutments. Typically these bridges have stub-type abutments supported on piles and continuous bridge deck from one embankment to the other. Foundations are usually designed to be small and flexible to facilitate horizontal movement or rocking of the support. Integrally bridges are simple or multiple span ones t...

  2. Cable deformation simulation and a hierarchical framework for Nb{sub 3}Sn Rutherford cables

    Energy Technology Data Exchange (ETDEWEB)

    Arbelaez, D; Prestemon, S O; Ferracin, P; Godeke, A; Dietderich, D R; Sabbi, G, E-mail: darbelaez@lbl.go [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2010-06-01

    Knowledge of the three-dimensional strain state induced in the superconducting filaments due to loads on Rutherford cables is essential to analyze the performance of Nb{sub 3}Sn magnets. Due to the large range of length scales involved, we develop a hierarchical computational scheme that includes models at both the cable and strand levels. At the Rutherford cable level, where the strands are treated as a homogeneous medium, a three-dimensional computational model is developed to determine the deformed shape of the cable that can subsequently be used to determine the strain state under specified loading conditions, which may be of thermal, magnetic, and mechanical origins. The results can then be transferred to the model at the strand/macro-filament level for rod restack process (RRP) strands, where the geometric details of the strand are included. This hierarchical scheme can be used to estimate the three-dimensional strain state in the conductor as well as to determine the effective properties of the strands and cables from the properties of individual components. Examples of the modeling results obtained for the orthotropic mechanical properties of the Rutherford cables are presented.

  3. Cable deformation simulation and a hierarchical framework for Nb3Sn Rutherford cables

    Energy Technology Data Exchange (ETDEWEB)

    Arbelaez, D.; Prestemon, S. O.; Ferracin, P.; Godeke, A.; Dietderich, D. R.; Sabbi, G.

    2009-09-13

    Knowledge of the three-dimensional strain state induced in the superconducting filaments due to loads on Rutherford cables is essential to analyze the performance of Nb{sub 3}Sn magnets. Due to the large range of length scales involved, we develop a hierarchical computational scheme that includes models at both the cable and strand levels. At the Rutherford cable level, where the strands are treated as a homogeneous medium, a three-dimensional computational model is developed to determine the deformed shape of the cable that can subsequently be used to determine the strain state under specified loading conditions, which may be of thermal, magnetic, and mechanical origins. The results can then be transferred to the model at the strand/macro-filament level for rod restack process (RRP) strands, where the geometric details of the strand are included. This hierarchical scheme can be used to estimate the three-dimensional strain state in the conductor as well as to determine the effective properties of the strands and cables from the properties of individual components. Examples of the modeling results obtained for the orthotropic mechanical properties of the Rutherford cables are presented.

  4. A unique cabling designed to produce Rutherford-type superconducting cable for the SSC project

    International Nuclear Information System (INIS)

    Up to 25,000 Km of keystoned flat cable must be produced for the SSC project. Starting from a specification developed by Lawrence Berkeley Laboratory (LBL), a special cabling machine has been designed by Dour Metal. It has been designed to be able to run at a speed corresponding to a maximum production rate of 10 m/min. This cabling machine is the key part of the production line which consists of a precision Turkshead equipped with a variable power drive, a caterpillar, a dimensional control bench, a data acquisition system, and a take-up unit. The main features of the cabling unit to be described are a design with nearly equal path length between spool and assembling point for all the wires, and the possibility to run the machine with several over- or under-twisting ratios between cable and wires. These requirements led Dour Metal to the choice of an unconventional mechanical concept for a cabling machine. 4 refs., 2 figs

  5. Energy dispatching analysis of lightning surges on underground cables in a cable connection station

    International Nuclear Information System (INIS)

    The paper aimed to simulate the transient over-voltage phenomena which occur at 345 kV and 161 kV underground cables, when lighting strikes on or near the cable connection station, by using the Electro-Magnetic Transients Program (EMTP). A feasibility study on changing related parameters, as well as cable connections and grounding methods to reduce the impact caused by lightning strikes, will be thoroughly conducted. The various components required for a detailed simulation including; lightning surges, transmission line and tower, arrester, and underground cables are all considered. Then, the transient voltage of the cables will be analyzed under different situations including; connection methods, grounding locations, length of the grounding wire of arrester, and the grounding resistance for different locations. The simulation results show that the length of the grounding wire is more sensitive to the transient over-voltage which occurred when a common grounding topology was adopted. In contrast, the use of an independent grounding topology resulted in a reduction of the grounding resistance, which effectively decreased the over-voltage, thereby avoiding surpassing the shielding voltage level of the cable, caused by the rise of ground voltage.

  6. Application of Time Delay Consideration on Bridge Vibration Control Method with Active Tendons

    Directory of Open Access Journals (Sweden)

    Lezin Seba MINSILI

    2010-12-01

    Full Text Available For many years bridge structures have been designed or constructed as passive structures that rely on their mass and solidity to resist external forces, while being incapable of adapting to the dynamics of an ever-changing environment. When the rigidity assumption is not met in particular for high-rise structures like bridge towers, a proper dynamic model should be established and conclusions made on the differential vibration of the tower when it is investigated out of the bridge system. The present work outlines a vibration control method by tendons on the tower of cable supported structures considering time delay effects, based on the discrete-time Linearization of the Feedback Gain Matrix. The efficiency of this vibration control method first proposed on the design process of a local bridge in Cameroon, is more compatible to the control of civil structures and is of great interest in accordance with simulation results.

  7. Superconducting power cables in Denmark - a case study

    DEFF Research Database (Denmark)

    Østergaard, Jacob

    1997-01-01

    HTS cables will be less expensive for high power ratings, have lower losses for lines with a high load, and have a reduced reactive power production. The use of superconducting cables in Denmark accommodate plans by the Danish utility to make a substantial conversion of overhead lines to underground......A case study of a 450 MVA, 132 kV high temperature superconducting (HTS) power transmission cable has been carried out. In the study, a superconducting cable system is compared to a conventional cable system which is under construction for an actual transmission line in the Danish grid. The study...

  8. Comparison of advanced high power underground cable designs

    International Nuclear Information System (INIS)

    In this paper, advanced high power underground cable designs are compared in the light of available literature, of reports and information supplied by participating industries (AEG, BICC, CGE, Pirelli, Siemens), spontaneous contributions by EdF, France, BBC and Felten and Guilleaume Kabelwerke A.G., Germany, and Hitachi, Furukawa, Fujikura and Sumitomo, Japan, and earlier studies carried out at German public research centres. The study covers cables with forced cooling by oil or water, SF6-cables, polyethylene cables, cryoresistive and superconducting cables. (orig.)

  9. 2nd International Conference on Cable-Driven Parallel Robots

    CERN Document Server

    Bruckmann, Tobias

    2015-01-01

    This volume presents the outcome of the second forum to cable-driven parallel robots, bringing the cable robot community together. It shows the new ideas of the active researchers developing cable-driven robots. The book presents the state of the art, including both summarizing contributions as well as latest research and future options. The book cover all topics which are essential for cable-driven robots: Classification Kinematics, Workspace and Singularity Analysis Statics and Dynamics Cable Modeling Control and Calibration Design Methodology Hardware Development Experimental Evaluation Prototypes, Application Reports and new Application concepts

  10. D0 Silicon Upgrade: End Calorimeter Transfer Bridge Modification

    International Nuclear Information System (INIS)

    During the assembly of major components into the D0 Detector, a transfer bridge was required to move the North-End Calorimeter from the clean room,over the cable bridge and onto the north sidewalk of the assembly hall. This experiment is now at the beginning stages of the next phase, namely the upgrade of this Detector for future physics research. A major piece of this upgrade is the installation of a solenoid magnet into the Central Calorimeter. In order to accomplish this, the South End Calorimeter has to be removed from the detector and the North End Calorimeter must be moved an additional 20-inch from its nominal open position (total 60-inch movement). The South End Calorimeter will be removed from the detector using the equipment designed for its installation. The calorimeter will be staged on the south sidewalk during the installation of the solenoid magnet and the central tracking systems. The North End Calorimeter is moved 60-inch to give more space between calorimeters during magnet, tracker and cable installation work. This movement will allow the calorimeter to remain coupled to the cryo system. However, this movement requires an extension be added to the center beam. This extension will support the rear wheels of the calorimeter and in the case of the end calorimeters, carry the majority of the weight. The extension is to be a modification of the transfer bridge. This modification, basically has T1 steel blocks added to one end and legs to the sidewalk supports at the other. The T1 steel blocks are notched to fit into the center beam porches and are welded to bridge rails. This design is the same as that for the installation bridge (3740.312-ME-273456), including the welds and weld procedures which are identical in both cases. Since load testing is impractical, the critical welds will be non-destructive tested by ultrasonic means. The laboratory, through the FESS Department, has a contract with M.Q.S. Inspection Inc. The results of this testing will be

  11. Lyapunov-Based Control for Suppression of Wind-Induced Galloping in Suspension Bridges

    Directory of Open Access Journals (Sweden)

    Naif B. Almutairi

    2011-01-01

    Full Text Available This paper investigates the suppression of galloping in a suspension bridge due to wind loads. The galloping phenomenon can be destructive due to the high-amplitude oscillations of the structure. Two controllers are proposed to generate the control force needed to suppress the vertical galloping in the suspended cables and in the bridge deck. SIMULINK software is used to simulate the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a tuned mass damper.

  12. Analytical Solution for the Current Distribution in Multistrand Superconducting Cables

    CERN Document Server

    Bottura, L; Fabbri, M G

    2002-01-01

    Current distribution in multistrand superconducting cables can be a major concern for stability in superconducting magnets and for field quality in particle accelerator magnets. In this paper we describe multistrand superconducting cables by means of a distributed parameters circuit model. We derive a system of partial differential equations governing current distribution in the cable and we give the analytical solution of the general system. We then specialize the general solution to the particular case of uniform cable properties. In the particular case of a two-strand cable, we show that the analytical solution presented here is identical to the one already available in the literature. For a cable made of N equal strands we give a closed form solution that to our knowledge was never presented before. We finally validate the analytical solution by comparison to numerical results in the case of a step-like spatial distribution of the magnetic field over a short Rutherford cable, both in transient and steady ...

  13. Deployment/Retrieval Modeling of Cable-Driven Parallel Robot

    Directory of Open Access Journals (Sweden)

    Q. J. Duan

    2010-01-01

    Full Text Available A steady-state dynamic model of a cable in air is put forward by using some tensor relations. For the dynamic motion of a long-span Cable-Driven Parallel Robot (CDPR system, a driven cable deployment and retrieval mathematical model of CDPR is developed by employing lumped mass method. The effects of cable mass are taken into account. The boundary condition of cable and initial values of equations is founded. The partial differential governing equation of each cable is thus transformed into a set of ordinary differential equations, which can be solved by adaptive Runge-Kutta algorithm. Simulation examples verify the effectiveness of the driven cable deployment and retrieval mathematical model of CDPR.

  14. RESPONSE CHARACTERISTICS OF WIND EXCITED CABLES WITH ARTIFICIAL RIVULET

    Institute of Scientific and Technical Information of China (English)

    顾明; 刘慈军; 徐幼麟; 项海帆

    2002-01-01

    A wind tunnel investigation of response characteristics of cables with artificial rivulet is presented.A series of cable section models of different mass and stiffness and damping ratio were designed with artificial rivulet.They were tested in smooth flow under different wind speed and yaw angle and for different position of artificial rivulet.The measured response of cable models was then analyzed and compared with the experimental results obtained by other researchers and the existing theories for wind-induced cable vibration.The results show that the measured response of horizontal cable models with artificial rivulet could be well predicted by Den Hartog' s galloping theory when wind is normal to the cable axis.For the wind with certain yaw angles, the cable models with artificial rivulet exhibit velocity-restricted response characteristics.

  15. A Study on the System and Method for Drawing 3-Dimensional Cable Object with the cable tracking Navigation

    International Nuclear Information System (INIS)

    3D cable tracking system with navigation makes it possible to easily search the objects which users want to retrieve and to measure the visual, spatial and structural distance by connecting the existing cable management system with 3D cable tracking system with navigation. With this consideration, we hope to create a more advanced cable management system in the future. I would like to describes the management system and method of the cable installed in the nuclear power plant, and how to build the database of the system. More specifically, it will be operated to the maintenance and management function, and the life management system of the cable, describing the creation method of three-dimensional cable object formed by the information of trace route through navigation and how to build the system database automatically

  16. A Study on the System and Method for Drawing 3-Dimensional Cable Object with the cable tracking Navigation

    Energy Technology Data Exchange (ETDEWEB)

    Bhang, Keugjin; Jung, Sunchul [Central Research Institute, Daejeon (Korea, Republic of); Hong, Junhee [Chungnam Univ., Daejeon (Korea, Republic of)

    2013-05-15

    3D cable tracking system with navigation makes it possible to easily search the objects which users want to retrieve and to measure the visual, spatial and structural distance by connecting the existing cable management system with 3D cable tracking system with navigation. With this consideration, we hope to create a more advanced cable management system in the future. I would like to describes the management system and method of the cable installed in the nuclear power plant, and how to build the database of the system. More specifically, it will be operated to the maintenance and management function, and the life management system of the cable, describing the creation method of three-dimensional cable object formed by the information of trace route through navigation and how to build the system database automatically.

  17. Istanbul Bridge Conference 2014

    CERN Document Server

    Gülkan, Polat; Mahmoud, Khaled

    2016-01-01

      The book includes peer-reviewed contributions selected from presentations given at the Istanbul Bridge Conference 2014, held from August 11 – 13 in Istanbul, Turkey. It reports on the current challenges in bridge engineering faced by professionals around the globe, giving a special emphasis to recently developed techniques, innovations and opportunities. The book covers key topics in the field, including modeling and analysis methods; construction and erection techniques; design for extreme events and condition assessment and structural health monitoring. There is a balanced presentation of theory, research and practice. This book, which provides the readers with a comprehensive and timely reference guide on current practices in bridge engineering, is intended for professionals, academic researchers and students alike.

  18. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps are...

  19. Southwire's High Temperature Superconducting Cable Development - Summary Report

    International Nuclear Information System (INIS)

    Final technical report on Southwire HTS cable development program. Southwire started an HTS cable development program beginning early 1995 with a Co-operative Research and Development Agreement (CRADA) with Oak Ridge National Laboratory. The development task was to study the properties of HTS tapes, and construct hand wound 1-m cables to study the winding characteristics of the tapes. Within a short time several 1-m long cables were constructed and tested. A goal was established to construct a 30-m long, three single-phase cables suitable to carry 1250-Aac at 12.4 kV and power Southwire's two main manufacturing plants, machinery division, and part of the corporate headquarters building. Southwire chose to construct a cold dielectric (CD) design cable that has the advantage of shielding magnetic fields and suitable for carrying larger amounts of current for future applications. The CD design however, required a dielectric material that would be suitable at liquid nitrogen temperature. After considerable testing, a polymer based tape called ''Cryoflex'' was developed by Southwire for use as a cold dielectric. Southwire developed a HTS cable making facility for the winding of HTS and dielectric tapes. At the same time Southwire and ORNL developed at Oak Ridge a dielectric testing laboratory and a 5-m cable test bed. The HTS cable requires special terminations that connect cables at 77 K and high pressures (design pressure of 150 psi) with outside power at ambient temperature and pressure. Two types of terminations called Vacuum (T-1) and Pressure termination (T-2) were developed. The vacuum termination needed very high vacuum (10-5 bar) and cold ceramic bushings that were expensive and unreliable. The modified pressure termination eliminated vacuum, utilize industrial bushings, reduced cost, and increased reliability. Two 5-m cables were designed and constructed at Southwire with the same rating as needed for the 30-m cables. The 5-m cables were tested successfully at

  20. Offshore wind farm electrical cable layout optimization

    Science.gov (United States)

    Pillai, A. C.; Chick, J.; Johanning, L.; Khorasanchi, M.; de Laleu, V.

    2015-12-01

    This article explores an automated approach for the efficient placement of substations and the design of an inter-array electrical collection network for an offshore wind farm through the minimization of the cost. To accomplish this, the problem is represented as a number of sub-problems that are solved in series using a combination of heuristic algorithms. The overall problem is first solved by clustering the turbines to generate valid substation positions. From this, a navigational mesh pathfinding algorithm based on Delaunay triangulation is applied to identify valid cable paths, which are then used in a mixed-integer linear programming problem to solve for a constrained capacitated minimum spanning tree considering all realistic constraints. The final tree that is produced represents the solution to the inter-array cable problem. This method is applied to a planned wind farm to illustrate the suitability of the approach and the resulting layout that is generated.

  1. Development of polymer packaging for power cable

    Directory of Open Access Journals (Sweden)

    S. Sremac

    2014-10-01

    Full Text Available This paper discusses the issues of product design and the procedure of developing polymer packaging as one of the most important engineering tasks. For the purpose of packing power cables a polymer packaging has been designed in the form of drum. Packaging and many other consumer products are largely produced using polymeric materials due to many positive features. High Density Polyethylene is the type of polyethylene proposed for packaging purposes due to its low degree of branching and strong intermolecular forces. Transport and storage processes were automated based on the radio-frequency identification technology. The proposed system is flexible in terms of its possibility of accepting and processing different types of cables and other products.

  2. Aging assessment of cable for NPP

    International Nuclear Information System (INIS)

    Activation energy is measured with UTM (Universal Testing Machine), TGA (Thermo-gravimetric Analyzer) and DMA (Dynamic Mechanical Analyzer) to analyze the aging degree of cables for NPP (Nuclear Power Plant). Insulation power cables containing EPR (Ethylene Propylene Rubber) are arranged for two kinds of specimens which are intact specimens and aged specimens by exposing to LOCA (Loss of Coolant Accident) environmental conditions regulated in IEEE 323. In case of intact specimen, values of activation energy are 1.1 eV for UTM, 1.24 eV with storage modulus and 1.13 eV with loss modulus for DMA, 1.29 eV for TGA, respectively. Damping of specimen under LOCA conditions decreases the activation energy to 0.88 eV for TGA. (author)

  3. Horizon-T Experiment Calibrations - Cables

    CERN Document Server

    Beznosko, D; Iakovlev, A; Makhataeva, Z; Vildanova, M I; Yelshibekov, K; Zhukov, V V

    2016-01-01

    An innovative detector system called Horizon-T is constructed to study Extensive Air Showers (EAS) in the energy range above 1016 eV coming from a wide range of zenith angles (0o - 85o). The system is located at Tien Shan high-altitude Science Station of Lebedev Physical Institute of the Russian Academy of Sciences at approximately 3340 meters above the sea level. The detector consists of eight charged particle detection points separated by the distance up to one kilometer as well as optical detector to view the Vavilov-\\v{C}erenkov light from the EAS. Each detector connects to the Data Acquisition system via cables. The calibration of the time delay for each cable and the signal attenuation is provided in this article.

  4. Development of radiation resistant electrical cable insulations

    International Nuclear Information System (INIS)

    Two new polyethylene cable insulations have been formulated for nuclear applications, and have been tested under gamma radiation. Both insulations are based on low density polyethylene, one with PbO and the other with Sb2O3 as additives. The test results show that the concept of using inorganic antioxidants to retard radiation initiated oxidation (RIO) is viable. PbO is more effective than Sb2O3 in minimizing RIO

  5. Optical fibre cable selection for electricity utilities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The report provides an assessment of the range of optical fibre cable solutions available, by type e.g. OPGW, ADSS, rather than by design. it also examines the key issues which will influence an electricity utilities decisions and proposes a method of evaluating the options to identify the one which most closely matches the utility's critical needs, with measurements against time, cost and quality targets. (author)

  6. Ultrasonic security seal with a cable

    International Nuclear Information System (INIS)

    The sonic delay line of the seal is prolongated by a truncated part and terminated by a spherical cap which can be marked. The sealing capsule has a bore adapted to the size of the truncated part of the identity module. The sealing cable is fastened between the sealing capsule and the module. Application is made to the monitoring of containers for dangerous or radioactive materials

  7. Space charge fields in DC cables

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson; Crichton, George C; Pedersen, Aage

    The space charge that accumulates in DC cables can, mathematically, be resolved into two components. One is related to the temperature and the other to the magnitude of the electric field strength. Analytical expressions for the electric fields arising from each of these space charge components are...... derived. Thereafter, the significance of these field components under both normal operating conditions and immediately following polarity reversal is discussed...

  8. Commercialization of Medium Voltage HTS Triax TM Cable Systems

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, David

    2012-12-31

    The original project scope that was established in 2007 aimed to install a 1,700 meter (1.1 mile) medium voltage HTS Triax{TM} cable system into the utility grid in New Orleans, LA. In 2010, however, the utility partner withdrew from the project, so the 1,700 meter cable installation was cancelled and the scope of work was reduced. The work then concentrated on the specific barriers to commercialization of HTS cable technology. The modified scope included long-length HTS cable design and testing, high voltage factory test development, optimized cooling system development, and HTS cable life-cycle analysis. In 2012, Southwire again analyzed the market for HTS cables and deemed the near term market acceptance to be low. The scope of work was further reduced to the completion of tasks already started and to testing of the existing HTS cable system in Columbus, OH. The work completed under the project included: • Long-length cable modeling and analysis • HTS wire evaluation and testing • Cable testing for AC losses • Optimized cooling system design • Life cycle testing of the HTS cable in Columbus, OH • Project management. The 200 meter long HTS Triax{TM} cable in Columbus, OH was incorporated into the project under the initial scope changes as a test bed for life cycle testing as well as the site for an optimized HTS cable cooling system. The Columbus cable utilizes the HTS TriaxTM design, so it provided an economical tool for these of the project tasks.

  9. Prospective barrier coatings for superconducting cables

    Science.gov (United States)

    Ipatov, Y.; Dolgosheev, P.; Sytnikov, V.

    1997-07-01

    Known and prospective types of chromium coatings, used in the production of superconducting `cable-in-conduit' conductors designed for the ITER and other projects, are considered. The influence of the technological conditions during the galvanic plating of hard, grey, black and combined chromium coatings in various electrolytes and the annealing conditions in air and in vacuum on the contact electrical resistance of copper and superconducting wire at room temperature and 4.2 K as well as on other physical properties, e.g. resistance to abrasion, elasticity and thickness of the coatings, is investigated. Black oxide - chromium coatings and combined chromium coatings, containing oxides of chromium and a number of other metals, ensure the possibility of a significant increase of contact resistance as well as its regulation in a broad range of values in comparison with hard chromium. The results of the present work and also an independent investigation of the cable containing the strand, manufactured in JSC `VNIIKP', allow us to propose the oxide - chromium coating as a barrier layer for multistrand superconducting cables.

  10. Cable energy function of cortical axons.

    Science.gov (United States)

    Ju, Huiwen; Hines, Michael L; Yu, Yuguo

    2016-01-01

    Accurate estimation of action potential (AP)-related metabolic cost is essential for understanding energetic constraints on brain connections and signaling processes. Most previous energy estimates of the AP were obtained using the Na(+)-counting method, which seriously limits accurate assessment of metabolic cost of ionic currents that underlie AP conduction along the axon. Here, we first derive a full cable energy function for cortical axons based on classic Hodgkin-Huxley (HH) neuronal equations and then apply the cable energy function to precisely estimate the energy consumption of AP conduction along axons with different geometric shapes. Our analytical approach predicts an inhomogeneous distribution of metabolic cost along an axon with either uniformly or nonuniformly distributed ion channels. The results show that the Na(+)-counting method severely underestimates energy cost in the cable model by 20-70%. AP propagation along axons that differ in length may require over 15% more energy per unit of axon area than that required by a point model. However, actual energy cost can vary greatly depending on axonal branching complexity, ion channel density distributions, and AP conduction states. We also infer that the metabolic rate (i.e. energy consumption rate) of cortical axonal branches as a function of spatial volume exhibits a 3/4 power law relationship. PMID:27439954

  11. Cable energy function of cortical axons

    Science.gov (United States)

    Ju, Huiwen; Hines, Michael L.; Yu, Yuguo

    2016-01-01

    Accurate estimation of action potential (AP)-related metabolic cost is essential for understanding energetic constraints on brain connections and signaling processes. Most previous energy estimates of the AP were obtained using the Na+-counting method, which seriously limits accurate assessment of metabolic cost of ionic currents that underlie AP conduction along the axon. Here, we first derive a full cable energy function for cortical axons based on classic Hodgkin-Huxley (HH) neuronal equations and then apply the cable energy function to precisely estimate the energy consumption of AP conduction along axons with different geometric shapes. Our analytical approach predicts an inhomogeneous distribution of metabolic cost along an axon with either uniformly or nonuniformly distributed ion channels. The results show that the Na+-counting method severely underestimates energy cost in the cable model by 20–70%. AP propagation along axons that differ in length may require over 15% more energy per unit of axon area than that required by a point model. However, actual energy cost can vary greatly depending on axonal branching complexity, ion channel density distributions, and AP conduction states. We also infer that the metabolic rate (i.e. energy consumption rate) of cortical axonal branches as a function of spatial volume exhibits a 3/4 power law relationship. PMID:27439954

  12. Investigation of integrity of steel inserts and of homogeneity of filling of suspension of the first suspension bridge in Czechoslovakia

    International Nuclear Information System (INIS)

    X-ray radiography inspection was made of samples of suspensions of the first suspension bridge in Czechoslovakia. The X-ray ANDREX system type CMA 30 was used for testing. The samples used had the following artificial detects: one sample had steel cable defects, the other had defects of filling. The location and shape of the defects are shown in figures. As for samples with artificial cable defects, the system showed all defects, as for samples with filling defects the device showed all but the so-called small defects. (E.S.). 7 figs., 1 ref

  13. Building Migratory Bridges

    Science.gov (United States)

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  14. Quantum Bidding in Bridge

    Science.gov (United States)

    Muhammad, Sadiq; Tavakoli, Armin; Kurant, Maciej; Pawłowski, Marcin; Żukowski, Marek; Bourennane, Mohamed

    2014-04-01

    Quantum methods allow us to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this have thus far been limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain an advantage in a famous, immensely popular, card game—bridge. The essence of a winning strategy in bridge is efficient communication between the partners. The rules of the game allow only a specific form of communication, of very low complexity (effectively, one has strong limitations on the number of exchanged bits). Surprisingly, our quantum technique does not violate the existing rules of the game (as there is no increase in information flow). We show that our quantum bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt game, which is equivalent to a 2→1 quantum random access code. Thus, our experiment is also a realization of such protocols. However, this correspondence is not complete, which enables the bridge players to have efficient strategies regardless of the quality of their detectors.

  15. Bridge of Light

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Lying gleaming white under a brooding sky,the Lhasa River Railway Bridge forms a gate to Lhasa City.Built as a part of Qinghai-Tibet Railway,on July 1,2011, the highest altitude railway in the world has been in service for five years. Lhasa,Tibet

  16. Bridge over troubled water?

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Nannestad, Peter; Svendsen, Gert Tinggaard

    2008-01-01

    The problem of integrating non-Western immigrants into Western welfare states is the focus of this paper. To address this issue, we suggest a social capital approach in which we apply the conceptual pair of bridging social capital (BR), which connects an individual to the broader social structure...

  17. Rapid optimization of tension distribution for cable-driven parallel manipulators with redundant cables

    Science.gov (United States)

    Ouyang, Bo; Shang, Weiwei

    2016-03-01

    The solution of tension distributions is infinite for cable-driven parallel manipulators(CDPMs) with redundant cables. A rapid optimization method for determining the optimal tension distribution is presented. The new optimization method is primarily based on the geometry properties of a polyhedron and convex analysis. The computational efficiency of the optimization method is improved by the designed projection algorithm, and a fast algorithm is proposed to determine which two of the lines are intersected at the optimal point. Moreover, a method for avoiding the operating point on the lower tension limit is developed. Simulation experiments are implemented on a six degree-of-freedom(6-DOF) CDPM with eight cables, and the results indicate that the new method is one order of magnitude faster than the standard simplex method. The optimal distribution of tension distribution is thus rapidly established on real-time by the proposed method.

  18. Field Application of Automated Power Arc Spraying System on Steel Bridge Deck

    Institute of Scientific and Technical Information of China (English)

    YI Chun-long; SUO Shuang-fu; SUN Zhi; PANG Xu-nan

    2004-01-01

    The effective corrosion protection coating and high productive coating equipment for steel bridge deck has been a challenge for bridge engineers for many years. An automated power arc spraying system was first designed and field applied to coating the deck of Wuhan Junshan Yangtze River Bridge in high efficiency. This steel bridge is a continuous orthotropic deck box girder cable-stayed bridge with 962 m in length and 38.8 m in width, whose width is the No. 1 in China. The whole orthotropic deck with over 35,000 m2surface area was arc-sprayed a protective coating of zinc on site, followed by a sealant and SMA paving material. The side face and bottom of box girders were arc-sprayed with aluminum in factory.Field application indicated that the newly designed automated power arc spraying system with fan nozzle and separate primary & secondary atomizing air had some advantages over the conventional arc spraying system, such as automated operation,big arc spray current, high spraying rate, big breadth of each coat, even and small atomized particles, high density and low porosity of sprayed coating, and high adhesive strength to the substrate.Working procedure of surface preparation and automated arc spraying on bridge deck were introduced, and the quality of sprayed coating is controlled strictly. Field tests proved that the application of this automated power arc spraying system is successful and suitable for coating the steel bridge deck.

  19. Numerical method of thermal design of power cables

    Energy Technology Data Exchange (ETDEWEB)

    Bryukhanov, O.N.; Trigorlyy, S.V.

    1985-05-01

    Increasing the accuracy of computation of permissible current loads in cables requires that thermal calculations be performed considering the actual distribution of temperatures in the cables. An analysis of methods of thermal design of cables showed that numerical methods allowing most complete consideration of various heat exchange factors are superior. The authors suggest the use of the method of finite elements to study thermal states of multiple-conductor power cables laid in various ways. As an example, thermal calculation of three-conductor cable with circular conductors is studied. For a number of cables the permissible current loads calculated by the method of finite elements are greater than those established by the standards documents of calculated according to previous methods.

  20. Aging assessment of electrical cables from NPD nuclear generating station

    International Nuclear Information System (INIS)

    Degradation of NPD Nuclear Generating Station control and power cables after approximately 25 years of service was assessed. The PVC and SBR insulated cables were also exposed to radiation, accident and post-accident conditions, and accelerated aging to simulate extended service life. The degradation of the samples from the containment boiler room was minimal, caused mainly by thermal conditions rather than radiation. Although irradiation to 55 Mrad, simulating normal operation and accident radiation levels, caused degradation, the cables could still function during accident and post-accident conditions. Accelerated thermal aging to simulate an additional 10 years of service at 45 degrees C caused embrittlement of the PVC and a 60% decrease in elongation of the SBR. Comparison of test results of aged NPD cables with newer PVC cables obtained from Pickering NGS 'A' shows that the newer cables have improved aging stability and therefore should provide adequate service during their design life of 31 years

  1. Optimization and stability of a cable-in-conduit superconductor

    International Nuclear Information System (INIS)

    The optimization process for strand number and diameter, cable void fraction, and Cu/NbTi-ratio of the cable-in-conduit conductor for the superconducting magnet system of the planned stellarator fusion experiment Wendelstein 7-X is presented. Main optimization criteria are stability and cable cooling requirements, taking into account transient disturbances and losses. A simple stability criterion regarding transient disturbances is used which is derived from cable compression experiments. The resulting data for the 16 kA, 6 T cable are: cable and strand diameter ∼11.5 mm and ∼0.57 mm, respectively, strand number ∼250, void ∼36%, and Cu/sc-ratio ∼2.7

  2. Dynamic behavior of stay cables with passive negative stiffness dampers

    Science.gov (United States)

    Shi, Xiang; Zhu, Songye; Li, Jin-Yang; Spencer, Billie F., Jr.

    2016-07-01

    This paper systematically investigates the dynamic behavior of stay cables with passive negative stiffness dampers (NSD) installed close to the cable end. A passive NSD is modeled as a combination of a negative stiffness spring and a viscous damper. Through both analytical and numerical approaches, parametric analysis of negative stiffness and viscous damping are conducted to systematically evaluate the vibration control performance of passive NSD on stay cables. Since negative stiffness is an unstable element, the boundary of passive negative stiffness for stay cables to maintain stability is also derived. Results reveal that the asymptotic approach is only applicable to passive dampers with positive or moderate negative stiffness, and loses its accuracy when a passive NSD possesses significant negative stiffness. It has been found that the performance of passive NSD can be much better than those of conventional viscous dampers. The superior control performance of passive NSD in cable vibration mitigation is validated through numerical simulations of a full-scale stay cable.

  3. Analytical dynamic solution of a flexible cable-suspended manipulator

    Science.gov (United States)

    Bamdad, Mahdi

    2013-12-01

    Cable-suspended manipulators are used in large scale applications with, heavy in weight and long in span cables. It seems impractical to maintain cable assumptions of smaller robots for large scale manipulators. The interactions among the cables, platforms and actuators can fully evaluate the coupled dynamic analysis. The structural flexibility of the cables becomes more pronounced in large manipulators. In this paper, an analytic solution is provided to solve cable vibration. Also, a closed form solution can be adopted to improve the dynamic response to flexibility. The output is provided by the optimal torque generation subject to the actuator limitations in a mechatronic sense. Finally, the performance of the proposed algorithm is examined through simulations.

  4. Antenna mechanism of length control of actin cables

    CERN Document Server

    Mohapatra, Lishibanya; Kondev, Jane

    2014-01-01

    Actin cables are linear cytoskeletal structures that serve as tracks for myosin-based intracellular transport of vesicles and organelles in both yeast and mammalian cells. In a yeast cell undergoing budding, cables are in constant dynamic turnover yet some cables grow from the bud neck toward the back of the mother cell until their length roughly equals the diameter of the mother cell. This raises the question: how is the length of these cables controlled? Here we describe a novel molecular mechanism for cable length control inspired by recent experimental observations in cells. This antenna mechanism involves three key proteins: formins, which polymerize actin, Smy1 proteins, which bind formins and inhibit actin polymerization, and myosin motors, which deliver Smy1 to formins, leading to a length-dependent actin polymerization rate. We compute the probability distribution of cable lengths as a function of several experimentally tuneable parameters such as the formin-binding affinity of Smy1 and the concentra...

  5. Transverse stress effects in Nb3Sn cables

    International Nuclear Information System (INIS)

    The effect of transverse compressive stress on the critical current of solder-filled and unfilled Nb3Sn cables is reported. The conductor used in this study is a Nb3Sn Rutherford cable manufactured with a bronze-process wire of 0.92 mm diameter. Like epoxy-impregnated cables, solder-filled cables exhibit much less degradation than wire samples when subjected to the same stresses. On the other hand, unfilled specimens are irreversibly damaged at the thin edge when loaded to 160 MPa, and show significantly higher degradation than similar specimens of the solder-filled cable. A finite-element calculation of the stress state inside a particular composite superconductor indicates that more compressive stress is developed in the virgin wire than in a straight wire segment in a real cable environment

  6. The Coupling Effect of Spatial Reticulated Shell Structure with Cables

    Institute of Scientific and Technical Information of China (English)

    MA Jun; ZHOU Dai; FU Xu-chen

    2005-01-01

    The spatial reticulated shell structure with cables (RSC) is a kind of coupling working system, which consists of flexible cables, reticulated shell structure (RS) and tower columns. The dynamic analysis of RSC based on the coupling model was carried out. Three kinds of elements such as the spatial bar element, cable element and beam element were introduced to analyze the reticulated shell, cable and tower column respectively. Furthermore,such parameter influences as structural boundary conditions, grid configuration, the span-to-depth ratio and the arrangement of cable system upon structural dynamics were analyzed. The structural vibration modes can be divided into four groups based on some numerical examples. And the frequencies in the same group are very close while the frequencies in different groups are different from each other obviously. It is clear that the sequence of the appearance of the each mode group heavily depends on the comparative stiffness of the tower column system, RS and cables.

  7. Study on the Configuration of Towed Flexible Cables

    Institute of Scientific and Technical Information of China (English)

    陈敏康; 张仁颐

    2003-01-01

    Based on the fundamental equation of flexible cable dynamics for a towed system, an easily solved mathematical model is set up in this paper by means of appropriate simplification. Several regular patterns of spatial motion of towed flexible cables in water are obtained through numerical simulation with the finite difference method, and then modification and verification by trial results at sea. A technical support is provided for the towing ship to maneuver properly when a flexible cable is towed. Furthermore, the relations between two towed flexible cables, which are towed simultaneously by a ship, are investigated. The results show that the ship towing two flexible cables is safe under the suggested arrangement of two winches for the towing system, and the coiling/uncoiling sequences of the cables as well as the suggested way of maneuvering.

  8. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Jensen, F. M.; Middleton, C.; Blackmore, A.

    This paper is based on research performed for the Highway Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: Concrete Bridges" It contains details of a methodology which can be used to generate Whole Life (WL) reliability profiles....... These WL reliability profiles may be used to establish revised rules for Concrete Bridges....

  9. DC Cable Short Circuit Fault Protection in VSC-MTDC

    OpenAIRE

    Lu, Shining

    2015-01-01

    With the development of offshore wind farms, Voltage Source Converter based High Voltage Direct Current or Multi-terminal High Voltage Direct Current Technology (VSC-HVDC/MTDC) is becoming promising in the field of large-capacity and long-distance power transmission. However, its extreme vulnerability to DC contingencies remains a challenge in both research and practice. DC cable short circuit faults, or cable pole-to-pole faults, though less common than DC cable ground faults, can cause the ...

  10. 46 CFR 111.60-6 - Fiber optic cable.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fiber optic cable. 111.60-6 Section 111.60-6 Shipping... REQUIREMENTS Wiring Materials and Methods § 111.60-6 Fiber optic cable. Each fiber optic cable must— (a) Be... 60332-3-22 (all three standards incorporated by reference; see 46 CFR 110.10-1); or (b) Be installed...

  11. Similarity Analysis of Cable Insulations by Chemical Test

    International Nuclear Information System (INIS)

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  12. Total Magnetic Field Signatures over Submarine HVDC Power Cables

    Science.gov (United States)

    Johnson, R. M.; Tchernychev, M.; Johnston, J. M.; Tryggestad, J.

    2013-12-01

    Mikhail Tchernychev, Geometrics, Inc. Ross Johnson, Geometrics, Inc. Jeff Johnston, Geometrics, Inc. High Voltage Direct Current (HVDC) technology is widely used to transmit electrical power over considerable distances using submarine cables. The most commonly known examples are the HVDC cable between Italy and Greece (160 km), Victoria-Tasmania (300 km), New Jersey - Long Island (82 km) and the Transbay cable (Pittsburg, California - San-Francisco). These cables are inspected periodically and their location and burial depth verified. This inspection applies to live and idle cables; in particular a survey company could be required to locate pieces of a dead cable for subsequent removal from the sea floor. Most HVDC cables produce a constant magnetic field; therefore one of the possible survey tools would be Marine Total Field Magnetometer. We present mathematical expressions of the expected magnetic fields and compare them with fields observed during actual surveys. We also compare these anomalies fields with magnetic fields produced by other long objects, such as submarine pipelines The data processing techniques are discussed. There include the use of Analytic Signal and direct modeling of Total Magnetic Field. The Analytic Signal analysis can be adapted using ground truth where available, but the total field allows better discrimination of the cable parameters, in particular to distinguish between live and idle cable. Use of a Transverse Gradiometer (TVG) allows for easy discrimination between cable and pipe line objects. Considerable magnetic gradient is present in the case of a pipeline whereas there is less gradient for the DC power cable. Thus the TVG is used to validate assumptions made during the data interpretation process. Data obtained during the TVG surveys suggest that the magnetic field of a live HVDC cable is described by an expression for two infinite long wires carrying current in opposite directions.

  13. A linear model of stationary elevator traveling and compensation cables

    Science.gov (United States)

    Zhu, W. D.; Ren, H.

    2013-06-01

    Based on a recent asymptotic analysis of a nonlinear model of a slack cable, a computationally efficient, linear model is developed for calculating the natural frequencies, mode shapes, and dynamic responses of stationary elevator traveling and compensation cables. The linear cable model consists of two vertical cable segments connected by a half-circular lower loop. The two vertical cable segments are modeled as a string with a variable tension due to the weight of the cable. The horizontal displacements of the cable segments consist of boundary-induced displacements and relative elastic displacements, where the boundary-induced displacements are interpolated from the displacements of the two lower ends of the cable segments, and the relative elastic displacements satisfy the corresponding homogeneous boundary conditions of the cable segments. The horizontal displacement of the lower loop is interpolated from those of the two lower ends of the two cable segments, and the bending stiffness of the lower loop is modeled by a spring with a constant stiffness, which can be calculated from the nonlinear model. Given a car position, the natural frequencies and mode shapes of an elevator traveling or compensation cable are calculated using the linear model and compared with those from the nonlinear model. The calculated natural frequencies are also compared with those from a full-scale experiment. In addition, the dynamic responses of a cable under a boundary excitation are calculated and compared with those from the nonlinear model. There is a good agreement between the predictions from the linear and nonlinear models and between the measured natural frequencies from the full-scale experiment and the corresponding calculated ones.

  14. Similarity Analysis of Cable Insulations by Chemical Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  15. Prospects of Research on Cable Logging in Forest Engineering Community

    OpenAIRE

    Cavalli, Raffaele

    2012-01-01

    An analysis of researches on cable logging carried out in the past 12 years (2000–2011) as found in the scientific literature at international level is proposed in order to evaluate which have been the main topics of interest of the researchers and to evaluate the evolution of the research in the field of cable logging in the next future. International scientific literature on cable logging was extracted from the main databases, scientific journals and conference proceedings on forest enginee...

  16. Underwater-cable power-transmission system: bottom segment design

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    After a survey of the state of the art for bottom cables, some possible configurations are considered for candidate OTEC sites. General considerations on laying and embedding are discussed, and solutions are considered. Optimization of cable dimensions and the problem of flexible joints are covered. The state of the art of cable installation and repair is reviewed and discussed with reference to the representative OTEC sites. Costs for shore terminal stations are evaluated. (LEW)

  17. Demand Pull and Supply Push in Portuguese Cable Television

    OpenAIRE

    João Leitão

    2004-01-01

    In this paper a Vector Autoregressive Model is applied to the most representative Portuguese cable television operators, in order to obtain a dynamic analysis of the interactivity established between the supply and the demand of network services, through the strategy of vertical integration of services. The results reveal the existence of two driving forces in the Portuguese main cable networks, on the one hand, the supply push which contributes to the enhancement of the basic cable demand, a...

  18. Losses in armoured three-phase submarine cables

    DEFF Research Database (Denmark)

    Ebdrup, Thomas; Silva, Filipe Miguel Faria da; Bak, Claus Leth;

    2014-01-01

    The number of offshore wind farms will keep increasing in the future as a part of the shift towards a CO2 free energy production. The energy harvested from the wind farm must be brought to shore, which is often done by using a three-phase armoured submarine power cable. The use of an armour...... increases the losses in armoured cables compared to unarmoured cables. In this paper a thorough state of the art analysis is conducted on armour losses in three-phase armoured submarine power cables. The analysis shows that the IEC 60287-1-1 standard overestimates the armour losses which lead to the...

  19. Modelling Subsea Coaxial Cable as FIR Filter on MATLAB

    Science.gov (United States)

    Kanisin, D.; Nordin, M. S.; Hazrul, M. H.; Kumar, E. A.

    2011-05-01

    The paper presents the modelling of subsea coaxial cable as a FIR filter on MATLAB. The subsea coaxial cables are commonly used in telecommunication industry and, oil and gas industry. Furthermore, this cable is unlike a filter circuit, which is a "lumped network" as individual components appear as discrete items. Therefore, a subsea coaxial network can be represented as a digital filter. In overall, the study has been conducted using MATLAB to model the subsea coaxial channel model base on primary and secondary parameters of subsea coaxial cable.

  20. Research on Cable Assembly Technology Facing Tridimention Layout in Spacecraft

    Science.gov (United States)

    Song, Xiaohui; Liu, Zhe; Wang, Zaicheng; Zhang, Yidan; Zhang, Jie; Liu, Zhibin

    According to the requirement for cables tridimensional layout in spacecraft, the research on new transmission line support (NTLS) is carried out. NTLS is namely T support. Based on the analysis of NTLS's physical parameters, the scheme of cable installing is established. Experimentations of statics and vibration prove the feasibility and dependability of the scheme. The results of experimentation indicate that the scheme of cable installing on T support is reasonable along with the requirement of cables tridimensional layout is satisfied. Therefore the efficiency of spacecraft assembly and integration is greatly enhanced.

  1. Interstrand contact resistances of Bi-2212 Rutherford cables for SMES

    Energy Technology Data Exchange (ETDEWEB)

    Kawagoe, A. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan)]. E-mail: kawagoe@eee.kagoshima-u.ac.jp; Kawabata, Y. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan); Sumiyoshi, F. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan); Nagaya, S. [Chubu Electric Power Co. Inc., Kitazekiyama 20-1, Ohtakacho-aza, Midori-ku, Nagoya 249-8522 (Japan); Hirano, N. [Chubu Electric Power Co. Inc., Kitazekiyama 20-1, Ohtakacho-aza, Midori-ku, Nagoya 249-8522 (Japan)

    2006-10-01

    Interstrand contact resistances of Bi-2212 Rutherford cables for SMES coils were evaluated from a comparison between measured data and 2D-FEM analyses on interstrand coupling losses in these cables. The cables were composed of 30 non-twisted Bi-2212 strands with a diameter of 0.81 mm and a cable twist pitch of 90 mm. Three samples were measured; one of them had NiCr cores and the others had no cores. One of the latter two samples repeatedly experienced bending. The interstrand coupling losses were measured in liquid helium for the straight samples under transverse ac ripple magnetic fields superposed on dc bias magnetic fields. The transverse magnetic field was applied to the samples in directions both perpendicular and parallel to the flat face of the cable. The effect of the bending on the interstrand coupling losses could be neglected for the non-cored samples. The interstrand coupling losses of NiCr cored sample decreased by about 30% compared with the non-cored samples, in case the direction of the transverse magnetic fields applied to the cable is perpendicular to the flat face of the cable. Using these results and 2D-FEM analyses, taking into account that interstrand contact conditions vary from the center to the edge in the cross-section of cables, gave us the conclusion that the between side-by-side strands contact with metallurgical bond only in both edges of the cables.

  2. Strand critical current degradation in $Nb_{3}$ Sn Rutherford cables

    CERN Document Server

    Barzi, E; Higley, H C; Scanlan, R M; Yamada, R; Zlobin, A V

    2001-01-01

    Fermilab is developing 11 Tesla superconducting accelerator magnets based on Nb/sub 3/Sn superconductor. Multifilamentary Nb/sub 3/Sn strands produced using the modified jelly roll, internal tin, and powder-in-tube technologies were used for the development and test of the prototype cable. To optimize the cable geometry with respect to the critical current, short samples of Rutherford cable with packing factors in the 85 to 95% range were fabricated and studied. In this paper, the results of measurements of critical current, n-value and RRR made on the round virgin strands and on the strands extracted from the cable samples are presented. (5 refs).

  3. Development mineral insulated cables for nuclear instrumentation of reactors

    International Nuclear Information System (INIS)

    In-core and out-of-core neutron detectors for reactor and safety control systems are usually connected by means of mineral insulated cables. The electrical signal, either a pulse or a current, is transmitted along the cable at high temperature, pressure and radiation and should not be influenced by electromagnetic interfereces from the environment. In this paper it is presented the result of the analysis of the mechanical and electrical properties of several types of mineral insulated cables and also the design, manufacture, sealing, cable ends and their applications to nuclear detectors of various types. (author)

  4. BEHAVIOR OF ELASTIC TOWING CABLES IN SHEAR CURRENTS

    Institute of Scientific and Technical Information of China (English)

    HOU Guo-xiang; LI Hong-bin; ZHANG Sheng-jun; YANG Yun-tao; XU Shi-hua; XIE Wei

    2005-01-01

    The formulation and solution of governing equations that can be used to analyse the three-dimensional behaviour of elastic towing cables subjected to arbitrary sheared currents were presented in this paper. The elastic cable geometry was described in terms of two angles, elevation and azimuth, which are related to Cartesian co-ordinates by geometry compatibility relations. These relations were combined with the cable equilibrium equations to obtain a system of non-linear differential equations. In the end, results for cable tension, angles, geometry and elongation are presented for example cases.

  5. A concrete balanced cantilever box girder bridge in the Netherlands with carbon fibre prestressing cables

    NARCIS (Netherlands)

    Hordijk, D.A.; Bruggeling, A.S.G.; Kaptijn, N.

    1998-01-01

    In the Netherlands a pilot project has started to recognize the possibilities of non-metallic materials for prestressing. This project will also serve to gather more knowledge regarding the properties of non-metallic wires, their anchorages and their application in large tendons. It is intended to a

  6. Maintenance with EMSM and KSNV carried by cable-hoists from a crane bridge

    International Nuclear Information System (INIS)

    Since its very first beginnings the crane is older than the notion engineer. In accordance with scientific Knowledge on formation of image its attributes, which seem not to match the demands of remote operations, can be recited from nearly every ''expert'', such as: load on the hook swings uncontrollable; neither horizontal pull nor push is possible; force of the rope is not perceivable; man has to guide the load by hands on, for only to name those ''knowledges'' which are most widespread. But by looking into the details it becomes obvious, that facts from a variety of very different operating conditions, with most different equipment and with operators of high to very low qualifications are lumped together and that soup is being sold as the only true experience, valid for all times and every place. In course of the tests on remotely controlled maintenance work, done in DWK's test facilities Vilsen and Lahde, to proove that these tasks can be accomplished successfully in the large FEMO-process cells of the German reprocessing plant for spent fuel of LWRs to be built, among other things those crane operation techniques were tested, which are known from isotope separation plants in the United States. It became inevitable to avoid the term ''maintenance from crane'' and the later on impressed ''MTS-maintenance'', because of being too inaccurate, but to describe the in fact used combination of operational means (COOM)

  7. Passive Seismic Protection of Cable-Stayed Bridges Applying Fluid Viscous Dampers under Strong Motion

    OpenAIRE

    Valdebenito, Galo E.

    2009-01-01

    Terremotos recientes han demostrado la gran vulnerabilidad de algunos puentes ante movimiento fuerte. Los de tipo atirantado constituyen una tipología estructural muy atractiva, y que actualmente es empleada para muchos fines prácticos, por lo que es necesaria su protección sísmica. Entre las actuales estrategias de protección, el uso de dispositivos pasivos es la más robusta, económica y apropiada opción para mejorar el desempeño sísmico de estructuras, de entre los que destacan los sistemas...

  8. Comparison of FT-IR and NIR method for cable classification

    International Nuclear Information System (INIS)

    There are about 50,000 cables in NPP. The number of the cables need to be environmentally qualified are 1,000 cables to 3,000 cables depending on the NPP respectively. Some EQ cables are environmentally qualified and the steam test reports prepared, but some other EQ cables are not environmentally qualified or not prepared steam test reports. Not qualified EQ cables need to be qualified by steam test; high temperature and high pressure with the same condition of DBAs. There are thousands of EQ cables in NPP but all the EQ cables don't have to be tested entirely. The steam tests can be carried out by the same types of cables. One type of cable is tested and demonstrated that the cable's capability for the duration of the installed life, all the same type of cables are qualified. Therefore, the classification the EQ cables is very important to carry out the steam test effectively. Also cable classification method selection is important, too. I tried two kinds of methods to classify the Wolsong Unit 1 EQ cables, Near InfraRed (NIR) spectroscopy and Fourier Transform InfraRed (FT-IR) spectroscopy. In case of old NPPs, lots of cables are missing their material information or have the wrong material information. The two methods are capable of searching for the material information of the cable. Briefly, the purpose FT-IR and NIR scanning is to find out their material information and classification of the EQ cables

  9. [Retention of adhesive bridges].

    Science.gov (United States)

    Raes, F; De Boever, J

    1994-04-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rests, interocclusal clearance and cingulum stops is equally important. Including more teeth in the design does not necessarily lead to an improved retention. Besides the material and technical aspects, the whole clinical procedure needs much attention. The retention does not depend on one single factor, but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 80% can be obtained. PMID:11830965

  10. Chemical-Sensing Cables Detect Potential Threats

    Science.gov (United States)

    2007-01-01

    Intelligent Optical Systems Inc. (IOS) completed Phase I and II Small Business Innovation Research (SBIR) contracts with NASA's Langley Research Center to develop moisture- and pH-sensitive sensors to detect corrosion or pre-corrosive conditions, warning of potentially dangerous conditions before significant structural damage occurs. This new type of sensor uses a specially manufactured optical fiber whose entire length is chemically sensitive, changing color in response to contact with its target, and demonstrated to detect potentially corrosive moisture incursions to within 2 cm. After completing the work with NASA, the company received a Defense Advanced Research Projects Agency (DARPA) Phase III SBIR to develop the sensors further for detecting chemical warfare agents, for which they proved just as successful. The company then worked with the U.S. Department of Defense (DoD) to fine tune the sensors for detecting potential threats, such as toxic industrial compounds and nerve agents. In addition to the work with government agencies, Intelligent Optical Systems has sold the chemically sensitive fiber optic cables to major automotive and aerospace companies, who are finding a variety of uses for the devices. Marketed under the brand name Distributed Intrinsic Chemical Agent Sensing and Transmission (DICAST), these unique continuous-cable fiber optic chemical sensors can serve in a variety of applications: Corrosive-condition monitoring, aiding experimentation with nontraditional power sources, as an economical means of detecting chemical release in large facilities, as an inexpensive "alarm" systems to alert the user to a change in the chemical environment anywhere along the cable, or in distance-resolved optical time domain reflectometry systems to provide detailed profiles of chemical concentration versus length.

  11. The technology of cable and cable fault locating : part 4, high voltage non persistent fault finding

    Energy Technology Data Exchange (ETDEWEB)

    Parker, G. [Radiodetection Ltd., Calgary, AB (Canada)

    2001-04-01

    The use of high voltage surge generators known as 'thumpers' was discussed in this last of a four part series on cable and fault locating technologies. The thumper is a portable source of high voltage, which repeatedly connects high voltage to a buried cable under test (CUT). The problem often associated with thumpers is that different ground conditions, vehicle traffic patters and fault types can make the noise they generate difficult to discern. In addition, repeated thumping can have negative side effects to the CUT, including weakening of adjacent cables. Thumped cables also fail prematurely, therefore thumping should be used only as a last resort. Advancements in thumper systems have included better listening devices, and the integration of safety systems, self-discharge systems, grounding, manual discharge hot-sticks, key switch lockouts and other methods to minimize injury. Other advancements have included a visual pre-locator which made the thumper more like a high voltage TDR. Pre-locators usually indicate the fault with an accuracy of 10 to 15 per cent. The Secondary Impulse Method (SIM) is the latest development in thumper technology. It was developed mainly to enhance trace interpretation. 2 figs.

  12. Nasal Bridge Intramuscular Hemangioma

    OpenAIRE

    Zulkifli Hamir Basah; Irfan Mohamad; Ramiza Ramza Ramli; Maha Khadum Gayadh; Samarendra Singh Mutum

    2015-01-01

    Intramuscular haemangioma (IMH) is a benign mesenchymal tumour. It appears as a deep, nontender mass within the soft tissue, particularly in the extremities. This tumour may not be obvious on clinical examination. Head and neck IMHs represent only 13.5% of the total IMHs. The most common site for a head and neck IMH is the masseter muscle, followed by trapezius, sternocleidomastoid, and very rarely temporalis muscle. We present a patient with left nasal bridge swelling which was excised and h...

  13. BRIDGING SERVICE QUALITY GAPS

    OpenAIRE

    BARKATH UNISSA

    2012-01-01

    Bridging the Service quality gaps is one of the foremost areas of concern for amarketer. Service marketing is inherently different from product or goods marketing.Services are distinctively characterized by their intangible, heterogeneous, inseparableand perishable nature. The importance of the service sector in today's world is a verywidely accepted and renowned idea. “We are already experiencing a service society“services do have some basic characteristics which make them fundamentally diff...

  14. Bridging as Coercive Accommodation

    CERN Document Server

    Bos, J W; Mineur, A M; Bos, Johan; Buitelaar, Paul; Mineur, Anne-Marie

    1995-01-01

    In this paper we discuss the notion of "bridging" in Discourse Representation Theory as a tool to account for discourse referents that have only been established implicitly, through the lexical semantics of other referents. In doing so, we use ideas from Generative Lexicon theory, to introduce antecedents for anaphoric expressions that cannot be "linked" to a proper antecedent, but that do not need to be "accommodated" because they have some connection to the network of discourse referents that is already established.

  15. Nematic liquid crystal bridges

    Science.gov (United States)

    Doss, Susannah; Ellis, Perry; Vallamkondu, Jayalakshmi; Danemiller, Edward; Vernon, Mark; Fernandez-Nieves, Alberto

    We study the effects of confining a nematic liquid crystal between two parallel glass plates with homeotropic boundary conditions for the director at all bounding surfaces. We find that the free surface of the nematic bridge is a surface of constant mean curvature. In addition, by changing the distance between the plates and the contact angle with the glass plates, we transition between loops and hedgehogs that can be either radial or hyperbolic.

  16. Copper Cable Recycling Technology. Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  17. Kinetostatic Analysis of Cable-Driven Parallel Robots with Consideration of Sagging and Pulleys

    OpenAIRE

    Gouttefarde, Marc; Nguyen, Dinh Quan; Baradat, Cédric

    2014-01-01

    Cable-driven parallel robots manipulating heavy payloads typically use cables having non-negligible diameters and mass. The associated cable guiding pulleys may then have non-negligible radii whose influence on the robot kinematics can hardly be neglected. This paper focuses on the output pulleys from which the cables extend to the robot mobile platform. A kinetostatic analysis of cable-driven parallel robots considering both cable mass and output pulleys is presented.

  18. An Analytical Study of Power Line Effect on UTP Cable using Lumped Circuit Components

    OpenAIRE

    Mitamoni Sarma; Shikhar Kr. Sarma

    2013-01-01

    The paper defines the term electrical noise with its types. Electromagnetic Interference (EMI), which is one type of electrical noise, is also defined and general techniques used for controlling EMI are described. Networking cables are affected by the EMI effect caused by a nearby power cable and data transmission through Unshielded Twisted Pair (UTP) cable, which is the mostly effected cable by EMI, may be degraded for it. Today, UTP cable is the most popular networking cable supporting 10G ...

  19. Ageing research of cable insulation materials

    International Nuclear Information System (INIS)

    The research on cable degradation mechanisms were successfully proceeded by our group for 5 years in 2006 - 2010 as the project research of plant life management for nuclear power plant by NISA (Nuclear and Industrial Safety Agency) of METI (Ministry of Economy, Trade, and Industry). At the finish of above research, the many reports on cable degradation were reviewed on the point of degradation mechanisms of the insulation materials by thermal and radiation ageing. Comparing the recent knowledge, the analysis and evaluation of the ported data were reconstructed, and proposed the new schema with the chemical reactions. The reports published after 1970 were mainly surveyed and the reliable facts, data which were described well in the experimental technique were selected. The verified facts, the reasonable interpretation of the facts, unresolved aspects were reviewed on the view point of recent techniques and knowledge. Especially, the review was focused to the oxidation mechanisms of polymer insulation materials by thermal and radiation ageing, and the interaction and contribution of antioxidant among the important stabilizers were discussed. (author)

  20. Tactical aircraft optical cable plant program plan

    Science.gov (United States)

    Weaver, Thomas L.; Murdock, John K.; Ide, James R.

    1995-05-01

    A program was created with joint industry and government funding to apply fiber optic technologies to tactical aircraft. The technology offers many potential benefits, including increased electromagnetic interference immunity and the possibility of reduced weight, increased reliability, and enlarged capability from redesigning architectures to use the large bandwidth of fiber optics. Those benefits will only be realized if fiber optics meets the unique requirements of aircraft networks. The application of fiber optics to tactical aircraft presents challenges to physical components which can only be met by a methodical attention to what is required, what are the conditions of use, and how will the components be produced in the broad context of a fiber optics using economy. For this purpose, the FLASH program has outlined a plan, and developed a team to evaluate requirements, delineate environmental and use conditions, and design practical, low cost components for tactical aircraft fiber optic cable plants including cables, connectors, splices, backplanes, manufacturing and installation methods, and test and maintenance methods.

  1. Metal flame spray coating protects electrical cables in extreme environment

    Science.gov (United States)

    Brady, R. D.; Fox, H. A.

    1967-01-01

    Metal flame spray coating prevents EMF measurement error in sheathed instrumentation cables which are externally attached to cylinders which were cooled on the inside, but exposed to gamma radiation on the outside. The coating provides a thermoconductive path for radiation induced high temperatures within the cables.

  2. Improved Method for PD-Quantification in Power Cables

    DEFF Research Database (Denmark)

    Holbøll, Joachim T.; Villefrance, Rasmus; Henriksen, Mogens

    n this paper, a method is described for improved quantification of partial discharges(PD) in power cables. The method is suitable for PD-detection and location systems in the MHz-range, where pulse attenuation and distortion along the cable cannot be neglected. The system transfer function was...

  3. Evaluation of cable aging degradation based on plant operating condition

    International Nuclear Information System (INIS)

    Extending the lifetime of nuclear power plant [(hereafter referred simply as ''NPP'')] is one of the most important concerns in the world nuclear industry. Cables are one of the long live items which have not been considered to be replaced during the design life of NPP. To extend the cable life beyond the design life, we need to prove that the design life is too conservative compared with the actual aging. Condition monitoring is one of the useful ways for evaluating the aging condition of cable. In order to simulate the natural aging in nuclear power plant, a study on accelerated aging needs to be conducted first. In this paper, evaluations of mechanical aging degradation for cable jacket were performed after accelerated aging under the continuous heating and intermittent heating. Contrary to general expectation, the intermittent heating to cable jacket showed low aging degradation, 50% break-elongation and 60% indenter modulus, compared with continuous heating. With the plant maintenance period of 1 month after every 12 or 18 months operation, we can easily deduce that the life time of cable jacket can be extended much longer than estimated through the general EQ (Environmental Qualification) test, which adopts continuous accelerated aging for determining cable life. Therefore, a systematic approach which considers the actual environment condition of nuclear power plant is required for determining the life of cables. (author)

  4. Environmental tests of electric cables for nuclear power plants

    International Nuclear Information System (INIS)

    The evaluation of the materials for flame retardation of cables for nuclear power plants and the tests of their environmental resistivity are reported. Several cables to meet the severe requirements for these cables have been produced for trial, which have been subjected to the simulated environment test including Loss of Coolant Accident. The results are summarized as follows: (a) the ethylene-proylene rubber-insulated, chloroprene-sheathed cable has the sufficient properties to use in BWR containment vessels, such as radiation resistance and flame resistance. (b) It is the same in the chloroprene-sheathed cable, that has glass braids on the outermost layer and around each core, and the insulation layer of the silicone rubber electrically stable but mechanically low in radiation resistivity. (c) The flame-resistant cross-linking polyethylene-insulated, low hydrochloric acid vinyl-sheathed cable is usable near but outside BWR containment vessels. (d) The flame-resistant cross-linking polyethylene-insulated, chloroprene-sheathed cable having the insulating layer of polyethylene for each core can be used in PWR containment vessels. (e) Chloroprene and polyvinyl chloride, the flame-resistant sheath materials, deteriorate owing to heat aging alone. Only the insulating layers mainly contribute to the environmental resistivity of cables. (f) The environmental conditions are severer when heat aging is carried out prior to irradiation. The influence of dose rate is rather little. (Wakatsuki, Y.)

  5. The AJ-conjecture and cabled knots over torus knots

    OpenAIRE

    Ruppe, Dennis; Zhang, Xingru

    2014-01-01

    We show that most cabled knots over torus knots in $S^3$ satisfy the AJ-conjecture, namely each $(r,s)$-cabled knot over each $(p,q)$-torus knot satisfies the $AJ$-conjecture if $r$ is not a number between $0$ and $pqs$.

  6. Optimal semi-active damping of cables with bending stiffness

    Science.gov (United States)

    Boston, C.; Weber, F.; Guzzella, L.

    2011-05-01

    The problem of optimal semi-active damping of cables with bending stiffness is investigated with an evolutionary algorithm. The developed damping strategy is validated on a single strand cable with a linear motor attached close to the anchor position. The motor is operated in force feedback mode during free decay of cable vibrations, during which time the decay ratios of the cable modes are measured. It is shown from these experiments that the damping ratios predicted in simulation are close to those measured. The semi-active damping strategy found by the evolutionary algorithm is very similar in character to that for a cable without bending stiffness, being the superposition of an amplitude-dependent friction and negative stiffness element. However, due to the bending stiffness of the cable, the tuning of the above elements as a function of the relevant cable parameters is greatly altered, especially for damper positions close to a fixed end anchor, where the mode shape depends strongly on bending stiffness. It is furthermore demonstrated that a semi-active damper is able to dissipate significantly more energy for a cable with simply supported ends compared to fixed ends due to larger damper strokes and thereby increased energy dissipation in the device.

  7. Optimized and practical electrical joints for CORC type HTS cables

    CERN Document Server

    Mulder, T; van der Laan, D C; Mentink, M G T; Dhallé, M; ten Kate, H H J

    2015-01-01

    Within CERN the development of REBCO-CORC (Conductor On Round Core) type cables is pursued in view of possible application in future detector and accelerator magnets. An important issue is the design and qualification of terminations for connecting CORC cables mutually or to bus-bars. A termination design is envisaged that combines a simple manufacturing process with a lowest possible joint terminal resistance in the few nΩ range at 4.2 K, first for a single CORC cable and subsequently for CORC based Cable-in-Conduit Conductors. The investigation concerns the effect of tapering the CORC cable within the joint to form a staircase like geometry, which allows current to pass more directly from the copper joint casing to the inner REBCO layers of the CORC cable. Simulations have shown a substantial decrease in joint resistance at operating current in the case both CORC cable and joint casing are tapered. The CORC cable and new joint were tested at CERN. In this paper, some details of the new joint design, fabric...

  8. The development of mineral insulated cable for nucleonic instrumentation

    International Nuclear Information System (INIS)

    The development and manufacture of high quality mineral insulated cable for reactor instrumentation use is described. Electrical specifications are set out. The possible conductivity mechanisms in cable MgO and the likelihood that ionic conductivity predominates in the temperature range 300-7000 is discussed. The oxidation of iron impurities is considered and the influence of water is identified. (U.K.)

  9. Transverse oscillations of an underwater beam-cable system

    OpenAIRE

    Blanco, Max; Wilson, P.A.

    2010-01-01

    An Autonomous Underwater Vehicle refuel station is proposed. The power source is located on board a surface vessel, while the AUV is serviced at depth. The structure which connects the two craft is modelled as a cable-beam. Transverse oscillations of this cable-beam system are investigated through a fourth-order differential equation.

  10. Double Layered Sheath in Accurate HV XLPE Cable Modeling

    DEFF Research Database (Denmark)

    Gudmundsdottir, Unnur Stella; Silva, J. De; Bak, Claus Leth;

    2010-01-01

    This paper discusses modelling of high voltage AC underground cables. For long cables, when crossbonding points are present, not only the coaxial mode of propagation is excited during transient phenomena, but also the intersheath mode. This causes inaccurate simulation results for high frequency...

  11. A Coaxial Cable Fabry-Perot Interferometer for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Ming Luo

    2013-11-01

    Full Text Available This paper reports a novel coaxial cable Fabry-Perot interferometer for sensing applications. The sensor is fabricated by drilling two holes half-way into a coaxial cable. The device physics was described. The temperature and strain responses of the sensor were tested. The measurement error was calculated and analyzed.

  12. Cable systems for experimental facilities in JAERI TANDEM ACCELERATOR BUILDING

    International Nuclear Information System (INIS)

    Measuring cable systems for experimental facilities in JAERI TANDEM ACCELERATOR BUILDING were completed recently. Measures are taken to prevent penetration of noises into the measuring systems. The cable systems are described in detail, including power supplies and grounding for the measuring systems. (author)

  13. Medium and high voltage power cables market in Europe

    International Nuclear Information System (INIS)

    This note gives an overview of the European market for medium and high voltage power cables. In this text, emphasis is placed on suppliers and important European clients; there is also a brief review of the different techniques for cable laying and utilization in Europe. This not has mainly been drafted from informations supplied by EUROPACABLE

  14. Heat resistant wire and cable and heat shrinkable tubes

    International Nuclear Information System (INIS)

    Radiation processes have been used in industrial fields (e.g. wire and cable, heat shrinkable tubes) for about 30 years. In Japan, 60 electron beam accelerators were used in R and D, 54 in wire and cable, 24 in tire rubber, 16 in paint curing, 14 in PE foam and 9 accelerators were used in heat shrinkable tubes in 1993. Many properties (e.g. solder resistance, thermal deformation, and solven resistance) of wire and cable are improved by using radiation processes, and many kinds of radiation crosslinked wire and cable are used in the consumer market (TV sets, VTR's, audio disc players, etc.), automobiles (automobile wire harnesses, fusible link wires, sensor cables etc.), and the industrial market (computer cables, cables for keyboards, coaxial cables, etc.). Another important industrial application of Eβ radiation process is heat shrinkable tubes. Heat shinkable tubes, heated by a hot gun, shrink 1/2 ∼ 1/3 of their inner diameters. Heat shrinkable tubes are used for covers of distributing line terminals, joint covers of telecommunication lines, protection of fuel pipe lines and so on. In this seminar, actual applications and characteristic properties of radiation crosslinked materials are presented

  15. Eurodif plant 225-kV supply cables

    International Nuclear Information System (INIS)

    Details are given about the characteristics of the low-density polyethylene insulated cables installed at Tricastin. The reasons for choosing this solution are analysed in particular as concerns fire hazards. The patterns adopted for the installation of these cables are described

  16. Levitation of Superconductive Cable in Earth Magnetic Field

    Directory of Open Access Journals (Sweden)

    Bohus Ulrych

    2006-01-01

    Full Text Available The paper represents an introductory study about a superconductive cable levitating in Earth’s magnetic field. Built are two mathematical models of the problem providing both the shape of the arc of the cable and forces acting along it. The theoretical analysis is supplemented with an illustrative example.

  17. Levitation of superconductive cable in earth magnetic field

    OpenAIRE

    Pavel Karban; Ivo Dolezel; Bohus Ulrych

    2006-01-01

    The paper represents an introductory study about a superconductive cable levitating in Earth’s magnetic field. Built are two mathematical models of the problem providing both the shape of the arc of the cable and forces acting along it. The theoretical analysis is supplemented with an illustrative example.

  18. Critical Current Measurements of the Main LHC Superconducting Cables

    CERN Document Server

    Verweij, A P

    2007-01-01

    For the main dipole and quadrupole magnets of the LHC, CERN has ordered from industry about 7000 km of superconducting Nb-Ti Rutherford type cables, delivered between 1999 and 2005. The strands of these cables are produced by six different companies, and cabled on five different machines. In the framework of the US contribution to the LHC, BNL has been testing and analyzing the electrical properties of samples of these cables. The main purpose of these tests was to qualify the critical current of the entire cable production in the frame of the quality assurance program implemented by CERN to assure the overall strand and cable performances. In total more than 2100 cable samples have been evaluated at 4.3 K in terms of critical current $I_{C}$, n-value and the residual resistance ratio, RRR. This paper will present an overview of the results, and show the correlations of the critical current and n-value between virgin strands, extracted strands, and cables. Also described are correlations of $I_{C}$ measured a...

  19. Proposed Ordinance for the Regulation of Cable Television. Working Draft.

    Science.gov (United States)

    Chicago City Council, IL.

    A model ordinance is proposed for the regulation of cable television in the city of Chicago. It defines the language of the ordinance, sets forth the method of granting franchises, and describes the terms of the franchises. The duties of a commission to regulate cable television are listed and the method of selecting commission members is…

  20. 47 CFR 15.118 - Cable ready consumer electronics equipment.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Cable ready consumer electronics equipment. 15... Unintentional Radiators § 15.118 Cable ready consumer electronics equipment. (a) All consumer electronics TV... provisions of this section. Consumer electronics TV receiving equipment that includes features intended...

  1. Radio wave guard device on a radiative cable

    Directory of Open Access Journals (Sweden)

    Prudyus I. N.

    2010-02-01

    Full Text Available The results of development and research of radio wave guard device with the use of radiative cable and receiving aerial are shown. Two variants of their mutual location are considered. Theoretical and experimental researches of allocation of sensitivity on length of radiative cable are performed.

  2. On stiffening cables of a long reach manipulator

    International Nuclear Information System (INIS)

    A long reach manipulator will be used for waste remediation in large underground storage tanks. The manipulator's slenderness makes it flexible and difficult to control. A low-cost and effective method to enhance the manipulator's stiffness is proposed in this research by using suspension cables. These cables can also be used to accurately measure the position of the manipulator's wrist

  3. Intelligent control for braking-induced longitudinal vibration responses of floating-type railway bridges

    International Nuclear Information System (INIS)

    This paper presents an intelligent control method and its engineering application in the control of braking-induced longitudinal vibration of floating-type railway bridges. Equations of motion for the controlled floating-type railway bridges have been established based on the analysis of the longitudinal vibration responses of floating-type railway bridges to train braking and axle-loads of moving trains. For engineering applications of the developed theory, a full-scale 500 kN smart magnetorheologic (MR) damper has been designed, fabricated and used to carry out experiments on the intelligent control of braking-induced longitudinal vibration. The procedure for using the developed intelligent method in conjunction with the full-scale 500 kN MR dampers has been proposed and used to control the longitudinal vibration responses of the deck of floating-type railway bridges induced by train braking and axle-loads of moving trains. This procedure has been applied to the longitudinal vibration control of the Tian Xingzhou highway and railway cable-stayed bridge over the Yangtze River in China. The simulated results have shown that the intelligent control system using the smart MR dampers can effectively control the longitudinal response of the floating-type railway bridge under excitations of braking and axle-loads of moving trains

  4. Application of Composite Structures in Bridge Engineering. Problems of Construction Process and Strength Analysis

    Science.gov (United States)

    Flaga, Kazimierz; Furtak, Kazimierz

    2015-03-01

    Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed) deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life). The most commonly found in practice are composite girder bridges, particularly in highway bridges of small and medium spans, but the spans may reach over 200 m. In larger spans steel truss girders are applied. Bridge composite structures are also employed in cable-stayed bridge decks of the main girder spans of the order of 600, 800 m. The aim of the article is to present the cionstruction process and strength analysis problems concerning of this type of structures. Much attention is paid to the design and calculation of the shear connectors characteristic for the discussed objects. The authors focused mainly on the issues of single composite structures. The effect of assembly states on the stresses and strains in composite members are highlighted. A separate part of problems is devoted to the influence of rheological factors, i.e. concrete shrinkage and creep, as well as thermal factors on the stresses and strains and redistribution of internal forces.

  5. 淦河桥梁方案设计研究%Design and Research on Bridge Scheme of Gan River

    Institute of Scientific and Technical Information of China (English)

    蔡忠华

    2016-01-01

    Following the principal of applicable,economical,safe and beautiful and taking the bridge crossing Gan River in Jingui west road in Xianning City as the engineering background,four types of bridge design schemes are introduced,namely simple supported girder bridge,continuous girder bridge,through tied-arch bridge,and cable-stayed bridge without backstays.The tied arch bridge is chosen as the recommended proposal by taking bridge design,landscape feature,construction feasibil-ity and economy into comprehensive consideration.%遵循“适用、经济、安全、美观”的桥梁设计基本原则,以咸宁市金桂西路跨淦河大桥为工程背景,提供了4种桥梁设计方案:无背索斜拉桥,预应力混凝土连续梁桥、预应力混凝土简支 T梁桥、下承式系杆拱桥。综合考虑论证桥梁构造设计、景观特色、施工可行性和经济性等因素,选取下承式系杆拱桥作为推荐方案。

  6. Inductance and current distribution analysis of a prototype HTS cable

    International Nuclear Information System (INIS)

    This project is partly supported by NSFC Grant 51207146, RAEng Research Exchange scheme of UK and EPSRC EP/K01496X/1. Superconducting cable is an emerging technology for electricity power transmission. Since the high power capacity HTS transmission cables are manufactured using a multi-layer conductor structure, the current distribution among the multilayer structure would be nonuniform without proper optimization and hence lead to large transmission losses. Therefore a novel optimization method has been developed to achieve evenly distributed current among different layers considering the HTS cable structure parameters: radius, pitch angle and winding direction which determine the self and mutual inductance. A prototype HTS cable has been built using BSCCO tape and tested to validate the design the optimal design method. A superconductor characterization system has been developed using the Labview and NI data acquisition system. It can be used to measure the AC loss and current distribution of short HTS cables.

  7. Analytical Calculation of Current Distribution in Multistrand Superconducting Cables

    CERN Document Server

    Bottura, L; Fabbri, M G

    2003-01-01

    In recent years the problem of current distribution in multistrand superconducting cables has received increasing attention for large scale superconductivity applications due to its effect on the stability of fusion magnets and the field quality of accelerator magnets. A modelling approach based on distributed parameters has revealed to be very effective in dealing with long cables made of some tens or hundreds of strands. In this paper we present a fully analytical solution equation for a distributed parameters model in cables made of an arbitrary number of strands, whose validity is subjected to symmetry conditions generally satisfied in practical cables. We give in particular analytical formulae of practical use for the estimation of the maximum strand currents, time constants and redistribution lengths as a function of the cable properties and the external voltage source.

  8. Measurement of rock mass deformation with grouted coaxial antenna cables

    Science.gov (United States)

    Dowding, C. H.; Su, M. B.; O'Connor, K.

    1989-01-01

    Techniques presented herein show how reflected voltage pulses from coaxial antenna cable grouted in rock masses can be employed to quantify the type and magnitude of rock mass deformation. This measurement is similar to that obtained from a combined full profile extensometer (to measure local extension) and inclinometer (to measure local shearing). Rock mass movements deform the grouted cable, which locally changes cable capacitance and thereby the reflected wave form of the voltage pulse. Thus, by monitoring changes in these reflection signatures, it is possible to monitor rock mass deformation. This paper presents laboratory measurements necessary to quantitatively interpret the reflected voltage signatures. Cables were sheared and extended to correlate measured cable deformation with reflected voltage signals. Laboratory testing included development of grout mixtures with optimum properties for field installation and performance of a TDR (Time Domain Reflectometry) monitoring system. Finally, the interpretive techniques developed through laboratory measurements were applied to previously collected field data to extract hitherto unrealized information.

  9. System and method for sub-sea cable termination

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qin; Yin, Weijun; Zhang, Lili

    2016-04-05

    An electrical connector includes a first cable termination chamber configured to receive a first power cable having at least a first conductor sheathed at least in part by a first insulating layer and a first insulation screen layer. Also, the electrical connector includes a first non-linear resistive layer configured to be coupled to a portion of the first conductor unsheathed by at least the first insulation screen layer and configured to control a direct current electric field generated in the first cable termination chamber. In addition, the electrical connector includes a first deflector configured to be coupled to the first power cable and control an alternating current electric field generated in the first cable termination chamber.

  10. Ground Loop Impedance of Long EHV Cable Lines

    DEFF Research Database (Denmark)

    Ohno, Teruo; Bak, Claus Leth; Sørensen, Thomas K.

    2012-01-01

    The distance protection scheme without communication is often applied to the backup protection of EHV cable lines. For a reliable operation of a ground distance relay, the ground loop impedance of EHV cable lines needs to have a linear relationship to the distance from the relay location to the...... literature. Through the calculation of the ground loop impedance for cable lines, it has been found that, for long EHV cable lines, the reliable operation of the ground distance relay is possible with a typical relay setting. Effects of parameters, such as substation grounding, cable layouts and...... fault location. The discontinuity of the ground loop impedance at cross-bonding points may have an ill effect on the reliable operation of the ground distance relay. However, the cause and parameters of the discontinuity and its effects on the ground distance relay protection have not been discussed in...

  11. FORCED WAVE PROPAGATION IN VISCOELASTIC CABLE WITH SMALL SAG

    Institute of Scientific and Technical Information of China (English)

    Li Yinghui; Gao Qing; Jian Kailin; Yin Xuegang

    2001-01-01

    Based on the linear viscoelastic differential constitutive law and cable structural model, the coupled longitudinal-transverse waves that propagate along a viscoelastic cable with small curvature is investigated. A mathematical model is presented that describes the three-dimensional nonlinear response of a viscoelastic cable. An asymptotic form of this model is obtained for the linear response of cables having small equihbrium curvature. The spectral relation governing the propagating waves is derived using transform methods. The spectral relation is employed in deriving a Green's function that is then used to construct solutions for in-plane response under distributed harmonic excitation. Analysis of forced response reveals the existence of two types of periodic waves that propagate through the cable, one characterizing extension-comprehensive deformation and the other characteristic transverse deformation.

  12. First International Conference on Cable-Driven Parallel Robots

    CERN Document Server

    Pott, Andreas; Cable-Driven Parallel Robots

    2013-01-01

    This publication presents the outcome of the "First International Conference on Cable-Driven Parallel Robots" in 2012. This is the first conference to bring together the cable robot community and dedicate a forum for the international experts of this field. It contains the Know-how, ideas and experiences of active researchers developing cable-driven robots. The book presents the state of the art, including summarizing contributions and latest research results and, where relevant, the future outlook. The book covers the essential topics for cable-driven robots: classification and definition, kinematics, workspace analysis, cable modeling, control and calibration, design methodology, hardware/prototype development, experimental evaluation, application reports and new application concepts.

  13. Radio Coverage inside Tunnel Utilizing Leaky Coaxial Cable Base Station

    Directory of Open Access Journals (Sweden)

    F. Sayadi

    2009-01-01

    Full Text Available In this study, tunnels radio coverage utilizing leaky coaxial cable has been described. This cable can be deployed as a base station antenna for indoor wireless system such as tunnels. The older type of leaky cables is called coupled mode, while latest type is called radiation mode. These two modes can be distinguished by their radiation pattern, method of radiation (i.e., wave or energy and class of slot on outer conductor. To obtain the field radiation patterns, we use two models; diffuse and deterministic models. Then a modified ray tracing algorithm has been used and simulated to predict radio coverage in tunnels by leaky cable deployment. Simulations show that leaky cables achieve better RF coverage than distributed antennas in term of received signal level versus frequency for various lengths and cross section of tunnels.

  14. SIMULATION OF ELECTROMAGNETIC PICKUP ON CCTV COAXIAL CABLE

    Directory of Open Access Journals (Sweden)

    O. V. Boiprav

    2015-05-01

    Full Text Available The utilization of computer-aided design FEKO for simulation of electromagnetic interference on coaxial cables of different types, such as those used in CCTV (RG59/U, RG11/U, RG179/U is proposed. Item and parameters selection for this simulation rationale is given. The obtained results are described and analyzed. It was found that a cable RG179U is the most vulnerable to external electromagnetic radiation among of all coaxial cables used in the CCTV design. It was revealed that the electromagnetic interference levels on coaxial cable depends on this one length and takes maximum value when it is a multiple of the external electromagnetic radiation wavelength. A method for electromagnetic interference on the cable network CCTV reduction is proposed.

  15. Structural Basis for Autoinhibition of c-Abl Tyrosine Kinase

    Energy Technology Data Exchange (ETDEWEB)

    Nagar, Bhushan; Hantschel, Oliver; Young, Matthew A.; Scheffzek,Klaus; Veach, Darren; Bornmann, William; Clarkson, Bayard; Superti-Furga,Giulio; Kuriyan, John

    2003-03-21

    c-Abl is normally regulated by an autoinhibitory mechanism, the disruption of which leads to chronic myelogenous leukemia. The details of this mechanism have been elusive because c-Abl lacks aphosphotyrosine residue that triggers the assembly of the autoinhibited form of the closely related Src kinases by internally engaging the SH2 domain. Crystal structures of c-Abl show that the N-terminal myristoyl modification of c-Abl 1b binds to the kinase domain and induces conformational changes that allow the SH2 and SH3 domains to dock onto it. Autoinhibited c-Abl forms an assembly that is strikingly similar to that of inactive Src kinases but with specific differences that explain the differential ability of the drug STI-571/Gleevec/imatinib (STI-571)to inhibit the catalytic activity of Abl, but not that of c-Src.

  16. Dynamic Response Analysis of Towed Cable During Deployment/Retrieval

    Institute of Scientific and Technical Information of China (English)

    WANG Fei; HUANG Guo-liang; DENG De-heng

    2008-01-01

    A numerical approach was developed to analyze the transient behavior of towed cable during ac- tively controlled deployment/retrieval (DR). The cable motion is described by the lumped parameter method, its corresponding boundary conditions are presented. In view of its varying length during DR, two auxiliary arguments are introduced to describe its continuous varying length and discrete number of nodes(equations), the length is determined by the pay out(or reel-in) rate, which is then used to determine the node number by a logic relation. For the discrete mathematical model of towed cable, an algorithm was developed to deal with the discrete governing equations. The simulation results indicate that the cable experiences more com- plex motions due to its varying length, and tension fluctuates seriously in the startup and ending stage of deployment/retrieval. The effect of towing ship's motion in waves on cable during deployment/retrieval is also considered via numerical simulation.

  17. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Crosti, C.; Gentili, F.

    2012-01-01

    Even if recent effort in developing methodology and measures for design structures against fire and explosions has been mostly focused on buildings, bridges can also be very sensitive to those actions, as witnesses by some recent bridge accidents, which caused major economic losses and also...... endangered people safety in few cases. Purpose of this paper is making a focus on the state of the art of the research and current regulations concerning the response of bridges to fire. Several cases of bridge fires are reported and a focus is made on the occurrence and consequence of bridge fires......, considering both the costs deriving by structural damages and by limited serviceability and other indirect societal aspects. Few cases of recent bridge fire are reviewed in detail and structural consequences are highlighted, distinguishing between damages directly induced by fire and damages induced by local...

  18. 大倾斜度缆索机器人的研制%Development of Arbitrary-gradient Cable Robot

    Institute of Scientific and Technical Information of China (English)

    张家梁; 吕恬生; 罗均

    2001-01-01

    A new method of inspecting and maintaining high-altitude stay cables with a cab l e robot is presented in this paper,to meet urgent needs of its automation. The robot is driven along the cable by a electric running mechanism held by wheels, or a pneumatic worming mechanism clamped by air cylinders, with an air spray coa ting mechanism or a magnetic detector. The robot was done experiments on the Xup u Bridge and the results show that the robot can climb, coat and test stay cable s safely and efficiently.%针对现代斜拉桥对安全和美观的越来越高要求,提出用大倾斜度缆索机器人进行高 空缆索检测和维护的新方法。采用电驱动摩擦轮压紧使机器人沿缆索连续爬升或气驱动气缸 夹紧蠕动爬升,利用随带的喷涂、磁检测等装置,实现了在役缆索的涂装、内部检测等作业 ,已在上海徐浦大桥上成功进行了现场试验,取得满意的效果。

  19. Evaluation of cable ageing in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The majority of power, control and instrumentation cables in nuclear power plants use polymers as their basic material for insulation and jacket. In many cases, these cables form part of safety-related circuits and should therefore be capable of operating correctly under both normal and accident conditions. Since polymeric materials are degraded by the long term action of the radiation and thermal environments found in the plant, it is important to be able to establish the cable condition during the plant lifetime. Nowadays there are a number of different methods to evaluate the remaining lifetime of cables. In the case of new plants, or new cables in old plants, accelerated ageing tests and predictive models can be used to establish the behaviour of the cable materials under operating conditions. There are verified techniques and considerable experience in the definition of predictive models. This type of approach is best carried out during the commissioning stage or in the early stages of operation. In older plants, particularly where there is a wide range of cable types in use, it is more appropriate to use condition monitoring methods to establish the state of degradation of cables in-plant. Over the last 10 years there have been considerable developments in methods for condition monitoring of cables and a tool-box of practical techniques are now available. There is no single technique which is suitable for all cable materials but the range of methods covers nearly all of the types currently in use, at present, the most established methods are the indented, thermal analysis (OIT, OITP and TGA) and dielectric loss measurements, All of these are either non-destructive methods or require only micro-samples of material. (Author) 15 refs

  20. Monitoring of concrete bridges

    Czech Academy of Sciences Publication Activity Database

    Pirner, Miroš; Urushadze, Shota

    Orlando,Florida: Society for Experimental Mechanics, Inc, 2007 - (Wicks, A.), s. 250-257 ISBN 0-912053-97-6. [IMAC, Conference & Exposition on Structural Dynamics/25./. Orlando (US), 17.02.2007-19.02.2007] R&D Projects: GA MDS(CZ) 1F45D/013/120; GA ČR(CZ) GA103/05/2066 Institutional research plan: CEZ:AV0Z20710524 Keywords : Long-term measurements * Dynamic response * Bridge * Strain gauges * Rain-flow Subject RIV: JM - Building Engineering