Composite Cables Research Articles

Development of a support mechanism for a finger joint torque using push-pull drive of composite metal cable

Development of a support mechanism for a finger joint torque using push-pull drive of composite metal cable

Theory-based approaches and microstructural analysis to evaluate the service life-retention of stressed carbon fiber composite strands for concrete bridge applications

Prestressed concrete girders and piles with steel strands are used in construction of bridges in North America, due to their economy of design, fabrication, and installation. However, they are often exposed to harsh environments, which results in rapid degradation. Therefore, carbon fiber reinforced polymer (CFRP) tendons have successfully been introduced as prestressing reinforcement for pile applications. This paper presents a study on the physical characterization, microstructural analysis, and durability performance of unstressed and stressed carbon-fiber composite cables (CFCCs) for prestressing applications. This is achieved through testing 120 CFCC specimens, subjected to stress levels of about 40% and 65% of their guaranteed strength, and 51 specimens without sustained load under tension. Moreover, prediction models were introduced to assess the long-term performance and retentions of CFCC strands. The models included Arrhenius model, Fick's law, Fib Bulletin (40) model, and a developed approach that incorporates the effects of temperature, design life, and relative humidity of exposure into the environmental reduction factor. Based on the predication model, the tensile strength retention (CE) for CFCC strands, is predicted to retain over 0.95 and 0.84 of ultimate tensile strength for a relative humidity (RH) < 90% and a moisture saturated environment (RH = 100%), respectively, after 100 years of service life with elevated temperature and sustained load.

Experimental Study on Mechanical and Sensing Properties of Smart Composite Prestressed Tendon.

It is typically difficult for engineers to detect the tension force of prestressed tendons in concrete structures. In this study, a smart bar is fabricated by embedding a Fiber Bragg Grating (FBG) in conjunction with its communication fiber into a composite bar surrounded by carbon fibers. Subsequently, a smart composite cable is twisted by using six outer steel wires and the smart bar. Given the embedded FBG, the proposed composite cable simultaneously provides two functions, namely withstanding tension force and self-sensing the stress state. It can be potentially used as an alternative to a prestressing reinforcement tendon for prestressed concrete (PC), and thereby provide a solution to detecting the stress state of the prestressing reinforcement tendons during construction and operation. In the study, both the mechanical properties and sensing performance of the proposed composite cable are investigated by experimental studies under different force standing conditions. These conditions are similar to those of ordinary prestressed tendons of a real PC components in service or in a construction stage. The results indicate that the proposed smart composite cable under the action of ultra-high pretension stress exhibits reliable mechanical performance and sensing performance, and can be used as a prestressed tendon in prestressed concrete structures.

Axial–Torsional Vibrational Modes of Braided and Trapezoidal Wires

The coupled axial–torsional modes of vibration are examined for three common types of braided wires: the well-known (1 + 6) configuration, the trapezoidal configuration, and the so-called twisted-pair. Representative volume elements of these systems with angles of twist ranging from 0 deg to 30 deg are described using three-dimensional elasticity theory and subjected to pure axial deformation and then pure twist to determine the stiffness coefficients that are used to describe the force–displacement relationship. These are compared with the results of existing braided wire models for the (1 + 6) geometry. Both analytical and finite element models of all three wires are then introduced to determine the level of coupling between the axial and torsional modes of vibration for representative homogeneous and composite cables.

Effect of applied sustained load and severe environments on durability performance of carbon-fiber composite cables

The research work reported in this paper involves investigation of the mechanical and durability performance of unstressed and stressed Tokyo Rope carbon-fiber composite cables for prestressing applications. This research is critical in order to establish the critical (allowable) stress and safety factors for the use of carbon-fiber composite cable tendons for prestressed precast-concrete members. The carbon-fiber composite cable specimens were exposed to simultaneous high alkali environment and sustained loading at different elevated exposure temperatures (22℃ and 60℃) for 3000, 5000, and 7000 h. The high alkali environment (12.8 pH) simulated the concrete pore solution and the elevated temperature was used to accelerate the aging process. The applied sustained stress on the carbon-fiber composite cable strands was equivalent to 40% and 65% of their guaranteed tensile strength. This was achieved through testing 171 carbon-fiber composite cable specimens subjected to stress levels of 0%, 40%, and 65% of their guaranteed strength, under tensile load. Also, 136 carbon-fiber composite cable specimens were tested to investigate the transverse shear strength. In addition, the durability characteristics of the constituent materials of the carbon-fiber composite cable strands were assessed to understand the long-term behavior of these materials. The results showed the effect of sustained stress on the degradation of carbon-fiber composite cable strands. Under sustained stress of 40% and 65%, the reductions in tensile strength were 10.6% and 12.3%, respectively. Scanning electron microscope results on epoxy resin indicated that no degradation is detected since the surface remains smooth without any pitting or loose material.

Strength analysis of composite cables

Abstract Carbon Fiber Reinforced Polymer (CFRP) cables, due to their outstanding performance in terms of specific stiffness and strength, are usually found in civil construction applications and, more recently, in the Oil & Gas sector. However, experimental data and theoretical solutions for these cables are very limited. On the contrary, several theoretical and numerical approaches are available for isotropic cables (metallic wire ropes), some of them with severe simplifications, nonetheless showing good agreement with experimental data. In this study, experimental tensile results for 1×7 CRFP cables were compared to a simplified analytical model (assumed transversally isotropic) and to a 3D finite element model incorporating the experimental uncertainty in important input parameters: longitudinal elastic modulus, Poisson’s ratio, static friction coefficient and ultimate tensile strain. The average experimental breaking load of the cable was 190.25 kN (coefficient of variation of 1.74%) and the agreement with the numerical model predictions were good, with an average-value deviation of –1.15%, which is lower than the experimental variations. The simplified analytical model yielded a discrepancy above 10%, indicating that it needs further refinement although much less time consuming than the numerical model. These conclusions were corroborated by statistical analyses (i.e. Kruskal–Wallis and Mann-Whitney).

Design and Characteristic Study of a Novel Internal Cooling High Temperature Superconducting Composite Cable With REBCO for Energy Storage Applications

High temperature superconducting magnetic energy storage systems (HTS SMES) have attracted significant attention for fast response and ensure a reliable power supply. However, the current carrying capacity of single superconducting tape often meets limitation for the large scale HTS SMES applied in the power grid. Therefore, a high temperature superconducting composite cable with inner helical cooling tunnel and kA class current carrying ability is proposed for SMES magnet by using REBCO tape. The critical current characteristics of this internal cooling composite cable are analyzed considering the influence of anisotropy in magnetic field. A 100 m length, high temperature composite cable is manufactured in China Electric Power Research Institute (CEPRI). The critical current experimental system with a 3 kA DC current power source and a high-precision Digital Data Acquisition system have been set up to investigate the current carrying ability of a straight and a bending demo composite cable in LN2. The results show that critical current of HTS composite cable consisted of 4 REBCO tapes can achieve 780 A at 77 K self-field and the experimental I–V curve of each REBCO tape in the composite cable is not uniform because of the influence of anisotropy. When the HTS composite cable is bent, its critical current is about 90% of the straight HTS composite cable. Therefore, the design method and the proposed experimental system are proved to be effective as well.

Damage assessment for submarine photoelectric composite cable under anchor impact

The impact of dropped anchor on submarine photoelectric composite cables may possibly cause electrical faults, i.e. electricity and optical signal transmission failure. In order to study the impact capacity and structural impact failure mechanism, a test setup is designed originally to examine the structural and functional integrity. A detailed finite element model (FEM) is created, considering material nonlinearity and component interaction. A parametric analysis has been performed to predict the deformation of components and impact forces, under different impact velocities and collision directions. Relationships between the armor layer indentation rate and that of internal power and optical units are achieved. The impact deformation of internal entities can be evaluated intuitively by armor layer indentation. The proposed experimental and numerical methods are well correlated, suitable to assess the impact capacity of subsea power cables and assist the protection design of subsea power cables in engineering.

Metallic and composite cables: a brief review

For cable-moored offshore tension-lag platforms in ultra-deep waters (2000 m), the usage of metallic cables is impractical, making carbon fibre reinforced polymer (CFRP) natural substitutes. CFRP cables have been applied in different situations, such as in cable-stayed bridges, in order to take advantage of its outstanding fatigue behaviour, higher specific stiffness and strength, and good corrosion resistance. However, there are not much experimental data available in the literature for these cables and theoretical solutions still need to be further developed. On the other hand, several theoretical approaches have already been developed for isotropic (metallic) cables, some of them with many simplifications nonetheless still showing good agreement compared to experimental data. On this context, this paper aims to report recent advances on composite cables, comparing previous research results on both composite and isotropic cables on the experimental, analytical and numerical fields.

Metallic and composite cables: a brief review

For cable-moored offshore tension-lag platforms in ultra-deep waters (2000 m), the usage of metallic cables is impractical, making carbon fibre reinforced polymer (CFRP) natural substitutes. CFRP cables have been applied in different situations, such as in cable-stayed bridges, in order to take advantage of its outstanding fatigue behaviour, higher specific stiffness and strength, and good corrosion resistance. However, there are not much experimental data available in the literature for these cables and theoretical solutions still need to be further developed. On the other hand, several theoretical approaches have already been developed for isotropic (metallic) cables, some of them with many simplifications nonetheless still showing good agreement compared to experimental data. On this context, this paper aims to report recent advances on composite cables, comparing previous research results on both composite and isotropic cables on the experimental, analytical and numerical fields.

Long-term Application of Carbon Fiber Composite Cable Tendon in the Prestressed Concrete Bridge-Shinmiya Bridge in Japan

Carbon fiber reinforced plastic (Carbon Fiber Composite Cable, CFCC) has the outstanding features in comparison with regular steel. In October 1988, CFCC was applied as the tensioning material in main girders of new Shinmiya Bridge in Ishikawa, Japan. This was the first bridge in Japan and in the world, which CFCC tendons were used in the prestressed concrete bridge to counter salt damage. To investigate the serviceability and durability of the main girders and CFCC, three full-scale test girders were fabricated in 1988. At the same time, a bending experiment was conducted on one girder to investigate the ultimate behavior, load carrying capacity of the PC girder, as well the strain behavior of the CFCC. Besides, two PC girders were placed next to the main girders of the bridge in the same conditions. One of them was used for a destructive test after six years of the construction time (1994). In this study, another test specimen that was exposed to the actual corrosive environment after nearly 30 years was subjected to a destructive test by bending load. The load carrying capacity of the girder was clarified, and the durability of the PC girders using CFCC tendon was confirmed.

Numerical model updating applied to the simulation of carbon fiber–reinforced polymer cables under bending and tensile stress

Wire ropes are widely used in applications where the axial stress is high and flexural and torsional stresses are relatively low. Study of their mechanical behavior encompasses many factors, bringing considerable complexity to the construction of numerical or analytical models that suitably represent their behavior, including contact stresses between rods, helical geometry, rotation of wires when extended and also, in the case of carbon fiber–reinforced polymer (composite) cables, their anisotropic behavior. In view of the lack of suitable analytical solutions, this work focuses on the updating of a finite element model by incorporating factors commonly neglected by simplified analytical approaches. The carbon fiber–reinforced polymer cable was modeled under tensile stress and under four-point bending. After that a sensitivity analysis of the main parameters governing the problem was conducted. The updating process minimized the deviation between numerical and experimental data, and the model was able to reproduce the tensile and bending behavior with deviations smaller than 1%. The adopted methodology can be extended to similar cases.

Software Architecture for Streaming and Packet Loss Recovery Schemes in Road Monitoring Surveillance Camera Control Systems

Background/Objectives: This paper is about software architecture for security system design using surveillance control system. Various challenges are faced in surveillance control systems using monitoring cameras like packet loose, latency, quality of Closed-Circuit Television (CCTV) data, inconsistency and conflict among multiple sources etc. In this paper an attempt is made to solve some of the problems which are faced by surveillance control systems like road monitoring systems. Methods/Statistical analysis: Experimentation setup is proposed for the given software architecture and algorithm is developed for system. The Digital Video (DV) streaming system is a client-server model for the real-time delivery of DV streams over Internet Protocol (IP) networks based on Real-time Transport Protocol (RTP) / Real-time Transport Control Protocol (RTCP) protocol. The system includes two PCs, one at the server side and one at the client side, connected together with a Fast Ethernet LAN. Server has got a fire wire interface for capturing the data. Capturing device is connected to a DV converter (Canopus ADVC 1000) through a composite conversion cable. Converted DV stream is given to the server through IEEE 1394 interface. In the road monitoring systems such architecture is very much needed to recover from packet losses and it will help in reducing road accidents. Findings: In this paper attempt is made to propose the best possible architecture for arranging surveillance camera for getting the best streaming. Packet loss recovery schemes are proposed in the camera control systems which are used for monitoring roads and it can minimize the death rate using these monitoring camera systems. Applications/Improvements: The proposed software architecture is used in packet loss recovery systems of surveillance systems and very useful application for security systems which are used for monitoring road and it can reduce deaths caused due to road accidents.

Исследование композитного кабеля для нефтяных скважин

Исследование композитного кабеля для нефтяных скважин

Durability Performance and Service Life of CFCC Tendons Exposed to Elevated Temperature and Alkaline Environment

AbstractThis paper presents the physical, mechanical, and durability characterization of Tokyo Rope carbon fiber composite cables (CFCCs). Specimens were exposed to and alkaline solution (12.8 pH) for 1,000, 3,000, 5,000, and 7,000 h at different elevated exposure temperatures (22, 40, 50, and 60°C) to yield a simulated acceleration of the effect of a concrete environment. The durability performance of the Tokyo Rope CFCC tendons was assessed by conducting tensile tests on the specimens after different exposure periods. In addition, the microstructure of the CFCCs—both conditioned and unconditioned specimens—was investigated with scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to assess any changes or degradation. The preexposure and postexposure tensile strengths of the conditioned and unconditioned specimens were used for long-term behavior/performance predictions based on the Arrhenius theory. The test results revealed that the average tensile strength retentions o...

Computation of Fusing Currents in Composite Conductors

Fusing currents in composite cables are calculated by coupling the non-linear heat equation with the calculation of the joules heating in a non-linear finite element process that includes conduction and radiation effects. The method is verified using analytical formulas available for simple copper cables. The method is useful in multi-material composite cables as well as in conductors of arbitrary cross section such as traces on printed circuit boards where analytic formulas are not available. It is also useful for the calculation of temperatures and temperature distributions in power lines or any other current-carrying conductor. For short fusing times, the effects of conduction and radiation are negligible, simplifying the solution.

Experimental Evaluation of the Inverse Scattering Method for Electrical Cable Fault Diagnosis

Recently published theoretic and experimental results have shown the ability of inverse scattering-based methods to detect and to locate soft faults in electric cables, in particular, faults implying smooth spatial variations of cable characteristic parameters. The purpose of the present paper is to further experimentally evaluate the inverse scattering method for retrieving spatially distributed characteristic impedance from reflectometry measurements. With high quality coaxial cables connected in parallel, composite cables of piecewise constant characteristic impedance profiles are built in order to evaluate the accuracy of the inverse scattering method and its robustness in the presence of impedance discontinuities.

Suitability of carbon fiber-reinforced polymers as power cable cores: Galvanic corrosion and thermal stability evaluation

The increasing demand for electrical energy and the difficulties involved in installing new transmission lines presents a global challenge. Transmission line cables need to conduct more current, which creates the problem of excessive cable sag and limits the distance between towers. Therefore, it is necessary to develop new cables that have low thermal expansion coefficients, low densities, and high resistance to mechanical stress and corrosion. Continuous fiber-reinforced polymers are now widely used in many industries, including electrical utilities, and provide properties that are superior to those of traditional ACSR (aluminum conductor steel reinforced) cables. Although composite core cables show good performance in terms of corrosion, the contact of carbon fibers with aluminum promotes galvanic corrosion, which compromises mechanical performance. In this work, three different fiber coatings were tested (phenol formaldehyde resin, epoxy-based resin, and epoxy resin with polyester braiding), with measurements of the galvanic current. The use of epoxy resin combined with polyester braiding provided the best inhibition of galvanic corrosion. Investigation of thermal stability revealed that use of phenol formaldehyde resin resulted in a higher glass transition temperature. On the other hand, a post-cure process applied to epoxy-based resin enabled it to achieve glass transition temperatures of up to 200°C.

Free Vibration of High-Rise Chemical Tower Controlled by Super-Elastic Shape Memory Alloy Cables

In this paper, the super-elastic shape memory alloy (SMA) composite cables are used for vibration control of high-rise chemical towers during the free vibration. The displacement and velocity response to initial displacements were studied by the lumped mass method combined with Newmark integration method. It is found that super-elastic SMA cables can reduce the free vibration amplitudes and shorten the attenuation period of high-rise chemical towers effectively.

EMTP를 이용한 광 복합 지중송전케이블 광 유니트 금속관의 시스템 영향분석

This paper describes the effects on SUS tube of power optical fiber composite cable on underground transmission lines. The effects on grounding, air gap between SUS tube and metal sheath, contact resistance between outer semi-conducting layer and metal sheath and grounding of SUS tube application or not are variously analysed using EMTP in normal operating condition as well as single line to ground fault. From these results, in this paper, the scheme for protecting the electrically abnormal phenomena will be established on power-optical fiber composite cable of underground transmission lines. This paper can contribute to specification of grounding reference of SUS tube of optical fiber composite power cable system.