Properties Of Cables Research Articles

Transient induced response on cables by lightning electromagnetic pulse with different experimental conditions

The coupling of lightning electromagnetic pulse (LEMP) on cables can generate disruptive surge current and voltage, which may cause damage to devices or systems connected with cables. In this paper, a double toroidal magnetic field, through injection of an 8/20 μs lightning current into a double toroidal coil, is generated to induce indirect effects on nine communication/electrical cables. The impacts of different types and shielding methods of communication cables on induced surge current are evaluated, and the results show that twisted-pair cables with shielding layer have the best shielding effectiveness, with the ability to absorb more energy on the communication cables from LEMP. In addition, the study's findings demonstrate that the induction properties of cables are independent of the number of cores, but related to the shielding layer of cables. Meanwhile, simulation analysis in CST Studio Suite is carried out here, and results are basically similar to experimental results, with the difference attributed to the ignorance of some losses in the simulation environment. Finally, the magnetic field strength at each point of the LEMP is simulated, with some engineering proposals for the actual and simulated experiments.

Dynamics Modeling and Motion Evaluation of a Near-Ground Tethered Balloon Cable System under Severe Wind Environments

Weather survival poses a significant challenge for the utilization of tethered balloons. The dynamic modeling of tethered balloon systems presents challenges due to the flexible nature of the cables and the intricate nature of gust forces. The present study introduces a new approach for modeling near-ground tethered balloon systems, which enables the analysis of their dynamic responses and performance evaluation under complex boundary conditions. First, finite cylindrical rigid bodies that are joined together by bushing forces to describe the dynamics of the tethered cable. The properties of the flexible cables under severe bending and translation can be illustrated by the dynamics model. Second, a three-dimensional dynamics model based on the multibody dynamics theory is created to deal with the interaction of the tethered balloon system and flexible cables. The dynamic responses of the tethered balloon system under challenging operating conditions are investigated, focusing on the number of cable segments and the place and direction of gust wind impacts. This model allows for precise assessment and optimization of the system’s overall performance to improve weather resistance. The results show that compared to computational fluid dynamics (CFDs) methods, the multibody system dynamics-based balloon model improved the solution time by 80%, with a pitch angle deviation of only 0.0016°. Moreover, the bushing model effectively reduced cable force and enabled accurate reflection of the system’s motion characteristics.

Fundamental study on performances of fiber-superconducting composite CORC cable: electromagnetic, thermal, mechanical and quench behaviors

Abstract Common terminal voltage measurement can be hardly applied to detect quenches in long high temperature superconducting (HTS) conductor on round core (CORC) cable because not only the HTS normal zone propagation velocity (NZPV) is low but also immobilizing a large number of voltage leads is inconvenient. Distributed optical fiber sensing (DOFS) technology is a promising method for quench detection of long superconductors. To sense the thermal changes of CORC cables during quenches more directly and prevent optical fibers from damages by external stress, a fiber-superconducting composite (FSC) CORC cable was fabricated. For this cable, three optical fibers were placed in three grooves of the copper core respectively, then three HTS tapes were spirally wound on the copper core in sequence. Comparing to a traditional CORC cable, obviously, the FSC CORC cable structure has been changed. To promote FSC CORC cable engineering applications, it is necessary to study the fundamental performance of the cable. In this paper, we investigated the electromagnetic, thermal and mechanical properties of the FSC CORC cable by comparing those with a common one. The results demonstrated that, compared to the common one, the magnetic distribution of the FSC CORC cable hardly changed, but the current distribution of the copper core in the FSC CORC cable slightly changed which led to decreases of transport AC loss, in addition, the thermal characteristics of the FSC CORC cable was slightly changed and the bending tolerance ability of the cables reduced within a bending diameter range of 15 cm. What’s more, the embedded optical fibers combined with DOFS system are successfully used to detect the temperature changes of the cable surface. Finally, to study the quench behaviors of the cable, we built a quench detection platform, which equips with a voltage acquisition system, a thermocouple temperature acquisition system and the DOFS system. By using the platform to detect the quenches of the FSC CORC cable, minimum quench energy of the cable and NZPV of the tape and cable at different currents was tested.

Research progress on high-temperature properties of carbon fiber reinforced polymer composites for cables

Carbon fiber reinforced polymer composites (CFRP) cable has advantages of lightweight, high strength, and excellent durability, providing a new materials for cables and bringing out potential breakthrough in spanning capacity of structures. At present, CFRP cable has already been applied in some engineering bridges. The fire resistance performance of CFRP cable is critical for ensuring structure safety when suffering accidental fire disaster, and clarifying mechanical performance deterioration and failure mechanism of CFRP cable at elevated temperature is fundamental for research of its fire resistance. This paper summarizes current research progress on high-temperature properties of CFRP cable from two levels, including epoxy resin matrix and CFRP composites. Firstly, at resin matrix level, mechanical properties of epoxy resin and its degradation at elevated temperatures are reviewed and analysed, and potential ways to improve high-temperature performance of epoxy resin are suggested. Secondly, at CFRP composites level, high-temperature properties test methods and mechanical performance of CFRP composites in longitudinal direction and transverse direction at elevated temperatures are summarized and discussed. In addition, research shortage of high-temperature properties of CFRP cable is summarized, and corresponding further research is recommended.

Design and test of a compact twisted stacked YBCO cable for fusion application

To meet the application requirements of high magnetic field and high current in future fusion magnet systems, a compact twisted stacked tape cable with high current density is proposed. Three stepped grooves are evenly distributed around a circular former, and a 20+10 superconducting tapes configuration is arranged in each single groove. The performance of the cable under self-field is investigated through simulation modeling and experiment on a 1-meter sample. Firstly, the electromagnetic and mechanical properties of cables are studied through simulation. According to the simulation results, the prospective critical current reaches 5090 A under self-field at 77 K while the maximum von Mises stress and volumetric strain obtained from the simulation during the current-carrying process are within acceptable ranges. A sample with a twist pitch of 300 mm is fabricated, consisting of 18 superconducting tapes and 72 copper tapes. The measured and simulated results of the critical current of this sample are 1900 A and 1970 A respectively, with a deviation of 3.5 percent. The feasibility of the proposed cable has been preliminarily demonstrated through these experimental and simulation results. Subsequent research will be conducted on the optimization of cable parameters, including geometric dimensions and tape capacity, to achieve better performance.

Impact of thermal aging temperatures on the combustion behavior and mechanical properties of flame-retardant electrical cables

Impact of thermal aging temperatures on the combustion behavior and mechanical properties of flame-retardant electrical cables

Comprehensive investigation of bond properties of CFRP cables with concrete and mortar

This study investigated the bond properties of carbon fiber reinforced polymer (CFRP) cables with concrete and mortar. Analyses focused on the bond-slip behavior considering various factors, such as CFRP cable types (e.g., CFRP rod and strand), surface treatments, fixed end materials (e.g., concrete and mortar). Remarkably, the material type and compressive strength at the fixed end were found to have no discernible impact on bond-slip behavior. Conversely, the type of CFRP cable and its surface treatment emerged as pivotal factors influencing bonding strength outcomes. Employing the modified Bertero-Popov-Eligehanusen (BPE) model, a comparative evaluation was performed between experimental results and theoretical estimation of bond-slip behavior. Furthermore, image processing analysis revealed a similar bonding strength of CFRP cables with both concrete and mortar. This similarity can be attributed to the sparser distribution of coarse aggregates around cables in concrete samples, implying that the cementitious phase primarily governed the bond properties, resulting in consistent bonding strengths across different fixed end materials. Overall, this study sheds light on the intricate interplay between CFRP cable types, surface treatments, and material compositions, ultimately contributing to a deeper understanding of bond properties and their implications for various structural applications.

Design, preparation, and mechanical properties of glass fiber reinforced thermoplastic self‐anchor plate cable exposed in alkaline solution environment

AbstractThe reliable anchorage and long‐term durability of high‐performance fiber reinforced polymer composites were the decisive factors for engineering applications owing to the anisotropy of materials and the complexity of service environment. In this paper, an innovative glass fiber reinforced polypropylene (GFRPP) self‐anchor plate cable was developed to utilize the high toughness/durability of thermoplastic resin and self‐anchor load‐bearing system. The effects of different reinforcement methods and cable arc angles (10°, 20°, and 30°) on mechanical properties of plate cable were investigated. Water absorption behavior and mechanical properties immersed in alkali solution were tested to evaluate its long‐term service behavior. The thermogravimetric and surface morphology analysis were conducted to reveal the performance evolution mechanism. The results showed through the combination of secondary melting, carbon fiber winding confinement and epoxy reinforcements, the splitting failure of transition zone and interlaminar cracking failure of straight zone for plate cable were effectively avoided. The tensile strength retention of plate cable for arc angles of 10°, 20° and 30° were 45.6%, 41.3%, and 34.0% of GFRPP plate, respectively. Larger arc angle increased the curvature of arc‐straight transition zone and stress concentration near the straight section, leading to interlaminar splitting failure of plate cable at weak transition zone. The tensile strength of plate cable with the immersion time deteriorated obviously until the lowest retention of 29.7%. The degradation mechanism was mainly due to the etching of glass fibers in alkali solution and the formation of pores and internal defects, including fiber/resin interface debonding and resin swelling. The research results were of significance for solving the anchoring problems and promoting the long‐term service reliability in bridge applications.Highlights The mold can realize reliable molding of glass fiber reinforced polypropylene cables after the reinforcements. The tensile strength retention of plate cable was up to 34.0%–45.6% of plate. Larger arc angle increased the stress concentration near the straight section. Non‐polar polypropylene plate was proved to have better hydrophobic performance. The degradation mechanism of plate cable in alkali solution was revealed.

Research on the Thermal Aging Characteristics of Crosslinked Polyethylene Cables Based on Polarization and Depolarization Current Measurement

Although XLPE cables are widely used in power transmission and distribution systems, their insulating properties are susceptible to degradation due to thermal aging. In order to clarify the influence law of the thermal aging process on the structural and dielectric properties of XLPE cables, this paper investigates the thermal aging characteristics of XLPE cables by using polarization and depolarization current measurement. Results show that when the XLPE cable is aged at 140 °C, the crystallinity of the insulation layer appears to increase and then decrease. With the increase in aging time, micron-sized microvoids appear on the surface of the XLPE. At the same time, the DC conductivity and 0.1 Hz dielectric loss factor of the insulating layer increase with the aging time. The average DC conductivity increased from 2.26 × 10−16 S/m for new cables to 4.47 × 10−16 S/m after aging for 432 h, while the dielectric loss increased from 0.11% to 0.42%. The polarization characteristics of thermal-aged cables were further analyzed using the extended Debye model. Results indicate that the time constant of the third branch of the model increased significantly with increasing aging time. A correspondence between this parameter and the thermal aging time of the cable was established. Thermal aging can damage the crystalline structure of XLPE, so that the number of interfaces between the crystalline and amorphous regions of the material increases, resulting in structural damages and a decline in the dielectric properties of the cable insulation.

Numerical assessment and characterization of automobile high-voltage cable coverings

In the automotive industry, arranging wire harnesses in assembly plants requires manual work. The stiffness of the high-voltage cable implies that personnel applies sufficient force on the cable to achieve a proper installation. Sometimes, the applied force is not strong enough; thus, the cable is not properly installed, or the personnel gets injured, raising ergonomic concerns that need attention. The challenges arise from the intrinsic cable characteristics such as diameter, copper type, cable strand quantity, first-layer insulator, cable insulator glue, and protective covering. The primary objective of this research is to examine how various factors, such as cable length and protective covering, impact the mechanical properties that influence the assembly of high-voltage cables. The methodology proposed consisted of characterizing the mechanical properties of the high-voltage cables in a cantilever beam test to measure deflection in response to an applied force. The measured properties were contrasted through a Finite Element Analysis of the high-voltage cable. The results validated the initial hypothesis, revealing two key findings. Firstly, the stiffness of cables varies with increasing length. Secondly, cables with tape exhibit greater stiffness than those with conduit and cables without covering, as detailed in the results section. In conclusion, extending cables without attachment points is recommended until the interfaces and environment permit. Furthermore, minimizing tape for cable protection while exploring alternative safeguards can enhance stiffness and facilitate an ergonomic installation assembly under favorable conditions. This study contributes valuable insights for optimizing high-voltage cable installation processes in assembly plants, addressing stiffness concerns through informed choices and design considerations.

Elevated-temperature mechanical property and constitutive model of galvanized parallel wire strands

High-temperature conditions lead to severe degradation of the mechanical properties of steel cables. This study conducted uniaxial tensile tests on 19-wire galvanized parallel wire strands (GPWSs) at elevated temperatures. Using a non-contact measurement system, the failure modes under high-temperature conditions were observed, and stress-strain curves were obtained for 12 temperature levels ranging from 20 °C to 700 °C. The yield strength corresponding to a strain level of 1.5% was determined as the nominal yield strength, which ensures both material strength and sufficient safety. By analyzing the stress-strain curves, reduction factors for the proportional limit, elastic modulus, nominal yield strength, and ultimate strength at various temperatures were obtained for the GPWS. Additionally, a Boltzmann curve was used to fit the reduction factors of the mechanical properties of the GPWS. A constitutive model for the entire process of the GPWSs was established through the segmented fitting of the elastic, plastic hardening, and necking stages. High temperatures severely affect the tensile strength of the GPWS. When the temperature reaches 400 °C, the ultimate tensile strength of the GPWS is only about 50% of that at room temperature. At 700 °C, the ultimate tensile strength of the GPWS is reduced to only 2.5%.

Experimental Study on the Characterization of Aging Resistance Properties of Optical Cables in the Hydrogen-Containing Downhole Environment.

The utilization of downhole optical cables has significantly enhanced the efficiency and reliability of oilfield production operations; however, the challenging high-temperature and high-pressure conditions prevalent in oil-gas fields markedly reduce the service lifespan of these optical cables. This limitation severely impedes their application and further development in subterranean environments. In this study, a qualitative analysis was conducted on the structural materials utilized in two types of optical cables to identify these materials and assess the high-temperature tolerance and aging resistance properties of the optical fibers incorporated within. It was discovered that hydrogen infiltration into the subterranean optical cables predominantly accounts for their operational failure. To address this issue, an optical loss testing platform was established, facilitating the execution of a high-temperature and high-pressure hydrogen permeation aging experiment on the optical fibers, allowing for the evaluation of the hydrogen resistance capabilities of the two types of optical fibers. The findings from this study provide a theoretical foundation and methodological guidance for the optimization of optical fibers, aiming to enhance their durability and functional performance in adverse environmental conditions encountered in oil-gas field applications.

Simulation analysis of flow field and vortex-induced vibration characteristics of submarine cable under single/parallel-laying mode

Due to the long-term erosion of current, the submarine cable buried on the seabed surface easily causes fatigue damage to the lead sheath, which gradually progresses with time. In this paper, a two-dimensional spring-damping vortex vibration model is established considering the effect of transverse flow and in-line flow. The vortex-induced vibration response of suspended submarine cables under the influence of different parameters is simulated by using the slice method based on nested grids. The simulation model is used to simulate the flow field characteristics and vortex-induced vibration response of submarine cables under single laying and parallel laying conditions. The fluid-solid coupling mechanism between fluid and structure and the interaction law of parallel laying submarine cables are analyzed. Our study overcame the difficulty in testing the vortex-induced vibration of submarine cables and provided a viable method and empirical support for investigating the vortex-induced vibration properties of submarine cables and fatigue analysis.

Experimental investigation of mechanical properties of NiTi superelastic shape memory alloy cables

As a self-centering element in a recoverable functional structure, shape memory alloys (SMAs) usually require a large diameter to provide sufficient bearing capacity, and pre-strain is applied to obtain good self-centering performance and initial stiffness. This study aims to explore the mechanical properties of large-diameter NiTi SMA cables and their potential applications in recoverable functional structures. Through the uniaxial tensile test of 11 SMA cables with 7 × 7 × 1.0 mm, the mechanical properties of SMA cables under different strain amplitudes, cyclic loading effects, loading rates, and different pre-strain modes were evaluated. The results indicate that the energy dissipation capacity of SMA cable increases with the increase of strain amplitude, but at the same time, it will reduce its self-centering capabilities. The equivalent viscous damping ratio decreases after the SMA cable enters the martensitic hardening stage. The residual strain of SMA cable depends on the combined effect of strain amplitude and number of cycles. The larger the strain amplitude and the number of cycles, the more significant the degradation of self-centering performance. After 20 times of constant amplitude loading and unloading, the mechanical properties of SMA cable are relatively stable. The reverse phase transformation stress of the pre-strained SMA cable gradually decreases with the increase of the tensile strain amplitude. The pre-strained SMA cable exhibits a stable restoring force strength in the sub-cycle, and the residual strain is zero. The test results support experimental data for applying large-diameter SMA cables in recoverable functional structures.

In-service performance assessment of fire-corrosion damaged cables of bridges

Cable-supported bridges are prone to fire hazards, and the corrosion within further compromises their structural integrity. The present study provides a novel framework for assessing fire-corrosion damage of steel wires currently in use. The relations and failure modes of steel wires under coupled effects of fire-corrosion are established by conducting the tensile test utilizing the replaced steel wires after the fire. Experimental studies found that the deterioration tendency of in-service steel wires after the fire is consistent with that of intact ones, while the corrosion level and position of steel wire have a significant impact on its ultimate strain. To predict the residual mechanical properties of cables after the fire-corrosion coupled damage, a comprehensive database of steel wires properties after the fire is established, and then a data-driven surrogate model is proposed. Finally, four grades are suggested to evaluate various damage degrees of in-service cables under corrosion and fire. The findings can provide bridge owners with guidance on how to replace or repair the damaged components after accidents or natural disaster, thereby increasing the reliability and lifespan of bridges and decreasing the costs associated with maintenance, reconstruction, and replacement.

Towards realistic nonlinear elastic bending behavior for cable simulation

AbstractThis contribution aims to characterize and model the nonlinear elastic behavior of cables for reliable simulations. To simulate the nonlinear elastic behavior of cables, we use an iterative method, where at each step, an algorithmic local bending stiffness constant is used and updated according to the current cable state. We also formulate an inverse problem to determine the properties of real cables. By solving the inverse problem, the nonlinear elastic behavior for given measurement data is identified, yielding a curvature‐dependent bending stiffness characteristic. In addition, we propose an alternative method based on the balance equations for rods in static equilibrium to identify the bending stiffness characteristic. We apply both methods to experimental data, and the results are compared and discussed.

A nonlinear finite element framework and Gaussian process-based prediction of stick/slip behaviour in semi-parallel wire cables

This paper addresses the effect of wire slipping on the mechanical properties of structural cables. Based on parameter calibration with experimental data, the paper proposes a Finite Element modelling framework aimed at enhancing the prediction accuracy of the stick/slip behaviour of semi-parallel wire (SPW) cables. The model considers the specific arrangement of the SPW cable composition, interwire friction, and residual interlock between wires. Gaussian Process regression is employed as a surrogate model to reduce the model’s computational cost, optimise parameters and quantify uncertainty. The results show high prediction accuracy when compared with experimental data for different pretension forces. The study finds that wire slip varies considerably between wire layers and is significantly influenced by residual interlock between wires. Additionally, cyclic loading under high bending curvatures reveals that the hysteresis behaviour is dependent on wire slip and loading history. The proposed model accurately predicts the stick/slip behaviour of SPW cables, emphasising the importance of accounting for wire slipping in cable analysis models for various applications.

Characterization of the Mechanical Properties of Low Stiffness Marine Power Cables through Tension, Bending, Torsion, and Fatigue Testing

The exploitation and harnessing of offshore marine renewable energy have led to an increased demand for reliable marine power cables with long service lives. These cables constitute a considerable share of the total installation cost of offshore renewable energy facilities and have high maintenance and repair costs. The critical characteristics of these power cables must be determined to reduce the risk of exceeding their ultimate strength or fatigue life, which can result in unwanted and unexpected failures. This study investigates dynamic marine power cables that are suitable for application in devices that harness energy from ocean currents, waves, and tides. Tension, bending, torsion, and fatigue tests were conducted on three dynamic power cables (1 kV, 3.6 kV, and 24 kV) that have high flexibility, i.e., low mechanical stiffness. The specimen lengths and axial pretension force were varied during the tests. The results are discussed in terms of the mechanical fatigue degradation and ultimate design load, and the key observations and lessons learned from the tests are clarified. The study’s main contribution is the results from physical component testing of the dynamic marine power cables without metallic armors, which can be used to calibrate numerical models of this type of dynamic marine power cable in the initial design of, e.g., inter-array cables between floating wave energy converters. The benefits offered by this type of cable and the importance of the results for creating reliable numerical simulation models in the future are highlighted.

Use of Cable Vibration Isolators for Vibration Protection of Quartz Generators

Vibration isolators with damping properties of steel multiwire cables for vibration protection of quartz oscillators have been studied. Modeling of vibration characteristics of structural elements was carried out using numerical methods. The elastic characteristics and design parameters of the cable for the vibration isolator are calculated. A harmonic analysis was carried out with given values of mass and stiffness under the influence of external vibrations. A sample of a cable vibration isolator has been developed and manufactured. To verify the calculated results obtained, the structure of the test bench is proposed, which allows determining the values of na tural re sonant frequencies. The study of the dependence of vibration acceleration on the frequency of oscillations with a disturbing effect according to the sinusoidal and random laws with a variable frequency in the range of 10–2000 Hz was carried out. Tests of the cable vibration isolator have shown the effectiveness of vibration suppression for frequencies above 120 Hz. In the lower range of random vibrations, various resonances have a significant effect on each other. The experiments confirmed the simulation results and the effectiveness of the solution used: the difference in indicators in determining the resonant frequencies was less than 10 % with a decrease in the vibration level to a given indicator.

Canted Cosine Theta Dipole Magnet Wound Using REBCO CORC Cables–The Effect of Magnetization on Magnetic Field Quality

This paper presents the results of FEM analysis of the effect of REBCO CORC cable magnetization on the field quality of a canted cosine theta (CCT) dipole magnet. The magnetic properties of the CORC cable were the results of our measurements of its <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</i> ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> ) curves at 4.2 K and magnetic fields up to 8 T. This magnetization data was used to calculate the field error for a CCT experimental magnet developed by LBNL. The results of analysis and experiment were compared. To make the computation less “expensive”, we modelled only a section of 10 or 8 turns of the magnet central part and calculated <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b₁</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b₃</i> fields on a circle 2/3 of the innermost layer center line. Calculated <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b₃</i> fields were compared with experimentally obtained values on the dipole operating in self-field mode. Reasonable agreement of the numerical and experiment values was achieved. The work continued with calculating of field errors for a 7 double layer version of that design.