Wire Core Research Articles

A neural network model for predicting the temperature of insulated overhead lines

In this work, we develop a neural network model based on experimental heating and cooling curves of insulated wires of overhead lines under changes in wind speed and its direction relative to the wire axis. Insulated SIP-3 wire used in overhead lines was investigated. A multilayer perceptron neural network was employed to model the process of heating and cooling of insulated wire under changes in wind speed and its direction. The average absolute error was taken as a criterion for evaluating the prediction accuracy of wire core and insulation temperatures. The main parameters of the developed neural network model include the number of hidden layers and neurons in each hidden layer, the degree of regulation, and the regulatory rigidity of the model. The modelled heating and cooling curves of insulated wire were compared with those obtained experimentally. The average absolute error was equal to 1.74 and –4.08°C for the predicted core and insulation temperatures, respectively. The difference between the heating curves at low wind speeds was found to range within 9°C. It was shown that an increase in wind speed leads to a decrease in the difference between the curves. Our analysis showed that neural network models used for predicting variations in the temperature of insulated overhead lines should be trained using a larger number of input parameters. This is the main prerequisite for high prediction accuracy of such models, when the difference between the simulated and experimental data does not exceed 5%.

Membandingkan Kekuatan Pengelasan Single Dan Double Kawat Inti Elektroda (Filler Rod) Menggunakan Las Smaw

Advances in welding technology are very helpful in making, repairing or repairing chassis jobs that have a high level of difficulty and requirements. Especially in the chassis, many welding elements are involved because welded joints have an important role to support the body, engine, and vehicle load. In practical work at CV. Pringgandani Welding Analysis Comparing the Strength of Welding Results of Single Electrode Core Wire and Double Electrode Core Wire (Filler Rod) Using SMAW welding which is carried out for chassis welding which is claimed by mechanics in welding with a depth and width of more than 5 mm, it is better to use double electrode core wire which can speed up and strengthen the weld. Then a test is carried out to prove the results of the Single Wire Electrode Core and Double Electrode Core Wire (Filler Rod) welds which are stronger and faster in the process. By testing the weld results on an iron plate with dimensions of 250 mm x 50 mm x 10 mm, the welding process uses the SMAW (Shielded Metal Arc Welding) welding method. Using an E6013 type electrode with a diameter of 2 mm with a current of 90 A, polarity DCEP (Direct Current Electrode Positive) The welding position used is the 1G position or horizontal position with the welding process using a single v-groove bevel butt joint and an angle of 60o with a weld width of 10 mm and a weld depth of 8 mm. The plate samples used were two samples. In sample 1 using a single wire core electrode, and sample 2 using a double wire core electrode. All samples were made of tensile test specimens with the ASME-IX standard, a tensile test was carried out to determine and prove the respective strengths of the welding results of Single Wire Core Electrode and Double Wire Core Electrode (Filler Rod).

Структура та властивості багатошарового металу, наплавленого електродними порошковими дротами з осердям із порошків феросплавів та гранульованих твердосплавних матеріалів

Comparative studies of the possibility of using granulated hard alloy powders as a charge of flux-cored wires for electric arc surfacing have been carried out. In the studies, granulated powder of the PG-R6M5 brand with a fraction of 50...300 μm was used. As a standard, a flux-cored wire was used, in the core of which there was a composition of powders of different ferroalloys of the same fraction. The content of the charge components in the core of the standard wire was selected and calculated so as to obtain a similar chemical composition to the wire containing granulated hard alloy powder. The test samples were obtained by layer-by-layer electric arc surfacing under the flux layer with flux-cored wires on low-carbon steel plates. To obtain identical dependences, the flux-cored wires had the same diameter and filling factor and differed only in the content of the core. The test samples were deposited under the same conditions with strict adherence to the deposition regimes, which were monitored using a high-speed analog-to-digital converter. It was determined that the use of granulated hard alloy powder as a charge of flux-cored wire has a positive effect on the melting characteristics of the wire and the stability of the welding process in general in comparison with the standard reference wire, the charge of which contains ferroalloys. This effect can be explained by the greater chemical purity of the granulated powder and the uniformity of the physicochemical properties of its particles in comparison with the powders of various ferroalloys. The determined features of the melting of the wire with a charge with granulated hard alloy powder have a positive effect on the quality of the formation of the multilayer deposited metal and its structure, leading to an increase in its homogeneity, some grinding of the grain and a decrease in the number and size of microdefects, which should positively affect the operational properties of the deposited metal. Keywords: electric arc surfacing, multilayer deposited metal, tool steels, granular hard alloy powder, ferroalloy, metal structure.

CORC® wires allowing bending to 20 mm radius with 97.5% retention in critical current and having an engineering current density of 530 A mm−2 at 20 T

Abstract Low-inductance, high-field insert solenoid magnets and 20 T dipole magnets for particle accelerators require flexible cables, wound from high-temperature superconductors (HTS) such as RE-Ba2Cu3O7-δ (REBCO) coated conductors, that allow bending to a 20 mm radius without significant degradation in performance. They require an operating current of at least 5 kA and a high engineering current density (Je) exceeding 500 A/mm2 at 20 T. HTS cable technologies that target such demanding magnet applications so far haven’t been able to meet the combination of these requirements.
Here we present the development of the next generation of Conductor on Round Core (CORC®) wires that improves their bending flexibility by factor of more than 2 compared to previous generation CORC® wires. CORC® wires now allow for a bending radius of 20 mm with only 2 – 3 % performance degradation. They allow bending to a radius of 15 mm with a performance retention of 83.5 %. The performance of 30-tape CORC® wires wound from 2 mm wide REBCO tapes from SuperPower Inc, SuperOx and Shanghai Superconductor Technologies was measured at magnetic fields up to 12 T. The overall performance at high magnetic fields of the next generation of CORC® wires improved by a factor of 1.5 – 1.8, depending on the REBCO tape manufacturer. CORC® wires wound from production REBCO tapes achieved a new record Je of 751 A/mm2 at a current of 8.3 kA at 12 T, and a Je of 530 A/mm2 at a current of 5.8 kA when extrapolated to 20 T. 

Effect of current probe location on response law of shielded multi-core wire

Abstract Bulk current injection (BCI) is a commonly used method in electromagnetic compatibility testing. In order to enhance the injection efficiency of the current probe, the interference process into the internal core wire is analyzed. Theoretical calculations indicate that the shielded multi-core wire exhibits a frequency selective response under BCI conditions. The-peak of the terminal load response voltage occurs at frequencies corresponding to the integral multiples of half the relative length of the cable. The position of the current probe along the cable only affects the amplitude of the distributed current on the shielding layer, but not its distribution pattern. The response of the internal core wire at the resonant frequencies is positively correlated with the distribution pattern of the distributed current on the shielding layer. The probe position has a significant effect on the magnitude of the wire-to-terminal response. Placing the current probe at both ends of the cable results in high injection efficiency and significant power savings.

Suppression of the sausaging effect in (Ba,Na)Fe2As2 round wires by using Ag1−zSnz/Cu double sheath

We report the fabrication of (Ba,Na)Fe2As2 round wires that are processed using the hot isostatic pressing (HIP) technique. We employed double sheaths composed of Cu and Ag1−zSnz alloy because they offer superior mechanical strength compared to pure Ag. The cross-sectional area of the wire core was measured using X-ray computed tomography. The findings of this study demonstrate that utilizing Ag1−zSnz alloy as the inner sheath material helps reduce the degree of the sausaging effect in the wire, resulting in a more uniform cross-sectional area of the wire core. However, transport critical current density (Jc) of the wires with the Ag1−zSnz alloy decreased gradually as the Sn content, z, increased, which may be attributed to the nonoptimized sintering temperatures during the HIP process. These results suggest that when heat-treated at an appropriate temperature during the HIP process, the use of Ag1−zSnz alloy holds great potential for use in high-performance applications.

Exploring the impact of wire core diameter on microstructure and joint properties in ultrasonic wire harness welding

The present study investigates ultrasonic metal welding to manufacture 10 mm2 copper (Cu) wire joints with different core diameters. The primary purpose of this study is to explore the influence of wire core diameter on the performance of ultrasonic welded joints. Wire core diameter is positively correlated with the peeling resistance of the joint. Superior mechanical properties of the joint are achieved with an increased diameter of the wire core. The peeling strength of the welded joint of two wires with a wire core diameter of 0.25 mm reaches 306.8 N. Examining the welding temperature and assessing the joint's porosity reveals a significant impact of temperature on porosity. However, relying solely on porosity as a criterion for judging the overall forming quality of joints may be insufficient. Scanning electron microscope and energy-dispersive X-ray elemental analysis revealed that certain wires underwent plastic deformation at elevated temperatures without attaining atomic bonding. Additionally, the welded joint exhibits a compact structure externally and a more relaxed structure internally. The upper side of the joint in contact with the briquette and the lower side in contact with the welding head exhibit minimal gaps, while numerous gaps are evident in the middle of the joint. Furthermore, upon examining the fracture morphology, two distinct failure modes are identified at the joint surface of the conductor. The first involves the fracture of the wire core with a completely separated joint surface, resulting in poor mechanical properties of the joint. The second mode entails the ductile fracture of the wire core at the joint surface, indicating good mechanical properties of the joint.

Investigation into the overcurrent failure and combustion characteristics of copper‐clad aluminum conductors

AbstractElectrical fires perennially rank first in fire occurrence types, with conductor overcurrent being one of the main inducements. This topic draws significant attention from scientific researchers and fire investigators. To understand the overcurrent fault and combustion characteristics of copper‐clad aluminum conductors, this paper examines 2.5 mm2 copper‐clad aluminum conductors that meet national standards, investigating morphological changes, temperature variations in the core and insulation layer, and flame propagation patterns under overcurrent conditions. Experiments using an electrical fault simulation device were conducted to study overcurrent failures of copper‐clad aluminum conductors under 52.5–105 A conditions. The results indicate that when the current exceeds 67.5 A, the conductor undergoes a series of changes during energization, including smoking, expanding, carbonizing, burning, and breaking; at 52.5 A, the insulation layer reaches thermal equilibrium at 150 s without combustion; for currents between 60–67.5 A, wire core temperature variations can be divided into three stages; at 75 A, the insulation layer reaches thermal equilibrium 10s before breaking; currents above 82.5 A see a sharp increase in temperature in both the core and insulation layer before the conductor breaks; above 97.5 A, the conductor first breaks and then burns. The research results have significant theoretical value in improving the scientific rigor of fire accident investigations and forensic evidence examinations.

Modelling of opposed flame spread over thin electric wires: estimation of flame spread rates and limiting oxygen concentrations

A model of opposed flame spread along thin electric wires is developed to estimate the variation of flame spread rate ( V f ) with oxygen concentrations and oxidiser flow velocity. The length of pyrolysis zone ( L py ) and V f are treated as eigenvalues of the problem, and one-dimensional energy balance equations for the wire core and insulation are formulated to derive their solutions. To obtain a set of steady solutions for L py and V f , the macroscopic energy balance equation for the entire system is calculated from the one-dimensional energy balance equations with appropriate boundary conditions. Since the equations are nonlinear function of L py and V f , multiple solutions appear. The physical meaning of each solution is evaluated based on the deviation of energy from the equilibrium. Comparison of the temperature distribution along the wire with experimental data confirms that the model reproduces well the actual flame spread process. The variation of V f with oxygen concentration shows a C-shaped curve. The upper branch is the stable solution, and the lower branch is the unstable solution and the merging point of two branches correspond to the limit condition for flame spread. Therefore, the model can be used to estimate the limiting oxygen concentration based on the existence of a solution for V f . Furthermore, the variation of V f with oxidiser flow velocity shows O-shaped curve, and it is confirmed that radiative extinction under low flow velocity and blow-off under high flow velocity can also be estimated with the model. Mapping of variations of radiative extinction and blow-off extinction with oxygen concentration reveals the U-shaped flammability diagram. The predicted flame spread limits are in good agreement with the limiting oxygen concentrations measured in both microgravity and normal gravity, demonstrating the validity of using this model to predict flammability characteristics of electric wires under various oxidiser flow velocity.

Structural factors influencing the clinical performance of 0.025-inch guidewires for pancreatobiliary endoscopy: An experimental study.

Background and study aims To develop a pancreatobiliary endoscopic guidewire with good clinical performance, an understanding of its structure is necessary. This study aimed to investigate the structural factors influencing the clinical performance of pancreatobiliary endoscopic guidewires. Methods Eight types of 0.025-inch guidewires were evaluated. The following structural properties were measured: tip length, tip deflection height, tip weight (TW), ratio of tip core weight to TW, shaft coating type (flat or uneven), outer diameter, and core wire diameter (CWD). Four performance tests were conducted to evaluate shaft stiffness as bending force (BF), shaft lubricity as friction force (FF), torque response as torque response rate (TRR), and seeking ability as total insertion success (TIS) in a technical test using a 3D bile duct model. The correlation coefficients of each variable were analyzed. Results The BF and CWDs were strongly correlated, as well as the FF and CWDs and BF. Among the guidewires with similar CWDs, the guidewires with uneven coating had significantly lower FF than those with flat coating. The TRR was strongly correlated with the CWDs; furthermore, guidewires with lower FF had better TRR. TIS was strongly correlated with the TRR, TWs, and ratio of the tip core weight to TW. Conclusions CWD affects shaft stiffness; CWD and coating type affect shaft lubricity and torque response. Because TRR and TW are correlated with seeking ability, an appropriate combination of core wire thickness, TW, and coating design is required to develop a guidewire with good seeking ability.

Pre-stress evaluation for steel strand based on energy leakage ratio of ultrasonic guided wave

Accurate prediction of the effective pre-stress in steel strands is of great importance for service performance assessment in pre-stressed structures. In this study, a new parameter for characterizing the pre-stress in steel strand is proposed, named energy leakage ratio (αEL) of ultrasonic guided wave (UGW). Firstly, the propagation of UGW between wires of the strand was theoretically analyzed. Then, finite element (FE) models of steel strand were established and laboratory experiments were conducted to verify the effectiveness and accuracy of the proposed αEL-based pre-stress evaluation approach. Results show that αEL increases linearly with inter-wire contact width. αEL can be taken as a new parameter for strand pre-stress identification, it shows a high linear correlation with pre-stress level, no matter whether the excitation position is located in core or helical wire. In terms of numerical and experimental results, the αEL-based pre-stress evaluation errors are within 3% and 4% respectively. Compared with the acoustoelastic effect based and nonlinear ultrasonic based approaches, the αEL-based approach showed the advantage in pre-stress identification accuracy.

Study of ablation phase in double-wire Z-pinch based on optical Thomson scattering

Measurement of plasma parameters during the ablation phase in the Z-pinch is crucial for investigating the dynamic behaviors. In this study, optical Thomson scattering was employed to measure the temperature and velocity of the ablation plasma in a double-wire Z-pinch. The scattering spectra profiles were fitted using a model that considered the velocity distribution. The experimental results revealed the energy evolution of ablation plasma, the establishment of the global magnetic field and the development of axial non-uniformities. The precursor plasma was found to play a key role in strengthening the global magnetic field. A resistive layer near the wire core with a size of 1.5 mm was observed in the ablation plasma after the precursor plasma column formed. The plasma underwent rapid heating in this layer, the electron temperature rises from 17 eV to 22 eV. Upon leaving this layer, electron the temperature is stable at around 22 eV. The radial distribution of the ablation rate increases and decreases, indicating the axial motion of the ablation plasma, which could be caused by the tilt motion of the stream and the secondary modulation of the natural wavelength.

Lightning current Risetime influence on inductive coupling effect of secondary shield cable in substation

Secondary cables are susceptible to lightning surge currents when substation is struck by lightning. Little work has been made to the effects of surge currents in substation secondary cables, particularly the effects of surge current rise time. Six types of simulated lightning surge currents with different rise times, ranging from 5.7 μs to 25.4 μs, were injected into the substation grounding grid, and the inductive voltage from core wire to ground and the shield current in the closed loop of the buried secondary cable were measured simultaneously. The inductive coupling characteristics and the effect of rise time on shielding factor (SF) of buried secondary cables were investigated using time-frequency domain method. The results indicate that the surge current with shorter rise time will induce higher core-wire voltage and higher the shield current on the secondary cable. Double-end grounding of the shielding layer can significantly reduce the cable coupling response, especially reduce the high-frequency component of the inductive voltage at 10 to 100 kHz with steeper surge currents. The SF of secondary cable increases exponentially from 1.91 dB to 8.15 dB as the rise time of the lightning surge current decreases.

Cable-stranded wire-fed laser cladding of high-aluminum lightweight high-entropy alloys

The wire-fed laser cladding has gained significant attention recently due to its advantages as high material utilization rate and a favorable working environment. However, it's limited by the availability of wires, especially for advanced materials like high entropy alloys which are difficult to shape into wires. Cable-stranded wires offer a potential solution to this problem and can expand the application of wire-fed laser cladding. Nevertheless, issues related to tensile failure and loose strands in skein twisting need addressing. Here, we propose an improved skein twisting process, reengineer and fabricate a wire twisting machine for preparing cable-stranded wires. Specifically, Al50Si6Ti8Fe12Cu12Ni12 and Al50Si6Ti8Cr12Cu12Ni12 - two novel lightweight high-aluminum high-entropy alloys - were designed and stranded into Core-Periphery structured wires while the core wire possesses good high-temperature fluidity to ensure uniformity of the cladding layer. The resulting coatings exhibit no cracks with uniform compositions, and exhibit enhanced hardness and corrosion properties.

Experimental Investigation of the Three-Point Bending Property of a Sandwich Panel with a Metal Rubber Core

Sandwich structures and porous materials have been applied widely in various fields due to their excellent mechanical performance, and multifunctional composites will have a significant engineering demand in the future. Studying damped composites’ mechanical properties and failure forms has significant engineering value and significance. However, the current connecting processes for sandwich panels and porous materials must be improved. Therefore, to explore the ambiguity of the connection interface between the core material and panel in sandwich panels, as well as the mechanical properties of such structures, a sandwich panel with a metal rubber core material was prepared using vacuum brazing and cementing processes. Microscopic examinations using scanning electron microscopy and energy-dispersive spectroscopy were conducted to observe the physical bonding mechanism at the interface of the sandwich panel. The results indicate that the brazed sandwich panels exhibited a more uniform and continuous interface than the cemented sandwich panels. This work designs three-point bending compression experiments to investigate the effects of core material thickness, density, and preparation process on the bending mechanical properties of the sandwich panel. Failure modes of the sandwich panel during the experiments are analyzed. The experimental results show that the failures of the brazed sandwich panels are attributable to the bending deformation of the panel and the shear failure of the metal wire core material. The cemented sandwich panels exhibit separation failures in the area below the indenter and at both ends of the panel. The core material’s thickness and density significantly influence the bending performance of the sandwich panels. An increase in the core material’s thickness and density effectively enhances the sandwich panels’ peak load and energy absorption capacity.

Experimental and numerical investigation on cold cracking susceptibility of naval grade high strength steel welds for lightweight shipbuilding structures

In this study the cold cracking (CC) susceptibility of naval grade high strength steel (HSS) welds developed using flux core wires of different yield strength levels was analyzed for lightweight shipbuilding structures. The steel plates of the PCE500 TM grade were welded in T-joint configuration using automatic flux core arc welding under the shielding gas. The CC susceptibility of weld metals was evaluated using Tekken weldability test. The microstructure of weld metal and the hardness of welded joint were analyzed using optical microscope and Vickers microhardness tester, respectively. Software package Sysweld was used for finite element simulation of CC susceptibility of weld metals. Results showed that the probability of CC increases with increase in the strength of filler wires, especially under conditions of limited welding deformations and exposure to low temperatures. The maximum resistance to the formation of cold cracks (CCs) in microstructure of the weld metal is observed in the presence acicular ferrite of at least 60%. To assess the structural strength of T-joint with soft welds, a calculation method has been developed, which allows ranking various structural and technological solutions of the T-joint from the condition of resistance to various types of fracture. Numerical calculation showed that the margin for brittle fracture at 11–23% and the gain in fatigue durability at 40% for welded joint with soft weld greater than for a welded joint with an equally strong weld. The use of low strength filler wires for welding thick plates of HSSs can successfully resolve the problem of CCs and ensure structural strength of joints.

Application of magnetic flux leakage method in the crimping inspection of carbon fiber conductor

Compared with steel core aluminum strand wire, carbon fiber composite core wire has many excellent characteristics such as large flow capacity, good heat resistance, light weight, but its mechanical properties are poor, and the unqualified crimping quality is easy to lead to wire breakage accidents, which greatly affects its popularization. For this reason, a scheme for the detection of crimping defects of carbon fiber composite mandrel based on magnetic leakage method is proposed. Firstly, the finite element analysis model of the clamping fixture was established, and then the magnetic pole distance k and radial air gap n of the magnetic leakage testing device were explored. Based on the signal-to-noise ratio under the two typical defect conditions of fracture and low pressure, the most suitable excitation structure parameters of the magnetic leakage device were obtained. The results show that when k=55mm and n=3.5mm, the signal-to-noise ratio of MFL detection device reaches the best effect. The research results are of great significance to the quality inspection of compacts of carbon fiber composite mandrel.

Improved automatic defect detection from X-ray scans for aluminum conductor composite core wire based on modified Skip-GANomaly

The Aluminium Conductor Composite Core (ACCC) is a critical component of power transmission that needs automated nondestructive defect detection to prevent wire breaking accidents and ensure regular city operations. Unfortunately, the current supervised target detection scheme is limited in its generalization ability due to the diversity of defect morphology and the high cost of acquiring samples. To overcome these challenges, we propose an automatic defect detection method based on a modified Skip-GANomaly model using X-ray images of ACCC wires as input. We experiment with semi-supervised deep learning reconstruction methods to mitigate the lack of abnormal samples and improve the generalization ability of unknown defects. We also explore hierarchical reconstruction and Skip-Connection adjustment to enhance the reconstruction effect and defect identification based on Resnet50. The results show that our method can achieve high accuracy, recall, and precision levels of over 99 %, significantly highlighting the difference in defect morphology. Compared to existing supervised schemes, our Defect Detection Scheme with Hierarchical Reconstruction and Anomaly-Subtracted Image Discrimination (DHRAD) eliminates dependence on the number of abnormal samples and the diversity of defect types in the training set, and has the ability to detect defects with unknown morphology. Therefore, DHRAD provides an effective detection scheme for automatic nondestructive defect detection of ACCC in operation, based on computer vision and semi-supervised learning.

Characterization of n-doped branches in nanotree LEDs

Nanotree LEDs with n-doped branch nanowires grown on the sidewall of pin-doped core wires with higher bandgap. Broadband light is emitted with the core wires under bias, and charge carriers diffuse to the branches and recombine there.

A Comparative Assessment of Chromium-Boron Hardfacing Using SMAW and FCAW Techniques.

This research paper investigates the effectiveness of shielded metal arc welding (SMAW) and flux-cored arc welding (FCAW) on mild steel substrates for chromium-boron hardfacing. Chromium-boron alloys are hard-wearing and corrosion-resistant materials used in industries where wear resistance is critical. The study aims to identify the best welding technique for increasing surface hardness and wear resistance. Standard test specimens were chosen and deposited using SMAW and FCAW processes. SMAW uses an electrode covered with flux, which turns into a sticky state when heated, while FCAW uses a core wire fabricated from flux, which generates a shielded gas upon melting. The effectiveness of each welding technique is assessed based on deposition efficiency, dilution rate, microstructure, hardness distribution, and wear resistance. This research helps industries choose the most efficient material and method for improving wear and corrosion resistance in applications like mining, construction, agriculture, and manufacturing. On average, FCAW offers a 1.67% improvement in hardness and 28.12% improvement in mass loss reduction when compared to SMAW.