Wire Angle Research Articles

Study on the tribological performance at the interface between a steel wire rope and groove during a twisting process

In actual use, a steel wire rope is often stretched and twisted around a groove, increasing the risks of contact fatigue, friction and wear at the rope-groove interface under a long-term service condition. With the consideration of influence factors such as the nonlinear contact and wear between the rope and groove, the tribological performance at the rope-groove interface during a twisting process is analyzed in this study. A winding rope-groove model is first established in order to obtain the contact and sliding solutions at the interface between the rope and groove, which are then used as the load conditions of a simplified local model that is built for wear solution using a modified Archard's wear theory. Based on the finite element simulation software ABAQUS, the ALE adaptive mesh technology and UMESHMOTION subroutine secondary development are adopted to analyze the evolutions of wear topography and contact behavior between the rope and the groove. The results show that the twisting movement of the steel wire rope around the groove causes an interfacial wear between them. The wear scars occur on the outside wire of the steel wire rope and the bottom area of the groove, and the wear scar on the groove is smaller but deeper. A ring-shaped region of stress concentration happens near the edge of wear region. As the wear process proceeds, the depths and dimensions of the wear scars increase, while the contact pressure decreases. The contact performance and wear change dramatically at the beginning of wear process and tend to be stable subsequently. An increment of lay angle of the outside wire aggravates the wear and contact between the steel wire rope and the groove.

A Practical Analysis of Wire Drawing Operation Effects on the Die and Product Behaviors

This study analyse the effects of different wire drawing experimental tests on the die and product properties. Drawing load, temperature, and wear rate are main die factors, that concerned with the interaction effects of drawing speed variation, wire angle alignment and lubrication. For the product, two factors; tensile strength and hardness are taken. A copper wire is drawing from (4.3 mm) into (3.5 mm) diameter with an area reduction of 1.65, 34% ratio.Six dies were employed in various alignments at three different angles (0°, 1°, and 2°), each has two different drawing speeds of (20 mm/min and 40 mm/min). Results show, the highest drawing load and temperature values in die no.5. The effect of using grease on the die wear rate found that the die wear decreases compared to without. But, when using mixed gradients under the same working conditions, the wear rate changed into coating layer on the die surface. The interaction effect of wire alignment on the product strength showing very small when dealing with low or higher speed, but elongation and ductility are significantly reduced with increasing the angle. The wire produced from die no.1, gives the highest micro hardness.

Experimental-Numerical Assessment of Mechanical Behavior of Laboratory-Made Steel and NiTi Shape Memory Alloy Wire Ropes

The mechanical behaviors of laboratory-fabricated steel and superelastic shape memory alloy (SMA) wire ropes are assessed in this study through a comprehensive approach encompassing both experimental investigations and finite element (FE) numerical simulations. The assessment of steel wire ropes involves experimental scrutiny under sinusoidal cyclic loading and natural earthquake loading conditions. In parallel, SMA wire ropes’ behaviors are analyzed utilizing FE simulations employing the widely acknowledged ABAQUS software version 2020. The validation of all numerical simulations is undertaken against the experimentally observed behaviors. Moreover, full-scale steel wire ropes are subjected to shaking table tests to validate the simulations, facilitating a comparative analysis between the mechanical responses of SMA and steel wire ropes. The findings demonstrate that SMA wire ropes exhibit superelastic behavior akin to SMA wires, with marginal variations in overall response observed across distinct configurations, akin to steel wire ropes. Furthermore, augmenting the helix angle of SMA wire ropes results in reduced stress and increased strain when exposed to the El Centro earthquake scenario. Nevertheless, the mechanical response of SMA wire ropes closely mirrors that of a single wire.

Parameter sensitivity analysis of the axial stability for a marine flexible pipe

Marine unbonded flexible pipes serve as the most essential equipment in offshore oil and gas exploration and exploitation. Axial compressive loads during installation or in service in the complex marine environment usually lead to buckling failure. A flexible pipe is a composite structure with multiple functional layers, of which the tensile armor layer plays a key role with regard to the response of the pipe subjected to axial loads. In this paper, a simplified three-dimensional finite element model is developed, focusing on the tensile layer and replacing the carcass layer, pressure sheath layer, and pressure armor layer by a cylindrical rigid body to reduce computational expense. By using this model, the buckling failure modes of the tensile armor layer (in particular the birdcaging phenomenon) are analyzed. Several key parameters that affect the stability of the flexible pipe under axial compression and torsion are emphasized, and their effects on its axial and torsional stiffness are compared and discussed. The results show that both the lay angle of the steel wires and the interlayer friction coefficient have a significant influence on the axial and torsional stiffness of the pipe, whereas the damaged length of the outer sheath has virtually no effect.

Specularly-Reflected Wave Guidance of Terahertz Plasmonic Metamaterial Based on the Metal-Wire-Woven Hole Arrays: Functional Design and Application of Transmission Spectral Dips.

Terahertz (THz) plasmonic metamaterial, based on a metal-wire-woven hole array (MWW-HA), is investigated for the distinct power depletion in the transmittance spectrum of 0.1-2 THz, including the reflected waves from metal holes and woven metal wires. Woven metal wires have four orders of power depletion, which perform sharp dips in a transmittance spectrum. However, only the first-order dip at the metal-hole-reflection band dominates specular reflection with a phase retardation of approximately π. The optical path length and metal surface conductivity are modified to study MWW-HA specular reflection. This experimental modification shows that the first order of MWW-HA power depletion is sustainable and sensitively correlated with a bending angle of the woven metal wire. Specularly reflected THz waves are successfully presented in hollow-core pipe wave guidance specified from MWW-HA pipe wall reflectivity.

Three-dimensional finite element simulations of fretting wear in steel wires used in coal mine hoisting system

Fretting wear is a surface damage phenomenon that occurs at contacting surfaces due to the micro relative movements of contacting surfaces. It is not easy to consider the parametric study of this phenomenon by experimental methods. For example, it is not straightforward to measure the contact stresses and wear scars under different loading conditions during the experimental process. Furthermore, the experimental process is economically expensive and time-consuming. In this paper, the fretting wear behavior of steel wire ropes used in coal mine technology is numerically investigated and the results are compared with experimental data. The numerical results of the effect of contact parameters on the fretting wear process during the fretting cycles are also analyzed. For this purpose, a three-dimensional Finite Element (FE) model is created and validated with an analytical solution. The simulations of the FE model are performed using the commercially available FE tool ABAQUS combined with subroutine UMESHMOTION. The available experimental data of fretted wires in the form of coefficient of friction is used to define the interaction between the contacting surfaces of FE model and the maximum wear depth is used to validate the wear depth obtained through the numerical model. A convergence study is also carried out to select the most suitable parameters for the simulation of contacting surfaces. After the validation of the FE model, the effect of fretting amplitude, contact load and different contacting angles of fretted wires on wear characteristics is considered. The results show that higher fretting amplitude and contact load have a significant effect on wear profile, wear depth, and wear scar. The maximum wear depth, wear depth increasing rate and contact stress decreasing rate is high for higher contact angles compared to smaller contact angles.

Simultaneous separation of different magnetic particles by sputtering magnetic wires at the bottom of a microchip: Novel geometry in magnetophoresis

In this paper, sputtered magnetic electrodes at the bottom of the microchannel is used to separate different magnetic particles in a microfluidic device, simultaneously. The proposed design consists of a microchannel with a length of 30 mm with three different outlets. The Nickel electrodes with different angles and thicknesses are used to separate different particles. A permanent magnet is used to produce a uniform magnetic field and the presence of the magnetic wires disturbs the uniformity of the magnetic field which leads to magnetic force applied to the magnetic particles in the channel’s environment. In order to validate the results, numerical solution was compared with analytical relations. Important parameters such as microparticle size and characteristic (M−450, Myone, Oligo (dT)25), wire dimensions, wire spacing, wire angle and the flow rate were analyzed. The results show that M−450 particles are affected by greater force in comparison to Myone and Oligo (dT)25 microparticles due to their higher magnetism property and size. It was shown that by increasing the angle of the sputtered wires (at the bottom of the channel), the particle deviation was reduced. Also, the effect of wire thickness of the electrodes is investigated for thicknesses of 10, 15 and 20 μm. The maximum deviation was related to the thickness of 20 μm, thus, the particles were not able to pass off over the electrodes and moves along the wire path. By increasing the distance between the wires from 400 μm to 700 μm, the microparticle deviation was increased. As the flow rate of the inlet fluid increases (from 25 to 75 mm/s), the hydrodynamic force on the microparticles increases and therefore, the particle deviation decreases when crossing off over the electrodes. It is observed that for speed of 50 mm/s, the best separation efficiency (94%) was obtained for the proposed microchip design.

Conductive woven fabrics made of metallic/modal core yarns: manufacturing techniques and electromagnetic shielding effectiveness

We independently invented the feeding wire device and combined it with the drawing device of the spinning frame to accurately realize the wire in the middle of the core yarn, effectively solve the problem that the wire is easy to expose the fabric surface. Using a degradable and environmentally friendly modal as roving, Cu and SS as conductive yarns, preparing conductive fabrics, and exploring the effect of shielding networks, lamination layer number, lamination angle, and number of metallic wires. When both the warp and weft yarns are composed of conductive core yarns, the conductive woven fabrics with lamination angle of 0° can build a complete conductive network, and the average EMI SE of single-layered conductive woven fabrics is 30 dB. When only the weft yarn is composed of a conductive yarn, varieties of lamination angles and lamination layers improve the EMI SE of the conductive woven fabrics considerably. However, the shielding value of the two metal fabrics is not a multiple of the single metal fabric. Increasing the lamination layers, the thickness of the fabric will increase, and the gas permeability and SSE/t value decrease.

P‐7.9: The Specification Study of Taper Angle in Metal Wire Electrode of TFT‐LCD

The electrodes of Gate (GE) and Source & Drain (SE) in thin Film Transistor (TFT) devices which are made of metal wires are fabricated by getting patterned through WET Etching. The taper angle of these metal wires play key roles in liquid crystal display (LCD). Excessive taper angle of the metal wires after WET etching will lead to poor coverage of the insulating layer and light leakage at the edge of the metal and thus reduce the contrast of the LCD. The overlarge taper angle of the electrodes will result in a series of defects in the TFT LCD as stated above, however, the taper angle of the electrodes can not be too small. The lower taper will increase the resistance of the metal electrodes. Beyond that, the photoresist (PR) will peeling and thus the metal line disappearing if the taper angle are too small. This article mainly focus on developing the specifications of the taper angle in the GE and SE electrodes.

Over-the-Scope-Clips Can Be Fired Safely Over a Guidewire: Proof of Concept in an Ex-Vivo Porcine Model.

To assist in achieving optimal position when deploying over-the-scope (OTS)-clips, the concept of cannulating the defect with a guidewire, backloading the endoscope onto the wire, and firing the OTS-clip over the wire with subsequent wire removal has been demonstrated. The safety of this technique has not been evaluated. An ex-vivo porcine foregut model was utilized. Biopsy punches were used to create 3-mm diameter full-thickness gastrointestinal tract defects through which a guidewire was threaded. An endoscope was backloaded over the wire and OTS-clips (OVESCO, Tuebingen, Germany) were fired over the mucosal defect and wire. The wire was removed through the endoscope and the removal difficulty was graded using a Likert scale. This process was repeated for each unique combination of nine OTS-clip types, two wire types, four wire angles, and three tissue types. Statistical analysis included t test and ANOVA. Two hundred sixteen OTS-clip firings with wire removal attempts were performed with the following Likert score breakdown: 1 - No difficulty (80.6%), 2 - mild difficulty (16.2%), 3 - moderate difficulty (2.3%), 4 - extreme difficulty (0.9%), and 5 - unable to remove (0%). Statistically significant differences were noted in removal difficulty between OTS-clip sizes (p < 0.05). No differences were identified between clip teeth types, wire types, tissue types, and wire angles (p > 0.05). In this ex-vivo model, the guidewire was successfully removed through the endoscope in all cases. This technique can be employed to facilitate OTS-clip closure of gastrointestinal tract defects, but further study is indicated before wide clinical implementation.

Design of orthogonal directional shear horizontal electromagnetic acoustic transducer

This research proposed an electromagnetic acoustic transducer (EMAT) for generating and receiving orthogonal directional shear horizontal (ODSH) guided waves in the metal plate-like structure. The proposed EMAT generates the fundamental mode of SH wave in the horizontal and vertical direction in the plane of the test sample. The ODSHEMAT combines a new Chevron-like coil design which generates an eddy current effect in the skin depth of the plate surface, and a periodic permanent magnet that applies a static magnetic field vertically with a periodicity equal to its wavelength. The direction of the resultant Lorentz force acting on the test surface-controlled PPM underneath a specific chevron angle of the coil wire. The constructive interference of propagated waves has been developed in the orthogonal directions, enhancing the ultrasonic signals and improving the signal-to-noise ratio. A finite element simulation has been carried out with a thin aluminum plate, keeping the proposed EMAT at the center of the sample. Further, the simulation results show good agreement with the proposed design.

Study on the effects from spacer wires on coolant flow within a CiADS fuel assembly

Spacer wires are frequently applied as the positioning components of fuel rods in lead-based fast reactors. It is extremely important to carry out the research of the impacts from spacer wires on coolant flow within fuel assemblies, and therefore the safety performances of reactor core. In this paper, the open source CFD calculation software OpenFOAM was adopted to perform the refined numerical simulation on the rod bundle of the fuel assembly in CiADS. The results show that spacer wires will increase the pressure drop along the rod bundle section of the fuel assembly. The empirical formula of Remhe and Novendstern can better evaluate the pressure drop along the rod bundle section of the fuel assembly in CiADS. The mixing effect of spacer wires may enhance the LBE flow velocity and heat transfer coefficiency. The winding pattern has a noticeable effect on the temperature distribution at the assembly outlet. When the winding angle of spacer wires is set at 30°, the temperature distribution at the outlet of the assembly will be more uniform.

Research on the lightning shielding performance of strained angled tower for the [formula omitted]1100 kV UHVDC transmission project

Rigid jumper is usually used in the strained angled tower for the UHV transmission project, which makes the protection angle of the ground wire to the jumper end larger, thus the lightning shielding failure risk of the strained angled tower may increase. In order to study the lightning shielding performance of strained angled tower for the ±1100 kV ultra-high voltage direct current (UHVDC) transmission project, a numerical model for the simulation of lightning attachment to the strained angled tower was established based on the research results in the aspects of lightning downward leader, inception and propagation characteristic of upward connecting leader and so on. The maximum lightning shielding failure current and the shielding failure flashover rate (SFFOR) of rigid jumper were calculated under different line angles and overhead ground wire cross-arm lengths based on the proposed model. Results show that the lightning flashover of rigid jumper mainly occurs on the outer side while the rigid jumper on the inner side is in a good shielding state. When the cross-arm length of overhead ground wire on the outer side of J27104A1 tower with 90° line angle is greater than 21.7 m, the SFFOR of rigid jumper will be below 0.1 times/(100 km a), which can meet the operation requirement. The analysis provides technical references for the lightning protection design of strained angled tower for the UHVDC transmission project.

A lightweight bending actuator based on shape memory alloy and application to gripper

The shape memory alloy (SMA) material is embedded into elastic material to make the bending actuator through the shrinkage property of SMA material during being heated. This production method is with the characteristics of long production time and cumbersome making process. As the SMA material is embedded in the elastic actuator, the heat dissipation with the environment is slow, resulting in low actuating efficiency. In this article, a new lightweight bending actuator is developed based on pre-bent SMA wire. The SMA wire is used as the body and actuator, and realizes the initial shape recovery through active control mode instead of relying on heat exchange only. The manufacturing process of the bending actuator is very simple and low-price. The pre-bent angle of SMA wire can be programmed to control the actuator's output angle. By modeling the phase transformation process of SMA wire, the change in Young's modulus at different temperatures is analyzed, and the actuating current and pre-bent angle of SMA wire are calculated. Based on the changing resistance of SMA wire during being heated, the strategy to avoid overheating is designed and achieved. Imitated the form of human hand grasping, a lightweight gripper with palm function is made, and four grasping strategies are designed for the gripper and tested. Finally, the gripper is tested on the continuum arm made of pre-bent actuator. The actuator broadens the application form of SMA wire actuated actuator and provides a new method for designing lightweight and miniaturized soft gripper.

Crack damage control for diamond wire sawing of silicon: The selection of processing parameters

Fixed diamond wire sawing has been the most common technology to cut mono- and multi-crystalline silicon into wafers in the fields of photovoltaics and integrated circuits. The crack damage inevitably occurred in wire sawing is preventing the further reduction of wafer manufacturing cost due to wafer breakage and subsequent crack damage removal. This paper presents a numerical model to predict the processing parameters for a given expected crack damage depth of as-cut wafers, aiming to realize the control of crack damage. The model adopts a classic median-and-lateral crack system to describe the crack damage induced by the scratching of diamond abrasives randomly distributed on wire. The key processing parameter - the ratio of feed speed to wire speed - is determined by making the calculated crack damage depth equal to the expected value. The deflection/bow angle of wire is checked to avoid excessive end-cutting time and severe shape deviation of wafers. The established model is verified by wire sawing experiments using the processing parameters predicted by this model. The maximum relative error between experimental values and expected values of the crack damage depth is 5.26%. This model can be applied to the industrial crack damage control of as-cut wafers by the selection of processing parameters.

Machine Vision-Based Method for Measuring and Controlling the Angle of Conductive Slip Ring Brushes

The conductive slip ring is used for power or signal transmission between two objects rotating relative to each other. It has become an essential part of modern industrial development. In traditional automated production measurements, the typical method is to use calipers, goniometers, or angle gauges to measure a parameter of the workpiece several times and then average it. These inspection means have low measurement accuracy and slow measurement speed, and measurement data cannot be processed in a timely manner. A machine vision-based method for measuring and controlling the angle of the brushes is proposed for this problem. First, the brush angle forming device was built for the conductive slip ring brush wire, forming the principle and rebound characteristics. Then, machine vision and image processing algorithms were applied to measure the key parts of the conductive slip ring brushes. The data of the forming angle value and rebound angle value were obtained during the forming process of the brush wire angle. Finally, a pre-compensation model for the brush filament rebound was developed and validated based on the curve fitting method. The test results show that the error of the angle measurement is within 0.05°. The average error of the measured rebound angle and the calculated rebound angle of the brush filament pre-compensation model was 0.112°, which verifies the correctness of the pre-compensation model. The forming angle can be controlled more precisely, and the contact performance between the brush wire and the ring body can be improved effectively. This method has the potential to be extended to engineering applications.

Characterization of an X-ray Source Generated by a Portable Low-Current X-Pinch

An X-pinch scheme of a low-current generator (45 kA, 50 ns rise time) is characterized as a potential efficient source of soft X-rays. The X-pinch target consists of wires of 5 μm in diameter—made from either tungsten (W) or gold (Au)-plated W—loaded at two angles of 55° and 98° between the crossed wires. Time-resolved soft X-ray emission measurements are performed to provide a secure correlation with the optical probing results. A reconstruction of the actual photodiode current profile procedure was adopted, capable of overcoming the limits of the slow rising and falling times due to the “slow” response of the diodes and the noise. The pure and Au-plated W deliver an average X-ray yield, which depends only on the angle of the crossed wires, and is measured to be ~50 mJ and ~70 mJ for the 98° and 55° crossed wire angles, respectively. An additional experimental setup was developed to characterize the X-pinch as a source of X-rays with energy higher than ~6 keV, via time-integrated measurements. The X-ray emission spectrum was found to have an upper limit at 13 keV for the Au-plated W configuration at 55°. The portable tabletop X-pinch proved to be ideal for use in X-ray radiography applications, such as the detection of interior defects in biological samples.

Effects of Contact Load and Torsion Angle on Crack Propagation Behaviors of Inclined Crossed Steel Wires during Tension–Torsion Fretting Fatigue in Acid Solution

The hoisting rope in the kilometer-deep coal mine exhibits the tension–torsion fretting fatigue behaviors of inclined crossed steel wires in acid solution. Distinct contact load and torsion angles of steel wires in the rope cause different crack propagation behaviors, which greatly affect the fatigue lives of steel wires. Therefore, the effects of contact load and torsion angle on the crack propagation behaviors of inclined crossed steel wires during tension–torsion fretting fatigue in acid solution were investigated in the present study. The three-dimensional X-ray tomographic micro-imaging system was used to reveal evolutions of crack profiles and crack propagation depths during the test. The evolution of friction coefficient between steel wires during the test is presented. The three-dimensional white light interference microscope, electrochemical analyzer, and scanning electron microscope were employed to investigate the wear depth profiles, Tafel polarization curves and impedance spectra, and wear scar morphologies, respectively, of steel wires. Effects of contact load and torsion angle on crack propagation behaviors of inclined crossed steel wires during the tests were explored through analyses of friction and wear mechanisms and electrochemical corrosion damage. The results show that as the contact load and torsion angle increase, the crack propagation depth and rate of steel wire both increase and the fatigue life of steel wire decreases. Those are mainly attributed to the increases in the average tangential force between steel wires, wear depth, electrochemical corrosion tendency, and surface damage of steel wire as well as the decrease in corrosion resistance.

Air-Launch Experiment Using Suspended Rail Launcher for Rockoon

The method of air-launching a rocket using a launcher suspended from a balloon, referred to as a rockoon, can improve the flight performance of small rockets. However, there have been safety issues and flight trajectory errors due to uncertainty with respect to the launch direction. Air-launch experiments were performed to demonstrate a rail launcher equipped with a control moment gyroscope to actively control the azimuth angle. As a preliminary study, it was suspended via a crane instead of a balloon. The rockets successfully flew along the target azimuth line and impacted the predicted safe area. The elevation angle of the launcher rail exhibited a fluctuation composed of two frequency components. A double-pendulum model with a rigid rod suspended by a wire was proposed to predict this behavior. Significant design parameters and error sources were investigated using this model, revealing the constraining effect of a large mass above the wire and elevation angle fluctuation, which caused trajectory errors due to the friction force on the rail guide and thrust misalignment. Finally, tradeoffs in designing the rail length were found between the launcher clear velocity and elevation fluctuations.

Influence of silicon anisotropy on surface shape deviation of wafer by diamond wire saw

Single crystal silicon is an important material in the semiconductor industry. Slicing is the first process of silicon machining, and silicon is usually sliced by the diamond wire saw. Silicon is an anisotropic material. In slicing, properties of silicon at different positions contacting with the diamond grits on the diamond wire saw would be different. As a result, the cutting forces on the diamond grits in different positions would be different. The difference of cutting force would lead to the deviation of diamond wire saw in the direction of the wafer thickness and form surface shape deviation. The surface shape deviation would affect the amount of material removed in the subsequent process and the positioning accuracy of silicon crystal plane. In the condition that the diameter of the wafer is large or the wafer is ultra-thin, the influence of the surface shape deviation would be particularly serious. The (100), (110), (111), (112) and (120) crystal planes are studied in this paper. A diamond wire saw model considering the anisotropy of silicon is established and the sawing force is obtained. While the anisotropic properties of silicon are obtained by the coordinate transformation. The surface shape deviation of the wafer is then obtained based on the sawing force. Also, the shape of silicon the wafer is simulated. Based on the model established in this paper, the variation of the surface shape deviation with the feed angle of diamond wire saw is obtained. Experiments are carried out and the results are verified. According to the research results of this paper, certain feed angles of the diamond wire saw can be chosen to obtain the least surface shape deviation and reduce the influence of anisotropy of silicon.