Tape Wound Research Articles

Reliability Analysis of Tape Winding Hydraulic System Based on Continuous-Time T-S Dynamic Fault Tree

It is necessary to make the tape winding system have good reliability. Because the power system usually is a pneumatic or hydraulic system, the static reliability analysis lacks the ability to describe the dynamic state transfer, component fault correlation, and propagation effect of the system; it is difficult to accurately reflect the actual behavior of the complex system. Most of the existing research results lack the situation that the importance of bottom events changes with time; only a single number cannot express the impact of bottom events on top events at different times. Therefore, this study uses the dynamic reliability analysis method to quantitatively analyze the reliability of the tape winding power hydraulic system. Firstly, the dynamic reliability model of hydraulic system is established by using the continuous-time T-S dynamic fault tree to solve the fault rate of the system. Secondly, the results are compared with the traditional Markov chain analysis method of dynamic fault tree. The feasibility and advantages of the continuous-time T-S dynamic fault tree analysis method are verified. Finally, the probability importance and key importance of the system unit are calculated, and the law of importance changing with time is expressed. According to the importance of different time, it can help the regular maintenance and fault diagnosis of equipment.

Особенности расчета механической характеристики моментного двигателя с ленточной намоткой с учетом неоднородности магнитного поля ротора

Рассмотрена задача определения механической характеристики моментного двигателя с ленточной намоткой в случае распределенного магнитного потока полюса ротора. Проведенные исследования показали возможность численного моделирования в среде COMSOL одновременного действия как тока от источника питания, так и от токов, вызванных появлением ЭДС вращения. Предложено ЭДС вращения задавать косвенно при помощи опции «плотность внутреннего тока» (Inward current flow). Численные исследования показали возможность использования принципа суперпозиции при определении характеристик двигателя в рабочем режиме. Соответствующее сочетание пускового режима и режима торможения позволило получить искомую механическую характеристику двигателя. Численные исследования макета двигателя показали линейность семейства механических характеристик. Большое количество расчетных величин, приведенных в таблицах, является доказательством корректности выдвинутых положений и представляет основу дальнейших исследований, в частности, пульсаций момента при вращении ротора. Результаты исследований дают возможность оценить ожидаемые характеристики создаваемого макета двигателя и являются составной частью разрабатываемой методики расчета двигателя с ленточной намоткой статора.

Discussion on Causes and Solutions of the Biting Mechanism of Stainless Steel Bolts

Due to the influence of the peculiar material characteristics, austenitic stainless steel bolts are always easy to be locked during disassembly. This is not only seriously affected the service performance of austenitic stainless steel bolts, but also affects the reuse of bolts. In this paper, the main causes and mechanism of the locking of austenitic stainless steel blots in the process of fastening is summarized, and the effective measures containing correct material selection, carefully clean before assembly, spraying loosening agent, thermal expansion method, raw material belt tape winding and development of anti-locking austenitic stainless steel fastening bolt to prevent locking through theoretical analysis and experimental verification are also provided, which is hoped that certain guiding significance can be provided to prevent the phenomenon of bolt locking from the source as far as possible.

Magnetization Loss Characteristics in Superconducting Conductor on Round Core Cables With a Copper Former

The High Temperature Superconducting (HTS) Conductor on Round Core (CORC) cables have been widely utilized to fabricate various superconducting applications for power transmission, fusion, and magnets with high current density. Understanding the AC loss behavior of CORC cables during the cable design process is essential for analyzing its electromagnetic performance and evaluating its future industry potential. The aim of our research is to investigate the AC loss dependence caused by the magnitude and frequency of applied external variations to the magnetic field. This paper describes the simulation models of HTS CORC cables based on the finite-element method (FEM) by using an H-formulation in a commercial software named COMSOL Multiphysics. Three-dimensional (3-D) CORC models, with three HTS tapes wound around each layer, were built and analyzed. The 3-D CORC models, built using the FEM method, were then verified with published experimental results. AC losses dissipated in the CORC cables, resulting from applied external varying magnetic field, were calculated and examined.

High-temperature superconducting CORC® wires with record-breaking axial tensile strain tolerance present a breakthrough for high-field magnets

Cuprate high-temperature superconductors (HTS), such as RE-Ba2Cu3O7−δ (REBCO, RE = rare earth), (Bi,Pb)2Sr2Ca2Cu3O10−x and Bi2Sr2CaCu2O8−x , have enabled the development of high-field superconducting magnets capable of generating magnetic fields far exceeding 20 T. The brittle nature of HTS requires elaborate means to protect them against the high stresses and strains associated with high-field magnet operation, and so far, has prevented reliable high-field HTS magnets from becoming a reality. Here we report a more than tenfold increase in the irreversible strain limit under axial tension (ϵ irr) to over 7% in optimized high-current conductor on round core (CORC®) conductors, compared to the REBCO tapes from which the CORC® conductor is wound. Minimizing the tape winding pitch of the helical wind mechanically decouples the brittle REBCO film from the overall conductor. The REBCO tapes behave as springs, limiting the rate at which applied strain is transferred to the ceramic film. In addition, high-strength alloy cores allow the critical stress (ϵ crit) under axial tension at which initial degradation of CORC® conductors occurs to exceed 600 MPa, making them one of the strongest superconductors available. Mechanically decoupling the ceramic REBCO films from the overall CORC® conductor allows effective protection against the high operating stresses in high-field magnets. This breakthrough presents a monumental shift for HTS magnet technology, bringing reliable high-field superconducting magnets for compact fusion machines, the next generation of particle accelerators, and 40–60 T research solenoids within reach.

К ВОПРОСУ О ПРОЧНОСТИ КОМПОЗИТНОГО ШАРОБАЛЛОНА

In modern launch vehicles, combined composite structures in the form of thin-walled spherical shells are used as pressure accumulators and tanks. Such balloons consist of an inner metal body (liner), which ensures tightness, and an outer reinforcing composite shell, which ensures the operability of the structure.The paper presents a methodology for the design calculation of a combined composite balloon by using zonal winding on a liner. An analysis of publications on this topic showed that the requirements for the strength and continuity of the tape covering the entire surface of the balloon depend on the tape geometry, its width, thickness, the ultimate strength of the bundle along the fibers, the number of zones and the angular coordinates of the beginning of the zones. The even distribution of the location of the beginning of each zone, accepted by the authors in publications, leads to the need to use an excess number of winding turns to fulfill the strength conditions than is necessary for a continuous coverage of the zone surface.A rational design of the reinforcing composite shell will be in the case when the strength conditions and the conditions of the coating continuity are met in each zone with the same number of required tape turns. The algorithm is based on a sequential calculation of zone parameters. According to the known coordinate of the beginning of the first zone, the required number of turns of the tape is determined, which is necessary to fulfill the condition of the continuity of the coverage of the zone. The strength conditions in the first zone determine the angular coordinate of the beginning of the second zone. The calculation of the parameters of each zone is made taking into account the influence of the value of the width and thickness of the wound tape. Each subsequent zone is determined in the same way, taking into account all the previous zones.The paper compares the results obtained by the proposed method with the results known in the press. The performed numerical experiments showed that the proposed engineering technique allows to reduce the weight of the composite tape by 30%, and the designed spherical shell in this case will be thinner and has a more uniform distribution of the shell thickness along the meridian.

Experimental study on critical current of bent ReBCO tapes in CORC type cable

Cabling the ReBCO conductor on a round core (CORC) has potential of application for future fusion magnets to carry high current and generate high magnetic field. However, the tape needs to experience the combined tension, compression, bending and torsion stresses during magnet manufacturing. In order to understand the stress effect on the critical current of ReBCO tape with a substrate thickness of 0.05 mm and width of 3 mm, one and multi- layers of CORC specimens have been prepared and bent with a diameter ranging from 300 mm to 60 mm. Critical current measurements were carried out on the tapes located on the outermost layer at 77 K and self-field. The aim is to check the response of the tape's critical current with respect to the cable bending diameter. Simultaneously, a small 2-turn solenoid was constructed and measured at 77 K and self-field to check whether it affect by the cable length or not. These CORC cables are flexible and most of the wound tapes on cable retain around 90% of their initial critical current after bending to a diameter of 100 mm. It will provide parameter support for design of insert solenoid magnets in the future.

High strength tape layer modeling for analysis of flexible pipe axisymmetric behavior and birdcaging limit

Flexible pipes are critical elements for offshore oil and gas development and determining its response in axisymmetric loadings is of paramount importance. Often the anti-birdcage tape layer is represented by a tubular structure with either isotropic or orthotropic material properties. However, it is recognized that a tubular structure cannot fully replicate the stiffness and strength and deformation mechanisms of helically wound tape layers. This paper presents a mathematical model for the local analysis of unbonded flexible pipes subjected to axisymmetric loadings where three anti-birdcage tape layer modeling strategies are presented including helical tape, orthotropic and isotropic tubes. This model is then verified against existing test data. The deviations caused by the orthotropic and isotropic tube modeling strategies in different loading conditions are discussed. This is followed by parametric studies on the effects of anti-birdcage tape tensile stiffness, laying angle and direction on the flexible pipe mechanical behaviors in tension, axial rotation in both directions, axial compression, as well as birdcaging limit loads. The importance of considering non-uniform tensions in the filaments that constitute the tape is discussed.

Short Circuit and Recovery Time Tests in a helical bifilar R-SFCL module

Superconducting Fault Current Limiter (SFCL) modules with distinct arrangements have been investigated, seeking design and performance enhancements. In this context, this work aims to propose a design for resistive SFCL (R-SFCL) modules, using RE-Ba-Cu-O high-temperature superconducting tapes (HTS) wound on an alternative support material. An R-SFCL bench prototype was designed for 400 A and 500 V. Two pieces of 2G tapes, arranged in a bifilar antiparallel configuration were wound on Acrylonitrile Butadiene Styrene (ABS) tubes, which were made by means of a 3D printer. During the experiments, the SFCL was immersed in an open bath cryostat with liquid nitrogen and several measurements were carried out. The average limited current is about three times lower than the prospective one. To test the SFCL recovery time, the following procedure was adopted: The fault is induced during three cycles, and after, the current is reduced to zero. The SFCL is reconnected after some time considering that the fault was extinct, and the voltage level returned to normal operation. The results showed promising levels of limitation and recovery time for further developments.

Improved Method of Pasting and Fixing Metal Conduit Heating Tape

In the development process of my country’s spacecraft, the heating of the working medium in the metal conduit primarily adopts the method of winding a heating tape on the outer wall of the metal conduit. Silicone rubber is usually used as the filling medium to reach good heat transfer between the heating tape and the metal conduit. The heating tape winding and fixing method of the cotton thread used at this stage has disadvantages such as time-consuming, labor-intensive, and low work efficiency. Based on the experience of the spacecraft’s final assembly, a method of winding and fixing the heating tape with a fixing clip is proposed in this paper. This method is simple and convenient, improving the efficiency of pasting and winding the heating tape of the metal conduit.

Design of Magnetic Cloak for an Alternating Magnetic Field With Multilayer ReBCO Insert

Use of superconductors for the shielding of the magnetic field is a common solution nowadays. In case when the magnetic signature of the shielding device matters, forming a magnetic cloak by combining superconductor with ferromagnetic material is a viable option. When considering the operation in alternating magnetic fields the AC loss linked to the delay in phase of the shielding currents represents an important topic. It is well known that the coated conductor (CC) tapes represent a valid alternative to bulk superconducting material when an AC loss reduction appears as a significant requirement. However, the commercially available coated conductors are usually limited to 12 mm width, therefore finding a suitable arrangement of tapes plays a significant role in the magnetic cloak design. We made a set of experiments on two possible arrangements in the superconducting part (helically wound tapes or straight pieces of the tape) and with the total number of layers up to six. For understanding the mechanism of magnetic field penetration inside the cloak the 2D and 3D numerical models were built. Presented numerical models helped in the localization of the cloak component with high energy dissipation. Analysis of the experimental and computation results allow us to formulate some recommendations for the construction of the superconducting part of the magnetic cloak.

Optimization of thermal model and prediction of crystallinity during the laser-assisted tape winding process

Laser-assisted tape placement and tape winding represent the most advanced automated manufacturing technologies for thermoplastic composites. It is important to accurately predict the complete thermal history of the manufacturing process, on which many properties of the product are strongly dependent, such as interlaminar bonding strength and crystallization. In this article, a nonlinear two-dimensional transient heat transfer model was established in ANSYS APDL, and a new temperature closed-loop controlled near-infrared laser heat source was described. Most importantly, the thermal contact pairs were introduced following the activation of elements, and the value of interlaminar thermal contact resistance was obtained by fitting an independent experiment and finite element analysis, which greatly optimized the heat transfer process in the direction of thickness. The thermal model was verified by infrared cameras and an online temperature measuring system based on thermocouples. The results of thermal history are in good agreement with the experiment, which were input into the crystallization kinetics model to predict the evolution and distribution of crystallinity in the laser-assisted tape winding process. The calculated results are coincident with the differential scanning calorimeter test very well, and the crystallinity was about 17% higher than that before manufacturing.

An Example of Controlling the Obtained Characteristics of Technological Stress Distributions in a Layer-By-Layer Manufactured Product, Based on a Model of Additive Process Mechanics

Technological processes of layer-by-layer manufacturing of cylindrical products by the method of power winding of a thin tape on a sufficiently rigid circular base are considered. A characteristic factor for the processes under consideration is the creation of initial stresses in the elementary layers of additional material, which are sequentially included in the composition of the being formed product. It is assumed that the applied winding technology allows us to arbitrarily influence these stresses. This makes it possible to control the technological stresses developing in the resulting product. This paper is devoted to the formulation and solution of one of the problems of such control using current approaches of additive process mechanics. The simulation is performed in a quasi-static approximation within the limits of small elastic strains. A non-classical mechanical model of the process under study is proposed, and a mathematical formulation of the corresponding initial boundary value problem and its closed analytical solution are given. Based on the constructed solution, the regularities of the influence of the initial stress state of the attached material on the nature of the development of the contact pressure on the used base from the side of the material layer formed on it are studied. The problem of providing the required law of change in the value of this pressure in the process under consideration by setting the appropriate program for varying the initial stresses is formulated and solved. Corollaries of an applied nature are made.

Structure Optimization of a Superconducting Linear Generator With YBCO Tape Windings

The paper proposed double-sided superconducting linear generator with YBCO tape windings. An analytical model of linear generator was developed based on electromagnetic field theory. A parameter-scanning method is used to search for optimal dimension parameters with the purpose of minimizing the non-sinusoidal components of the induced voltage curve. The results obtained show a significant improvement in the quality of air-gap magnetic field, and reduction of the higher harmonic in voltage wave obviously. The induction voltage in the generator coils at the speed of 130 m/s are studied. Finally, the feasibility of the superconducting linear generator was analyzed and confirmed.

Speed-Torque Characteristics of Torque Motor with Tape Winding Stator

The speed-torque characteristics of a torque motor with a new type of active element – the tape winding is considered. The analytical studies of the motor speed-torque characteristics determination is difficult because it is required to take into account the distributed current flowing through the winding elements. This leads to the numerical methods application, in particular, COMSOL Multiphysics software based on the finite element method (FEM). Attention is paid to the changing of the motor developed torque in the presence of EMF created in the winding during the rotor rotation. It is shown that the motor torque with a rotor rotation frequency changing depends mainly on the nature of the distributed current lines flowing through the winding elements, despite the fact that the consumed current value changes to a lesser extent. The obtained speed-torque characteristics of the torque motor has a form similar to ones of separately excited DC motors. The research results allow assessing the expected characteristics of the motor model and are an integral part of the developed design policy of the torque motor with the tape winding stator.

Stability analysis and control for composite tape winding process

In the composite winding process of thermal protection materials, the thickness errors of prepreg tape will result in an unstable winding process. In order to alleviate this problem, a control system is required. Therefore, a winding control system had been designed to control the stability by eliminate the winding error based on the analysis of stability winding process. The control system consists a speed controlled rotational roller. The thickness errors of the tape can be detected, and the rotational roller can be controlled to eliminate the errors and maintain the stability of winding process. Experimental results illustrate that the winding speed is converged in 30 second with a 30% initial thickness error, and winding control system could maintain the stability of winding process.

Optimization of the laser-assisted tape winding process using an inverse kinematic-optical-thermal model

A new inverse kinematic-optical-thermal (IKOT) model is introduced to control the process temperature in laser assisted tape winding and placement processes. The optimum time-dependent laser power distribution is obtained by employing a grid of independent laser cells while keeping the temperature of substrate and tape at the target temperature. Multi-layer cylindrical hoop winding with laser grids of 1 × 1, 28 × 1, and 28 × 11 and helical winding of a pressure vessel with laser grids of 22 × 1 and 22 × 11 are considered. It is found that the optimized laser power distribution pattern remains the same during the consecutive hoop winding process while the total power reduces to compensate the heat accumulation. A more non-uniform laser power distribution is obtained for the helical winding because the substrate curvature changes drastically at the dome section of the pressure vessel. The change in the optimum total laser power is found to be almost constant for the helical winding case. Finally, the IKOT model is evaluated by analyzing the effect of the computational parameters on the optimized process temperature.

Investigation of the influence of corrosion defects on the durability of main oil pipelines

For the sake of ensuring the energy security of Ukraine, the trouble-free operation of the oil transportation system becomes of strategic importance. The problem is exacerbated in connection with the long service life of individual objects of the system, which leads to degradation of the properties of the pipe material due to corrosive and erosion processes, which is enhanced by the effect of time-varying loads. Today, in world practice, various methods are used to strengthen defective sections of pipelines: installation of steel, plastic and fiberglass couplings, winding of an elastic composite tape, the use of reinforcing composite couplings, etc. To study the effect of microcracks, corrosion and erosion defects on the Druzhba oil pipeline of OJSC Ukrtransnafta with an installed bandage, full-scale tests of a defective section of a pipe (material - 17GS steel) reinforced with bandages made of a similar material using a UI1 / 200 GK installation were carried out. As a result of research, the pressure of its destruction was determined. During the tests, strain gauging was used to determine pipe deformations. Comparison of the values of stresses obtained experimentally and analytically confirmed that the use of bands on defective sections of the pipeline is an effective means for extending their service life. For a more accurate and detailed analysis of the reliability and durability of oil pipelines, a study of the defective parts (break point) cut from the pipeline was carried out. As a result of the studies carried out on the models - "cutouts", corrosion defects with a depth of up to 5 mm were registered, which is about 55% of the loss of metal, however, the pipe was not destroyed by these defects, but by a defect of the "crack" type. To obtain the profile of the defect from the model - "cutout", scanning was carried out using a sensor fixed on a mobile tripod connected to a computer via an ADC. At the next stage of research, the assessment of the residual resource was carried out using the analysis of full-scale kinetic curves of damage to hazardous sections of the oil pipeline through experimental studies of models - "cutouts". A fatigue curve has been constructed, which can later be used to predict the fatigue life of such elements.

Comparative study of degradation between the carbon black back coat layer and magnetic layer in magnetic audio tapes using attenuated total reflectance Fourier transform infrared spectroscopy and machine learning techniques

AbstractMost magnetic audio tapes in the industry were initially made with only two layers, the base film with polyethylene terephthalate (PET) and the binder layer with polyester polyurethane (PEU). The binder layer seems to undergo degradation from hydrolysis, causing the condition “sticky shed syndrome (SSS).” Hydrolysis is a reversible reaction where atmospheric moisture reacts with weak ester bonds to form degradation products, alcohols, and carboxylic acids, which produce sticky materials, hindering the playability of tapes. Later, another layer called “back coat” was introduced to magnetic audio tapes. This layer consists of carbon black embedded in PEU or polyether polyurethane. Carbon black particles in this layer absorb water, facilitate high‐speed tape winding, and remove static electricity charges. However, due to the ability to absorb water, hydrolysis can occur in the back coat layer as well. For this reason, there is a study claiming that the back coat is responsible for the degradation of magnetic audio tapes, and by removing it, SSS can be overcome. To test the validity of the above claim, this study uses attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT‐IR) with multivariate statistics to determine the degradation of the back coat layer and compare the results with the magnetic layer of the same tape identities. Results obtained show poor predictability in the back coat test set when compared with the results collected from the magnetic side, which indicates that to determine the playability status of this specific magnetic audio tape collection, the preferred side to obtain spectra is the magnetic layer.

Non-uniform crystallinity and temperature distribution during adjacent laser-assisted tape winding process of carbon/PA12 pipes

The non-uniform temperature and crystallinity distributions present in carbon fiber–reinforced PA12 composite pipes, produced via laser-assisted tape winding (LATW), are investigated in this paper. The width of the laser source is usually larger than the substrate width which causes multiple heating and cooling of some regions of the (neighboring) substrate and hence temperature and crystallinity gradients during the adjacent hoop winding. A kinematic-optical-thermal (KOT) model coupled with a non-isothermal crystallinity model is developed to capture the transient temperature and crystallinity distributions for growing substrate thickness and width. The predicted temperature trends are validated with thermocouple and thermal camera measurements. The substrate temperature varies in the width direction up to 52%. This will lead to extra polymer remelting and possible degradation. The maximum variation of the crystallinity degree across the width is found to be 270% which shows agreement with the trend of the measured crystallinity degree. It is found that a more realistic description of the melting behavior of the matrix is needed to obtain a more accurate prediction of the crystallinity distribution.