bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Study on Aerodynamic Characteristics of Variable-sweep Morphing Aircraft at Transonic Speeds
Authors: Lei Yuchang , Zhang Dengcheng , Zhang Yanhua , Su Guangxu
Published: February 2020

The variable-sweep morphing aircraft (VMA) has both high speed and low speed flight performance, and can be competent for combat tasks and practical requirements in different flight environments. Aerodynamic characteristics of VMA have a great impact on flight performance. The transonic stage is particularly important in the whole variation process. It is also one of the most difficult problems in aerodynamic layout design of aircraft. In order to explore the aerodynamic characteristics of the VMA at transonic speeds, this paper adopts an efficient engineering algorithm. The aerodynamic characteristics of VMA at different Sweepback Angle, Angle of attack, Mach number and Altitude are analysed. The result demonstrates that: Sweepback Angle has great influence on aerodynamic characteristics of aircraft. For the lift coefficient, at subsonic speeds, small sweep has great influence. When the Angle of attack (AOA) is 12°, the sweepback changes from 45° to 25°, and the lift coefficient increases by 48.9%. At transonic speeds, large sweepback has great influence. When the AOA is 12°, the sweepback changes from 75° to 55°, and the lift coefficient increases by 85.7%. For the drag coefficient, at subsonic speeds, small sweepback has great influence. When the AOA is 12°, the sweepback changes from 45° to 25°, and the drag coefficient increases by 45.5%.All the changes of sweepback have great influence on drag coefficient at transonic speeds. The influence of sweepback on lift-drag ratio is complex. In general, when the Mach number increases, the sweepback corresponding to the maximum lift-drag ratio increases. The altitude factor only has some influence on the drag coefficient at subsonic speeds. These aerodynamic change rules can provide a basis for the shape design and dynamic analysis of VMA.
Study on Magnet Eddy Current Losses in Interior Permanent Magnet Machines for Aircraft Electric Green Taxiing Systems
Authors: Hu Yaohua , Zhang Pengfei
Published: February 2020

The magnet eddy current of multi-layered interior permanent magnet (IPM) machines is studied in the paper for the aircraft electric green taxiing systems. The armature reaction flux density distribution, eddy current density and harmonic spectrum at the end of permanent magnet are analysed. A method to reduce the magnet eddy current of multi-layered IPM machines is presented. That is to increase the distance between outer permanent magnet and rotor surface and the distance between two layers of permanent magnet so as to provide a larger core path for armature reactive flux. This method can effectively reduce the magnet eddy-current loss of the multi-layered IPM machines and improve the operation efficiency.
Investigation of the Influence of Blocking Effect on the Aerodynamic and Hydrodynamic Characteristics of a Powered Aircraft Model
Authors: Xiao Zhijian , Wu Bin , Wang Mingzhen , Hu Qi , Yang Wenjing
Published: February 2020

This paper investigated the influence of blocking effect on the aerodynamic characteristics of a powered aircraft model by experimental and numerical methods. Firstly, the towing test were carried out in the bottom and front of the trailer. The experimental results showed that the darg and trim of two conditions were different, indicating that the blocking effect was obvious. RANS method, slidding mesh and overset grid were adopted in numerical simulation. The simulation of the wind field in the bottom and front of the trailer were carried out. And the numerical results were compared with the experimental results to verify the accuracy of numerical method adopted in this paper. The results showed that the wind speed in the bottom of the trailer was larger than that in the front of the trailer on average and there was stable speed increment interval when the wind filed simulation was conducted in the front and the bottom of the trailer without model. Then the hydrodynamic performance of the powered aircraft model in infinite domain, in the bottom of the trailer and in front of the trailer were carried out respectively. The aerodynamic downward moment was larger when the model was in the bottom, but the overall aerodynamic lift force of the model was similar under the two conditions. The heave amplitude was also similar under the two conditions, but the trim angle and the total drag was smaller when the model was in the bottom of the trailer.
Spacecraft’s Partially Invariant Stabilization System
Authors: Zosimovych Nickolay
Published: February 2020

In most of the known spacecraft stabilization systems the control signal in the centre of mass movement channel is generated according to proportional plus integral control law, based on the measurements of tangential velocity of the centre of mass and its integral-linear drift. In the angular stabilization channel, the control signal shall be generated in proportion to the spacecraft deviation angle in the transverse plane and the angular velocity of the spacecraft rotation in this plane. In practice, a spacecraft’s stabilization system, which is partially invariant to the disturbing moment, is the easiest to implement. The velocity performance limitation of the control actuator has the most influence upon stability of the system among all the nonlinearities considered in the mathematical modelling. Therefore, we shall consider a model of an invariant stabilization system with due regard to nonlinearity. For the system under consideration, it is possible to construct lines of equal values of the auto oscillation amplitude in a two-parameter plane. The study of the stability of the proposed partially invariant stabilization system revealed that it is possible to ensure sufficient stability margins in the system under consideration by choosing parameters for the stabilization controller. At the same time, it allows to provide high quality of the transition process.
Quick Trajectory Optimization Method for Mars Airplane Based on Adaptive Gauss Pseudospectral Method
Authors: Sun Z Y , Liu Z Y , Zhang P
Published: February 2020

This paper gives a new method based on adaptive Gauss pseudospectral method for quick trajectory optimization problem of Mars airplane. The method converts the trajectory optimization problem to a non-linear programming problem, taking into account for the dynamic constrains, the boundary constrains, the path constrains and the control constrains during the cruise phase of the Mars airplane. And the sequential quadratic programming is adapted to solve the non-linear programming problem. In combination with the adaptive Gauss pseudospectral method and sequential quadratic programming in Matlab, numerical results of the optimal trajectory with 267 collocations could be obtained in 800s with an approximation accuracy of 10−6.
Certification Techniques for the Deformation Compliance of Civil Aviation Passenger Seat
Authors: Jianbin Zhou , Xinyuan Zhang , Xiaozheng Wang
Published: February 2020

The deformation requirements for passenger seats of civil aviation are complicated. The author provides the experience of real civil aviation programs for seat deformations’ certification, including the significance of seat deformations’ airworthiness compliance, relevant regulations and tests and the measuring requirements for passenger seat deformations. FAR25 and CCAR25 both require that the passenger seats shall not yield to the extend they would impede rapid evacuation of the airplane occupants, but the relevant factors are not defined clearly. Seat deformations are the key factors that would impede occupants’ rapid evacuation. This article discussed the related requirement and the right way to measure and analyze seat deformations.
Experimental Study on the Attitude of Civil Aircraft Ditching with High Horizontal Tail Configuration
Authors: Nanbo Xu , Yuping Wang , Lin Fu , Qing Zhou
Published: February 2020

The airplane must meet the airworthiness requirements if certification with ditching provisions is requested. The probable behavior of the airplane ditching must be investigated by model tests or by comparison with airplanes of similar configuration. In this paper, aircraft with high horizontal tail configuration is considered as a research object, then the attitudes of civil aircraft in ditching is studied through a scaled model verification experiment. On this basis, this paper researches the effects of different parameters after ditching into the water, such as initial pitch angle, flap slat configuration and sinking speed. The research results in this paper can help to determine the ditching attitudes and parameters and thus develop strategies for ditching.
Research on Risk Assessment with Uncontrollable High Thrust for Civil Airplane
Authors: Candong Zou , Nanbo Xu
Published: February 2020

Not all single failures and probable combinations of failures that can cause UHT malfunction can be eliminated for the civil airplanes, a petition for a partial exemption from FAR25.901(c)/CCAR25.901(c) related to UHT is usually requested. The risks associated with exempting the UHT from FAR25.901(c)/CCAR25.901(c) should not be greater than those currently known and accepted for comparable existing transport category airplanes. Based on the development of a high horizontal tail airplane with 2 rear-mounted engines, this paper proposes a method for UHT malfunction risk assessment from handling qualities aspect by simulation analysis and simulator tests.
Experimental Study of Hybrid Deicing System
Authors: Jun Shu , Dongguang Xu , Lin Ye , dongyu Zhu
Published: February 2020

The hybrid deicing system combines the traditional electrothermal deicing system with the electro impulse deicing system. Firstly, the prototype design of the ice wind tunnel hybrid deicing system is carried out, and the electrothermal deicing system and the electro impulse deicing system are integrated in the airfoil model. Then, through the laboratory plate deicing experiment to study the deicing effect of different heating and excitation combinations, explore the work control law of the hybrid deicing system, and finally verify the effect of the hybrid deicing system through the ice wind tunnel test. The plate panel test found that with the increase of the surface temperature of the skin, there is a minimum binding force between the ice and the skin. In the ice wind tunnel deicing experiment, the prototype of the hybrid deicing system shows a good deicing effect with less energy consumption.
Electrochemical Kinetic Property Determination of MIECs by Comprehensive Multi-physical Coupling Model
Authors: Wang Jianhua , Khalid Salman , He Fei , Wu Wanfan
Published: February 2020

Surface exchange and bulk diffusion coefficients are important electrochemical kinetic properties of mixed ionic-electronic conductors (MIECs), which are usually obtained through electrical conductivity relaxation (ECR) experiments. However, the extensively employed method is built upon the ideal diffusion described by Fick’s second law with linear absorbing boundary, which is almost impossible to achieve in actual experiments. To simulate the actual experiment system and improve the estiamtion accuracy, a comprehensive mathematical model is established to describe the coupled multi-physical processes involved, such as convection-diffusion in the surrounding atmosphere, surface exchange, bulk diffusion of MIECs, and heat transfer. A comparison between different models is carried out, and the results show that the new model established is more accurate and compatible with more complex conductivity curves.
Energy and Exergy Analysis of Steam Source Optimization for Boiler Soot Blowing System
Authors: Wu Wanfan , Ran Fangyuan , He Fei , Wang Jianhua
Published: February 2020

In order to improve the economy of boiler soot blowing system, the steam source position of boiler soot blowing system should be optimized. For a 1000MW ultra-supercritical coal-fired unit, the thermodynamic process of soot blowing steam in temperature and pressure reducing station was studied through energy analysis and exergy analysis in this paper, and it was revealed that the annual water and energy consumption of boiler soot blowing system was independent of the steam source position, the change of steam source position only affected the annual exergy loss of soot blowing system. The comparion results indicated that the annual exergy loss of soot blowing system with cryogenic reheater outlet as steam source was minimal. After adopting cryogenic reheater outlet as the steam source position of soot blowing system, it would be more economical than the original soot blowing system with platen superheater outlet as steam source. The annual exergy loss would be reduced by about 2.183×1010kJ, and it was equivalent to an annual increase of power generation revenue by about 2486000CNY.
The Calculation of Friction Heat and Thermal Analysis of Spur Gears Based on Thermal Elastohydrodynamic Lubrication Theory
Authors: Liu Shuyi , Qi Chen
Published: February 2020

In order to predict the temperature distribution of gears more accurately, the influence of oil film on frictional heat generation should be taken into account in computational model. In this paper, based on the theory of thermal elastohydrodynamic lubrication, the calculation of frictional heat flux in the meshing process and the steady thermal analysis of spur gears is completed. The reliability of the model is verified by comparing the calculated results with the value of empirical formulas and experimental data. This paper provides an effective analysis method for gluing prediction, failure analysis and lubrication state analysis of aero-engine transmission gears.
Application of Weak Signal Denoising Based on Improved Wavelet Threshold
Authors: Zhang Ning , Lin Pengfei , Xu Lei
Published: February 2020

In this Study, the application of wavelet threshold denoising in weak signal detection of underwater targets under complex sea conditions is discussed. Firstly, the basic principle and steps of wavelet threshold denoising method based on Mallat decomposition are analyzed. Then a new threshold function is proposed to overcome the shortcomings of traditional Donoho hard and soft thresholds. The denoising effects of wavelet and wavelet packet threshold denoising methods under hard threshold, soft threshold and new threshold functions are simulated, and the signal-to-noise ratio (SNR) and mean square error (MSE) after denoising are taken as evaluation indexes. The results show that the improved threshold denoising method outperforms the traditional threshold denoising methods.
Design of Image Recognition Algorithm for Critical Flight Parameters in Civil Aircraft Display System
Authors: Zhang Maodi , Zhou Yuanhui , Gu Qingfan
Published: February 2020

In the current civil aircraft display system design, complex COTS devices such as CPU and GPU have been widely used. While improving product performance, it also greatly increases the difficulty of airworthiness certification. Taking the display system as an example, the data integrity of the critical flight parameters which is displayed on the display unit must reach 1.0E-7 or higher, and the development assurance level of each software and hardware module must reach level B or higher. However, according to industry experience, the data integrity of CPU and GPU can only reach the level of 1.0E-6. Therefore, for the critical flight parameters in the display system, it must be monitored to cover the entire data path from data processing to image generation to prove the data validity. Aiming at the numeric critical flight parameters of civil aircraft display system, this paper proposes a numeric image recognition technology realized by FPGA image processing function, which can be used to monitor the integrity of numeric critical flight parameters, and this technology has been performed and verified in real display unit.
Improving Clamping Accuracy of Thin-walled Workpiece in Turning Operation
Authors: Elsheikh Ammar H. , Guo Jiajie , Bai Kun , Lee Kok-Meng
Published: February 2020

This study presents theoretical and experimental error analysis and avoidance which results from the fixation of a thin-walled metal disk workpiece on a duplex turning machine. The distance between the rotating workpiece surface and a fixed datum point is measured using a laser displacement sensor (LDS). The measured data are analyzed numerically to get the error in the fixation system in terms of Euler angles. Then the workpiece clamping points are axially adjusted according to the calculated angles. Moreover, the problem formulation and the solution procedures are presented in details. Finally, a case study has been used to verify the proposed approach. The results indicate that the proposed technique can be used to decrease the fixation error to a reasonable range.
Experimental Evaluation for the Interference-fit Electromagnetic Rveting Joint with Headless Rivet
Authors: Song Danlong , Zhang Xiangyang , Liu Kai , Zhang Yanchao , Yang Zhenchao
Published: February 2020

Electromagnetic riveting (EMR) technology as a relatively new mechanical joining process has many advantages compared to traditional riveting methods. However, it needs to be investigated whether the traditional pressing riveting can be replaced by EMR process in aerospace manufacturing engineering. Therefore, in this paper, the differences of riveting quality between automatic riveting and handheld EMR were compared by riveting and mechanical experiments including the uniformity of interference fit, shear and pull-off strength and fatigue life of the joints respectively. It was observed that the interference fit of the riveting joint using EMR is more uniform along the axial direction of rivet than that of automatic riveting. In addition, the overhang of the rivet was difficult to control by handheld EMR, so the quality of rivets for EMR was poorer than that of automatic riveting. Thus, the shear and pull-off strength and fatigue life of EMR joints were affected by the quality of rivets, and a longer rivet is needed for the EMR.
Research on Hull Assembly Process Planning Based on Rule Reasoning
Authors: Lei Li , Di Liu , Pengyu Wang , Honggen Zhou
Published: February 2020

Currently, hull assembly process is mainly dependent on experience, and lack of normative standard. In this paper, hull structure for assembly features is systematically studied, and an assembly sequence planning method based on Rule Reasoning is proposed. Firstly, assembly feature and sequence expression of hull structure is analyzed and the constraint relation of connection information is described. Secondly, the relationship between established structures and the constraint function is designed. Setting the double bottom of the ship as an example, hull assembly sequence is obtained based on geometric constraints and optimized by the fuzzy evaluation method and finally realized the computer aided evaluation of the hull assembly sequence.
Improvement of Microstructural and Mechanical Characteristics of Friction Stir Welded AA6061 Aluminium Alloy Joint
Authors: Shehabeldeen Taher A. , Mahmoud T. S. , Nemat-Alla Mahmoud , Elkady E.Y. , Yin Yajun , Ji Xiaoyuan , Shen Xu , Zhou Jianxin
Published: February 2020

To improve mechanical characteristics of friction stir welded joint made of AA6061-T6, AA2024 was used as a filler material due to its high strength and compatibility with AA6061 aluminium alloy. Different filler strip thickness (1, 1.5, and 2 mm) were investigated. Homogenous plastic deformation of the mixture with soft and refined grains was observed in the stir zone due to dynamic recrystallization of the grains. Friction stir welded joints with filler strip showed high hardness and tensile strength compared with filler-free joints. Welded joint with 1 mm filler strip has the highest tensile strength among other joints due to the dynamic recrystallization of the refined grains as a result of heat concentration. In addition, using greater thickness of filler strips makes the joining process more difficult, causes joint defects and reduces the tensile strength of welded joints.
Temperature Field Measurement in a Cutting Tool by Laser Interferometry
Authors: Efimovich I A , Zolotukhin I S
Published: February 2020

To increase machining efficiency, in addition to determining the temperature distribution on the tool surface, it is also necessary to determine the internal temperature distribution. The existing methods for determining the cutting tool temperature distribution and temperature field measurement have significant disadvantages, which limit their applicability and accuracy. The purpose of this study is to develop and test a novel cutting tool temperature field measurement method. The method involves recording the cutting tool thermal expansion fields by laser interferometry and calculating the tool material temperatures with its coefficient of thermal expansion (CTE). Compared with the methods employing infrared thermometry, the method developed in the present study has a higher spatial resolution and a lower achievable field of view due to its usage of light in the visible region. In addition, since the oxidation film has a higher reflection coefficient for visible light, the present method is less sensitive to the thin-film interference on an oxidized tool surface than those using infrared thermometry, eliminating the false shift of the measured temperature. Moreover, by utilizing cheaper optical components and equipment for interference fringe pattern registration, this method is more affordable. Unlike the emissivity coefficient in infrared thermometry, CTE is independent of changes in the surface quality and can be measured with high accuracy by modern dilatometry. Therefore, the developed method, which employs CTE to calculate the temperature, has a higher reliability. In the present study, the efficiency of this method is tested by the orthogonal turning of difficult-to-cut martensitic heat-treated steel with a cemented tungsten carbide tool. Through the experiment, the temperature distributions along the rake face and flank of the tool, as well as the temperature field inside the tool, were obtained. The results can improve the temperature field measurement in machining cutting tools.
Boundary element analysis of dynamic interaction of anisotropic elastic half-space and structure under impact load
Authors: Markov I P , Igumnov L A
Published: February 2020

In this paper, a direct boundary element formulation for numerical modelling of threedimensional dynamic soil-structure interaction is briefly described. Formulation is applicable to problems involving isotropic and anisotropic elastic materials. It is based on the Laplace domain regularized boundary integral equations for the displacements under assumption of vanishing initial conditions and zero body forces. Mixed boundary elements are employed for the spatial discretization of the boundary integral equations. Subdomain technique is used to tackle problems involving piecewise homogeneous material properties. The described formulation is employed for the boundary element analysis of dynamic soil-structure interaction problem involving a structure which contains a cavity with a complex geometrical form. Soil is represented by a transversely isotropic elastic half-space. Effect of material anisotropy of half-space on the transient response of the embedded structure is assessed. It is observed that the shear modulus anisotropy have substantial impact on the displacements response. Influence of the Young’s modulus in the plane of isotropy is lesser but still pronounced.
Research of surface microstructure of the steel 40CrNiMo after EDM
Authors: Grisharin A , Ablyaz T , Muratov K , Shlykov E , Morozov E , Shafranov A , Matigullina E , Sirotenko L
Published: February 2020

The aim of the work is to study the influence of modes of electrical discharge machining, on the microstructure and microhardness of the treated surface of thermally hardened steel 40CrNiMo. To fulfill the task, a sample was made of hardened steel 40CrNiMo. The sample was processed in various modes of electrical discharge machining. Microsections were made from the obtained sample. Metallographic and microdurometric analysis was carried out. The study of the microstructure showed that no clearly defined altered layer was detected in all processing modes. The study of microhardness showed that near the surface of the studied samples there is a drop in the level of microhardness. This phenomenon is caused by tempering during the surface heating during processing. The heat-affected zone does not exceed 1.2 mm, and is minimal under high-performance modes.
Design of tools with the cutting part of the original profile for high-speed milling
Authors: Vakulin M S , Gordeev Yu I , Yasinsky V B
Published: February 2020

This paper considers and justifies the design of the cutting part of multi-edge contour mills with the increased performance and surface quality. The numerical experiments using the finite element method (FEM) allow determining stresses and deformations in the layer of the material being cut when processed by multi-edge mills of a new type, i.e. they allow evaluating indirectly unit loads during milling. The required shape and dimensions of the cutting wedge were determined taking into account various values of the geometric parameters of the cutting part, the properties of the workpiece material and cutting conditions. All the above resulted in a 3D model of the end mill, which had got a trapeze-shaped tooth located along two intersecting helical lines with tilt angles of 22 and 85 degrees. Along with improving the quality of the processed surface, the experimental studies also showed a change of chip shape. The chip has a finely crushed structure; the sizes of its elements are about 2 μm, which agrees nicely with the results of the FEM preliminary estimates.
Experimental analysis of the EDM process of dissimilar materials
Authors: Ablyaz T , Shlykov E , Muratov K , Oglezneva S , Karmanov V , Osinnikov I , Sarabjeet S S , Sahil D
Published: February 2020

The aim of the present study is to investigate the surface roughness of Electrical Discharged Machined (EDM) samples with Electrode Tool (ET) materials. For the experiments, three different types of ETs were considered which are made of different materials viz. composite, copper, and graphite. Aluminium, low alloy 35GS steel and OT4 titanium alloy were selected as the workpiece materials. Machining parameters used were: current (I) 8 A, voltage (U) 100 V, and pulse duration (Ton) as 150 μs. It was found that the ET made of composite material performs best in EDM of 35GS steel and OT4 titanium alloy. Specifically it was concluded that in the first case, the performance of composite ET is higher than graphite ET by 59 %. Similarly, in the second case, its productivity was found to be 74% and 95% higher when machined with graphite and copper ET respectively. Moreover, the surface roughness values of 35GS steel machined with composite ET was found to be 15% higher when machined with copper and graphite ET. While processing titanium alloy with composite ET, surface roughness values were observed as high as 44% and 25% when machined with copper and graphite ET respectively.
Experience of forming combined low-energy electron-ion beams in plasma sources of charged particles
Authors: Antonovich D A , Gruzdev V A
Published: February 2020

The paper shows the possibility of forming combined electron-ion beams in a single multi-discharge structure that does not contain incandescent elements. A design of the electrode structure of an electron-ion source is proposed, which consists of two «Penning type» discharge cells connected in series (along the axis). It is shown that the interconnection of separately controlled discharges in the structure increases the degree of gas ionization at reduced pressure, as well as the formation of double electric layers in the plasma, which ensure the formation of combined ion-electron flows in a single structure. This is ensured by creating conditions for the drift of the electron beam through the entire part of the electrode structure, which ensures the formation of the ion current of the source, and helps to increase the degree of ionization of the gas in this region. In addition, the deceleration of the electron beam in the ion acceleration gap ensures the return of electrons, which have lost part of their energy to gas ionization, into the region of the formation of the plasma emitting ions. This contributes to an increase in the density of the ion emission current. Some experimental parameters of the beams formed by the developed structure are presented.
Evaluation of influence of technological parameters on width of strengthened layer in plasma surface hardening of structural steels
Authors: Balanovsky A E , Gozbenko V E , Kargapol’tsev S K , Karlina A I , Karlina Yu I
Published: February 2020

The article presents the results of the studies of the influence of technological parameters of plasma hardening on the geometric dimensions of the hardening track using modern research methods. The visualization of the heating spot on the metal surface according to the methodology made it possible to further evaluate the role of anode and cathode spots on the formation of a common heating spot in the process of plasma hardening of metals. It was established that, depending on the effective thermal power of the plasma arc, there are several modes of combustion of the plasma arc. For example, at an arc current of 20 A, there are several characteristic anode spots on the surface in the form of regular circles, which, with an increase in the arc current, contract to the center of the common heating spot. It has been established that the speed and distance of hardening affects the width of the hardened zone during plasma surface hardening of metals. The region of existence of several regimes of plasma hardening in a common heating spot was revealed, for which both single and group anode spots are characteristic.
Beam diagnostics on the electron beam welding installation at Budker Institute of Nuclear Physics
Authors: Blokhina K A , Devyataykina T A , Medvedev A M , Semenov Yu I , Sizov M M , Starostenko A A , Tsyganov A S
Published: February 2020

This paper describes the equipment and methods of the beam diagnostics, namely, the beam current density distribution measuring and the beam position and inclines angle determination. Such a diagnosis is aimed at applying on the electron-beam technological installations, in particular, on the electron-beam welding installations. The paper presents the results of the beam current density distribution measurement, describes the design of the beam position and inclines angle measurement system, and presents the results of preliminary tests of the prototype of this system.
Electron-beam welding of large thickness parts in a narrow gap
Authors: Chulkov I S , Goncharov A L , Chulkova A V
Published: February 2020

The paper presents a method of large thickness parts welding in a narrow gap with filler wire. A modernized deflection magnet is proposed, which allows deflecting an electron beam directly in the zone of weld pool. The distribution of magnetic induction in a local magnetic field along the axis of electron beam guide was measured and the results obtained were compared to the calculated ones. A photographic recording of electron beam deviation in a local magnetic field created by the presented deflection magnet was carried out. The angle of electron beam deviation about electron beam guide axis is estimated.
Creation of corrosion resistant coatings on ductile iron by re-melting flame sprayed layers using laser and electron beam
Authors: Drimal D , Kolenic F , Simek M
Published: February 2020

The paper presents the results of the research of the formation of thin surface corrosion resistant layers on ductile iron with spheroidal graphite. Surface layers were created by a two-step technological process. In a first step, the surface layer material was applied to the surface of the ductile iron by means of a flame-powder coating in a thickness of 0.8 to 1 mm. The treatment of the layer was carried out in the second step by means of a defocused laser beam or a programmed-deflected electron beam. The influence of the laser beam defocusing and the influence of the energy distribution of the deflected electron beam on the characteristics of the formed thin surface layer was studied. 40 mm thick GGG 40 ductile iron samples were used as the substrate experimental material. The Ni-B-Si-type nickel powder with the designation NP22 and Ni-Cr-B-Si-type nickel powders of the type NP52 were used to form the surface layer. The quality of layers was assessed on the basis of surface forming, metallographic evaluation of selected properties of the layer and measurement of micro-hardness at the interface of the layer and the substrate material.
Researches of metal texture after friction stir welding
Authors: Gozbenko V E , Balanovsky A E , Kargapol’tsev S K , Karlina Yu I , Karlina A I
Published: February 2020

The results of studies of the structure of an aluminum alloy by the method of backscattered electron diffraction (EBSD) are presented, which allows determining disorientation angles between grains, present data in the form of an array of angles and sizes, direct and inverse pole figures and many other types of useful information, as well as identify boundaries and sub-boundaries grains. It has been shown that friction stir welding is a process with a predominance of shear; the observed shear texture can indicate the local orientation of the material flow during welding. The three-dimensional material flow detected by these texture orientations shows important changes, especially on the advancing side of the weld.
Possibility of obtaining complex form details using additive surface technology
Authors: Kargapol’tsev S K , Balanovsky A E , Gozbenko V E , Karlina Yu I , Karlina A I
Published: February 2020

The authors consider the possibilities of using welding in protective gasses with a melting electrode for the manufacture of parts of complex shape. The results of surfacing parts such as square and cylinder are presented. In the course of the research, the technological features associated with the parameters of the welding arc and melting of the surfacing wire were established. Arc current has the greatest effect on the appearance of the molding. The wire feed speed affects the height of the deposited roller. It is shown that the stability of the formation of deposited rollers depends on the transfer modes of the metal, which depend on the conditions of supply and input of wire into the melt pool. The additive technology of metal deposition allows one obtaining parts with a surface different from the base metal, high wear resistance at normal and elevated temperatures, and corrosion resistance. Surfacing can be performed both in the manufacture of new parts and in repair and restoration work, significantly extending the life of parts and assemblies, thereby ensuring a high economic effect.
Effect of molybdenum on the hot-tearing susceptibility of the Ni-Cr-Mo-B system
Authors: Nazarko A S , Plomoyalo R L , Dmitrenko D V
Published: February 2020

The paper presents data on the effect of molybdenum on the hot-tearing susceptibility of the Ni-Cr-Mo-B system when surfacing with nickel-based alloys. With a boron content of 2.5-3.2%, as well as low carbon and silicon content, the alloying elements, depending on a doping concentration, have different effects on the technological strength of the deposited metal. Molybdenum increases the technological strength of alloys. Alloying the deposited metal with molybdenum in an amount up to 12% in alloys with 2.5% boron concentration at 20% chromium does not lead to the disappearance of cracks. At a molybdenum concentration of more than 12%, the number of cracks in the deposited bead decreases and when the molybdenum concentration is equal to 15%, the cracks disappear, and only increasing the molybdenum content to 20%, in the presence of at least 20% chromium in the alloy, makes it possible to obtain deposited metal without cracks.
Simulation of fractional efficiency of direct-flow cyclone with intermediate dust collector
Authors: Aslamova V S , Aslamov A A , Arschinskii M I , Zhilycov Y V , Rudykh E A
Published: February 2020

By means of numerical modeling in the program ANSYS Fluent CFX the evaluation of fractional efficiency in a direct-flow cyclone with intermediate dust collector has been carried out. The boundary conditions were as close as possible to the experimental ones. As a gas phase, the authors take the air under normal conditions, as the solid phase – spherical particles of 30 and 80 microns in size. In order to evaluate the adequacy of the calculation model, a laboratory installation of a DCIC with two separate chambers for the selection of collected particles was made. This design allowed estimating the fractional efficiency of both individual chambers of a direct-flow cyclone DCIC and the apparatus as a whole. The results of the experiments carried out on different types of dust (fly ash, cement) showed a good convergence with the design model
Expert system for aggregate industrial safety assessment at enterprises based on knowledge technologies
Authors: Aslamova E A , Arshinsky L V , Aslamova V S , Krivov M V
Published: February 2020

The work presents the knowledge base of the expert system of the aggregate assessment of the level of industrial safety at a hazardous production facility, based on the use of the logico-axiological approach. The fundamental hypothesis: the reduction in production safety is due to the presence of “NE-factors”: poor implementation of organizational measures, improper working conditions, inadequate personal protective equipment and so on. Failure to take measures to provide protection against industrial accidents leads to a reduction in the level of industrial safety. According to the approach used, the influence of “NOT-factors” on the level of “non-safety” of production is formalized by products of the type: (SIC)A ->(SIC)B.
Design of the tooling of a complex geometric shape for electrothermal processing of the polymer covering plate of the bogie friction wedge
Authors: Butorin D V , Larchenko A G , Alexandrov A A
Published: February 2020

The article analyzes the operation of the bogie friction wedge. It considers the question of the necessity and possibility of enhancing the reliability and operational resource of wedge-type shock absorbers of railway bogies by increasing the operational properties of a polymer covering plate of a bogie friction wedge. A method for increasing the operational properties of the polymer covering plate, consisting in its processing by high-frequency currents, is proposed. To implement the high-frequency processing of the considered polymeric covering plate and achieve its uniform warming-up throughout the volume, a specialized tooling is developed and constructed according to the technique established earlier. The developed tooling made it possible to implement a uniform non-inertial self-regulating high-frequency heating throughout the entire volume of the polymer covering plate in laboratory conditions with high intensity. As a result of full-scale tests of the developed tooling and the proposed method of high-frequency processing, deviations of temperature values in different parts of the heated polymer plate became apparent. All of this shows that the heating is not completely uniform. The greatest deviation value was 7.9%. As a result of the work, it was possible to establish the reasons for the lack of full uniformity and to determine the direction of further research.
Research of high-frequency influence on polymeric materials of rolling stock products
Authors: Filippenko N G
Published: February 2020

The paper presents the main directions of the technological process of high-frequency processing of polymeric materials used in rolling stock products. The necessity of developing a mathematical model of the critical process of exposure to high-frequency energy is substantiated. As a model, an imitational mathematical model of the process of high-frequency processing of polymeric materials that takes into account breakdown phenomena is proposed (based on experimental studies of a large number of the most used polymer materials).
Analysis of dynamic characteristics of frequency-dependent links
Authors: Kolmakov V O , Kolmakov O V , Ilyin E S , Ratushnyak V S
Published: February 2020

The article is devoted to an experimental study of the dynamic characteristics of the four-beam frequency filter under consideration in various power consumption modes. Based on the PSpice program, a typical power supply circuit for LED lamps was modeled. The peaks of the harmonic series reflect the power of the higher harmonics relative to the fundamental harmonic. In the three-phase mode of the lighting systems switching, the filter compensating device according to the four-beam “star connection” scheme is more efficient. The experimental results showed that the content of the 3rd harmonic, when the filter of the compensating device is turned on, exceeds the permissible state standard specification by 5% only in the 6-fold asymmetry mode in the current of the main power supply. Thus, in three-phase networks, using a four-beam passive harmonic filter, it is possible to suppress the higher harmonics of non-sinusoidal voltages and currents effectively. The filtering level of the harmonic components provides a significant reduction in the non-sinusoidality of the current and, as a result, an increase in the quality of electricity, as well as a reduction in power losses in the filter compensating device, a decrease in the overall dimensions of the filter and its cost.
Determining the geometrical parameters of spring suspension of locomotives
Authors: Kopanev M V , Arsentiev M O , Kuchera L Y
Published: February 2020

Annotation

The paper considers the issues of measuring the geometric parameters of the springs using a laser-optical sensor. The features of an automated rig for measuring the parameters of the springs are presented. The work also investigates the operation of the laser-optical sensor. The results obtained allow using the laser-optical sensor for measuring the geometric parameters of the springs of a rolling stock. The measurements obtained with the laser-optical sensor to determine the parameters of the locomotive suspension springs are presented.
Magnetic vibrations in synchronous machines with permanent magnets and fractional slot concentrated winding
Authors: Toporkov D M , Kovtun M A , Popov I L
Published: February 2020

Nowadays synchronous machines with permanent magnets are widely used in motor manufacturing due to output parameters. The paper aims to analyse the radial magnetic forces that cause the stator vibration of a synchronous machine with permanent magnets and a fractional slot concentrated winding. The method to assess the vibration parameters of synchronous machine is proposed.
Simulation of non-sinusoidal modes in railway power supply systems during movement of high-speed trains
Authors: Kryukov A V , Cherepanov A V , Shafikov A R , Bezridnyj E S
Published: February 2020

Rectifier locomotives have non-linear current-voltage characteristics and generate higher harmonics (HH) in the power supply networks, which is accompanied by the following negative effects: reduced equipment service life, distortion of electricity metering, occurrence of resonant processes, etc. Therefore, the problem of reducing the levels of harmonic distortion in the networks adjacent to the traction substations of the AC railways is of increased relevance. The level of HH generation depends on the design features of electric locomotives. Electric stock with zone-and-phase regulation creates high harmonic distortions, which results in increased losses, increased electromagnetic effects on adjacent power and telecommunication lines and reduced reliability of power supply. Electric locomotives with asynchronous traction motors (ATM) connected via 4q – S converters virtually do not distort the sinusoidality of the current curve. To measure the degree of reduction of harmonic distortion during the movement of locomotives with ATM, simulation modeling of non-sinusoidal modes of a typical 25 kV traction power supply system was carried out for two variants of the locomotives used: 1) VL-80R with DC motors; 2) UTY –1 with asynchronous traction motors. The methodology for determining non-sinusoidal modes is based on the technology of modeling electric power systems (EPS) in phase coordinates; at the same time, the models of EPS elements were formed as lattice schemes characterized by a fully connected topology. The parameters of these circuits can be recalculated to the frequencies of HH. The proposed approach is universal and can be used to study non-sinusoidal modes in existing and future traction power supply systems. The simulation results showed that the problem of increased harmonic distortion in the networks feeding the traction substations can be completely solved by replacing the acting locomotives with new-generation electric locomotives with asynchronous electric drives and four-quadrant converters.
Diagnostic operation of fabrications of rolling stock by high-frequency method
Authors: Larchenko A G , Filippenko N G , Livshits A.V. , Kargapoltcev S.K.
Published: February 2020

In this scientific work, the authors consider the issue of non-destructive testing. In the article, the authors describe the process of improving the performance properties of polymeric products of complex configuration. In the article, the authors choose the method of high-frequency control as the most suitable for assessing the quality of products in the manufacture and during repair work. The scientific work describes the process of diagnosing products made from polymeric materials on the developed diagnostic device. This article describes the development of methods for designing a technological additional device for diagnosing products of complex configuration. In this paper, the authors solved the problem of manufacturing electrodes for experimental diagnostics. The authors drew conclusions and set goals for further research.
The correction system for the direction of a locomotive spotlight’s luminous flux
Authors: Manikovskij A S , Komogorcev M G , Stepanov V V
Published: February 2020

In this article the authors propose their concept of a correction system for the direction of a locomotive spotlight’s luminous flux in the horizontal plane during train movement. This solution will keep the railway tracks well-lit while the locomotive moves on curved track during night time and in limited visibility conditions and drastically increase the railway traffic safety.
Thermodynamic estimination of adsorption ability of modified zeolites
Authors: Obuzdina M V , Rush E A
Published: February 2020

The article presents the results of original investigations of the thermodynamic laws of sorption extraction of Ni2+, Zn2+, Cu2+from wastewater. As an adsorbent, a natural zeolite from the Holinsky deposit of the klinoptilolite type, modified with a sulphur polymer, obtained from waste in the production of epichlorohydrin was proposed. The limiting parameters of the adsorption process are described by the Langmuir equation. The graphical method the limiting value of adsorption, the adsorption equilibrium constant, the differential heat of adsorption, the adsorption rate constant, the activation energy, the Gibbs energy was founded. It is proved that the investigated processes obey the laws of physical adsorption and are spontaneous.