bluuebunny/crossref_metadata_2025 huggingface dataset:
The Application of Overset Grid in the Analysis of Impact Loads of Amphibious Aircraft during Landing on the Water
Authors: Hu Qi , Wang Ming-Zhen , Wu Bin , Zhang Jia-Xu , Xiao ZhiJian
Published: February 2020

In view of the complex three-phase coupling problem of gas, liquid and solid when amphibious aircraft landed on the water surface, based on the finite volume method, the overset grid technology was used to simulate the landing load characteristics of amphibious aircraft; firstly, the overset grid technology was used to establish the landing model of amphibious aircraft, and the load characteristics under different landing conditions were obtained, and compared with the model test results. The results show that, firstly, the larger the sinking speed is, the larger the load is, and the more obvious bounce phenomenon occurs; secondly, the transverse distribution of the bottom pressure gradually increases along the keel to bilge; thirdly, the load characteristics obtained by numerical simulation are basically consistent with the model test. Therefore, the overset grid technology can simulate the landing load characteristics of amphibious aircraft and provide an effective method for the landing load design of amphibious aircraft.
The Influence of Angle Parameters on Pulsation Characteristics of Elastomer Rotor Pump
Authors: Lian Jiadi , Bai Yan , Zhu Zefei , Xu Jing , Ma Jingxuan
Published: February 2020

In view of the poor sealing performance of elastomer rotor profile and the defect of particle sticking in the tip of rotor, the pulsation characteristics of rotor cavity under 5°, 8°, 11°, 15° and 18° conditions are studied by transient calculation of the whole flow field of rotor pump based on CFX immersion solid technology and RNG k − ξ turbulence model. When the wrap angle increases, the instantaneous mass pulsation rate decreases. When the wrap angle increases, the cavitation possibility at the inlet meshing point increases, and the pressure at the outlet meshing point increases. In order to improve the periodic impact of liquid on the elastomer and prevent the adhesion surface from falling off, the elastomer rotor should adopt the structure of small wrap angle under the condition of ensuring the width of sealing at the top of rotor.
Model-based Balancing Method of Rotors using Differential Evolution Algorithm
Authors: Zhang Yun , Li Meng , Hu Yang
Published: February 2020

As a major source of undesired vibration, unbalance is a ubiquitous phenomenon for many types of rotor system. To suppress the unbalance vibration and avoid the complicated and dangerous process of taking trial weights during the balancing process, a model-based balancing method of rotors is proposed in this paper. The rotor model is built to analyse the dynamic characteristics of the unbalance rotor, an unbalance identification method is presented and the optimization objective function of the unbalance vectors is given, then the differential evolution algorithm is employed to acquire the optimization solution. Finally, the accuracy of the rotor model is verified by modal tests, and the performance of the proposed method is evaluated in balancing experiment, results reflect its effectiveness.
Vibration signal Processing of Cutting Gearbox Based on Haar-Wavelet Denoise
Authors: Zhang X F , Ma F W , Wang N N , Guo Z F
Published: February 2020

Cutting gearbox with complex structure is difficult to obtain mechanical parameters and conduct fault diagnosis, aiming at this problem, a novel handling method is proposed after studying vibration theory of gearbox. Firstly, traditional calculation method and modal analysis are combined to acquire mechanical parameters of gearbox, especially inherent frequencies of decelerator housing and gear transmissions which are difficult to calculate. Based on Haar-Wavelet, vibration test signal of cutting gearbox is de-noised. And Fast Fourier Transform (FFT) is conducted for de-noised signal, thus operation status of gearbox can be analyzed in time domain and frequency domain. Taking a mine cutting gearbox as an example, the method proposed is used to detect parts damage in maintenance process. It is found that the tooth surface of second-stage gear transmission arise even wear, and this is consistent with actual situation. Therefore the practicability and effectiveness of this method are verified, and a new solution is provided for other gearboxes with complex structure.
Aircraft Inflight Icing Detection Based on Statistical Decision Theory
Authors: Ding D , Qian W Q , Wang Q
Published: February 2020

Aircraft inflight icing detection is very important for aviation flight safety. The ice alarm signal given by detectors can help the pilot to actuate the ice protection system. The application of a Neyman Pearson (NP) based statistical decision approach in icing detection is discussed in this paper. First, the flight dynamics for icing aircraft is modelled, the dynamic behaviour of an airbus influenced by ice accreting on the leading edge of wings is analysed. Then the residuals which are directly affected by the aerodynamic parameters are presented and their generation way is given. The Generalized Likelihood Ratio Test (GLRT) method is utilized in detecting the changes of residuals inflight, its performance is assessed by a flight scenario with wing ice. The results show that the fault of wing icing can be detected by every residual under different window sizes. By comparing the results of the residuals, it can be concluded that the small window size will degrade the detection performance with the longer alarming time delay and the lower probability of detection; appropriately increasing the window size can reduce the alarming time delay; diagnosing by residual of normal overload is more reliable than by the other two residuals.
Feasibility and Uncertainty Analysis of Constitutive Parameters Identification for Composite Materials Using Displacement Field Data
Authors: Liu Zhaoyan , Liu Liu , He Tiren
Published: February 2020

Due to the normalized average strain error is remarkably higher than the displacement error, a new cost-effective method based on the Levenberg-Marquardt method, which is a gradient-based optimization method, was presented in this paper. The unknown constitutive properties are determined through minimization of the square difference between the reconstructed DIC-measured and the FEM-calculated displacements. The feasibility analysis of this method is presented by synthetic displacement data. The covariance matrix of the extracted material constitutive parameters has been given explicitly. It has been proved that this method can significantly reduce the uncertainty of the extracted material constitutive parameter induced by the approximation error due to reconstruction algorithm and the measurement noise. The material constants show strong robustness to the measurement noise. And the optimization procedure is not sensitive to the formulation and parameters in the initial approximation of the constitutive model. A sensitive matrix was derivation and evaluation iterative in this method to improve the convergence of the optimization procedure.
Stress Analysis and Strength Test of 2500 Fracturing Truck Frame
Authors: Li Lei , Zhang Bin , Fan Chunming
Published: February 2020

For the fracturing trucks, which is an important member of oil and gas fracturing, the stress and strength of fracturing truck’s frame have a very significant influence on the continuous fracturing operation. This paper takes the frame of 2500 fracturing truck as the research object, analyses its stress condition, and conducts the static strength test and dynamic strength test of the whole frame of fracturing truck, respectively tests the strain of 15 measuring points of the frame under the fully loaded static condition and the right front wheel lifting condition, and finds out the distribution rule of the stress and strain of the frame. The results show that the maximum stress position of the frame under migration condition is at the root of the rear support of the tank, the total stress is 146.76 MPa, the minimum safety factor reaches 2.35, and the strength of measuring point meets the requirements.
Copula-based Estimation Method of the Expected Value Function for Robust Design Optimization
Authors: Li Xinyao , Zhang Weihong , He Liangli
Published: February 2020

The expected value function (EVF), which defined as function of mean value with respect to the design parameters, can simplify the solving process of the RDO with nested-double loop. The traditional method for estimating the expected value function requires a nested procedure and the computational cost depends on the product of the optimal steps and the numbers of the random variable samples. In this paper, a novel method based on copula is proposed to estimate the EVF. In the proposed method, the EVF is derived as the copula function related to the design parameters and the model output, which can be estimated with a single loop samples and the computational cost of the copula-based method does not depend on the total number of design parameters or the number of the optimal steps. Additionally, a vine-copula is introduced to the EVF so that the estimation for the EVF by two-dimensional kernel density estimation (KDE) method can be extended to the multi-dimensional design parameters problems. The present example with two cases demonstrate the effectiveness of the proposed copula-based method.
Analysis of Geometric Characteristics of Cycloidal Transmissio
Authors: Huang Xiangmao , Zhang Jing
Published: February 2020

In order to improve the transmission performance of RV reducer, the equation of cycloid tooth profile is deduced according to the transmission principle of cycloid.The relationship between the curvature radius of cycloid tooth profile and the rotation angle is deduced. The rotation angle corresponding to the maximum curvature radius is solved and the value of the radius of needle tooth under the circumstance of avoiding top cutting is given. Pressure angle is an index to evaluate transmission performance. This paper deduces the relationship between pressure angle and rotation angle, simulates the influence of eccentricity, radius of pin teeth and radius of distribution circle of pin teeth on pressure angle. The simulation show that the position with pressure angle of 90 degrees appears at the top and root of cycloidal gear, which is not conducive to the transmission performance of cycloidal gear, the position with the best transmission performance appears in the middle of cycloidal gear.The change speed of pressure angle near the root of tooth is faster than that near the top of tooth. The results show that increasing the eccentricity properly or reducing the radius of the center circle of the pin teeth can make the minimum curvature close to the root of tooth, which is beneficial to improving the load-carrying capacity of cycloidal gear.
Static and Dynamic Analysis of a 2T3R Five-degree-of-freedom Parallel Mechanism
Authors: Lu Bofan , Cui Guohua , Guo Qiang
Published: February 2020

taking a 2T3R five-degree-of-freedom 4-SPRR-SPR parallel mechanism as the research object, a three-dimensional model and a finite element model of the parallel mechanism are established. Through the static analysis of the mechanism, the weak link of the whole mechanism is analyzed. It is then modally analyzed to analyze the natural frequency and mode shape of the mechanism. On the basis of the harmonic response analysis, the vibration resistance performance and the maximum influence frequency of the mechanism under external force are obtained.
Numerical Simulation of Liquid-vapor Phase Transition Induced by a Heated Surface in a Shear Flow
Authors: Shan Xiaopeng , Nie Deming
Published: February 2020

The influence of the external flow on the liquid-vapor phase transition is numerically studied in this work. The bubble growth and departure from a heated surface in a shear flow is realized through a pseudo-potential based lattice Boltzmann method. The benchmark test of the pool boiling induced by a single heated plate is adopted to validate the present method. The averaged heat flux, the bubble releasing frequency and flow features are presented, along with the effects of the flow intensity on them. It is shown that the external flow significantly enhances the heat transfer of the system in two respects: increasing the averaged heat flux and the bubble releasing frequency.
Analysis of Failure Effect of Cage Thickness on Spherical Roller Bearings
Authors: Li Fang , Biao Qiu Wang , Bin Cai Jia , Wang Kai , Pan Zheng
Published: February 2020

Spherical roller bearings are important parts of high-frequency crushers. Using the finite element analysis software to carry on the transient dynamics analysis to the bearing obtains the bearing deformation, the pressure and so on characteristis. Then, by contrasting and analysising, it is found that under pure radial load, radial load and axial load mixed force, influence of cage thickness on bearing performance. The results show that the thickness of the cage has little effect on the deformation of the bearing under pure radial load. Under the combined action of the radial load and the axial load, the radial deformation of the bearing decreases compared with the pure radial load. The deformation of the cage under the mixed load is increased than that under the radial load.
Design of Swinging Somatosensory Game Rehabilitation System
Authors: Kou Lili , Xia Chaoyu , Hu Zhihua , Jiang Xiaojun
Published: February 2020

This study designed an arm-swinging somatosensory game for physically uncoordinated personnel, which realized the movement attitude acquisition, data transmission, and motion-driven game character movement. The measurement results show that in the range of 0.3g to 0.5g, the probability distribution of the ordinary person is twice or more the accuracy of the limb dissonance in the face of the same action, which proves that the game has the ability to detect and measure the reaction speed of the person. It can be used as a standard for rehabilitation levels. In addition, the game calculates relative data of the acceleration and uses which to stimulate the movement of the game character, which relaxed the threshold. Therefore, it can stimulate participation interest and promote rehabilitation.
Intelligent Sequencing of Working Steps Using Genetic Algorithm
Authors: Zhu Y P , Zhou H G , Liu J F , Tian G Z
Published: February 2020

There are many factors that need to be considered in the operation sequencing, and there are mutual relations among them, so it has become a hot topic worthy of study. In this paper, based on the parallel consideration of process constraint and minimum manufacturing cost, the concepts of workingsteps sequence matrix and process constraint matrix are proposed. The process constraint matrix is used to ensure that the workingsteps sequences conform to the precedence relation constraint, and the genetic algorithm is used to ensure the minimum manufacturing cost. Finally, the optimal solution of the workingsteps sequence is obtained. The connecting rod of marine diesel engine is taken as an example to verify.
Availability Assessment of Avionics Display System based on MBSA using Fault Dependent Matrix
Authors: Dong Haiyong , Cao Zhiyuan , Zhai Zhengjun , Gu Qingfan , Lu Yanhong , Wang Guoqing , Wang Miao
Published: February 2020

The availability of avionics display systems plays an important role in flight safety and requires a safety analysis during the design phase. The current safety analysis process is not carried out based on the system design model, so there may be inconsistencies. This paper proposes a model-based safety analysis method using a fault dependent matrix, which can be applied to commonly used system modelling tools such as Enterprise Architect. This article illustrates the utilization of the method by providing the elapsed flight time function, using MATLAB to generate the fault dependent matrix, and then obtaining the availability of the function. This method can be used to aid system safety design and improve system design efficiency.
Performance Simulation Analysis of Composite Thermal Management System for Hypersonic Vehicle
Authors: Changbao Yang , Hui Zhou , Jingyang Zhang
Published: February 2020

A hybrid thermal management system model of hypersonic vehicle with liquid hydrogen as heat sink and thermoelectric conversion of Brayton cycle was established. The cooling effect, fuel flow demand and thermoelectric conversion characteristics of the thermal management system in flight envelope were studied by numerical simulation. The results show that the cooling fuel demand of refrigerant loop is about 0.22g/kW.s~0.24g/kW·s, that of aerothermal cooling fuel is about 0.11g/kW·s, and that of engine wall cooling fuel is about 0.08g/kW·s. The flow rate of engine wall cooling fuel can be saved by 25%∼40% during thermoelectric conversion. Thermoelectric conversion cycle efficiency and generation efficiency can reach up to 38% and 30%. When Mach number is 3.7∼4.2 under the condition of large aerodynamic heat load, the flow rate required for engine combustion is not enough to meet the cooling flow rate, and the maximum difference is 10%.
Research on Post-processing Microstructure and Property of Titanium Components with Selective Laser Melting (SLM)
Authors: Qiang Chu Ming , Yan Zhang Shu , Qiao Su Guan , Gen Ding Ren , Wang Lei , Padde Sanjooram
Published: February 2020

Additive manufacturing of titanium component holds promise to deliver benefit such as reduced cost, weight and carbon emissions during both manufacture and use. To capitalize on the benefits, it must be shown that the mechanical performance of parts produced by additive manufacturing can meet design requirement that are typically based on wrought material performance properties. Of particular concern for safety critical structures is the fatigue property of parts produced by additive manufacturing. Microstructure evolution, and its influence on mechanical properties of the alloy in the as-fabricated condition, has been documented by various researchers. However, fatigue crack propagation and the effects of the directional structure have not been sufficiently studied, imposing a barrier for this technology’s potential extension to high-integrity applications. In this study, fatigue life (S-N) and fatigue crack growth (FCG) both parallel and perpendicular to the build directions was studied. The interaction between the directional as-fabricated SLM microstructure and FCG was investigated and compared to that of the hot isostatic pressing (HIP) specimens with and without the stress relief after fabricating with SLM.
Method of luminescent analysis of the state of photosynthetic apparatus of plants
Authors: Bylkov D V , Turanov S B , Korepanov V I
Published: February 2020

Photosynthetic apparatus and its reaction to changes in external conditions carry information about the state of the plant. Thus, under different lighting conditions, as well as with changes in nutrition and microclimate conditions, the amount and composition of chlorophyll in plant cells changes, which will lead to changes in the optical parameters of plant chlorophyll. You can track the state of the plant by changing the parameters of chlorophyll fluorescence. To monitor the state of the photosynthetic apparatus, the method of analysis of induction curves of variable fluorescence is used. The purpose of this article is to design a research facility for testing the technique of fluorescent analysis and further accumulation of statistical data on the dependence of fluorescence characteristics on lighting parameters.
The influence of diverse optical wavelengths on growth rate of Chlorella Vulgaris microalgae
Authors: Trofimchuk O A , Yakovlev A N , Turanov S B , Trigub M V , Romanenko S A
Published: February 2020

The effect of different optical wavelengths on growth and development of microalgae had been examined repeatedly. Many articles had been published over the subject, although the results of these investigations were frequently controversial. Depending on the number of days spent on cultivation process, yield gain could be both significant and barely noticeable. Also, irradiation intensity plays vital part in microalgae functioning.
Hydrochemical Research and Geochemical Classification of Salt Lakes in the Pavlodar Region
Authors: Ubaskin A , Kassanova A , Lunkov A , Ahmetov K , Almagambetova K , Erzhanov N , Abylkhassanov T
Published: February 2020

This paper presents the results of a study of the macrocomponent composition of 15 salt lakes of the Pavlodar region. For the first time, based on the data of the chemical composition and pH of the waters, the geochemical classification of the lakes of this region has been proposed. The study shows that the majority of the analyzed objects are lakes of chloride type with sodium cationic composition.
Luminescence spectra of YAG:Ce phosphors synthesized in a field of radiation
Authors: Alpyssova G , Mussakhanov D , Karipbayev Zh , Grechkina T , Zheng Shiming , Kukenova A
Published: February 2020

The paper presents the measurement results of the luminescence band shape for YAG phosphors upon photoexcitation. It is shown that the position and FWHM does not depend on the excitation technique, but it depends on the phosphor prehistory. The observed difference is assumed to be due to the difference in the structure of nanodefects in phosphors synthesized under different conditions.
Effect of electronic irradiation on the properties of polyethyleneterephthalate films of various producers
Authors: Kupchishin A I , Taipova B G , Gerasimenko N N , Voronova N A , Abdukhairova AT
Published: February 2020

Studies on the effect of electron irradiation on the properties of polyethylene terephthalate films of various brands have been carried out. An analysis of the results shows that the relative elongation of the Mylar-type film is ~ 70%, for PET ε it is 48%. According to the strength properties, Russian-made PET is more resistant to electronic effects and is destroyed at doses of 109 Gy, while the Mylar ones at 105 Gy. The calculation made according to the proposed models (exponential and generalized) is in satisfactory agreement with experimental data.
Research of thermoelectric effects and their influence on electron beam in the process of welding of dissimilar steels
Authors: Goncharov A L , Sliva A P , Kharitonov I A , Chulkova A V , Terentyev E V
Published: February 2020

The results of studies of magnetic and thermoelectric properties of pearlite, martensitic and austenitic steels are given. The magnetization curves for the materials under study, as well as dependences of absolute thermoelectric power on the material temperature are obtained. The data of magnetic induction changing at the control points above the welded samples during EBW are achieved. The simulation of the magnetic field distribution during electron beam welding of dissimilar steels under the conditions of the thermopower currents generation is carried out. The shape of the electron beam being deflected in the magnetic field of thermoelectric currents is calculated. The calculated values are compared to the experimental results.
Research of mechanical properties and chemical composition of samples made of aluminium alloy AMg6 and obtained by electron beam additive manufacturing with wire feeding
Authors: Gudenko A V , Grigoriev G V , Sliva A P , Yu Agafonov R , Kasitsyn A N
Published: February 2020

This paper is devoted to the definition of mechanical properties, porosity and chemical composition of the samples made of wrought aluminium alloy AMg6 and obtained by electron beam additive manufacturing with wire feeding. It has been established that ultimate strength of the deposited metal is 90 % of the rolled metal. Chemical composition of the samples has not differed significantly from wire. According to rough estimations porosity has not exceeded 0.055%.
Challenges in path planning of high energy density beams for additive manufacturing
Authors: Karunakaran K P , Negi Seema , Nambolan Arun , Patel Ashik , Patil Yogesh , Pandya Milan , Kapil Sajan , Trushnikov Dmitriy , Sealy Michael , Bernard Alain
Published: February 2020

As there are no cutting forces in High Energy Density (HED) beams like lasers and Electron Beam (EB), their speeds are limited only by their positioning systems. On the other hand, as the entire matrix of the 3D printed part has to be addressed by the thin beam in multiple passes in multiple layers, they have to travel several kilometers in tiny motions. Therefore, the acceleration of the motion system becomes the limiting factor than velocity or precision. The authors have proposed an area-filling strategy for EB to fill the layer with optimal squares to exploit analog and hardware computing. 3D printing requires uniform intensity slanged as flat hat shape whereas the default is Gaussian. The authors have proposed an optimal algorithm that takes into account the maximum velocity and acceleration for achieving a flat hat without any compromise on productivity.
Express evaluation of welded joints cool resistance
Authors: Matyunin V M , Yu Marchenkov A , Karimbekov M A , Demidov A N , Volkov P V , Abusaif N , Geraskin E I , Zhgut D A
Published: February 2020

Low-temperature instrumented indentation tests of welded joints are carried out. The effect of metal cooling on indentation diagrams and metal hardness is investigated. Impact strength tests with a gradual decrease in temperature with the identification of the cold brittleness threshold and determination of the critical brittleness temperature for several structural steels are performed. For an express evaluation of a metal cold resistance, the parameter γ is proposed, which is equal to the ratio of hardness at a given low temperature to hardness at room temperature. The relation between the parameter γ and the temperature coefficient of hardness, which is included in the equation describing low-temperature dependence of hardness, is established. For several grades of carbon and alloy steels, the relation between the parameter γ and the critical brittleness temperature T
0.4, determined by the criterion value of impact strength KCV = 0.4 MJ/m2, is established. For welded joints obtained by electron beam welding and arc welding, the values of T
0.4 are determined by the parameter γ in various local zones, including parent metal, heat-affected zone and weld metal. The possibility of establishing the acceptable operation temperature of welded joints using the obtained distributions of the critical brittleness temperature T
0.4 is shown.
Influence of technological parameters of spraying on mechanical properties of gas-dynamic coatings
Authors: Moskvitin G V , Pugachev M S
Published: February 2020

A methodology for shear and tension “ring tear-off” tests of copper, aluminum, zinc and nickel coatings laid through gas-dynamic spraying has been considered. It has been shown that the shear and tension test methodology permits obtaining dependences of strength of the bond between the coatings and the substrate on their laying temperature. The cohesive strength tension tests of the copper, aluminum, and zinc coatings using the “ring tear-off” method have shown the minimal spread of the values (≤ 5%) at the brittle character of the coating failure, which enhances the plausibility of the obtained mechanical properties.
Computer simulation of metals ionization process during electron-beam welding
Authors: Rodyakina R V , Shcherbakov A V , Gaponova D A
Published: February 2020

One of the most actual problems during electron beam welding of metal materials is the determination of the laws of primary electrons interaction with a gas (vapor) flow, taking into account existing and generated (by charged particles) electric fields. The paper is devoted to the development of computer simulation method for the process of electron beam passage through a layer of evaporated metal. The analysis of simulation results showed a significant effect of ionization process on electric field in a gas-vapor channel. It was established that at the initial stage of the process, a region with a positive potential is formed in the lower part of gas-vapor channel, and in its upper part, on the contrary, potential decreases.
Threshold conditions for thermocapillary transition to deep penetration mode in selective laser melting of metal powder bed
Authors: Seidgazov R D , Kh Mirzade F
Published: February 2020

The keyhole mode of selective laser melting (SLM) of metal powder bed in additive technology is characterized by an intensive hydrodynamic process in a thin molten layer. Such a mode is widely used also in laser and electron beam welding indicating the similarity of hydrodynamic processes in these technologies despite a significant difference of operating parameters. The threshold conditions of thermocapillary keyhole mode transition for various metals (Cu, Fe, Ti) in a wide range of beam parameters used for selective laser melting of metal powder layer and laser welding are investigated. The condition of threshold for thermocapillary transition into keyhole mode by sticking of viscous layer to the solid boundary is formulated. The fulfillment of this condition is confirmed by the convergence of estimated values of the viscous layer thickness and the molten layer depth during the transition to a keyhole mode. Analytical estimates of keyhole threshold and comparisons with experimental values of beam power and spot size corresponding to the transition in keyhole mode for SLM processes and laser welding are presented. The correlation of these values confirms the thermocapillary mechanism of cavity formation and the similarity of hydrodynamic processes in laser welding and SLM processing in keyhole mode at wide range of operating parameters.
Mathematical model of a radial bearing with a low-melting metal coating of design models of hydrodynamic viscoelastic lubricant formed by melting the surface of a bearing bush coated with a metallic low-melting coating
Authors: Akhverdiev K S , Lagunova E O , Mukutadze M A
Published: February 2020

The work is based on equations of motion of viscoelastic lubricant (Maxwell fluid) for the case of “thin layer”, continuity and the formula of the rate of dissipation of mechanical energy. We found asymptotic solution to the degrees of small parameter K, characterizing the rate of dissipation of mechanical energy. This allows determining the molten surface of the bearing sleeve covered with a fusible metal melt, taking into account the dependence of the viscosity of the lubricant and the shear modulus of pressure in the adiabatic process. For zero approximation under adiabatic process conditions, i.e. without taking into account the melt surface, and a solution for the first approximation, i.e., taking into account the melt surface of the bearing sleeve covered with a fusible metal melt, the exact self-similar solution of the problem with incomplete (pre-emergency) filling of the working gap with a lubricant having viscoelastic properties is found.. On the basis of the results obtained for the zero and first approximation, the bearing capacity and friction force are found at incomplete filling of the working gap with a lubricant. In addition, for verification calculations of the obtained theoretical models, a numerical calculation was carried out and as a result, graphs showing a decrease in the friction coefficient by about 20% were constructed.
Parallel operation of an inverter with an electrical AC network
Authors: Alekseeva T L , Ryabchyonok N L , Astrakhantsev L A , Tikhomirov V A , Astashkov N P , Martusov A L , Alekseev M E
Published: February 2020

The paper studies the matters of the interaction of a source of non-sinusoidal current and voltage with a centralized power supply system for the electric energy recuperation during electric braking of rolling stock on the railroads. Revised energy conservation law in electromagnetic field and spectral analysis of non-sinusoidal voltage and current at the output of the inverter have been used to prove the cause of reduced current of RMS voltage in the overhead system. It has been calculated that controlling the active power of recuperation due to the phase shift of the harmonic current components relative to the similar harmonic voltage components is accompanied by a significant increase in the reactive component of the surge current compared to its active component. Losses of active power in the electric stock recuperating heat exchanger make up 83-87 % of the total power loss in the recuperating heat exchanger and in the overhead system. The reactive component of the equalizing current loads the transformers of the traction substations, therefore the voltage on the buses of the substation switchgear decreases. It is proposed to increase the voltage of the overhead system and the traction substation during the recuperation to maintain the minimum phase shift angle of the harmonic components of the non-sinusoidal current relative to the similar harmonic components in the overhead system.
Analysing oil and gas production facilities impact on atmospheric air of Potochnoye field
Authors: Almukhametova E M , Sitdikov R R , Zakirov A I
Published: February 2020

Environmental issues are always relevant. Nature is subject to constant human intervention. At the same time, associated institutions are being created to solve the tasks of reducing the level of harmful effects and the full restoration of environment. In this article, we assess the level of harmful emissions and wastes of oil and gas complex facilities during drilling, construction of facilities for field development and their operation, and present basic measures to reduce their impact on the air in Potochnoye field. We have examined the amount of emissions and waste from stationary and mobile sources. During wells drilling and facilities construction, the average annual evidence of pollutant emissions into the atmosphere caused by stationary sources will amount to 141.29 tons per year while the pollutant emissions caused by road and construction equipment and vehicles will be equal to 200.8 tons per year. Every year the amount of emissions into the atmosphere caused by the maintenance of the designed facilities will be 13730.9 tons per year, emissions from vehicles will be 47.1 tons per year. During field development, all work on the field should be carried out in compliance with the standards of the legislation of the Russian Federation. Having analyzed the amount of estimated emissions, a set of measures has been drawn up with the objective to reduce the impact of oil and gas complex on atmospheric air.
Verification of knowledge models by means of logic with vector semantics
Authors: Arshinskiy L V , Nitezhuk M S , Dunaev M P
Published: February 2020

The paper highlights the method of verification and identification of contradictions in the production knowledge bases using one class of logic with vector semantics, namely VTF-logic. The general verification algorithm is described. It is noted that the use of such logics, while maintaining the need to iterate over the input facts, offers a procedure of direct inference and analysis of the inconsistency only in the case of conclusions-hypotheses, characterized by the value of truth named “complete contradiction”. Tracing back the appropriate chain will identify and resolve the cause of the conflict.
Precision adjustment of electromagnetic emitter of large-scale systems such as GLONASS
Authors: Banshchikov A V , Daneev A V , Rusanov V A , Vetrov A A
Published: February 2020

The multidimensional nonlinear regression-tensor model is investigated in the substantiation of necessary and sufficient conditions for the optimal multi-factorial process of precision calibration of the parameters of the electromagnetic radiation source in the geostationary orbit (including the large-scale GLONASS system). A robust-adaptive strategy of a posteriori formation of the target functional of electromagnetic observability of a weighted-distributed signal in an established complex of stationary ground points is proposed on the basis of observations of this signal, made with a tolerance.
Application of geodetic devices for the operation of underground pipelines
Authors: Bikbulatova G G , Lyashko S V
Published: February 2020

The article deals with geodetic devices used for the operation of underground pipelines under the conditions of the northern territories of Russia. The electronic total station Trimble M3, the GPS-device Javad GPS Maxor and the pipeline locators Leica Digicat 650i and Ridgid SeekTech SR-20 are taken into consideration, and their characteristics and accuracy are analyzed.
Determining electromagnetic fields generated by overhead power transmission lines
Authors: Zakaryukin V P , Kryukov A V , Buyakova N V
Published: February 2020

Under actual operating conditions of electrical networks, it is hard to obtain experimental data that correspond to the maximum levels of the electromagnetic field strengths generated by overhead power transmission lines. Therefore, the analysis of the electromagnetic environment in electric power systems, both at the operated and newly created facilities, is recommended to be performed on the basis of mathematical modeling. The modeling methods and tools developed in IrGUPS and the Fazonord software package implemented on their basis make it possible, after determining the power system mode, to calculate the electromagnetic field strengths generated by multi-wire power transmission lines. In this case, the analyzed lines are considered in close connection with a complex electric power system. To check the adequacy of the simulation, measurements of electric and magnetic field strengths were performed, including comparative calculations for a 110 kV double-circuit line with a ground-wire located within the city. The comparison carried out in rather complex conditions is indicative of the correctness of the method of calculating a multi-wire line electromagnetic field developed in IrGUPS.
Search for additional criteria to estimate the electrical connection state under the impact of currents of different value
Authors: Ignatenko I V , Vlasenko S A
Published: February 2020

The paper reports on search for additional criteria to estimate the electrical connection state in the operating mode characterized by abrupt change in electric current parameters. The results obtained in the course of theoretical studies are based on the use of methods of mathematical and experimental modeling of thermal processes in electrical connections of a traction power supply system. New criteria for estimating the state of the electrical connection for cyclic traction load have been found out. Investigation of the defectiveness ratio in the “heating-cooling” cycle makes it possible to estimate the current state of the electrical connection under service conditions.
Experimental study of profile connections of auxiliary tool multi-purpose machines in cyclic loading
Authors: Ilyinykh V. A.
Published: February 2020

At present wide application in the machine tool industry has a professional connection with equiaxed circuit. These torque transmission connections have a number of operational advantages over traditionally used such as: high accuracy, stiffness, wear resistance, strength and vibration resistance. The practice of using these compounds in the critical nodes of metal-cutting machines in particular multi-purpose CNC machines has shown that these compounds have high flexibility in the requirements for reusable assemblies of the connection when replacing technological sets of tools. Experimental studies of these compounds of models made of optically active material allowed us to study the processes of contact interaction of parts of the compound under cyclic loading.
Study of the operation of high-frequency electrical plants of railway consumers
Authors: Pultyakov A V , Arsentiev O V , Kopanev M V , Alexeenko V A , Arsentiev G O , Shtykin E S
Published: February 2020

The article discusses the issues of improving the quality of electricity in the networks of nontraction railway consumers through the use of energy routers. Model studies of the electricity supply system of railways with high-frequency routers were carried out. Results have been obtained that allow using energy routers to supply electricity to plants of railway consumers with increased requirements for electric power quality. The article presents the results of the calculation of the high-frequency transformer and its experimental characteristics obtained in the study of high-frequency electrical plants of consumers.
Reactive power sources control in railroad power supply systems
Authors: Kryukov A V , Kutsyi A P , Cherepanov A V
Published: February 2020

This article presents computer modeling results for AC railroads power supply system modes. It considers various methods of connection of controlled reactive power sources (RPS). It is shown that the various problems of stabilizing the voltage levels in the traction network and reducing electrical energy losses can be solved. The computer-aided modeling indicates that to install RPS into all phases of traction substations is the best way to stabilize voltage levels in traction networks and reduce electrical energy losses. When the reactive power sources are present in the free phase, traction network losses increase in comparison with the option when the RPS are not present. The installation of sources in the retarding or leading phase allows stabilizing voltage in the load utilizing equipment, reducing losses and non-symmetry in supply mains. The best option in terms of electrical energy losses is connecting the RPS to the leading phase. In terms of non-symmetry in supply mains, the best performance is produced when the RPS are installed in the retarding phase.
Determination of the area of robust stability of the system with a PID controller
Authors: Kutsyi N N , Malanova T V , Kutsyi A P
Published: February 2020

An approach has been proposed to determine the area of change in the parameters of the controlled plant by the example of a system with PID controller. The search for ranges of parameter changes is based on the solution of the nonlinear programming problem, which is obtained as a conclusion of V.L. Kharitonov’s theorem on the robust stability of linear systems.
Applying information technologies to a bulldozer design
Authors: Leskovets I V
Published: February 2020

An analysis of the application of information technology in transport and technological machines is presented. The features of the use of information technology in the design and operation of transport equipment are given. The objectives of applying information technology at the stage of machine design are determined. The information model of the bulldozer is presented as the system comprising external environment – working equipment – caterpillar track - frame - transmission - engine - operator. A dynamic model of the bulldozer has been developed. Mathematical models of the elements of the dynamic model are presented. Also, characteristics are given which reflect the processes occurring during technological operations when using the bulldozer for carrying out excavation works. It has been established that the information model of the bulldozer makes it possible to obtain data to calculate loading of the bulldozer elements and to optimize selection of the best machine parameters at the stage of functional design.
Generation of a rational training sample when predicting power consumption for train traction
Authors: Osipova V.E. , Yakovlev D.A.
Published: February 2020

The paper considers peculiarities of forecasting in the field of railroad facilities based on approximation of time series and neural networks. The objects of traction power supply of the Transbaikal Railway are considered as the object of the study. Forecasting on the basis of approximation for consumers with maximum power consumption increases the accuracy of forecasting the electric energy consumption by 4…7%. The application of neural networks in forecasting of power consumption allows reducing the value of error to 2%, thus leading to significant reduction of costs for fuel and energy balance of a structural division or an enterprise as a whole.
Increasing efficiency of braking control algorithm for a two-wheeled motorcycle
Authors: Melnikov A S , Kim V A , Melnikov A A
Published: February 2020

The paper presents a new method for improving the efficiency of the braking control algorithm for a two-wheeled motorcycle. The method is based on the use of high quality information sources - direct measurement and analysis of forces in the wheel-road contact. The criterion for generating control signals by actuators is based on the negative sign of derivatives of lateral forces acting on wheels with respect to time. Experimental studies have shown that the negative sign of lateral force derivatives with respect to time determines side slip of wheels relative to the road surface. The consequence of the sideslip is loss of vehicle stability. The algorithm for generating vehicle control signals, which is based on the negative sign of the lateral force derivative with respect to time, is, to some extent, analogous to modern ESP systems (electronic stability control systems), which are currently being actively installed in two-wheeled vehicles (motorcycles).
Voltage regulation characteristics of a two-pack synchronous generator with combined excitation
Authors: Toporkov D M , Popov I L , Blinov A A , Kravchenko D P , Kovtun M A
Published: February 2020

The design, principle of operation, method for determining the inductance and the algorithm for plotting the voltage regulation characteristics of a two-packet synchronous generator with a combined excitation are described in this article. Characterization and inductance calculation were carried out for a prototype having a power of 11 kW, number of phases - 3, frequency of induced EMF in the AC winding - 550 Hz, number of pole pairs - 11.
Accuracy estimate of the paved surface of an automobile road after its reconstruction
Authors: Pronina L A , Kupreyeva E N
Published: February 2020

The article outlines the importance of engineering and geodetic survey during the reconstruction of automobile roads. The main phases of engineering and geodetic survey, such as the creation of a horizontal and vertical control, topographic plotting, technologies for the detailed staking of circular curves, and softwares for the execution of data processing, are taken into consideration. Possible tolerance limits in building and geodetic operations are reported. Research on the evenness of the upper surface of the asphaltic coating of an automobile road after its reconstruction is carried out.
Calculating the stress-strain state of connecting nodes in prefabricated structures from composite materials
Authors: Aleskovsky S L , Pykhalov A A , Lam Zyong Van
Published: February 2020

Annotation. The paper numerically studies adhesive-mechanical composite joints with metal and composite connecting elements (rivets and fasteners). The results of comparative experimental tests of metal and composite connectors are presented. The stress-strain state in various layers of composite plates reinforcing composite fibers and in an epoxy matrix is investigated.
Methods and algorithms of development of a CAD system to design automated process control systems in the transport sector
Authors: Sachkov D I , Dimov A V , Upyr R U
Published: February 2020

The article considers questions of creation of an intelligent CAD (Computer-Aided Design) system to design APCS (Automated Process Control System) in the transport sector. The CAD system should represent a graphic 2D engine adapted for the solution of problems of design of APCS, surrounded with an information support cloud in the form of a set of relational databases of the engineering information necessary for effective and error-free work of the APCS designers. Programs of processing information that appears on drawings, schemes and tables of the APCS projects on the basis of the algorithms adopted in this subject domain should become an essential part of information support. A CAD system should be equipped with artificial intelligence programs for processing and sorting of external information and search of mistakes in the project.