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scientific edition of Bauman MSTUSCIENCE & EDUCATIONBauman Moscow State Technical University. El № FS 77  48211. ISSN 19940408
# 05, May 2014
Machine Building and Engineering Science
Study Fidelity Spatial Contours of Industrial Robots
# 05, May 2014 DOI: 10.7463/0514.0709548 The paper presents the research results of fidelity spatial contours done by Fanuc M710iC/50 industrial robot when moving along a predetermined path. The proposed method uses a QC20W ballbar wireless system of Renishaw company, designed to diagnose the state of the measurement and playback linear and angular displacements of the CNC. The solutions to adapt the QC20W ballbar system to the constructive peculiarities of industrial robots with five or more independently controlled axes are presented. The stages of the preparation of diagnostic systems and software robot movements are described. According to study results of errors that arise while playing back the programmed motions of a fixed point of robot capture in three mutually perpendicular planes its practiсal accuracy has been defined when performing movements in a given region of the working area, thereby allowing us, eventually, to draw a conclusion on the possibility to use a robot in one technological process or another.
Constructional Material Processing in Machine Building
The Provement of the Conditions of End Mill Operation in External Panels of the Aluminum Alloys
# 05, May 2014 DOI: 10.7463/0514.0709770 We have worked out the calculation procedure of cutting force and contact pressures between the back surface of tool tooth and aluminum alloy component used for mill operation with endmilling cutter. This force calculation includes the aluminum alloy softening under the impact of cutting temperature. The calculated force figures and figures of contact pressures on the back surface of tool tooth are used for evaluation of the bottom strain and deformation appearing while digging and pocket mill operation inside the external panel of aluminum alloy. The cutting techniques and mill operation conditions have been also approved. The testing of the research results held within the processing the mill operation technologies of the external panels in manufacturing environment has also been carried out
Unbalanced Heat Isolation in HighFrequency Electrothermics of Polymers
# 05, May 2014 DOI: 10.7463/0514.0709325 The article describes a mathematical simulation of high frequency (HF) electrothermic of thermoplastics to be applied to a technological system in the form of the fivelayer plate, including electrodes, insulators, processed material and studies the influence of heat insulation on the thermoplastic heating. The article presents a mathematical model in the form of a system of nonstationary heat transfer considering the internal heat sources with different boundary conditions and the software to implement it. The software offered in the article enables to study the mutual influence of geometrical and electrophysical parameters of technological systems of HF thermoplastic heating. Based on the calculations presented in numerical and graphic form, the following areas of heating polymer are identified: uniform heating, regional zones of thermal influence of insulators. The article provides the research results of influence of different thickness heat insulation on the distribution of temperature field of thermoplastic. It is determined that one can shift the zone of maximum heating polymer modifying the parameters of insulating layers, thus allowing to improve the welding quality of polymeric items. According to research results, the conclusion has been drawn up that it is desirable to develop a technological process of electrothermal welding of polymers with the possibility for displacement of the zone of maximum heating (melting) polymer due to changing heat insulation thickness. The developed software allows a new approach to study the HFheating modes and have solution of practical tasks for improving the quality of welded joints of parts from thermoplastics.
Plasma Powder Coating of Rods of Hydraulic Cylinders with White Wear Resistance Cast Iron
# 05, May 2014 DOI: 10.7463/0514.0709302 The article considers the features to form a structure and properties of FeCCrV system coverings provided by the plasma and powder coating on the low carbon steel. It is shown that it is possible to restore a rod of hydraulic cylinders of small diameter by the plasma and powder coating. Thus, to avoid buckling and provide the builtup metal structure with the best wear resistance it is necessary to find a reasonable approach to a choice of the operation conditions to provide coating. The paper offers a way for efficient control of heat input at coating and a superheat value of the welding bath. It is noted that the coverings, which have been built up at the smallest heat input in a substrate, possess the best wear resistance, with a fusion zone formed with an austenitic crystallization interlayer.
Transportation, Mining and Construction Machine Building
The Mathematical Model of Gear Shifting in a Tractor Gearbox
# 05, May 2014 DOI: 10.7463/0514.0711329 A developed universal mathematical model to accelerate a tractor unit (TU) at gear shifting in the gearbox (GB) with different overlaps and at TU acceleration from rest, for different options of friction clutches (FC) installation on the shafts in the GB allows defining  at the designing stage of GB with FC  their work and slipping time and the acceleration time of a TU which may lead to designing the reliable friction clutches and gearboxes with friction clutches. The proposed calculation method of the work of the friction clutch slipping in the gearbox at bench tests allows transferring test results into the operation loading mode, and, therefore, to perform finetuning of gearboxes with friction clutches at bench tests.
Calculating the Spectral Density of the Loading Moment on the Working Body of the Deep Milling Machine at the Design Stage
# 05, May 2014 DOI: 10.7463/0514.0709758 The paper proposes a model to form the torque on the working body of the deep milling machine in the interaction with the soil and with the forestbush vegetation growing on the surface, its root system. The load is presented as a sequence of pulses with random parameters and complex structure. The developed approach enables us to determine the spectral density of the loading moment on the milling cutter taking into account the operation conditions, its structure, physical and mechanical properties of soils, and probabilistic characteristics of random operation conditions at the design stage. Probabilistic characteristics of the moment on a cutter are initial information for the analysis of dynamic loads in the drive elements of deep milling machine at the design stage.
A Development of the Distributive Law of Points on the MultiWheeled Machine Wheels with ElectroMechanical Transmission, Made Under the Scheme "MotorAxis"
# 05, May 2014 DOI: 10.7463/0514.0705516 Currently, developers of multiwheeled vehicles (MWV) show growing interest in an electromechanical drive in the «motoraxis»implementation. However, in designing such types of traction electric drive (TED) the problems arise, mainly, from a lack of creating experience and of ready algorithmic solutions to control the traction motors. Methods for implementing the individual TED cannot be used because of the crossaxle differential available in the leading axle drive, which does not enable the input torque control of each wheel singly. The paper offers a law to control a traction electric drive of MWV leading axles that includes the law to control the traction and braking torques on the leading axles as well as algorithms of antilock brake and traction control systems.Simulation methods of mathematical modeling have proven efficiency and effectiveness of the proposed control law, when performing MWV maneuvers. Research results can be useful for companies in automotive industry, which, first of all, deal with design and manufacturing of special multiwheeled vehicles of various classes and purposes, as well as for institutions, which develop control systems for wheeled transport equipment.
Aeronautical and Rocket Space Engineering
The Mathematical Model of Thread Unrolling from a Bobbin
# 05, May 2014 DOI: 10.7463/0514.0704634 The paper describes a mathematical model for simulating a flexible thread unrolling from a bobbin. The real kinematics of unrolling is considered, but the problem of contact between the thread and bobbin is avoided. This results in great reduction of model «stiffness». The model has a constant dimension thereby simplifying the algorithm. The feature of this model is that there is no need to have many nodes on one thread turn to ensure stability and convergence. This model is tested by the simplified problem of Heliogyro solar sail deploying. From simulation results it is clear that a transversal motion of solar sail is almost independent on simulation model parameters, i.e. the model convergence.
Instrument Engineering, Metrology and InformationMeasuring Devices and Systems
Development of Methods and Means to Improve a Performance of Microprocessor Shock Sensors for Car Alarms
# 05, May 2014 DOI: 10.7463/0514.0709342 Existing shock sensors for car protection using the sensitive elements (SE) of piezoelectric, microphone and electromagnetic types and the analogue circuits of signal processing, have a number of essential shortcomings, such as "false" operations, instable temperature characteristics, nonlinear adjusting characteristic, and inconvenient control via variable resistors. The article considers issues to design the twozone digital shock sensors with a SE of electromagnetic type. It offers a SE design, a circuitry solution, and algorithms of signal processing, which allow a remote control of prevention and alarm zones (with 16 gradations of sensitivity) and an algorithm for selfadapting to repeating external impacts. The method has been developed to form the basic levels of digital comparators for each gradation of sensitivity. Using this method enables the sensor to have the straightline adjusting characteristic. Prospects for using the 3axial micromechanical accelerometers as a SE of the shock sensors are proved.
Radio Engineering and Communication
A Novel Approach for SpaceTemporal Analysis of Tapered Slot Antennas
# 05, May 2014 DOI: 10.7463/0514.0710740 The paper presents a novel method for tapered slot antennas analysis in time domain. The method is based on «twostep» approximation, including both the radiating slot longitudinal segmentation and the fullwave model for each slot segment. Segment radiation is approximated using Green’s function for magnetic source on a conducting halfplane. Exploited earlier, mainly, for frequencydomain analysis of electrically long antennas, the method presented in this paper has been improved to apply it in analysis of arbitrary antenna shape. For the first time, timedomain antenna parameters were calculated using such approach for test geometries. Attained results have given evidence that the method is of high accuracy.
Informatics, Computer Science and Management
A Scale for Estimating the Ergonomics of Information Display Methods
# 05, May 2014 DOI: 10.7463/0514.0711864 The article offers a new scale for estimating the ergonomics of information display methods. Such methods are utilized in automated control and information processing systems. Special attention was paid to a smart housetype class of systems. This scale contains six points and allows one to estimate two aspects of the ergonomics i.e. usability and involvement. An empirical study to confirm reliability and high sensitivity of the proposed scale was carried out. The reliability was evaluated using a Cronbach’s coefficient while the analysisofvariance methods were used to estimate sensitivity.
A Mathematical Model of Urban Distribution ElectroNetwork Considering Its Future Development
# 05, May 2014 DOI: 10.7463/0514.0709781 The paper aims to present a developed mathematical model of the distribution urban power supply network taking into account its future development. Based on this model the task is set to optimize the prospective power supply network development through the solving a problem of multicriteria structural and parametrical optimization. Expediency is proved to use a method of reduction to the onecriteria task, which represents a problem of continuousdiscreteinteger programming to solve this task. Representation of this task is proved as a problem of discrete programming based on the discrete approximation of possible regions to construct new transforming and distributional substations.
The Comparison of Methods for Genetic and Variational Genetic Programming Using a Control Synthesis Problem for the Model "PredatorVictim" as an Example
# 05, May 2014 DOI: 10.7463/0514.0709252 The paper compares two methods of symbolic regression, namely a method of genetic programming and a variational method of genetic programming. The comparison is based on the computing experiment, which solves a problem of control system synthesis for a model of nonlinear control object, describing the interaction of the two systems i.e. "predator" and "victim". For the purity of the experiment the genetic algorithms parameters in both methods were identical. For variational genetic programming there was selected a trivial basic solution in the form of the sum of input variables products for custom settings. This basic solution is always chosen with a lack of meaningful task analysis. The methods are compared both in terms of the speed for problem solving and in terms of the quality of the achieved control.
Rational Orderliness of Study Course Modules
# 05, May 2014 DOI: 10.7463/0514.0710096 This paper considers the problem of appropriate orderliness of the electronic course modules. To solve this problem, we use the information that is specified by the structure of expert preferences or hypertext structure using a set of modules. For expert structure processing the theory of binary relations is applied. We propose a mathematical model to process the strongly linked fragments of expert structure. This model is based on a partition of a set of modules into tolerance classes. The task of searching an ordinal approximation of the hypertext structure is reduced to a problem of the least coverage matrix.
Mechanics
Study of Influence of Climber Motion on the Space Elevator Dynamics
# 05, May 2014 DOI: 10.7463/0514.0710704 This work studies dynamics of the space elevator taking into account the effect of climber motion. The motion occurs in a gravitational field of the Earth. The tether is considered as a pair of inelastic inextensible bars with variable length and area of crosssections. The climber consists of two cylinders that are connected by a strap, and a payload, that is considered as a material point. A mathematical model of the space elevator is developed. It is shown that steady lifting of the climber leads to swinging of the space elevator. A control torque providing steady lifting of the payload is obtained. An effect of the payload mass on the amplitude of the space elevator oscillation is studied. It is shown that an increasing payload mass leads to the growing amplitude of the space elevator oscillations.
The Study on StressStrain State of the Spring at High Temperature Using ABAQUS
# 05, May 2014 DOI: 10.7463/0514.0710723 This article presents the basic theory of helical spring, gives the stress formulas of each component in the cross section of spring, compares the analytical study with the simulation results, which are created using ABAQUS program. The research description presents a distribution and character of stress contour lines in the cross section of spring under the instantaneous load, explicates the relaxation law with time. The paper studies a relaxation phenomenon of stress. A finite element model for stress analysis is created to analyze the stress distribution of creep at high temperature. The article analyzes the change law of creep stress with time under constant load and at a fixed value of compression.
About Tensor  Nonlinear Model of Plastic Materials, Which Takes into Account Changes in the Structure of the Dissipative and Its SelfOrganization
# 05, May 2014 DOI: 10.7463/0514.0709269 The model proposed earlier, you were not able to accurately reflect the properties of aluminium and other alloys, different anomalous behavior of the transverse coefficient of deformation. These alloys attract the attention of many scientists who provide strong evidence of the fact that internal processes include the mechanism of "selfhealing " defects. The purpose of this work is to improve the dilating plastic material model. For a description of dilatancy, as the additional components of the volumetric strain and medium voltage found other equations. It is shown that in the selforganization patterns intense growth in the number of internal connections at decrease in volume strains. This explains the mentioned peculiarity and the possibility of "running neck" at high lead levels.
Equipment and methods of experimental physics
Experimental Investigation of Heterogeneous Power Systems on the Basis of Lyophobic Liquids and Porous Media
# 05, May 2014 DOI: 10.7463/0514.0711242 A mathematical model of the liquid flow in heterogeneous systems is developed. Heterogeneous systems consist of a porous body with the pore size from 20 nm to 360 nm and a lyophobic (nonwetting) liquid. The paper represents theoretical basics to describe a hysteresis of liquid filling and outflow processes from the pores under the pressure gradient, and also with no liquid outflow after reducing a pressure in the system to the atmospheric value under static and dynamic loads. The paper presents experimentally investigated and calculated results of the energy characteristics of models of the heterogeneous dissipation and accumulating devices of mechanical energy developed on the basis of abovementioned effects.
Electrical Engineering
A Development of the Direct Lyapunov Method for the Analysis of Transient Stability of a System of Synchronous Generators Based on the Determination of Non Stable Equilibria on a Multidimensional Sphere
# 05, May 2014 DOI: 10.7463/0514.0712062 We propose a method for determining the nonstable equilibria on a multidimensional sphere that can be used for the analysis of dynamical stability by the direct Lyapunov method, which, in turn, is used to control a system of synchronous generators. Our method is based on finding an extremum (a minimum) of Lyapunov function on a multidimensional sphere the center of which is a stable equilibrium. The radius of the sphere is enlarged until a nonstable equilibrium (a saddle point) appears. This allows to compute the critical value of Lyapunov function and to estimate the reserve stability. For the analysis of transient stability we use the Lyapunov function of energy type. The proposed method diminishes the computational expenses and improves reliability of the estimation of reserve transient stability of synchronous generators
MultiComponent Electrode Systems in GeoElectric Field Intensity Sensors for Moving Carriers
# 05, May 2014 DOI: 10.7463/0514.0710552 The paper considers two and three component electrode systems in contact electric field sensors. The design of electrode systems optimally meets the requirements for devices to be set on mobile platforms for specific needs. Electrode systems are characterized by minimum of electrodes used: the number of electrodes outnumbers the registered components of the electric field vector by one. Nearly identical flow conditions in the vicinity of electrodes, geometric symmetry of the electrode system, and electric symmetry of measuring channels are provided. The analytical expressions for the elements of the equivalent circuit of the sensor are obtained, and the preprocessing circuits of useful signals are offered.
Research of the Multipolar Induction Traction Frequency Regulated Motor
# 05, May 2014 DOI: 10.7463/0514.0709521 The paper considers the application features of traction induction electric motors in transmissions of vehicles. It shows that one of important stages in their designing is to choose the number of poles. The analysis of the initial multipolar traction induction motor is given as a part of the traction electric drive. The paper presents results of its simulation characteristics in the structure with vector control and estimates their compliance with the given traction characteristic. It is established that because of increased alternating frequency of currents in the range of high speeds there is an excessive decrease in the torque and the requirement for constancy of the target capacity, corresponding to the typical traction characteristic is not fulfilled. Given calculation results of electromagnetic field distribution in a groove of the engine stator are used to establish a substantial growth of additional losses in the engine, and an extent of flow loss because of damping actions of eddy currents in the laminated steel of stator at increased frequencies is estimated. The traction induction motor alternative with the improved characteristics is proved.
Power Engineering
Detonation Wave Parameters in a Variable Cross Section Channel in Gas Mixture of Methane with Oxygen and Nitrogen
# 05, May 2014 DOI: 10.7463/0614.0712204 Propagation of the detonation wave in gas mixtures of methane with oxygen in a channel of variable cross section was studied experimentally. Detonation initiation was carried out by spark gap. Deflagrationtodetonation transition was occurred. A composition of the mixtures was selected in such a way that the detonation cell width was several times smaller than the diameter of the channel. The waves velocities and peak pressures at the front of the detonation wave were measured depending on the mixture composition, including a presence of nitrogen. The sizes of the detonation cells were measured using smoked foil mounted inside the channel. The effect of the interference of the shock waves in a conical section was studied. Diagrams of the shock waves, flame fronts, and detonation waves in the combustion chamber depending on the mixture composition are presented.
Investigation of the Helium Proportion Influence on the Prandtl Number Value of Gas Mixtures
# 05, May 2014 DOI: 10.7463/0514.0710811 The paper investigates an influence of helium fraction on the Prandtl number value for various gas mixtures. It is shown that a low value of the Prandtl number allows us to raise efficiency of gasdynamic energy separation in Leontyev's tube. The paper conducts a numerical research of the influence of gas mixture composition on the Prandtl number value, and verifies the calculation procedure, using the known experimental data and calculation results of other authors. It is shown that there are binary mixtures of the "light" and "heavy" gases, possessing abnormally low value of the Prandtl number, and the used calculation procedure allows correct calculation of their thermophysical properties.
Yield Surface Investigation of Alloys During Model Disk Spin Tests
# 05, May 2014 DOI: 10.7463/0514.0710005 Disks of gasturbine engine are high loaded parts of irregular shape having intensive stress concentrators wherein 3D stress strain state occurs. The loss of loadcarrying capability or burst of disk can lead to accident or disaster. Therefore, development of methods to assess deformations and to predict burst is one of the critical goals. The article presents results of quasistatic numerical simulation of spin tests of model disk made from hightemperature forged alloy. To determine stressstrain state of disk during loading finite element analysis is used. Simulation of elasticplastic strain fields was carried out using the incremental theory of plasticity with isotropic hardening. V.Mises and Tresca yield criteria impact on the model sensitivity was investigated. To identify the material model parameters the eddy current sensors were used in the experimental approach to measure rim radial displacements during the loadunload of spin test. The results of calculations made using different parameters of material model were compared with the experimental results.
Metallurgical Engineering
Laws of Alloyed Cementite Particles Nucleation During HeatResistant Steels Carburizing
# 05, May 2014 DOI: 10.7463/0514.0710529 The article uses numerical experiments to verify a previously hypothesized mechanism of dislocation nucleation particles of chromium alloyed cementite during a process of carburizing heatresistant steels, which contain, at least, 3 % chromium. It is shown that alloyed cementite particle nucleation occurs on the chromium and carbon concentration fluctuations in dislocations, thus eliminating the formation of cementite lattice. The proposed mechanism of nucleation explains the origin of the lattice formation when introducing a significant amount of nickel into steel and increasing the process temperature. The guidelines to choose the optimal parameters of carburized layers for hotresistant steels, which contain nickel of 3% have been developed.
Porosity Design Procedure at the Directed Solidification of Castings
# 05, May 2014 DOI: 10.7463/0514.0709914 A series of special experiments using castings of the simple configuration (slabs and bars) defines a value of the feeding zone of a butt end and makes it out as the regressional dependences of the feeding butt end zone on the characteristic sizes of this or that casting. Thus, considerable material and time expenditures are demanded to define the value of the feeding butt end zone to be used further, including calculation of directional solidification of castings. The paper offers a design procedure to calculate a zone of the feeding butt end via computing simulation of solidification in the casting mould thereby sharply reducing expenditures for searching the desirable values. To reveal spaces in the casting, staggered with shrinkable porosity, the new criteria of porosity developed in BMSTU are used. The paper shows a possibility to use the effective size as a characteristic parameter of casting for the regressional dependence of the feeding butt end zone thus providing this dependence universality and a possibility to use it for making any shaped casting, but not just the castings of a simple configuration.
Documentary Data
Standard Symbols for Books, Journals, and Newspapers Through the Use of Barcode
# 05, May 2014 Barcode is the most applied technology in automatic identification. Barcode reminds of zebra with dark and light strips of different weight. It is very interesting that the first three positions of barcode have the indicia 978 for books and 977 for journals.
Appendix General Problems of Engineer Education
From a SchoolLeaver to a Lieutenant: Some Aspects of Officers’ Training S’ in the BMSTU Military Training Center
# 05, May 2014 In 2007 a new stage in training of officers began in BMSTU. As an experiment, 25 fresh students were accepted to study in the newly established training military center of the Military Faculty by officers’ training programs to become the career officers. The University has never trained career officers before, but an accumulated experience allowed to meet the challenge at all stages of its solution. First of all, a different approach to the enrolment was used. Secondly, the educational process for the cadets, who receive both the civil specialties and the military ones, was reorganized. Finally, the first graduates holding the rank of lieutenants were in 2013. Some of them went to serve in the Armed Forces of the RF. Now this training program launched as an experiment in 2007 continues on a regular basis. A new group of cadets is going to enter the training military center in the summer 2014.
Foreign Education
JAPAN: Comprehensive Food Textbooks Planned
# 05, May 2014 The education ministry has decided to distribute textbooks on food and nutrition to primary, middle and high school students from fiscal 2016, according to ministry sources.The move is intended to enhance school education regarding food and nutrition, a ministry official said.The Education, Culture, Sports, Science and Technology Ministry will shortly set up a panel comprising academics and nutrition teachers to produce comprehensive, crosscurricular textbooks that cover topics ranging from the importance of food and table manners to food culture.
Canadian Bschools Ranked Among World’s Best in Programs for Executives
# 05, May 2014 Six Canadian business schools – one of them new to the list – have made the Financial Times’ annual global ranking of executive education programs that cater to companies and individuals.Led by the University of Toronto’s Rotman School of Management, Canadian schools made the FT’s top70 global list of open enrolment programs (nondegree training for professionals from a crosssection of companies) and the top80 list of customized programs that are tailored for an individual company.



