The paper presents investigation results pertaining to the influence of such parameters as plasma jet (current, spraying distance, expenditure of plasma-forming gas – nitrogen), fraction composition of an initial powder and cooling rate with compressed air on characteristics of anti-meteoritic coatings. Due to simplicity of the apparatus design and its tangible efficiency a method of plasma spraying in aerial environment is mainly used presently for application of ceramic layer on the basis of partial stabilized zirconium dioxide. The main peculiar feature of plasma anti-meteoritic coating structure is formation of some controlled porosity in order to increase permissible deformations in ceramics. The idea to create structures with controlled porosity is based on the fact that porous bodies are less liable to macroscopic scattering of cracks under the action of internal stresses due to slowing-down or deviation of an extending crack by pores and also due to low elasticity modulus of porous materials in comparison with compact ones.

Methodology of the executed research works has been based on complex metallographic, X-ray and electronic and microscopic investigations of anti-meteoritic coatings on the basis of zirconium dioxide.

In order to ensure high impact strength the structure of anti-meteoritic coatings on the basis of zirconium dioxide should contain more than 90 % of tetragonal phase of zirconium dioxide and not less than 10 % of monoclinic phase. In this case phase composition and impact strength of coatings depend on chemical composition and production method of the powder. Optimization of parameters for spraying anti-meteoritic coatings based on zirconium dioxide has been carried out according to obtaining maximum coefficient of material usage and maximum content of tetragonal phase of zirconium dioxide in the sprayed coatings.

FEM-analysis of dynamics in the bearing system of a heavy-duty machine tool has been carried out in the paper. This is a prospective variant for a large-size multi-purpose machine tool with a horizontal sliding ram. A saddle and a ram are moving vertically along a subtle mono-column. A rigid double-column is used in the existing analog machine tool. A static, modal and harmonic analysis of the bearing system with the mono-column has been made in the paper. It has been done with the help of FEM-simulation prior to fabrication of a prototype sample. Previously conducted calculations for the analog machine tool have shown good compatibility of FEM-calculation with experiments.

Six common machine tool resonances have been revealed for the bearing system. Their oscillating cutting forces are actively exciting three-four resonance modes. Ranges of a flexure-torsion resonance (20–40 Hz) and nose-diving resonances (70–90 Hz) have been determined in the paper. The paper shows that the range of multi-wave resonances starts significantly higher from 140 Hz. These resonances are interconnected with bending oscillations of the ram and bucklings of the column walls which are matched with the oscillations. The paper demonstrates stability in resonance pattern. The torsional resonance of the column on the frequency of nearly 40 Hz is considered as the more dangerous one. Spindle rigidity goes down up to 3.8 Н/μm. It is possible to observe self-stabilization of the torsional resonance. Frequency of the torsional oscillations is practically unchangeable when there is a lifting or lowering down of the saddle and the ram. It is related to the migration of dynamical axis of torsion.

Frequency-response characteristics of the bearing system have been constructed for various saddle positions on the column. Three frequency intervals that make it possible to carry out machining operation have been determined in the paper. The first interval is a static one. The machine tool with a mono-column comes short of the analog machine tool in this interval. The main reason of it is low static rigidity of the subtle column. The second interval is narrow and it is located between flexure-torsion and nose-diving resonances. The third interval is considered as the most efficient one. The interval contains a section of inter-range pause between general machine tool and multi-wave resonances. In this case it is possible to observe a significant increase of the dynamic rigidity on the spindle that compensates the column subtility. High potential of the dynamic rigidity has been revealed in the direction of the ram axis (>2000 Н/μm). The paper shows liability of the machine tool to displacement crossings during oscillations. Peculiar features of this effect have been discussed in the paper. The diagram with a mono-column is recommended for practical application. The main condition is a transition to high-speed drive within the framework of concept on high-speed machining. It is necessary to ensure rigidity of the axial feed drive system.

The paper considers a process of turning structural steel with asymmetric tool vibrations directed along feeding. Asymmetric vibrations characterized by asymmetry coefficient of vibration cycle, their frequency and amplitude are additionally transferred to the tool in the turning process with the purpose to crush chips. Conditions of stable chip breaking and obtaining optimum dimensions of chip elements have been determined in the paper. In order to reduce a negative impact of the vibration amplitude on a cutting process and quality of the machined surfaces machining must be carried out with its minimum value. In this case certain ratio of the tool vibration frequency to the work-piece rotation speed has been ensured in the paper. A formula has been obtained for calculation of this ratio with due account of the expected length of chip elements and coefficient of vibration cycle asymmetry.

Influence of the asymmetric coefficient of the tool vibration cycle on roughness of the machined surfaces and cutting tool wear has been determined in the paper. According to the results pertaining to machining of work-pieces made of 45 and ШХ15 steel the paper presents mathematical relationships of machined surface roughness with cutting modes and asymmetry coefficient of tool vibration cycle. Tool feeding being one of the cutting modes exerts the most significant impact on the roughness value and increase of the tool feeding entails increase in roughness. Reduction in coefficient of vibration cycle asymmetry contributes to surface roughness reduction. However, the cutting tool wear occurs more intensive. Coefficient of the vibration cycle asymmetry must be increased in order to reduce wear rate. Therefore, the choice of the coefficient of the vibration cycle asymmetry is based on the parameters of surface roughness which must be obtained after machining and intensity of tool wear rate.

The paper considers a process of turning structural steel with asymmetric tool vibrations directed along feeding. Asymmetric vibrations characterized by asymmetry coefficient of vibration cycle, their frequency and amplitude are additionally transferred to the tool in the turning process with the purpose to crush chips. Conditions of stable chip breaking and obtaining optimum dimensions of chip elements have been determined in the paper. In order to reduce a negative impact of the vibration amplitude on a cutting process and quality of the machined surfaces machining must be carried out with its minimum value. In this case certain ratio of the tool vibration frequency to the work-piece rotation speed has been ensured in the paper. A formula has been obtained for calculation of this ratio with due account of the expected length of chip elements and coefficient of vibration cycle asymmetry.

Influence of the asymmetric coefficient of the tool vibration cycle on roughness of the machined surfaces and cutting tool wear has been determined in the paper. According to the results pertaining to machining of work-pieces made of 45 and ШХ15 steel the paper presents mathematical relationships of machined surface roughness with cutting modes and asymmetry coefficient of tool vibration cycle. Tool feeding being one of the cutting modes exerts the most significant impact on the roughness value and increase of the tool feeding entails increase in roughness. Reduction in coefficient of vibration cycle asymmetry contributes to surface roughness reduction. However, the cutting tool wear occurs more intensive. Coefficient of the vibration cycle asymmetry must be increased in order to reduce wear rate. Therefore, the choice of the coefficient of the vibration cycle asymmetry is based on the parameters of surface roughness which must be obtained after machining and intensity of tool wear rate.

An analysis of main design parameters that determine a level of droplet formation intensity at the generating stage of plasma flow has been given in the paper. The paper considers the most widely used designs of water cooled consumable cathodes. Ti or Ti–Si and Fe–Cr alloys have been taken as a material for cathodes. The following calculated data: average ionic charge Z_i for titanium plasma +1.6; for «titanium–silicon plasma» +1.2, an electronic discharge 1.6022 ⋅ 10^–19 C, an ion velocity v_i = 2 ⋅ 10⁴ m/s, an effective volt energy equivalent of heat flow diverted in the cathode U_к = 12 V, temperature of erosion cathode surface Т_п = 550 К; temperature of the cooled cathode surface Т_о = 350 К have been accepted in order to determine dependence of a maximum admissible arc discharge current on cathode height. The calculations have been carried out for various values of the cathode heights h_к (from 0.02 to 0.05 m). Diameter of a target cathode is equal to 0.08 m for a majority of technological plasma devices, therefore, the area of the erosion surface is S = 0.005 m².

A thickness selection for a consumable target cathode part in the vacuum arc plasma source has been justified in the paper. The thickness ensures formation of minimum drop phase in the plasma flow during arc cathode material evaporation. It has been shown that a maximum admissible current of an arc discharge is practically equal to the minimum current of stable arcing when thickness of the consumable cathode part is equal to 0.05 m. The admissible discharge current can be rather significant and ensure high productivity during coating process with formation of relatively low amount of droplet phase in the coating at small values of h_к.

The paper presents results of experimental investigations on determination of pressure force of power fluid-jet stream on plane surfaces of specimens having various shape. The results permit efficiently to realize a number of technological processes which directly depend on quality of surface cleaning from corrosion. A principle diagram has been developed for a dynamometer in order to measure a force F acting on the machined specimen with measuring range from 0 to 50 N and an error which constitutes 2 % of maximum value of the measured load. Two diagrams for jet stream flow after its interaction with the specimen have been proposed for a comparative analysis while measuring force F, namely: radial fluid spreading at angle β = 90° and reversible stream flow due to one-eighty stream turn after its interaction with plane surface of the specimen. Methodology has been established for registration of force F on plane specimens having various shape. Pressure at the nozzle input р_вх,i and distance L_i from the nozzle to the machined surface of the specimen have been taken as variable parameters for both loading diagrams (β = 90° and 180°).

Investigation results have made it possible to determine that usage of reversible stream flow ensures maximum force action on plane surface of the specimen in the investigated range of pressures р_вх = 3.5–10.0 MPa and distances from nozzle to the machined surface L = 8–30 mm. In this case maximum action force (irrespective of pressure at input р_вх and distance from nozzle to the machined surface L) is observed at stream squeezing ratio λ = 0.063 and this effect is attributed to optimum ratio of cavity diameter D0 and stream diameter d_cтр. The obtained results allow reasonably to select pump equipment and efficiently execute technology for cleaning plane surfaces from corrosion with due account of stream squeezing ratio λ which is taken as a criterion.

Road traffic with its share from 2/3 to 3/4 of the total volume of transport service represents rather large and complicated social and production system with several subsystems that include roads, transport facilities, road traffic organization, law enforcement, personnel training, road traffic service and others. Road traffic quality can be quantitatively evaluated in accordance with values of losses pertaining to social and economic cost of discretionary (unenforced) expenses for road traffic process. Road traffic contains accident, ecological, economic and social risks. Accidence is considered as the most important risk for participants involved in road traffic because it directly concerns their life, health and welfare. So accident response has rather high social significance and it is considered as a matter of national importance. In this connection role of road traffic organization has become very important and it is directed on improvement of its quality including security in the accident clusters.

Methodological principles for improvement of road traffic quality have been developed in the paper. These principles presuppose the following: maximization of danger while selecting investigation object; minimization of total losses while evaluating quality and selecting solutions on improvement in road traffic safety; balanced accountability of accidental and ecological losses while selecting solutions on higher road traffic safety in ambiguous situations; minimization of total cost pertaining to object operation while selecting measures on improvement of road traffic safety; obligatory operative control evaluation of accidence on the basis of method for conflict situations while introducing measures of road traffic safety. Such approaches will contribute to higher quality of the decisions taken in the field of road traffic organization.

Methodology for determination of optimum setting parameters for technological equipment that ensure the prescribed accuracy of a work-piece at the preliminary machining stage under conditions of free rubbing has been developed in the paper. The paper describes a scheme for dividing lens surface into elementary sites. The so called reference points are accepted in the centre of the sites and ways of their friction are calculated which are directly-proportional connected with intensity of metal envelope removal under machining conditions using free rubbing method. Methodology for determination of range in length change of line mark during tool oscillatory motion has been proposed and analytical expressions for calculation of this range for every specific case have been obtained in the paper. The paper contains calculation of friction ways in reference points of lens diametrical cross-section for various combinations of such setting parameters of technological equipment to ensure simultaneous lens processing as length of mark line during tool oscillatory motion, rotation frequency of a lens and an input element in an executing mechanism of a machine tool, tool diameter and ratio of its frequency rotation to lens frequency rotation.

The paper shows that if control over the shaping process is executed through regulation of rotation frequency of the lens and the input element in the machine tool executing mechanism then unacceptable accuracy of the machined surface is obtained in case of their equal values. The highest accuracy of the machined surface can be reached while regulating ratio value of tool and lens rotation in combination with the change of tool diameter. Experimental investigations on polishing of lens convex surface have been carried out and they correlate with theoretical calculations. Such method of investigations as a mathematical simulation of technological equipment operational zone for processing highly-accurate spherical surfaces under conditions of free rubbing has been used in the paper.

The paper considers existing qualitative indices of transport services. Indices for evaluation of qualitative operation indices of transport complex have been proposed in the paper. Special attention has been devoted to interaction and coordination of various types of transport as the highest level of qualitative operation of transport complexes. Operational coordination of transport facilities is considered as introduction of modern management, information and communication systems while using satellite navigation-information systems. The paper has studied the possibility to create a modern automated management system for transport complex at the Ministry of Transport of the Russian Federation that ensures an efficient organization of standardized information exchange between transport complex participants.

The paper provides efficient solutions on transport problems that lead to planned improvements of objective indices with small expenses. A special focus has been given to development of transport systems in large cities with the purpose to reveal their impact on operation of the national transport complex. The paper considers conceptual moments pertaining to designing and realization of an intellectual management system and creation of complex conditions that ensure maximally efficient transport management on city territory.

The main purpose of transport infrastructure modernization in accordance with its types is to create modern efficient transport facilities and equipment for provision of technological infrastructure required for the system of objects included in the transport infrastructure. The modernization strategy must be governed by national policy in the field of any transport and in accordance with international development tendencies in transport industry and transport construction. In this respect the transport infrastructure is the very first consumer of innovative high technologies that determine scientific-andtechnological advance and competitive ability of national economy.

Nowadays the work is in progress to develop wheeled and caterpillar tractors with electromechanical transmission. Range of changes in transmission gear ratio while using propulsion electric motor depends on mechanical characteristics of a tractor propulsion electric motor which is equipped with electromechanical transmission. In case when the range is rather high then it is possible to minimize number of gearings in the tractor gearing box or exclude its usage at all. Type of the applied propulsion electric motor and regulation method specify type of mechanical characteristics (characteristics family) of the propulsion electric motor.

The paper considers a propulsion asynchronous electric motor with frequency control. While using frequency control it is possible to regulate electric motor revolutions by mutual changes in voltage and voltage frequency. There are various laws of mutual changes in voltage and frequency (regulation laws). Selection of a regulation law influences on type of mechanical characteristics of a propulsion electric motor. Application of any law can be admissible only for some specific range of voltage frequency otherwise it is possible to exceed some parameters (for example, admissible voltage in the winding of electric motor stator). It is necessary to ensure the required moment within wide range for a tractor propulsion electric motor. In this case losses in the electric motor must be minimal. Losses in the rotor of the propulsion asynchronous electric motor are directly proportional to its sliding and its best propulsion and mechanical properties of a mobile machine will be ensured in the case when sliding is preserved at a constant value. According to these reasons selection of regulation laws has been carried out for operation of the propulsion asynchronous electric motor with nominal sliding and mechanical characteristics at nominal sliding is conventionally called a nominal characteristics.

The paper analyzes the possible laws of mutual application of voltage and voltage frequency and their application boundaries. A combination of laws for regulation of the propulsion asynchronous electric motor has been selected in the paper. The combination ensures the widest operational range of the electric motor with high moment value at nominal sliding and due account of limitations on application of every used regulation law. The following mechanical characteristics family has been constructed for the propulsion asynchronous electric motor regulated in accordance with the proposed law: at nominal sliding, at critical sliding, at changeable sliding and without changes in voltage and frequency.

Measures undertaken for improvement of road traffic safety presuppose clampdown on violation of road traffic regulations but no attention is paid to the fact that there is no possibility to ensure road traffic safety due to inconformity of roads to the modern safety requirements. Therefore reduction in accident rate is connected with some changes in approaches to designing, construction and maintenance of roads. Nowadays when the number of automobiles is extremely large and their number is increasing with every passing year driver’s professionalism becomes the most significant factor. In these circumstances the professionalism is demonstrated not so much while driving in bad road conditions as it was previously but the professionalism is more revealed in the case when it is necessary to drive in conditions of large workloads and high manoeuvring rate when a special important role is given to the capability to forecast a situation, in other words the capability to read the road. Moral climate on the road is no less important as well and it practically fully depends on a driver.

The paper contains an analysis of the Gomel traffic police data on quantitative distribution of road traffic accidents and their victims according to the time of day and month, lighting conditions, weather conditions, age and sex factors, types of violations. Situations of traffic behavior, motivations of drivers and road users, drivers training have been shown in terms of impact on the road traffic accident risk. The paper considers a human factor which rather often causes an accident. An evaluation has been given to such factor as road speed of transport facilities which exerts a significant influence on an accident risk and its severity.

The paper considers a problem on introduction of a conception and regularities of “squeezing effect of a rail loaded non centrally by semi-sleepers having L-shaped cross-section” exemplified by belt-type tramway. Its advantages are ensured by doubled non centrally loaded foundations these are semi-sleepers. Semi-sleeper of L-shape cross-section is a lever of L-shape form, transforming a vertical load into horizontal ones and foundation squeezing. Properties of two semi-sleepers being doubled, orientated to each other and non centrally loaded have been used in order to create a positive effect. A horizontal force creates squeezing and it is revealed as a component of a vertical load during displacements which functionally depend on foundation squeezing. These dependences demonstrate that strength and deformation properties of earth foundation of vertical direction are used for creation of horizontal properties of sleeper vertical shoulder.

The paper studies mechanics pertaining to a squeezing effect of a rail loaded by semi-sleepers having L-shaped cross-section. It has been established that the rail squeezing effect results from squeezing process executed in two mutually perpendicular directions (reduction of cross-sectional area) by load of a rail wheel with spacers if they are set inside of a sleeper-mechanism on an elastic foundation.

Methodology for calculation of parameters on the rail reduction effect is considered as a tool for handling of applied problems on belt-type tramways. Results of the proposed rail reduction effect in problem statement for elastic conditions, with unchanged cross-sectional dimension of a rail line and introduction of correction ratio coefficients due to new initial load data have recommended for practical application as reliable values.

The paper has revealed a proportional dependence of the rail reduction effect according to strength on the resultant value of reaction pressure, eccentricity difference of the resultant and load and inverse proportion due to distance along vertical line between reduction force vector and connection position of doubled foundations. Rail squeezing force will be increased if we reduce foundation height while having unchanged width and foundation pressure or if we increase an ordinate of the connection arrangement between them while having unchanged foundation height.