SELECTION OF THE DRIVE OF THE PULSE GENERATOR FOR WAVE DEFORMATION HARDENING

The article is devoted to the analysis of known structures of impact devices used in industry in order to obtain recommendations for their adaptation or when creating new structures for wave strain hardening by surface plastic deformation. The analysis was carried out on the used drive and on the main parameters of impact devices: impact energy, impact frequency, relative metal consumption and efficiency. The options are the best combinations of parameters for electric, pneumatic and hydraulic drives. Recommendations are given on the use of such devices, with appropriate adaptation, as pulse generators for wave strain hardening.

TECHNOLOGICAL CONTROL OF THE CONTACT PRESSURE ON THE CYLINDRICAL SUBSTRATE FROM THE SIDE OF THE COATING ADDITIVELY FORMED ON ITS EXTERNAL SURFACE

The article gives an example of controlling the stress state parameters of additively manufactured products. The study was carried out on the basis of a developed non-classical mechanical model of the process of layer-by-layer formation of a coating of arbitrary thickness on a cylindrical substrate. The model is based on modern concepts of the mechanics of continuously growing bodies and allows one to obtain fairly simple analytical dependencies. On the basis of the latter, the problem of technological control of the evolution of contact pressure at the substrate – coating interface is solved in the article. A number of practically significant conclusions have been made.

ON THE INTERACTION OF A VISCOELASTIC CYLINDRICAL PIPE WITH INNER UNIFORM COATING AND INSERTS WITH A COMPLEX PROFILE

This work is devoted to the formulation and construction of an analytical solution to the problem of contact between a cylindrical viscoelastic aging pipe with an internal thin coating and an insert having a complex shape placed inside the pipe with an interference fit. In practice, the presence of such coatings is required, for example, to protect the main structure from aggressive external or internal environments, for its electrical insulation, etc. The manufacturing process of the inner coating determines its possible heterogeneity (dependence of properties on coordinates). An insert placed inside a pipe can have a complex profile that has a rapidly changing function. Taking these features into account is important when analyzing the stress-strain state of pipes with an internal coating. Using an approach based on the use of special basis functions and the type of solution, a representation for the contact stresses in the pipe in the region of the rigid insert is obtained. This approach makes it possible to distinguish functions that describe the properties of the inner coating and the shape of the outer profile of the insert in the form of separate terms and factors in the expression for the contact stresses in the insert region. Therefore, in order to achieve high accuracy when carrying out calculations, it is sufficient to restrict ourselves to a relatively small number of terms

ANALYSIS OF THE CREW PART OF THE LOCOMOTIVE TEM23 AND PROPOSALS FOR ELIMINATION OF DISADVANTAGES

The analysis of the design features of the bogie of the TEM23 shunting diesel locomotive is carried out. In the process of analysis, the directions of its improvement are determined. It is proposed to rotate the bogie frame in the vertical plane by reducing the body supports to two and using a pivot with low lowering, equip the bogies with pneumatic spring suspension in the form of two corrugations installed in series with shortened suspension springs. The proposed options for improving the undercarriage of a diesel locomotive will increase the competitiveness of products and reduce costs

STRENGTHENING OF CARBIDE STEEL SURFACE BY TUNGSTEN CARBIDE POWDER BY PLASTIC DEFORMATION

The use of the technology of combined electromechanical processing, consisting of a high-temperature plastic deformation mode, when tungsten carbide powder is implanted into the surface of carbon steel, and a high-temperature thermal hardening mode, during which tungsten carbides are partially dissolved in the austenite of steel up to the limit of its saturation with tungsten, provided a gradient wear-resistant three-layer highly dispersed structure as a result of the decomposition of supercooled austenite oversaturated with tungsten. The results of tribotechnical tests of cylindrical specimens by the normalized method are presented.

RESEARCH OF THE PROCESSES OF NON-ISOTHERMAL FLOW OF MELTING OF A PROPYLENE BLOCKOPOLYMER WITH ETHYLENE IN THE CABLE HEAD CHANNEL

The article is devoted to the numerical study of the processes of nonisothermal melt flow of a block copolymer of propylene with ethylene in the channels of the forming tool of cable heads when two-layer insulation is applied. The influence of technological parameters on the fields of speeds and temperatures is determined

MANAGEMENT OF TECHNOLOGICAL HERITAGE ACCURACY ASSEMBLY OF HIGH-PRECISION PRODUCTS

The article is devoted to solving the problems of the production of thin-walled cases, where it is important to improve the accuracy of manufacturing. Based on the foregoing, it was decided to conduct research work. The technology of processing a long body from a hot-rolled thick-walled pipe using drawing is considered, which guarantees the required shape accuracy and the least effect of the properties of the initial state of the workpiece in comparison with the technology of manufacturing bodies by stamping from sheet metal. As a result of the work, it was determined that the difference in the diameter of the housing bore when basing on the pulling operation is mirrored onto the accuracy of the inner surface of the housing, and the maximum beating of the housing stem obeys the Rayleigh distribution law and fits into the tolerance with a two-fold margin. Experimental studies have shown that an increase in the accuracy of manufacturing extended bodies can be guaranteed by reducing the technological tolerance for the inner base hole of the workpiece for pulling

CALCULATED SIMULATION OF THE DYNAMICS OF A RAILWAY WHEEL WHEN ROLLING THROUGH A BUTT CLEARANCE

The article is devoted to the description of the creation of a computer model of the movement of a railway freight car along the section of the track adjacent to the rail joint. The model takes into account the elastic characteristics and ballast subsidence in the joint zone. The results of computer simulation are further used to solve the contact problem in the wheel-rail system. The study varied a number of parameters affecting this process of wheel movement. For the operating speeds of the freight car, the range of values ​​of the dynamic forces arising between the wheel and the rail during the passage of the joint is determined.

DETERMINATION OF RUT DEPTH AND RUTING POWER WHEN ROLLING WHEELS ON DEFORMABLE GROUND

Wheeled tractors and wheeled earth-moving machines are widely used in road construction, in municipal services. The group of wheeled vehicles, numerous and varied in purpose and design, are general transport vehicles used for the transportation of various types of bulk cargo, and specialized vehicles designed to perform narrow target functions. A characteristic feature of these types of wheeled vehicles is their ability to work not only on roads with asphalt-concrete pavement, but also on deformable soil surfaces. When the wheels roll on the ground, the power consumption required to ensure the movement of the wheeled vehicle increases sharply, questions arise related to the passability of the vehicles, their controllability, and the loads in the transmission. In this regard, it becomes necessary to consider various aspects of the movement of machines in these conditions, in particular, the determination of the power spent on rutting and the depth of the track, which is what this study is devoted to. The use of the “stamp wheel” model in this work made it possible to obtain relatively simple dependencies that make it possible to calculate the track depth and the power spent on rolling both a single wheel on deformable soil, and during the sequential passage of the wheels with an expansion of the track, when the next wheel does not move. in the next ", ie exactly along the track laid by the first wheel, and with some lateral displacement. In this case, part of the wheel moves along the laid track, and the other part expands the track, compacting the previously non-deformable soil. The results of calculations using the derived formulas are in good agreement with the experimental data, which indicates the practical applicability of the obtained dependences.

FEATURES OF THE METHODOLOGY FOR CALCULATING BUOYANCY AND STRENGTH OF A BLOCK PONTON FOR VERTICAL CYLINDRICAL TANKS

The paper considers a technique for analyzing the strength and buoyancy of block pontoons for vertical cylindrical tanks used for storing liquid oil products. A model is proposed for performing calculations by the finite element method of a pontoon for buoyancy and strength, taking into account the action of pushing forces. The results of calculations on strength and buoyancy of an aluminum pontoon with foam-urethane filling BPA5000 are presented. It has been established that BPA5000 pontoons have sufficient strength and buoyancy, as regulated by GOST 31385-2016.