Introduction. Transport and technological means based on tracked undercarriages have found their use in both military and civilian industries. Their widespread use is due to a number of advantages that contribute to the further development of mechanization of production, increasing the efficiency of transportation of minerals, and developing infrastructure during the development of new territories. Ensuring cross-country ability and mobility of vehicles with tracked undercarriages, including tracked conveyor-tractors, is possible through the use of hybrid electromechanical transmissions. One of the components of scientific research in this direction is carrying out simulation modeling of the movement of equipment. Modeling the motion process will make it possible to substantiate the energy characteristics of the electromechanical transmission of a tracked vehicle and confirm the adequacy of previously performed theoretical studies.

Research methods. The main objective of the simulation was to confirm the effectiveness of the theoretical studies performed. The studies in the VISSIM programming environment using typical motion cycles that equivalently reflect the operating conditions and use of a tracked machine were carried out.

Results. As a result of the research, quantitative estimates of the influence of the power of a diesel generator and the charge of an energy storage device on the dynamic performance of equipment were obtained. It has been established that in order to meet the requirements for promising samples, the power of the energy storage device should be at least 2.5 kWh when using a standard internal combustion engine.

Discussion and conclusion. The research results can be used to create, based on the existing scientific and technical background, a promising robotic complex with an electromechanical transmission.

Introduction. The work is devoted to the calculation of series standards for the design of high-pressure transmission devices used in various hydra jet technologies, which will provide the design of these devices based on dimensionless indicators describing the relationship between their geometric and technological parameters.

Materials and methods. The methodology includes the use of mathematical models and analytical approaches to assess the influence of various parameters on heat generation processes in equipment, as well as methods for statistical processing of results.

Results. A histogram of temperature distribution was constructed and the data was approximated using the distribution curve of temperature values and parametric series were generated for dimensionless parameters depending on various factors such as temperature, pressure, rotational speed and linear speed. It is possible to obtain parametric series for linear dimensions from five temperature ranges and seven standard sizes depending on the pressure and rotation speed of the drill shaft.

Discussion and conclusions. The results obtained provide a better definition of the relationships between rotation speed, geometric characteristics and temperature parameters through the use of dimensionless indicators and it is possible to optimize the design of such devices taking into account operating conditions and ensuring increased efficiency.

Introduction. To ensure the safety and effective cleaning of highways and sidewalks from snow and ice in winter, it is necessary to use special equipment. But even at the stage of creating such equipment, designers need to know what loads will occur on the working equipment during its operation. Therefore, in order to develop milling working bodies for removing ice from road surfaces, it is necessary to conduct an experimental study in order to determine the loads arising on its working body.

Materials and methods. The main purpose of the experimental study is to determine the cutting resistance force that occurs on the cutting element of milling working equipment during its application when cleaning ice and snow on highways and sidewalks. To implement the experiment, a pendulum stand was selected, which allows to study the effect of a separate cutting element of a milling cutter on ice.

Results. The results obtained make it possible to predict changes in loads on the milling working body during operation. This makes it possible to develop more advanced designs of road milling equipment and modernize existing ones. The use of these dependencies also enables to determine the necessary structural strength of the milling drum for the normal operation of the equipment and to choose a rational section of the cutting elements.

Discussion and conclusions. According to the results of the experimental work carried out, the dependences of the ice cutting resistance depending on the thickness of the cut layer, the type of ice (pure, a mixture of ice, sand and compacted snow with impurities, a mixture of frozen layers, frozen paving slabs and a sample of asphalt concrete) and its temperature were obtained.

Introduction. Vibrating rollers are the most common means of compacting soils in construction. The nature of stress development on the contact surface of the roller with the ground depends on the technical characteristics of the vibrating roller (the mass of the roller, the mass of the roller frame, the frequency and driving force of vibrations, the number and characteristics of the roller shock absorbers) and the properties of the soil.

Materials and methods. Simulation of the interaction of a vibrating roller with compacted soil was carried out using a three-mass rheological model of the frame-roller-soil system. Differential equations of mass motion in contact and separation modes were solved numerically. To determine the numerical values of the loading time (increase in contact stresses from zero to the maximum value) and the unloading time (decrease in contact stresses from the maximum value to zero), as well as the maximum reaction force of the soil, a computational experiment was conducted on a rheological model. The mass of the vibrating roller module (the mass of the front axle) and the relative driving force were used as independent parameters of the vibrating roller. The coefficients of elastic and viscous resistance of the soil were chosen as independent parameters of the soil. The total number of combinations of factors was 192. The values of the time of loading and unloading of the soil, as well as the maximum strength of the soil reaction, were determined by oscillograms of changes in the strength of the soil reaction over time.

Results. Using the STATISTICA program, regression equations, to calculate the numerical values of the loading and unloading time of the soil, as well as the maximum reaction force of the soil and the corresponding values of the reliability coefficients of the multiple approximation, were obtained.

Discussion and conclusion. The rheological model reproduces the asymmetric nature of changes in contact stresses during soil compaction by a vibrating roller, observed in experimental stress oscillograms obtained during field experimental studies. The results obtained are important for calculating the depth of stress propagation in the ground and the distribution of stresses in the ground after the passage of a vibrating roller using a wave approach to describing stress propagation in the ground. In the future, it is advisable to conduct a computational experiment with an expanded list of independent parameters of the roller, including the oscillation frequency.

Introduction. The model and results of calculating the smoothness of a light three-axle off-road vehicle for the Arctic zone of Russia are considered. The model on standard approaches and uses a system of assumptions that limits the number of degrees of freedom for the vehicle body to three, as well as one degree of freedom for the unsprung masses is based. The mathematical model is a system of ordinary differential equations and is supplemented with the necessary algebraic equations, as well as initial conditions. The system is integrated using the 4th order RungeKutta method, for which a program was written in C++. The calculations presented in the article demonstrate the possibility of conducting research on the smoothness of a vehicle under conditions of arbitrary terrain, typical for off-road conditions in the winter conditions of the Arctic zone. The dimensions and other parameters of the vehicle were taken from a full-scale model that was used in real expeditions in 2003-2019. Based on the model, suspension characteristics will be developed for a new all-terrain vehicle.

Theory. When operating a wheeled vehicle in a wide range of conditions, even in northern regions, transverseangular vibrations are very often insignificant, so only vertical linear and longitudinal-angular vibrations of the frame can be considered. This problem enables to construct a system of equations of vehicle motion using selected degrees of freedom. From a mathematical point of view, these equations are classified as second-order ordinary differential equations with a variable structure of the right-hand sides, which reflects the non-linear nature of the behavior of the suspension in terms of its geometric constraints.

Methods. The work uses numerical methods to solve the equations of the constructed model, which enables to gradually weaken the accepted assumptions and build more general calculation algorithms. The main integration method for ensuring the stability of solutions is the multi-step Adams method, which, with the correct choice of step, ensures the necessary stability of the solution over sufficiently long model times. However, in this work, the 4th order Runge-Kutta method was adopted, which turned out to be quite sufficient.

Results and conclusions. The paper presents the results of a numerical study of the oscillatory processes of an off-road vehicle during uniform translational motion of the vehicle on a horizontal surface with a given profile of irregularities. The graphs show a transition process of oscillations, which ends with reaching a steady state. The shape of oscillations in a steady state can be irregular and significantly depends on the given speed of the all-terrain vehicle. Analysis of the dependencies presented in the figures shows that the shape of the oscillations of the allterrain vehicle’s frame, as well as the amplitude and frequency, significantly depend on the speed of the vehicle (at a constant road profile). Changing the road profile leads to corresponding changes in the forms and characteristics of forced vibrations of a vehicle on a suspension, which makes it possible to build the necessary amplitude-frequency characteristics, optimize the elastic and dissipative parameters of suspensions, optimize their number and location, and also monitor the movements of arbitrary points at which various units are located.

Introduction. When driving cars in winter on intercity routes, problems may arise if the highways are covered with snow as a result of heavy snowfalls, which can last for several days or more, and movement during this period becomes impossible. An analysis of statistical data on weather events in winter has shown that in many regions, the closure of trails as a result of prolonged snowfalls can reach up to fifteen percent. In this case, an autonomous energy source, which it receives through the use of environmental properties, can provide significant assistance in improving the situation and increasing safety. The paper considers the technical solution and carries out a theoretical analysis of its characteristics aimed at solving the problem of autonomous power supply of the car interior in severe weather conditions.

Materials and methods. The paper presents a technical solution and a theoretical analysis of its characteristics aimed at solving the problem of autonomous power supply of the car interior in severe weather conditions.

Results. Based on the results of the information search, the design of a compact low-power wind power plant is proposed. The calculation of the heat loss of the car interior, the characteristics of a compact wind power plant was performed and the generated power required to heat the car interior in an extreme situation was determined.

Discussion and conclusions. It has been established that the presented design of a low-power wind power plant can be used as a prototype for the development of an industrial design of an autonomous energy source for heating a car in extreme conditions. Similar installations can be used in other industries, for example, tourism, agriculture, and geological exploration.

Introduction. The relevance of the topic of the presented article is determined by the improvement of the technology for repairing and restoring machine parts. Currently, the technology of restoring piston pins of internal combustion engines (ICE) by a high-energy method of plastic deformation of metal using the energy of a high-voltage pulse discharge in a liquid is widely used – the electrohydraulic effect, and on its basis electrohydraulic processing. The purpose of the article is to increase the efficiency of the method of restoring piston pins of internal combustion engines due to the use of the electrohydraulic distribution method.

Materials and methods. The research methods such as the analysis of the degree of influence of the electrical parameters of the electrohydraulic distribution process on the amount of deformation of the piston fingers depending on the relevant material were used. The article discusses a mathematical model of the electric discharge process when restoring piston pins. The calculation method determines the modes and parameters of the process of electrohydraulic distribution of piston pins while maintaining their fatigue life, static strength and wear resistance.

Results. In this work, the degree of influence of the electrical parameters of the electrohydraulic distribution process on the amount of deformation of the piston pins, depending on the product material used, is established. A mathematical model of the electric discharge process during the restoration of piston pins has been developed, and based on them, the modes and parameters of the process of electrohydraulic distribution of piston pins have been determined while maintaining their fatigue life, static strength and wear resistance.

Discussion and conclusions. The studies have shown that exploding wires made of iron, copper, and tungsten are not effective in restoring piston pins with an internal radius of up to 10 mm. The pressure in the case of their use does not exceed 100 MPa. Exploding Al wires with a diameter of less than one millimeter have the greatest effect. In this case, the inductance of the circuit should be minimal, because this provides the largest share of the energy released in the discharge channel from all stored in the capacitor. This ensures the highest pressure in the channel. Based on the same considerations, the capacity should be limited to a range of 3-12 UF. This method can be applied to the restoration of other car parts.

Introduction. One of the key problems in ensuring the quality of recreation for the population is the provision of transport services that meet the transport needs of vacationers. The study of the transport needs of the population of resort cities during the holiday season is caused by the need to assess changing passenger flows as a result of a multiple increase due to vacationers in accordance with their place of attraction and possible adjustments to the routes of regular passenger transportation by road. This determines the relevance of the topic of this article. The purpose of the article is to develop a methodology for determining the needs for transport services for the population and vacationers in cities with high resort potential during the busiest periods, which makes it possible to design transportation processes along regular routes.

Materials and methods. General scientific methods of analysis and synthesis, the provisions of probability theory and mathematical statistics, mathematical modeling, as well as the provisions of the technology of transport processes were used as the main research methods. The work carried out the zoning of the city into transport areas with a center of gravity at stopping points of urban passenger transport. Calculations of potential transport needs were carried out on the basis of a survey of vacationers and field observations, which were processed using standard Microsoft Excel and Statistika software.

Results. The main result of the work is a methodology for determining the potential transport needs of the population and vacationers in cities with high tourism potential for the development and adjustment of routes for regular passenger transportation by road during the holiday season, which represents the scientific novelty of the research. The technique contains a mathematical model and algorithm.

Discussion and conclusion. The use of this methodology will enable the organizer of transportation in resort cities to optimize the organization of regular passenger transportation by road during peak seasons.

Introduction. The use of restored parts of motor vehicles makes it possible to reduce the financial costs of repairing equipment. The cost of the restored parts should not exceed 50% of the cost of the new part. Increasing the productivity (deposition rate) of an electrolytic copper coating during the restoration of parts of motor vehicles requires taking into account the technological and economic aspects of the restoration process. The study of the factors (deposition conditions) that most affect the deposition process of the copper coating, the analysis of the experimental results and its statistical processing made it possible to optimize the technology of restoration of copper parts to create the most appropriate deposition modes with maximum productivity, thus reducing the cost of restoration of parts of motor vehicles. The purpose of the research is to develop a mathematical model of the effect of deposition conditions (electrolyte temperature, cathode current density) and electrolyte composition (concentration of copper sulfate and sulfuric acid) on the performance of the deposition process of copper coating, for further development of the most productive technology for restoring collectors of electric motors of motor vehicles.

Materials and methods. The studies on equipment that allows obtaining the necessary data with the required accuracy were carried out. Mathematical processing using modern statistical data processing tools that excluded possible errors, providing to obtain the dependence of factors with the necessary accuracy was carried out.

Results. In the course of studies of copper sulfate electrolytes to obtain an electrolytic copper coating, with the further development of technology for the restoration of automotive parts, it became necessary to determine the effect of deposition conditions – “factors” (cathode current density, electrolyte temperature, copper sulfate concentration, sulfuric acid concentration) on the deposition rate – “response”. It was found that the factor “cathode current density” and the combination of factors “cathode current density” and “sulfuric acid concentration” are the most significant. The deposition conditions in order to obtain the most productive technology for restoring collectors of electric motors of motor vehicles by depositing a copper coating have been optimized. According to the obtained model, the optimal values of the deposition conditions for obtaining the maximum deposition rate are the electrolyte temperature of 35...40 ° C, the cathode current density of more than 5 A/Dm2, the concentration of copper sulfate 200...250 g/l, the concentration of sulfuric acid 40...70 g/l.

Introduction. Currently, more than 96% of the roads in our country are built with non-rigid pavements with bases made of dispersed materials of crushed stone, sand-gravel mixtures, sand, etc. Significant disadvantages of such road structures are high material consumption and significant operating costs, including those associated with low service life between repairs. According to expert estimates, Russia’s losses due to the poor quality of the highway network amount to 3% of gross domestic product. In 2017, the government decided to increase service life between repairs of federal highways, for example, for major repairs from 12 to 24 years. To solve the problem of increasing the time between repairs, it is necessary to ensure a significant increase in the total modulus of elasticity on newly constructed or repaired roads. One of the effective ways to increase the strength characteristics of non-rigid road pavements is the wider use of monolithic bases made from soils or asphalt granulate treated with mineral binders, as well as industrial wastes with own binding properties. Replacing bases made of dispersed materials with monolithic ones makes it possible to reduce the material consumption of road pavement by 20-50%, the cost of construction work by up to 45% and increase the service life of roads by 35-40%.

Materials and methods. In order to study the influence of the type of filler on the processes of structure formation of sludge crushed stone material, research on the strengthening of granite crushed stone of the 0-15 mm fraction and crushed stone from low-active blast furnace slag, 15% nepheline sludge was carried out. Samples with a diameter and height of 7 cm from mixtures of optimal humidity by pressing under a load of 15 MPa were formed. The samples under normal conditions and tested at the ages of 1, 3, 6 and 9 months to determine the compressive and tensile strength in bending were stored. In order to determine the optimal dosages of sludge for strengthening slag crushed stone, samples with a sludge content of 5, 10, 20, 30% were formed using a similar method and tested for compression and splitting immediately after production and then after 1, 3, 6, 9 and 12 months hardening. When examining experimental sections of transitional type coatings at the first stage of construction of oil field roads, the total elastic moduli were determined using a MADI-TsNIL deflectometer and a loaded MAZ-500A vehicle. To study the hardening kinetics of sludge-granular concrete from asphalt granulate, reinforced with ground sludge, samples with a diameter of 71.4 mm by pressing under a pressure of 7 MPa, according to standard methods were prepared. The series of samples differed in the dosage of ground sludge (10℅ and 15℅) and their hardening conditions. The samples under normal conditions and in natural conditions (in the open air) in a box with sand, to simulate the temperature regime of hardening of the material in the base of the road pavement and tested at the age of 7, 28, 90, 180 and 360 days at temperatures of 200C and 500C were stored.

Results. The analysis of normative and literary sources on the issues of increasing the interrepair service life of highways is carried out. Separate proposals for amending current regulatory documents for public discussion are given. The physico-chemical and physico-mechanical properties of belite sludge – large-tonnage waste from alumina production – are presented. The scope of their application in the construction, reconstruction and repair of highways is shown. The high efficiency of using belite sludge as a slow-hardening binder in order to extend the service life of roads during the construction of monolithic bases and transitional coatings has been theoretically substantiated and experimentally confirmed. Rational pavement designs for the construction of oil field roads in the swampy regions of Siberia with the replacement of prefabricated reinforced concrete pavements at the first stage of construction with monolithic transitional pavements made of stone materials reinforced with belite sludge have been developed. Laboratory and experimental research to justify the replacement of traditional binders with ground nepheline sludge when repairing asphalt concrete pavements using the cold recycling method with an extension of the construction season were carried out.

Сonclusion. Over the past 30 years, the number of heavy vehicles has significantly increased on the roads of Russia. At the same time, the requirements for the service life between repairs of flexible road pavements have increased. Increasing service life, in principle, is quite possible, but requires the introduction of innovative design solutions at the design, construction, reconstruction and repair stages using highly efficient materials and technologies in order to significantly increase the total elastic modulus, in particular by replacing road pavement bases made of dispersed materials with monolithic ones. It is necessary to more widely introduce technologies for constructing foundations from local soils treated with mineral binders (cement, lime, active fly ash, etc.), as well as industrial waste with independent binding properties, for example belite sludge. In addition, it is necessary to continue research on the development of complex slow hardening non firing, including geopolymer binders based on industrial waste specifically for strengthening soils and stone materials with the development of regulatory documents in the development of TR CU 014/2011. When repairing and overhauling roads to restore the bearing capacity of layers of crushed stone (gravel) bases and strengthening flexible road pavements, preference should be given to the cold regeneration method. At each stage of the life cycle of highways, there are reserves for increasing the time between repairs that must be implemented.

Introduction. Over the past 20 years, the fleet of vehicles in the Republic of Belarus has increased significantly, and, consequently, the intensity of traffic on roads with a proportional increase in wear and tear of their surfaces. The need to protect asphalt concrete pavements from premature destruction dictates the search for new technological solutions. To effectively protect asphalt concrete pavements from the complex effects of water and traffic loads in the autumn-winter and spring-winter periods, the author has developed and implemented one of the options for protecting asphalt concrete pavements of a highway – treating them with a hydrophobic preventive Protekt- 01composition.

Materials and methods. The research used theoretical and practical results from the implementation of the developed hydrophobic prophylactic composition.

Results. The article presents an overview of the state of the problem of preventing destruction of asphalt concrete pavements abroad and in the Republic of Belarus, an analysis of the measures taken to implement the developed hydrophobic preventive Protekt-01composition at transport infrastructure facilities, and also, based on the data obtained from production testing a ‘System for organizing preventive treatment’ has been proposed, which will be aimed at preventing the beginning and future destruction of the asphalt concrete pavement of highways and will be based on monitoring the technical condition of the control object, planning, organizing, implementing and managing preventive and repair measures using navigation equipment and software that makes it possible to optimize the balance of costs and road surface defects.

Originality. Thus, based on the theoretical substantiation and the results of practical implementation of the developed composition, the following are proposed:

- method for ensuring the operation of a control system for liquid road-building materials which enables to eliminate overconsumption of the distributed substance;

- ‘System for organizing preventive treatment’, which enables to increase the service life of asphalt concrete pavement by 1.2–1.5 times.

Introduction. The active introduction into practice of the system of volumetric and functional design (OFP) is aimed at the large-scale development by the Russian road construction industry of advanced foreign approaches to the technology of designing asphalt concrete pavements (Superpave). One of the fundamental differences between the OFP methodology and the previously established practice of evaluating technical, technological and operational indicators of road construction materials is the introduction of new methods that characterize quantitative indicators with a high degree of accuracy, based on the actual physical, chemical and mechanical properties of the components used. Thus, as methods for assessing the low-temperature properties of bitumen binders, it is proposed to use the bending beam method (BBR), which has proven itself quite well when working with traditional (ordinary) bitumen. However, the natural and climatic conditions of operation of highways in Russia clearly require the use of binders modified with high- and low-molecular compounds, including polymers. In this study, the task of applying the ABCD method to evaluate the low-temperature parameters of ordinary bitumen and polymer-bitumen binders was realized.

Materials and methods. Samples of industrial batches of petroleum road viscous bitumen (GOST 33133-2014) and polymer-modified bitumen (GOST R 52056-2003) were used as objects of research. To determine the lowtemperature parameters, an ABCD 8.0 device and an air-cooled climate chamber were used. The study of bitumen binders according to the parameters laid down in the technical requirements of GOST R 58400.11–2019 ‘Automobile roads of general use. Petroleum-based bitumen binders. Method of determining the temperature of cracking using the device ABCD’ was carried out.

Results. The values of the cracking temperature for ordinary and modified bitumen binders were determined. It is shown that the low-temperature parameters of polymer-bitumen binders significantly exceed similar properties of oxidized road bitumen.

Discussion and conclusions. A comparative analysis of the low-temperature properties of ordinary and modified binders obtained during their determination by the direct method enables to confirm the effectiveness of the methodology developed in GOST R 58400.11-2019 for assessing the performance of binders of various component composition in difficult climatic conditions of Russia. The effectiveness of the domestic second-generation ABCD 8.0 device for direct assessment of the cracking temperature of bitumen binders of variable composition has been confirmed.