Introduction. Increasing the efficiency of using a warehouse with a constant volume is an urgent task, the solution of which is possible through block or deep-lane storage systems. One such solution is the pallet flow rack, which saves up to 25% of the distance travelled by a forklift compared to the single-deep racks. The main element of the safe operation of the gravity roller conveyors used in a pallet flow rack is a brake roller. The most promising design is a magnetic (eddy current) type brake roller.

The purpose of the work is to carry out a comparative analysis of the results of the calculated and experimental studies to determine the speed of movement of a pallet along a magnetic brake roller.

Materials and methods. The research area is the magnetic brake roller. Its construction and description of work presented. The results of calculated and experimental study of the coefficient of magnetic viscosity presented.

Results. The calculated and experimental dependences of the pallet movement speed along the magnetic brake roller were obtained. It was found that with an increase in the speed of movement of the pallet along the magnetic brake roller, the error of the mathematical model increases, and, first of all, after crossing with the straight line of a drag peak speed.

Conclusions. A comparative analysis of the results of the calculated and experimental studies to determine the speed of movement of the pallet along the magnetic brake roller carried out. It was found that the developed design of a magnetic brake roller in the operating range of the pallet masses from 100 to 600 kg with up to 16 magnets located on one side of the disc, and from 100 to 1150 kg with up to 8 pairs of the magnets located on both sides of the disc, provides a speed control within the limits not exceeding the permissible speeds of the pallet movement on the gravitational roller conveyor. The verification of the mathematical model showed that the average value of the error of the mathematical model in the entire range of the pallet masses at speeds not exceeding the permissible speeds of pallet movement on a gravitational roller conveyor and below the drag peak speed is no more than 8.2%.

Introduction. Drilling of frozen and permafrost soils is one of the complex and energy-intensive processes of earthworks. Drilling tools used on frozen soils implement the process of drilling the soil by deformation of cutting or crushing action. Current drilling tools are not efficient enough to use because they implement energy-intensive drilling processes and are not always suitable for various types of soils. A screw drill is considered, which implements the process of soil destruction by shear and shear deformation, which is less energy intensive.

Materials and methods. On the basis of theoretical studies of the interaction of 3 types of drilling tools with frozen soil, a comparative analysis was carried out to determine the efficiency of a screw drill use. The technical and economic indicators of the drilling process were compared. A method for determining the efficiency of the use a screw drill based on the analysis of special target functions is presented.

Results. The results of a comparative analysis of drilling tools have been obtained. Depending on the nature of soil deformation, the effectiveness of one drilling tool over another is determined. As a result of a comparative analysis of the drilling speed and the energy intensity of the drilling process, the efficiency of the screw drill was established.

Discussions and conclusion. In the course of the comparative analysis, the efficiency of the screw drill was determied, which implements shear deformation and soil separation, justifying the feasibility of further research.

Introduction. The problem of the shortage of energy-efficient restoration technologies makes it a priority to develop new technological equipment for the restoration of the rolling surfaces of railway wheels using highly concentrated energy sources. Currently, in the practice of repair DPO, discarded non-bonded wheels are increasingly replaced with new ones, but their resource potential is high during the operation. This approach is not technically and economically feasible.

Materials and methods. This article presents the results of the strength calculation of the main moments of forces and dynamic loads per wheel pair. The problem of repair equipment related to the lack of the independent mobile complexes that ensure prompt arrival at the work site and high quality restoration of the design geometry of the wheel surface is formulated.

Results. To solve this problem, a mobile complex was designed and developed, which allows to restore the design geometry and modify the high physical and mechanical properties of the riding surface with optimal stresses in the phase structure of the wheel base.

Discussion and conclusion. It is recommended to use the results of the research carried out for the design, creation and production of high-tech repair equipment.

Introduction. The ways of increasing the reliability of road construction machinery operation are considered. As a result, an option is proposed to replace the used 09Г2С steel with 30MnB5 boron steel. Using the example of a motor grader blade, the force effects on this working body of the road construction machinery are analyzed. In order to increase the level of physical and mechanical characteristics of 09Г2С and 30MnB5 steels, they are additionally exposed to thermo cyclic treatment. The experimental studies about the influence of this type thermal action on the structure and properties of steels are described. The comparative analysis of the obtained characteristics allows making a conclusion about the possibility of the considered replacement.

Materials and methods. Through the metallographic analysis the influence of the number of thermal effects cycles on the grain size of steel is investigated. Alongside a set of physical and mechanical characteristics of these steels was determined at various stages of the thermo cyclic treatment.

Results. It was determined that an increasing the level of physical and mechanical characteristics of the studied steels is possible through the use of thermo cyclic treatment. This is achieved by producing a fine-grained metal structure with a higher strength. The dependence of the tensile strength and yield strength of the steels under investigation on the number of cycles of thermal action is considered. Some correlation relationships were selected to describe these dependencies. The relationship between the yield stress and ultimate strength of 09Г2С and 30MnB5 steels and the grain size is considered. All investigated dependencies are presented in graphical form.

Discussion and conclusion. Based on a comparative analysis of the complex of physical and mechanical characteristics, the conclusion about the possibility of replacing 09Г2С steel with 30MnB5 steel was made.

Introduction. The reasons for the formation of an increased amount of condensate in the exhaust system of a car at a low ambient temperature are considered. Since the speed of the vehicle is one of the factors that determine the heating of the exhaust system and the formation of condensation, an experimental study was carried out to determine the temperature of the elements of the exhaust system at various vehicle speeds.

The purpose of this study: to establish the features of the temperature change of individual elements of the exhaust system, depending on time at different vehicle speeds

Materials and methods. The sequence of the experimental study consisted of starting the “cold” engine, accelerating the car and then moving the car at a constant speed for 20 minutes. Simultaneously with the start of the engine, the temperature of the elements of the exhaust system was recorded. In this study, thermocouples were used to measure the surface temperature of the exhaust system. Experimental studies were carried out on a Toyota Camry with a gasoline engine in the climatic conditions of the Perm Territory.

Results. The dependences of the temperature of the exhaust system elements on time were obtained at different speeds. In an experimental study, it was found that the temperature of the elements of the exhaust system is established within 8-12 minutes from the start of the vehicle at a constant speed; the rear muffler has the least surface heating, and therefore the greatest probability of the formation and accumulation of condensate.

Discussion and conclusion. The analysis of the peculiarities of the change in the temperature of the exhaust system during the movement of the vehicle in conditions of low ambient temperature is carried out. The established patterns can be used to obtain information on the processes of condensate accumulation in the exhaust system and are aimed at predicting the amount of condensate accumulation in the exhaust system; to develop new solutions to ensure reliable operation of the exhaust system.

Introduction. The need for a more efficient and varied use of waste from the pulp and paper industry dictates the need to search for new directions for the use of such waste in construction materials science technologies.

Materials and methods. In the studies the fibre waste of the Perm Cardboard LLC company with a moisture content after washing of 300% by weight was used. Currently, many issues of theory and practice the production of materials from the fibre waste are not entirely solved, resulting in a number of provisions borrowed from the theory of the production of concrete mineral aggregates, as well as the production of pulp and paper industry.

Results. Due to its chemical and material composition, the possibility of using the fibre waste in construction materials science technologies as an independent air binder is shown. The studies have established that the initial moisture content of the fibre waste as a binder affects the final quality indicators of a dry material. Thus, the lowest dry material density of 350 kg/m3 is observed at the initial humidity of the mixture in the range of 650% by weight. At a density of 350 kg/m3, the hygroscopicity of the material is 4.3%, the shrinkage from 10 to 25%. The drying time of the product is within 11 hours. A leveling high shrinkage is achieved by introducing light aggregates with a rough surface during the molding process.

Discussion and conclusions. The obtained data on the structure, the composition of the fibre waste, as well as the dependence and regularities of the behavior of a highly concentrated dispersed system of the ‘fibre waste-water’ type show the possibility of using the fibre waste for the production of thermal insulation materials, both as a main component and in a composition with aggregates as an independent air binder. At the same time, the final density indicators of thermal insulation products are within the limits established by regulatory documents.

Introduction. To control the concrete strength of reinforce concrete structures the shear test based on the empirical proportional dependence of concrete strength and tear force of a special purpose anchor with an expanding cone is used. The absence of a physical model of a concrete deterioration when tearing strength is a sign of the defect of the method which hampers the search of the ways for accuracy increase and test validity. The purpose of this study is to develop a physical model of concrete deterioration to determine the calculated strength by the shear test.

Materials and methods. The concrete strength model is a mechanism for local deterioration by tearing out a body of concrete in the form of an indicative cone when extracting it from a pre-fabricated anchor well. It is accepted that the deterioration occurs in two stages: from the melting of the concrete to the formation of cracks in the plane of the apex of the concrete cone in the first stage and the subsequent formation of cracks along the lateral surface of the cone during the extraction of the anchor. For transition to compression resistance, the average of the ratio of concrete resistance to compression and tensile or Fere formula shall be used. The model was verified by the calculation of 6 test measurements.

Conclusions. It has been established that the empirical correlation between the resistance of concrete to compression and the force of extraction of the anchor in the concrete test is only possible if the resistance of concrete is linearly related to compression and extension. However, the actual ratio of concrete resistance to compression and tensile is non-linear, so for relatively weak concrete the possibility of overestimating the strength of concrete on compression empirical dependence is offset by a reduction factor, and for more durable concrete, measurements are underestimated.