Articles of Volume : 5 Issue : 4, December, 2019 |
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Influence of gravel-pebble inclusions on the process of cutting frozen soils taking into account the wear of cutters of trenchers |
Author : Kravchenko S.M., Slepchenko V.A. |
Abstract | Full Text |
Abstract :Inhomogeneousfrozenandstrongsoilssignificantlyreducethelifecycleof the cutting tool of trenchers due to an increase in the average maximum soil resistance during cutting and an increase in contact pressure at the wear site. The paper presents an approach to determining the resistances at the site of wear of the cutters, which allows taking into account the effect of gravel-pebble inclusions on the strength of the cutting tool with the necessary accuracy. Various types of interaction of the cutter with gravel-pebble inclusions are considered. It is shown how the frequency of interaction of the cutter with inclusions is related to the size of these inclusions. The results of experimental studies to determine the pressure at the wear site and the coefficient of resistance to movement of the wear site of the cutters depending on the presence of gravel and pebble inclusions in the soil are presented. An estimate of the convergence of the obtained dependences with experimental data is presented. |
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Analysis of tractive and carrying belts interaction of intermediate drive of belt conveyor |
Author : Goncharov K.A. |
Abstract | Full Text |
Abstract :The paper presents the findings of the investigative study on the contact zone of the tractive and carrying belts of the intermediate belt conveyor drive in cross section using thermal filming. The description of the test bench, conditions and sequence of the study is provided. The regularities of belt interaction are identified; particularly the irregularity of their adhesion in width in the contact zone, resulting in a number of primary longitudinally oriented areas. The location of the areas in cross section corresponds to the contact points of the belt sections with the roller ribs of supporting roller carriages. On the basis of the investigative study, the design procedure of the reduced factor of belt adhesion is developed. The procedure takes into account lumpiness of the loads as well, particularly probable bearing of the load particle layer adjacent to the belt directly through the edges. The paper shows the limitations within the context of the proposed procedure depending on the types of transported materials. The example of traction coefficient calculation is shown. |
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Creation of a rating system for expert organizations operating in the field of industrial safety expertise |
Author : Kotelnikov V.V., Korotkiy A.A., Egelskaya E.V. |
Abstract | Full Text |
Abstract :Examination of industrial safety is a tool for industrial safety management of enterprises, which requires high quality of execution of expert works and compliance of expert organizations with the current requirements. The article analyzes the unfavorable factors and trends in the market of expert services and proposes ways to improve their quality by creating a rating system of expert organizations, which allows in the form of information to characterize the expert organization by the main criteria. The proposed system will structure them according to the degree of professionalism and integrity, as well as serve to create a «healthy» competition and information openness for customers, which as a result will affect the reduction of accident rates and accidents during the operation of hazardous production facilities. |
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Design and evaluation of operational characteristics of energy efficient crane-manipulator installation for mobile transport-technological machines |
Author : Lagerev A.V., Lagerev I.A. |
Abstract | Full Text |
Abstract :The article describes the design and features of the original energy-efficient manipulation system for loading and unloading operations using a mobile transport and technological machine. The design feature of this manipulation system is the replacement of the hydraulic mechanism of the rotary motion of the most loaded link with the mechanism of translational motion. This made it possible to solve two important tasks: to significantly reduce the magnitude of the operational load that the power cylinder needs to overcome in the process of moving the link of the manipulation system, as well as to ensure the constancy of the magnitude of the operational load throughout the entire vertical movement of the transported cargo. In relation to the design and technical characteristics of the manipulation system of a real mobile machine, a comparative analysis was made of the energy efficiency of operating the crane-manipulator of the considered and traditional design. The results of the analysis showed that the operation of the manipulation system of the proposed design is much more economical. This is due to a decrease in the power of the hydraulic drive of the mobile machine due to the use of a power cylinder of a smaller size, which requires less volumetric flow rate of the working fluid. In particular, for the considered mobile machine, a possible reduction in pumping unit capacity may be more than 30%. |
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New road rollers parameters modeling |
Author : Shishkin E.A., Ivanchenko S.N. |
Abstract | Full Text |
Abstract :Currently, the market for the road rollers production is actively developing. Each manufacturer has its own production experience and uses a developed approach to the new models design. The difference in design technologies leads to the emergence of a significant number of road rollers new models on the market. Practical studies of the roller drum interaction with hot asphalt mix show that many models with different structural parameters have a similar effect on the compacted material. Therefore, it is necessary to develop a universal approach to the choice of design parameters of rollers in their production. The paper attempts to develop a general methodology for determining the design parameters of rollers. For this purpose, a design parameters statistical analysis of more than 260 models of road rollers of leading manufacturers was carried out. The analysis results are presented in the form of a choice nomogram of road roller parameters. Taking into account the received nomogram it is possible to carry out the comparative analysis of rollers various on constructive parameters on the indicator of efficiency offered in work. The proposed algorithm allows us to recommend design parameters when designing new models of road rollers by manufacturers. As a consequence, it is possible to reduce the number of similar models of rollers. |
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Modeling operation modes of hydraulic drives with frequency-throttle regulation of mobile transport and overloading ropes complexes |
Author : Lagerev A.V., Tarichko V.I., Lagerev I.A. |
Abstract | Full Text |
Abstract :Mobile ropeways, the equipment of which is located on the base chassis of wheeled or tracked vehicles of high carrying capacity, are a promising type of transport and overloading equipment. Specific design features, modes and conditions of their operation in comparison with traditional freight and passenger fixed-line cableways require the development of special design methods and design calculations for this type of machine. The article discusses the problem of modeling working hydrodynamic processes in hydraulic drives with frequency-throttle regulation of the mechanisms of movement of traction and carrying ropes, at all stages of the movement mechanism — the stage of acceleration of the transported cargo, the stage of steady-state (stationary) movement at a constant speed and the stage of braking when approaching the final breakpoint. To solve this technical problem, a mathematical model of the hydraulic drive and a computer program that implements it were developed. The model provides computer simulation of the time-varying processes of such basic hydraulic drive technical characteristics as pressures and volumetric flow rates of the working fluid at characteristic points along the length of the hydraulic system, pressure drop across the hydraulic motor and instantaneous hydraulic drive power, as well as kinematic and force parameters of the movement of traction and carrying ropes (distance traveled, linear speed and acceleration, required power, overcome operational loads). In relation to a specific version of the mobile rope complex, the calculations of the indicated hydrodynamic, kinematic and power parameters were carried out, as well as the analysis of the results obtained. The influence of the adjustable throttle setting on the calculation results is shown. |
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Geometry and mass optimization of box-shape beams with non-linear walls for local buckling due to bending |
Author : Manzhula K.P., Naumov A.V. |
Abstract | Full Text |
Abstract :This article explores the possibility of optimizing geometry and mass of a beam based on the conditions for ensuring local buckling. The subject of the study is a box-shaped beam with non-linear walls. This type of beam is unpopular because it has not been studied properly. This fact only indicates its novelty. However, researches and experiments prove that this type of beam is superior to current types of beams in terms of local buckling. This indicates relevance of further research and use of beams with non-linear walls in structures, where local stability is the main aspect in choosing the geometric dimensions of the beam. To optimize this type of beam, a numerical experiment was performed by using the finite element method in ANSYS. The experiment confirmed the possibility of geometric optimization with maintaining similar performance of local stability. The results of this study are obtained formulas. The first formula is required to find the local buckling stresses of box-shaped beams with optimized non-linear walls. This formula was found by approximating the results of a numerical experiment using the least squares method in a MathCAD. The second formula is required to find benefit in mass when using optimized geometry. |
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Comprehensive model of the mobile transport and overloading rope complex |
Author : Tarichko V.I., Khimich A.V. |
Abstract | Full Text |
Abstract :The article considers the structure of a comprehensive mathematical model for the study of working processes and dynamic load of mobile ropeways. The complex mathematical model includes separate mathematical sub-models designed to take into account the influence of subsystem elements on the operation of the system. Within the framework of the proposed complex model, sub-models of deformable support surface, base chassis, ropeway’s equipment, cable system, cargo cabin with suspension are used. The differences in the operation of the drive and non-drive base stations of the mobile ropeway are taken into account. Sub-models are interconnected by joint parameters, which allows to take into account the presence of feedbacks between subsystems when modeling. |
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Control of tool wear during turning of parts of construction and road machines in conditions of repair production |
Author : Ovsyannikov V.E., Vasiliev V.I. |
Abstract | Full Text |
Abstract :During repair actions, turning (weeding) is a fairly common method of treatment. At the same time, repair production uses mainly obsolete equipment and the qualification of machine-tools is often lower than in the manufacture of new products. A significant problem which makes it difficult to provide the required surface quality parameters is the wear of the cutting tool. By improving processing efficiency, active monitoring is implemented. The purpose of the work is to develop technical solutions that make it possible to estimate the life of the cutting tool during processing. Experimental studies were carried out on a 1I611PF2-grade turn-cutting machine. As a diagnostic feature, an acoustic signal in the range of 6 to 12 kHz was used to evaluate the wear of the cutting tool, since preliminary studies found that the range was most sensitive to changes in processing modes. Studies were performed at different wear values of the cutting tool (estimated by the width of the wear chamfer).Neuro-fuzzy model of estimation of cutting tool operation resource is developed. Use of models of this class gives the chance of fine tuning under specific conditions (the machine, the tool, etc.) and it is correct to estimate a resource of operation of the tool. Model error by test sample does not exceed 10%. |
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Loading of the telescopic boom during a turn |
Author : Potakhov E.A. |
Abstract | Full Text |
Abstract :The article is devoted to the study of the loading of a telescopic boom of a jib crane. The research methods used are the numerical experiment method, carried out in the module of complex dynamic and kinematic analysis of SolidWorks Motion mechanisms, and the Finite Element Method, used in the Solid Edge Simu-lation module, based on the FEA Femap analysis tech-nology and NX Nastran solver. The following loading modes of telescopic boom equipment were considered: load lifting, normalized rotation, sudden drawdown of the outrigger. As a result of research, a numerical model of a jib crane equipped with a telescopic boom is developed, which is identical in its characteristics to a real prototype; the dependences of the amplitudes of the kinematic parameters of the frame motion and the crane load on the outrigger drawdown during the rotation of the crane are established; The character of loading of elements of the telescopic boom for each loading mode is obtained. The stress-strain state of the telescopic boom is determined taking into account the interaction of the sections with the side stops; the dependence of the highest structural stresses on the magnitude of the drawdown of the outrigger is established; The significance of the influence of vertical and horizontal external and local loads on the loading of telescopic boom equipment is determined. |
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Theoretical study of the boot process steeply inclined conveyor |
Author : Repin S.V., Aleinik V.I., Bazhenov A.A. |
Abstract | Full Text |
Abstract :Conveyor transport is widely used in various sectors of the economy. Very common are conveyors designed to move bulk cargo at significant angles of transportation, the so-called steeply inclined conveyors. At the same time, the theoretical aspects of the work have been studied relatively poorly, which does not allow to rely on previously accumulated knowledge in the design of new designs of steep-sided transporting machines. This leads to the fact that the characteristics of the conveyor in its design are selected very approximately, without careful theoretical calculation. This, in turn, leads to irrational use of resources, both in the construction of new conveyors and in the operation of existing ones. This article presents a theoretical calculation of the loading unit of the conveyor, in particular, the behavior of the load when loading the conveyor As a result of the formula for calculating the speed of the load on the conveyor belt, as well as the speed of its sliding on the loading device in different areas depending on its geometric parameters. Programs were also compiled to calculate these speeds at its various geometric parameters. The influence of geometric parameters of the feeder on the behavior of the load is analyzed. The mathematical model of the granular medium behavior is given. |
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Simulation of forces in the supports of machines of the main technological purpose on the example of a fully mobile crane |
Author : Sladkova L.A., Grigorev P.A., Krylov V.V. |
Abstract | Full Text |
Abstract :When working fully mobile crane on week soil due to drawdown of the outriggers, the possible misalignment of the frame with located on it a turntable with lifting equipment. This disrupts the operation of the crane, leads to loss of stability and disruption of its safe operation. Usually used to ensure the levelling under the chassis of the crane, outriggers (outriggers). It is also possible to use automated systems to ensure the stability of crane equipment, but they do not always provide the proper level of safety. The design of the device of ensuring stability working at the expense of increase in the area of a basic surface of the crane is offered. Considering a self-propelled crane (vehicle) as a connected system with an inertial reference system located in its center of gravity at an arbitrary time, the physical nature of the uneven pressure distribution under the supports of the running equipment at the initial installation of the crane was revealed. On the basis of the obtained theoretical dependences the variant of modernization of the fully mobile crane is offered. The practical implementation of the upgraded design will improve the stability of the crane when working on week soils and provide a high level of safety due to the reduction of specific pressure on the ground. |
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The influence of the mode of engine operation of transport and technological cars on the beating at the coupling piston-cylinder |
Author : Shtain G.V., Panfilov A.A. |
Abstract | Full Text |
Abstract :Relocation or beating of the piston occurs due to the action of lateral force in the crank mechanism, which leads to an increase in friction forces and shock loads in conjunction with the sleeve. Ultimately, this affects the operation of the engine, its noise, vibration and leads to intensive wear of the piston skirt. Therefore, the study of issues related to improving the reliability of the engine of transport and technological vehicles is an urgent task of technical operation. The aim of the work is to increase the reliability of the engine of transport-technological machines by reducing vibration during its operation. The article discusses a method that allows to reduce shock loads in the piston-cylinder coupling at a low crankshaft rotational speed at maximum torque, which is typical for the main engine modes of a transport-technological and road-building machine. It is proposed that under maximum load conditions with a minimum speed of rotation, the value of the total force when passing through the top dead center at the end of the compression stroke be equal to zero. In order for the gas pressure force at the top dead center to be equal to the inertia force of the translationally moving masses, it is recommended that the engine be tuned to change the valve timing during a compression stroke, i.e. increase the angle of delay in closing the intake valve. In confirmation of the above, a calculation was made to determine the angle of delay in closing the intake valve using the example of the YaMZ-65202.10 engine. To fulfill the equality of the gas pressure force and the inertia force at the top dead center, the value of the real engine compression ratio was found, which was 12.5. Next, the angle of the inlet valve closing lag is determined for this mode, which is calculated to be 540 crankshaft rotation after bottom dead center (according to the technical characteristics of this engine, this value is 480). The calculated data may be the initial parameters for the calibration of the program embedded in the electronic control unit of the transport and technological machine. |
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Research package efficiency general cargo |
Author : Makhkamov N.Ya., Ilesaliev D.I., Merganov M.M. |
Abstract | Full Text |
Abstract :Numerous studies in the field of packaging of general cargo confirm the effectiveness of the implementation of package transportation, especially in the presence of multiple congestion in the supply chain. However, today it is necessary to supplement the research, taking into account the comparison of the means of packaging, depending on various values of the parameters of the transport packaging. In this regard, the aim of the study is to search for rational shipping containers depending on various parameters that affect the final cost of delivery in supply chains. The main reasons for the backwardness of the countries of the former Soviet Union in the delivery of general cargo from economically developed countries is the lack of feasibility studies and specific organizational measures for the implementation of package transportation. Both of these circumstances acquire special meaning and significance in the conditions of a developing and in our country market economy. The objective of this article was to show that the delivery of general cargo is influenced by various factors, such as the size of vehicles, type of transport packaging, methods of stacking cargo units on transport packaging, etc. which are described in the article. The study applied economic criteria and principles of transport logistics and identified the scope of transport packaging for the delivery of general cargo based on specific technical and economic indicators. As a result of the study, the field of application of transport packaging has been determined depending on the specified parameters of the container-packing cargo. The necessity of a complete feasibility study of package transportation is shown, the costs of using transport packaging, as well as the cost of forming a transportation package, should be taken into account. |
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