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The Russian Automobile and Highway Industry Journal

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Vol 17, No 4 (2020)
View or download the full issue PDF (Russian)
https://doi.org/10.26518/2071-7296-2020-4

TRANSPORT, MINING AND BUILDING MACHINERY ENGINEERING

442-451 966
Abstract

Introduction. Many tasks in the field of operation of road machines in modern conditions have become irrelevant from a scientific point of view. This is due to the emergence of new regulatory documents that contribute to the solution of many problems, for example, the tasks of forming fleets of road machines for road maintenance. In addition, the active implementation of CALS-technologies; modern monitoring systems for road machines; the commitment to automate and robotic work processes; change in the volume and pace of road construction; increasing requirements for the quality of work performed; extension of the warranty period of road service; the existence of mega road organizations; the absence to date of generally accepted criteria for evaluating the effectiveness of one form or another of organizing maintenance and repair work (unscheduled repairs) of road machines; active development of a network of toll roads, etc. they require a radical review and systematization of issues related to the formulation of scientific problems in the study of the life cycle system of road vehicles in modern conditions.

Materials and methods. The well-known methods of mathematical, factor analysis and expert estimates of parameters were used that determine the main differences that affect mainly on the rational operation of road machines. 218.2.018-2012 ‘Methodological recommendations for determining the necessary fleet of road maintenance equipment for the maintenance of roads in the development of road maintenance projects’ industry road methodology (IRM) contributes to the integrated solution of the main tasks of forming parks with vehicles for road maintenance. Today, the ERA-GLONASS system and similar systems are actively used in all areas of the road economy and allow tracking the position and other technical parameters of road machines over a long period of time. In addition, automation and robotization of production processes are actively used.

Results. The factor analysis and the method of expert assessments made it possible to identify the main differences between the modern life cycle system of road machines used for the construction, reconstruction, repair and maintenance of highways than a similar life cycle system of road machines 10-20 years ago. Some features have been identified in the study of the life cycle system of road machines in modern conditions. The main tasks of modern research on the road machines life cycle system are outlined. It has been established that the basis of the industry road guidance documents that have been published at present, as well as those preparing to be published in the nearest future, are largely based on the scientific research conducted 10-20 years ago by Russian scientists. The current industry documents are advisory in modern conditions, which is not always applicable to specific construction objects and sets of road machines, and the installation of tracking systems on road machines only contributes to the scientific research.

Discussion and conclusions. In the course of the study, a vector was determined for the further development of such a scientific direction as the study of the life cycle system of the road machines in modern conditions. Some ways are proposed for solving scientific problems, taking into account the modern features of the road machines operations for the construction, reconstruction, repair and maintenance of roads, which allows scientists, especially the young ones, to more accurately and correctly formulate their scientific problems when setting them at the beginning of the research in this area.

452-463 607
Abstract

Introduction. To solve the problem of accelerating the construction of roads, improving their quality, it is advisable to use a continuous action unit to form a underlying layer. The main working bodies of this unit are buckets, which cut off the soil layer from below and on the side. At the same time, the bottom knife cuts off the ground layer from below, the right knife on the side, and the console knife partially cuts the top layer of soil from below for the next bucket. In particular, the analysis of interaction with the soil of the right knife of the continuous action unit is of theoretical and practical interest. To do this, the right knife is divided into elements and analyzed the interaction of these elements with the ground. The consistent impact on the soil of many right knives, within the width of the grip of the unit, is replaced by the impact on the ground of one conventional right knife at a distance necessary for the development of one cubic meter of soil. The forces of interaction of the conventional right knife with the ground are called conditional forces.

The method of research. The method for calculating the energy costs during punching the right knife into the ground is shown: on separating the formation of the ground from its body, on overcoming the ground friction on the edge of the blade, on overcoming the ground pressure on the edge of the blade, on accelerating the ground of the blade by means of the axle, on overcoming the ground friction on the shelf, to overcome the ground friction against the outside surface.The total energy costs of interacting with a soil of one cubic meter are derived from the addition of private energy costs. The method of calculating the horizontal longitudinal force needed to move the right knife is given.

Results. On the basis of the methodology developed, energy costs are calculated when introducing the right knife into the ground: on separating the soil from its body, on overcoming the friction of the ground on the edge of the blade, on overcoming the pressure of the ground on the face of the blade, on the acceleration of the ground with a fascia blade, on overcoming the ground friction on the face. The total energy costs of the right knife interact with the soil of one cubic meter. The horizontal long-lived force needed to move the right knife has been determined.

Conclusion. As a result of the calculations: the energy needed to cut the ground with the right knives, more than 71 J/cube. The horizontal longitudinal force needed to move the right knife is 730 N. To determine the total energy spent on cutting the ground by buckets of the unit to remove the top layer of soil from the underlying layer of the road, it is necessary to analyze the interaction with the soil of other elements of the bucket.

464-475 7869
Abstract

Introduction. The article examines the problem of choosing a material and method for increasing the wear resistance of construction machines elements. The performance of construction machines is affected by the reliability of the parts used. The selection of materials for their manufacture allows to calculate the probability of how such elements will affect its ability to work and productivity.

Materials and methods. In the process of determining the material and the method for increasing the wear resistance of construction machines, structural steels with various chemical compositions were selected: lowcarbon 08ps (as a model material), 10, 20.30, St3 and low-alloy steels 09G2S and 10HSND, as well as high-carbon steel 65G and boron steel 30MnB5. The methods as high temperature annealing, normalization, injection and high temperature release, thermocyclic processing, cold plastic deformation, thermocyclic processing of steels after cold plastic deformation were used.

Results. During the experiment, it was found that both for low-carbon 08ps, 10, 20, 30, St3, and for low-alloy structural steels 09G2S and 10HSND, as well as for high-carbon steel 65G and for boron-containing steel 30MnB5, an increase in the number of TCT cycles (thermal cycling) leads to an increase in the strength properties of the metal. With an increase in the number of cycles over 3-6, the increase in strength properties slows down significantly.

Conclusion. In contrast to heat treatment, TCO allows to identify the positive effect of alloying on strength and plastic properties to a greater extent. At the same time, significantly increasing the strength and plasticity, it is possible to obtain previously unattainable values of the work of destruction of alloy steels in the process of various types of loading. Accordingly, the preliminary preparation of steel for the production of individual elements of machines and mechanisms will increase their strength and wear resistance.

476-486 614
Abstract

Introduction. The human factor and the characteristics of construction and road machine operators, such as experience, work experience, professional skills, skill, etc., have a significant impact on the efficiency of equipment operation. The human factor, on average, is the cause of about a third of the failures of construction and road machines. One of the most effective ways out of this situation is to improve the machines from the point of view of ensuring the compatibility of the elements of the human-machine system. The article considers the issues of the engineering and psychological component of compatibility.

Materials and methods. The method of analysis of hierarchies is used, when solving the problem of identifying the causes of operators’ errors and fuzzy logic, to build a model for assessing the impact of the human factor on the efficiency of construction and road machines.

Results. As a result of a comprehensive assessment of the causes of errors, it was found that the largest combination of criteria is a group of errors associated with the peculiarities of the task being performed, as well as the properties of the information processed by a person. The developed model for assessing the influence of the human factor on the efficiency of machine operation uses risk as an output variable, and input variables a generalized indicator of the complexity of the algorithm and the level of qualification of the machine operator.

Discussion and conclusions. The resulting model allows you to make a primary assessment of the impact of the human factor and maintenance and repair planning, as well as be used in personnel management processes, for example, in terms of sending personnel for training. Further improvement is seen in the development of neurofuzzy anfys models which provide a knowledge base for more effective risk assessment by specific precedents. The structure of the model in terms of input variables for a more correct risk assessment is also possible to be changed.

TRANSPORT

488-499 898
Abstract

Introduction. Improving road safety is a state-level task reflected in many regulatory documents of the Russian Federation, such as a federal law, federal target program, national project, etc. The systematic approach considered in the article is aimed at developing an effective approach and targeted actions in the field of ensuring road safety in road transport. The use of an integrated approach instead of disparate single actions will allow achieving the tasks set for the state to reduce the accident rate on the country’s roads.

Materials and methods. Analytical methods based on analysis of links, flows, temporary analysis of events, methods of road traffic safety assessment based on detection of safety and accident factors, detection of accident concentration places, methods of probability theory and processing of research results, software-computing methods of information technologies.

Results. A system of road infrastructure indicators has been developed in a complex application with the analytical methods and methods of the accident forecasting system, an information technology tool and systems – an electronic receiving organization for road safety to develop a system organization and manage the level of road safety in the road participant – vehicle – road – external environment system.

Discussion and conclusions. The expediency of taking into account the mechanisms for achieving the results of the program-targeted approach and the direction of their implementation, the proven scientific results of studies of the concentration of road traffic accidents to improve the work of the state mechanism for ensuring road safety is substantiated.

500-511 894
Abstract

Introduction. The use of electroplating in the production and restoration of machine parts is important for increasing reliability and reducing costs in the operation of cars. At the same time, strengthening and restoring parts with chrome, iron and alloys based on them leads to additional costs, due to the specifics of technologies and the need to maintain certain operating temperatures of electrolytes to obtain high-quality and high-performance precipitation. Since existing devices for maintaining the temperature of the electrolyte have a complex design and require additional energy costs, we are constantly searching for ways and designs that will simplify the design, increase its reliability and reduce energy costs.

Materials and methods. The current method for maintaining the temperature of electrolytes of current bath is taken as a prototype for the research. An improved plant was designed and tested in real conditions for the production of chrome, iron precipitation and alloys based on them.

Results. The developed installation makes it possible to reduce energy consumption and improve the quality of electrolytic coatings. The developed installation allowed maintaining the temperature in the required range, both at low temperatures of 20÷35oC and at high temperatures of 40÷60oC.

Discussion and conclusion. As a result of the analysis of the existing methods for maintaining the temperature of the electrolyte, their shortcomings are identified and a new method is proposed that will allow controlling and maintaining the necessary operating temperature of the electrolyte in the required operating range without significant fluctuations. The developed installation can be put into production, which will allow industrial use of complex temperature-sensitive chrome plating technologies, while obtaining high-quality electroplating coatings.

512-522 805
Abstract

Introduction. The Road Traffic Safety Strategy in the Russian Federation for 2018-2023 includes the tasks of reducing an accident rate, among which the problem of accidents outside built-up areas is highlighted. The accidents outside built-up areas are characterized with high severity of consequences. The analysis of accident factors is necessary for the development of methods to improve road safety by preventing road accidents.Determining functional dependence is necessary for the development of information road safety management systems.The article is devoted to the study of the influence of precipitation amount on the change in the risk of road accidents.

Materials and methods. The study applied a relative risk analysis, which is calculated by comparing observed variables of two groups: total rainfall data (climatic frequencies) and accident sampling (frequency at time of accident).The study bases on the data of road accidents with victims and material damage that have been registered on the А-322 road (Barnaul – Rubtsovsk – the state border with the Republic of Kazakhstan) during the period from 2012 to 2017.

Results. A graph functional dependence and piece wise linear functional dependency were obtained. As the result of approximation, functional dependencies in the form of third-order polynomial function were found.

Practical importance. The obtained functional dependencies can be used in the management system to assess the current risk of road accidents on roads outside build-up areas. The regularity of the influence of precipitation on the risk of road accidents can be used to implement accident prevention measures at the stage of road design and operation.

Originality. The study contains new results on the nonlinear form of the functional dependence of the amount of precipitation on the risk of road accidents.

CONSTRUCTION AND ARCHITECTURE

524-536 652
Abstract

Introduction. This article addresses the issue of optimizing the movement of road users in an urban environment. The need to resolve this issue arose due to the suboptimal design of the city’s street-road network, consisting in an increase in traffic intensity to limit values and the inability of traffic lights to solve the problems of global demand for vehicle movement. It is also important to address the issue of the movement of ever-increasing pedestrian flows.Optimization of traffic conditions is assumed by the device of integrated transport schemes. The main disadvantage of solving this issue is the limited regulatory documentation that would be applicable in urban environments.

Materials and methods. In the article, the authors used, as a fundamental method of analogy, a comparison of the categories of streets and urban roads with suburban highways. Also, the advantages of individual road junctions and their systems and the level of convenience of the streets of Tiumen were analyzed.

Results. The results are variants of complex traffic intersections that satisfy the requirements defined in advance regarding various types of intersections with the following indicators: distance between minor streets, number of lanes on the streets, radii of circular curves.

Conclusion. Based on the results of this article, it is advisable to consider the third variant of the complex intersection, which is the most promising in terms of the considered parameters.



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ISSN 2071-7296 (Print)
ISSN 2658-5626 (Online)