Parts Of Rolling Stock Research Articles

Snow accretion on a model train: Climate wind tunnel experiments

Snow and ice accumulation on the main parts of rolling stock can lead to malfunctions and safety issues. This paper presents the results of snow accretion tests conducted in a climate wind tunnel to investigate the icing process on a model train at various ambient temperatures. A simplified 2/3-scale EMU-320 high-speed Korean train model was used without electrical power or heat sources. Before testing, the snow flux and liquid water content of snow were measured to enable their use as input conditions in future simulations and to inform further analysis of the icing process. Both qualitative and quantitative data from the tests were analyzed, including photographs and snow density and thickness measurements. Snow accretion was broader at higher ambient temperatures, and snow accretion on the nose tended to be thicker further away from the stagnation point at higher temperatures. Snow accreted on all components of the bogie, and the thickest snow accretion on the wheels occurred at arc angles of 15–40° for cases of lower temperature while occurring at a larger angle at the highest temperature. The comprehensive data from these experiments is expected to support future analysis and development of anti-icing systems.

Forecasting the Residual Life of Wheelsets of 81-740/741 «Rusich» Cars of the Metro Electric Trains

A modern approach to determining the useful life of components and parts of rolling stock allows not only to estimate the pre-failure state of an object, but also to predict its useful life.The objective of the study is to predict the mileage of wheelsets of modern electric trains of the «Rusich» series based on the use of statistical data and assessment of the residual life.The study used real data recorded during maintenance and repair of electric trains.The proposed approach allows getting a vivid presentation of the equipment wear rate, since it is based on the use of the measured parameters of the object. The analysis of these values makes it possible to determine the processes occurring in the product. When using large samples, it becomes possible to approximate the obtained numerical values and make a forecast of the technical condition with greater reliability.The task of predicting the residual life is quite complicated and must be solved separately for each type of equipment. That is why the generally accepted world practices are associated with preventive maintenance and repair system, while modern automated digital systems for technical diagnostics (including on-board and built-in ones) make it possible to partially switch to technical maintenance and repair considering the actual technical condition of the rolling stock.

Application of the fuzzy data theory in durability estimation

Aim. Problems associated with the study of material fatigue, while being relevant in terms of engineering practice, have a significant degree of uncertainty. The fatigue curve is censored (which indicates the presence of items that have passed the planned load cycle and destroyed by the end of the tests), while the load block made for calculating durability can be designed in a number of ways with a sufficient share of subjective decisions. The load block is intended for calculating durability and defining test plans. It is to fully reflect the entire expected operational history. Both factors are considered in the paper as elements of fuzzy logic. The author examines the creation of a scientifically substantiated load block that would take into account the possible operating modes in a right proportion and taking into account the variability. That is due to the fact that fatigue damage accumulates over the entire life of a machine and is to be scientifically evaluated for an adequate probabilistic assessment. Methods. As the modes of operation of a certain part are not precisely defined (and cannot be defined by virtue of the logic of random use of machines), projections of random fuzzy distributions are considered. A finite set of operating modes in a reasonable proportion was successfully scientifically substantiated. Using the example of load analysis of a critical part of rolling stock, distributions were constructed and the possible distribution of a part’s life was estimated. The output of the developed method will allow assessing the operational risks and predict the required number of spare parts. By taking into account the censored sample elements in the process of fatigue curve construction, the estimation of the fatigue curve parameters can be made more consistent. Conclusions. The use of fuzzy sets may prove to be very useful when examining fatigue curves and estimating durability variation. Examples are given of applying the proposed method.

Resurfacing the exhaust valve by plasma spraying versus electric arc and gas flame methods

In modern conditions of economic instability in various sectors of industry for the national economic complex, it is important to improve the technology for repairing parts of power units, while the development of modern technological methods for restoring the contact surfaces of parts should be carried out in the conditions of enterprises and be accessible. The article compares the most common methods of surface parts restoration, such as flame, plasma spraying and electric arc surfacing. Studied experience of various specialists working in this direction made it possible to implement these reduction methods using a charge based on a mineral tungsten-containing concentrate, boron and carbon. The process of alloying the resulting coatings was investigated, where tungsten is in the form of tungsten trioxide (WO3) and calcium tungstate (CaWO4). A comparative analysis of the methods for restoring the surface of the exhaust valve cone of the D49 diesel engine has been carried out. The article presents results of microand macroanalysis of the structures of the obtained coatings and the base metal of the restored part, the results of the analysis of the chemical composition, the evaluation of the microhardness and adhesive strength of the adhesion of the obtained coatings to the surface of the base metal. Authors substantiated the prospect of applying the methods of gas-thermal restoration of the surface of parts in relation to the method of electric arc surfacing. Subsequent studies will focus on the installation of remanufactured parts in the internal combustion engine of the locomotive, their operation in real conditions, and the assessment of reliability and durability. Research in this direction will improve the quality indicators of the restored surfaces of power unit parts of rolling stock.

Increasing Service Life of a Railway Wheel with Surface Hardening Technology

The article presents surface hardening technology as applied to solid-rolled wheels of rolling stock. The obtained results of the theoretical study on the process of strengthening the metal of the wheel will make it possible to develop scientifically grounded technological and technical solutions to prevent formation and development of defects on the rolling surface, as well as to eliminate them during maintenance.The objective of this work is to identify the optimal method for surface hardening of a railway wheel with defects.At present, the issue of extending service life of elements and critical parts of rolling stock is becoming increasingly acute. Due to the limited economic feasibility and limited availability of existing production technologies, it becomes necessary to create a new material modified with nanoclusters and hardened with surfactants.Nanoclusters have high plasticity and hardness values. To determine the hardness value of nanomaterials, the Vickers hardness test method is used, in which hardness is determined by the size of the area of the indentation after removing the load from the pyramid shaped diamond.Superplasticity is observed in nanostructures. For nickel and nickel-aluminium alloy NiAl3, low-temperature superplasticity is observed in the temperature range 450–470°C, which is three times lower than their melting point.

Improving the technology of restoration of spare parts of rolling stock

Improving the technology of restoration of spare parts of rolling stock

Combined approach to an assessment of maintenance of electrical equipment on traction rolling stock

A possible approach to assessment of factors influencing the service-life parameters of electrical equipment on locomotives and the variants of their states is considered. The scheme proposed for the variants of states can be carried out as a system of rolling-stock maintenance. The need to increase the reliability of electronic and electrical equipment is especially acute during the operation of high-speed rolling stock, given that circuitry and structural solutions are extremely complex. In developing the computational systems and their capacity, it becomes possible to calculate large data volumes and update the problem of constructing optimal variants of state development in complex technical systems. The costs for rolling-stock maintenance and repair can be reduced by using both maintenance-free elements of rolling stock and an assembly or a part of rolling stock with a complicated structure. In connection with this, new assemblies consist of several elements with known indices of reliability and service life, but have different characteristics as a whole. An approach to technical indices of assemblies and elements as static values of certain functions is considered. A decomposition approach to an integrated reliability index and variants of planning the extents of repair and maintenance that need to be undertaken is carried out depending on the variants of states of an electromechanical assembly in rolling stock.

ПЕРВООЧЕРЕДНЫЕ ЗАДАЧИ РАЗРАБОТКИ И ВНЕДРЕНИЯ СОВРЕМЕННЫХ СРЕДСТВ КОНТРОЛЯ И ДИАГНОСТИКИ СОСТОЯНИЯ ПОДВИЖНОГО СОСТАВА

The article analyzes the existing state of providing railway transport enterprises with modern means of monitoring and diagnostics of rolling stock, problematic issues of traffic safety, introduction of modern, effective control systems and technical diagnostics of the condition of units and parts of rolling stock. A set of measures is proposed to improve the quality of metrological support for rolling stock repair processes.

Technological Support of Critical Parts for Railway Transport Working Properties

The materials of complex research of operational properties of a new brand cast iron CHMN-35M. Optimal chemical composition was determined. The obtained results allow to conclude about possibility of its use for the manufacture of critical parts of rolling stock of railway transport, in particular of a side bearing cap

Сверхзвуковое электродуговое напыление ответственных деталей подвижного состава железнодорожного транспорта

Сверхзвуковое электродуговое напыление ответственных деталей подвижного состава железнодорожного транспорта

Supersonic electric arc spraying of critical parts of rolling stock of railway transport

Supersonic electric arc spraying of critical parts of rolling stock of railway transport