scholarly journals Increasing Service Life of a Railway Wheel with Surface Hardening Technology

2021 ◽  
Vol 19 (1) ◽  
pp. 48-59
Author(s):  
T. G. Bunkova
Keyword(s):  
Service Life ◽  
Surface Hardening ◽  
Hardness Test ◽  
Economic Feasibility ◽  
Test Method ◽  
Rolling Stock ◽  
High Plasticity ◽  
Optimal Method ◽  
Railway Wheel ◽  
Rolling Surface

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.

scholarly journals Influence of the axial loads of rolling stock on the contact-fatigue life of rails

2018 ◽  
Vol 77 (3) ◽  
pp. 149-156 ◽  
Author(s):  
V. S. Kossov ◽  
G. M. Volokhov ◽  
O. G. Krasnov ◽  
M. N. Ovechnikov ◽  
A. L. Protopopov ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Service Life ◽  
Contact Fatigue ◽  
Calculated Data ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Axial Loads ◽  
Rolling Surface ◽  
Contact Fatigue Life ◽  
The Impact

Analysis of operational data for defective and highly defective rails showed that up to 25 % is the contact-fatigue defects. In connection with the development of heavy haul traffic on the Russian railways, it is relevant to determine the influence of cars with increased axial loads of 25 and 27 tf on the contact fatigue life of rails. The solution of this problem is set forth in this article. The Brown-Miller model of multi-axial fatigue was used in the calculation. This model is integrated into the Fatigue software system, which is tied to the Marc calculation system through Pat-ran. Since under operating conditions the wheel moves (rolls) along the rail on meandering trajectory, in computer modeling weight coefficients were taken into account that characterize the percentage of wheels in the cross-sectional areas of the rail. Calculations of contact fatigue life took into account the variability of vertical loads from the impact on the track of trains formed from innovative open cars with axial loads of 23.5, 25 and 27 tf under operating conditions, loaded with real loading blocks. According to the analysis of calculated data with an increase in axial loads from 23.5 to 25 tf, it is necessary to expect a decrease in the service life of rails in contact fatigue resistance by 19 %, with a further increase in axle loads of up to 27 tf per 32 %. Considering that the share of freight cars with axial loads of 25 tf does not exceed 15...20 %, then on the routes of its use the service life of rails should be expected to decrease by 3...4 %. The method proposed by the authors for predicting the contact fatigue life of rails with increasing axial loads is advisable to improve in part of the experimental determination of the fatigue and strength characteristics of rail steel from the degree of hardening of the rolling surface, its probabilistic properties and the use of the integral distribution law for vertical forces, taking into account the structure of the freight traffic passing through the section. The work was carried out according to the RFBR project 17-20 01088.

scholarly journals New bench for testing the reliability of windows and doors of passenger cars

2021 ◽  
Vol 80 (2) ◽  
pp. 86-90
Author(s):  
V. A. Makarov
Keyword(s):  
Service Life ◽  
Construction Industry ◽  
High Speed ◽  
Moving Objects ◽  
Test Method ◽  
Rolling Stock ◽  
Passenger Cars ◽  
Bench Tests ◽  
Aerodynamic Pressure ◽  
High Speeds

The article describes a new bench for testing the reliability of passenger car windows and doors. The bench can be used in various industries, mainly in transport engineering, as well as in the construction industry. This bench is functionally designed to test the entire product (windows or doors), as well as to determine the service life of individual mechanisms of this product. In contrast to the known analogs, the new bench for testing the reliability of windows and doors allows testing under the influence of variable aerodynamic pressure arising from the operation of windows and doors on moving objects, for example on high-speed transport. Specially developed test method is proposed on this bench, which allows simulating alternating aerodynamic effects on windows and doors that occur when a train passes tunnels or when trains in opposite directions diverge at high speeds. Thanks to this, bench tests can serve as an actual addition to the existing methods of testing windows and doors of modern high-speed rolling stock.

Evaluation of the Resistance of Individual Si Die to Cracking

1998 ◽  
Author(s):  
R. Berriche ◽  
R.K. Lowry ◽  
M.I. Rosenfield
Keyword(s):  
Thermal Cycling ◽  
Hardness Test ◽  
Mechanical Stresses ◽  
Test Method ◽  
Processing Conditions ◽  
Micro Hardness ◽  
Test Methodology ◽  
Vickers Micro Hardness

Abstract The present work investigated the use of the Vickers micro-hardness test method to determine the resistance of individual die to cracking. The results are used as an indicator of resistance to failure under the thermal and mechanical stresses of packaging and subsequent thermal cycling. Indentation measurements on die back surfaces are used to determine how changes in wafer backside processing conditions affect cracks that form around impressions produced at different loads. Test methodology and results obtained at different processing conditions are discussed.

scholarly journals Effectiveness of a New Drainage System for Decreasing Erosion in Road Hillslopes

2021 ◽  
Vol 14 ◽  
pp. 117862212098872
Author(s):  
María Fernández-Raga ◽  
Iván García-Díez ◽  
Julian Campo ◽  
Julio Viejo ◽  
Covadonga Palencia
Keyword(s):  
Service Life ◽  
Drainage System ◽  
Economic Feasibility ◽  
Scale Model ◽  
Maintenance Cost ◽  
Road Maintenance ◽  
Experimental Conditions ◽  
Traditional System ◽  
Strategic Value ◽  
On The Road

Water is one of the most important erosive agents in roadside hillslopes. When these are built with ineffective drainage systems, erosion occurs, reducing road’s service life. However, these systems are not receiving the appropriate importance, given their strategic value. Therefore, a new drainage system called ‘branched’ is proposed in this study. Its technical and economic feasibility is compared with those of the traditional system, which consists of drainages with lines that follow maximum hillslope, to assess differences in relation to erosion, construction and maintenance costs, and service life. Different parameters were analysed, such as the average velocity of water (mm−1) running through the channels, its average specific energy (kJ), and its drag force (N). A scale model was constructed and used to test these factors before implementing it in natural terrain for testing it under field conditions. According to the theoretical and measured results, these factors were lower in the branched drainage than in the traditional one (from 24% to 34% in speed, from 37% to 60% in energy, and from 51% to 73% in force). The service life of hillslopes with a branched system of up to 0.5 m high and 1:2 grade is significantly longer than in those with a traditional drainage. Although the initial economic expense for the construction of the branched system is higher (€3534/m3 as opposed to €2930/m3 for the traditional one), its maintenance cost will be lower than the traditional one (€1230/m3 per year for the branched one as opposed to €1332/m3 per year for the traditional one). Consequently, under our experimental conditions, the proposed drainage will be profitable from the eighth year of construction, saving on the road maintenance in the following 15 years of service life.

scholarly journals TO THE QUESTION OF THE CHOICE OF MOBILE COMPOSITION IN THE BRT SYSTEM

2021 ◽  
Vol 1 (48) ◽  
pp. 257-269
Author(s):  
Poliakov V ◽  
◽  
Yaschenko D ◽  
Sharai S ◽  
◽  
...  
Keyword(s):  
Economic Feasibility ◽  
Maximum Length ◽  
Rolling Stock ◽  
Total Power ◽  
Motor Transport ◽  
The Road ◽  
Passenger Traffic ◽  
System Use ◽  
On The Road ◽  
System Power

In article the question at the choice of the rolling stock of passenger motor transport in the BRT system which provides movements of buses on specially allocated and often obgorodzheny strips, that is its full isolation on the road from other means of transport is considered. For increase in passenger capacity in the BRT system use three-link buses and trolleybuses. Along with indisputable advantages of three-link buses and trolleybuses also shortcomings - the worst maneuverability and stability of the movement in comparison with two-link are inherent in them. Besides, the efficiency of operation of such cars is provided with a passenger traffic which during the day can change many times. Therefore the road train as a part of two (or three) the buses or trolleybuses working in connection, і which passenger capacity similar to the jointed buses and trolleybuses can become perspective. In rush hours the bus train, and in interpeak the period - each bus separately works (the possible parking of one bus at allocated to the platform). In view of restriction of the maximum length of the bus train at the level of 24.26 m, as buses as making road trains, we will accept the 8th meter buses MAZ 206. Passenger capacity of such bus is 72 passenger, the power of the traction engine - 160 kW. The expediency of use of three-link hook-on road train is proved by the conducted researches that MAZ 206 with a total length up to 26 m and with a passenger capacity up to 220 passengers in the BRT system consists of three same buses. It is shown that the total power of engines is necessary for the movement of such bus train with a speed of 25 m/s has to make 300 kW while for one bus at the movement with the same speed it has to be at the level of 135 kW. It demonstrates about economic feasibility of use of the bus train from three buses working in connection because for their movement in all range of speeds there is enough power of two engines, that is one of buses can be used as the passive trailer that will lead to improvement of fuel profitability of the bus train. It is established that on maneuverability indicators three links the hook-on road train considerably exceeds three links pivotally - the jointed bus. So, the dimensional lane of the hook-on bus train at execution of the most typical maneuvers by it during the work on a city route does not exceed 3.9 and 4.1 m at turns respectively on 900 and 1800 that it is much less, than for three links pivotally the jointed bus 24 m long respectively of 6.8 and 8.2 m. KEYWORDS: THREE-UNIT THE ROAD TRAIN, THE BUS, PIVOTALLY-THE JOINTED BUS, THE BRT SYSTEM, POWER, MANEUVERABILITY, A TRAJECTORY, OVERALL STRIP

scholarly journals Thermoset Polymer Splicing Study Using a variation of welding

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Adi Prastyo Utomo ◽  
Prantasi Harmi Tjahjanti
Keyword(s):  
Hardness Test ◽  
Test Sample ◽  
Test Method ◽  
Polymer Materials ◽  
Hardness Testing ◽  
Hot Gas ◽  
Thermoset Polymer ◽  
Materials Used ◽  
Thickness Variations ◽  
Plastic Welding

There is not much plastic welding currently done and not much research has been done on plastic welding. The purpose of this study was to study the use of welding variations used to join the thermoset polymer material. The thermoset polymer materials used are acrylic, melamine and bakelit with the test sample measuring 80mm in length, 30mm in width and 3mm in thickness. Variations in welding are used using hot gas welding, electric soldering and gas torches. The test method is carried out after welding to determine the porosity of the weld using a penetrant liquid. Hardness testing was also carried out. The best welding results are shown on acrylic material using electric solder, showing that the amount of porosity is the least, and has the highest hardness test.

scholarly journals Comparison of Accelerated Decay and Graveyard Test on Selected Malaysian Timber Species

2015 ◽  
Vol 3 (1) ◽  
pp. 238-241
Author(s):  
Noor Azrieda A.R ◽  
Salmiah U ◽  
Rahim S
Keyword(s):  
Service Life ◽  
Wood Decay ◽  
Test Methods ◽  
Laboratory Method ◽  
Test Method ◽  
Natural Durability ◽  
Timber Species ◽  
Ground Contact ◽  
Paper Briefly ◽  
Geographical Locations

The natural durability of timber may be defined as ‘inherent resist ance of timber to attackby wood deteriorat ion agents such as wood decay ing fungi and wood destroying insects’. In Malay sia, natural durabilit y of t imber is det ermined using a ‘gravey ard’ test . The average time taken for this test is more than 10 years. The results of this test method donot provide information on longevity (service life) either out of ground contact, or inother geographical locations. Comparison of natural durability requires the use ofstandard test method where for example in Europe, the accepted laboratory method is EN350-1. This paper briefly describes the rating of natural durability based on comparisonresults of the two test methods stated i.e the exterior graveyard test and the interior laboratory test.

One of possible approaches to estimating the service life of a wheel set axle of high-speed rolling stock

2021 ◽  
Author(s):  
G. M. Volokhov ◽  
A. A. Lunin ◽  
D. A. Knyazev ◽  
V. V. Chunin ◽  
M. V. Timakov
Keyword(s):  
Service Life ◽  
High Speed ◽  
Rolling Stock

CHARACTERISATION OF BIOMEDICAL TITANIUM LAYERS DEPOSITED BY A VACUUM PLASMA SPRAY PROCESS

2021 ◽  
Vol 55 (2) ◽  
pp. 231-235
Author(s):  
Mihailo Mrdak ◽  
Darko Bajić ◽  
Darko Veljić ◽  
Marko Rakin
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hardness Test ◽  
Optical Microscope ◽  
Mechanical Tests ◽  
Test Method ◽  
Bonding Layer ◽  
Vacuum Plasma Spray ◽  
Porous Ti ◽  
Scanning Electron

In this paper we will describe the process of the deposition of thick layers of VPS-Ti coating, which is used as a bonding layer for the upper porous Ti coatings on implant substrates. In order to deposit the powder, we used HÖGANÄS Ti powder labelled as AMPERIT 154.086 -63 µm. In order to test the mechanical properties and microstructure of the VPS-Ti coating, the powder was deposited on Č.4171 (X15Cr13 EN10027) steel substrates. Mechanical tests of the microhardness of the coating were performed by the Vickers hardness test method (HV0.3) and tensile strength by measuring the force per unit area (MPa). The microhardness of the coating is 159 HV0.3, which is consistent with the microstructure. The coating was found to have a good bond strength of 68 MPa. The morphology of the powder particles was examined on a scanning electron microscope. The microstructure of the coating, both when deposited and etched, was examined with an optical microscope and a scanning electron microscope. By etching the coating layers, it was found that the structure is homogeneous and that it consists of a mixture of low-temperature and high-temperature titanium phases (α-Ti + β-Ti). Our tests have shown that the deposited layers of Ti coating can be used as a bonding layer for porous Ti coatings in the production of implants.

STUDY OF RESIDUAL RESOURCE AND ESTABLISHMENT OF THE LIMIT LIFE OF NON-PURCHASER PASSENGER CARS OF CONSTRUCTION OF KVZ

2020 ◽  
pp. 54-62
Author(s):  
N. Radkevich ◽  
S. Sapronova ◽  
V. Tkachenko
Keyword(s):  
Service Life ◽  
Residual Life ◽  
Rolling Stock ◽  
Technical Diagnostics ◽  
Passenger Cars ◽  
Load Bearing ◽  
Metal Structures ◽  
Passenger Traffic ◽  
Long Operation ◽  
Theoretical Results

In order to ensure the uninterrupted performance of passenger traffic, the task of ensuring the operation of rolling stock outside the extended service life, including passenger cars for the carriage of passengers, remains relevant. Based on this, there is a need for comprehensive research aimed at substantiating the possibility of ensuring operation while maintaining dynamic and strength characteristics. The article examines the residual life of load-bearing metal structures of passenger cars based on the results of technical diagnostics and standard tests. It is concluded that the condition of the load-bearing metal structures of passenger cars built by the Kryukiv Carriage Plant (KСP) after long operation does not approach the limit. The obtained practical and theoretical results make it possible to extend the service life of passenger cars for the construction of KCP beyond the factory set by 41 years.

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