scholarly journals Experience in ensuring the strength of the supporting structures of locomotives and electric multiple units

2019 ◽  
Vol 78 (2) ◽  
pp. 67-73
Author(s):  
V. V. KOCHERGIN ◽  
A. A. BUKHANTSEV ◽  
I. G. PANKRATOVA ◽  
O. A. RUSANOV
Keyword(s):  
Fatigue Strength ◽  
Fatigue Testing ◽  
Dynamic Strength ◽  
The Body ◽  
Rolling Stock ◽  
Load Bearing ◽  
Cyclic Stresses ◽  
Strength Tests ◽  
Cis Countries ◽  
Multiple Units

To ensure fatigue strength of metal structures in mechanical engineering, various approaches are practiced. One of them allows for the appearance of cyclic stresses in details with amplitudes exceeding the fatigue limit. Typically, this approach is justified where the loads are fairly regular and ample opportunities for fatigue testing exists, but the requirement of a minimum metal consumption is critically important as well. Another approach to ensuring fatigue strength does not allow the possibility of cyclic stresses with amplitudes exceeding its endurance limit in the designed structure. With regard to the supporting elements of locomotives and electric multiple units (EMU) to ensure the fatigue resistance characteristics in Russia and the CIS countries, the second of these approaches has been implemented and successfully practiced for many years. Its purpose is to ensure the absence of fatigue damage in the parts of the carriage and the body during the designated service life. Relevant requirements for strength and dynamic qualities for these types of rolling stock, as well as the method of conducting dynamic strength tests are currently formalized in the standards. The article presents the main provisions of the methodology currently used on the railways of the Russian Federation and CIS countries to control the strength requirements of load-bearing structures of locomotives and EMUs, as well as the admission of these types of rolling stock to operation. Types of dynamic strength tests are described, strength indicators are listed, methods for their determination are indicated. Today, this technique successfully solves the problem of the strength of load-bearing structures of traction rolling stock.

On assessment of fatigue strength of freight car structures for high-speed trains

2020 ◽  
pp. 36-40
Author(s):  
Grigoriy Mikhaylovich Volokhov ◽  
◽  
Gadzhimet Isamedinovich Gadzhimetov ◽  
Keyword(s):  
Fatigue Strength ◽  
High Speed ◽  
Rolling Stock ◽  
Customs Union ◽  
Load Bearing ◽  
Regulatory Documents ◽  
High Speed Trains ◽  
Weak Points ◽  
Freight Car ◽  
European Standards

The paper presents results of analysis of statements of relevant methods on assessment of fatigue strength of loadbearing structures of cars, locomotives and motive-coach rolling stock. It also discusses methods that are established by regulatory documents supporting technical regulations of the Customs Union and European standards. The authors have carried out an analysis of methods of both rolling stock tests on the line and rig tests of load-bearing structures. During the analysis they revealed strong and weak points of the existing methods for assessing fatigue strength. As a result, methodical approaches to assess fatigue strength of load-bearing structures of freight cars for high-speed trains were proposed.

scholarly journals Optimization of an EMU train carbody by the value of the natural bending frequency

2021 ◽  
Vol 80 (3) ◽  
pp. 152-159
Author(s):  
R. V. Guchinsky
Keyword(s):  
Vibration Frequency ◽  
Natural Vibration ◽  
The Body ◽  
Rolling Stock ◽  
Natural Vibration Frequency ◽  
Body Structure ◽  
Main Bearing ◽  
Bending Vibrations ◽  
Load Bearing ◽  
Target Values

Finding ways to optimize the body structure is an important point in the design of new electric train cars. Reducing the mass of the body leads to a lightening of the parts of the rolling stock associated with it, a reduction in energy consumption for operation and a decrease in wear in the “wheel — rail”system. Reducing the weight of the body is possible by assigning optimal rigidity to its main load-bearing elements. Increasing the rigidity of the body with a constant mass is also an important task to obtain the standard dynamic properties of the car body.The article presents method for optimizing the body structure based on calculating the value of its first frequency of natural bending vibrations. The calculation was carried out by the finite element method using a simplified beam-shell parametric model. Within the optimization calculations, 3125 working versions of sections of the main load-bearing structural elements with different rigidity were considered — bracing and cross-beams of the frame, inter-window racks and cross-beams of the roof. The sensitivity of the value of the natural vibration frequency to the change in the rigidity of the main bearing elements without taking into account the change in mass is analyzed. It was found that the rigidity of the frame bracing and cross beams has the greatest influence on the frequency value. It is shown that the ratio of the rigidity of the main bearing elements does not remain constant for optimal design options and depends on the design of the body, the target values of its mass and rigidity. When mass is limited, it is possible to choose designs that are characterized by the greatest overall body rigidity and are the most optimal in terms of manufacturability. By limiting the values of natural vibration frequency, it is possible to choose a body structure with the lowest metal mass. The presented approach allows making decisions on body modification based on the required parameters of mass and (or) the frequency of natural bending vibrations. This approach can be used in pre-design studies of the bodies of new passenger rolling stock.

scholarly journals ПОВЫШЕНИЕ КОРРОЗИОННОЙ СТОЙКОСТИ ДЕТАЛЕЙ КУЗОВА МИКРОАВТОБУСОВ СЕМЕЙСТВА “ГАЗЕЛЬ”

2021 ◽  
pp. 53-62
Author(s):  
G.S. Chibukhchyan
Keyword(s):  
Corrosion Resistance ◽  
Service Life ◽  
Automotive Industry ◽  
Effective Means ◽  
Operating Conditions ◽  
The Body ◽  
Rolling Stock ◽  
Corrosion Properties ◽  
Load Bearing ◽  
The World

The automotive industry makes a significant contribution to the global economic production. Its annual turnover is comparable to the sixth largest economy in the world. The automotive industry accounts for about 5% of the world Gross Domestic Product (GDP). The automotive industry has a powerful multiplier effect and stimulates the development of a number of other industries. Automotive products account for about half of the world's oil consumption, half of the rubber produced, 25% of glass and about 15% of steel. Note that the size and structure of the automotive market often act as indicators of the level of economic development, and its state quickly and accurately reflects the changes taking place in the world economy.0 The average service life of a car is up to 15-20 years, depending on many factors. The service life is significantly reduced when the car is exposed to aggressive operating conditions. Most often, the car fails due to corrosion damage (corrosion) of its parts: the body, pipelines, elements of brake systems, frames and other important components. The damage caused to humanity by corrosion is enormous. According to various sources, corrosion "eats" from 10 to 25% of the world's iron production. As a result of corrosion of the load-bearing and critical elements of the rolling stock of road transport, reliability and performance, passive safety and road safety are sharply reduced, which requires the use of new effective means and methods to increase the corrosion resistance of critical parts and components of the car. One of the effective solutions to improve the anti - corrosion properties is the application of an insulating coating on the surface of the metal, which can significantly reduce the rate of its corrosion. However, it is necessary to take into account the economic component and the complexity of the technological process. For minibuses of the “GAZEL” family operated in Yerevan, it is of particular importance to increase the corrosion resistance of parts and load-bearing elements of the body.

scholarly journals Strength Tests of Hardened Cement Slurries for Energy Piles, with the Addition of Graphite and Graphene, in Terms of Increasing the Heat Transfer Efficiency

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1190
Author(s):  
Tomasz Sliwa ◽  
Aneta Sapińska-Śliwa ◽  
Tomasz Wysogląd ◽  
Tomasz Kowalski ◽  
Izabela Konopka
Keyword(s):  
Hardened Cement ◽  
Environmental Aspects ◽  
Cement Slurry ◽  
Subsequent Increase ◽  
Load Bearing ◽  
Heat Transfer Efficiency ◽  
Strength Tests ◽  
Energy Piles ◽  
New Buildings ◽  
New Facility

The development of civilization, and subsequent increase in the number of new buildings, poses engineering problems which are progressively more difficult to solve, especially in the field of geotechnics and geoengineering. When designing new facilities, particular attention should be paid to environmental aspects, and thus any new facility should be a passive building, fully self-sufficient in energy. The use of load-bearing energy piles could be a solution. This article presents research on the cement slurry formulas with the addition of graphite and graphene, that can be used as a material for load-bearing piles. The proposed solution is to introduce U-tubes into the pile to exchange heat with the rock mass (the so-called energy piles). A comparison of four slurry formulas is presented: the first one consisting mainly of cement (CEM I), graphite, and water, and the remaining three with different percentages of graphene relative to the weight of dry cement. The results could contribute to the industrial application of those formulas in the future.

Fatigue Life Improvement of Welded Elements and Structures by Ultrasonic Impact Treatment

2011 ◽  
Author(s):  
Yuriy Kudryavtsev ◽  
Jacob Kleiman
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Highway Bridges ◽  
Surface Layers ◽  
Ultrasonic Impact Treatment ◽  
Stress Relieving ◽  
Life Improvement

The ultrasonic impact treatment (UIT) is relatively new and promising process for fatigue life improvement of welded elements and structures. In most industrial applications this process is known as ultrasonic peening (UP). The beneficial effect of UIT/UP is achieved mainly by relieving of harmful tensile residual stresses and introducing of compressive residual stresses into surface layers of a material, decreasing of stress concentration in weld toe zones and enhancement of mechanical properties of the surface layers of the material. The UP technique is based on the combined effect of high frequency impacts of special strikers and ultrasonic oscillations in treated material. Fatigue testing of welded specimens showed that UP is the most efficient improvement treatment as compared with traditional techniques such as grinding, TIG-dressing, heat treatment, hammer peening and application of LTT electrodes. The developed computerized complex for UP was successfully applied for increasing the fatigue life and corrosion resistance of welded elements, elimination of distortions caused by welding and other technological processes, residual stress relieving, increasing of the hardness of the surface of materials. The UP could be effectively applied for fatigue life improvement during manufacturing, rehabilitation and repair of welded elements and structures. The areas/industries where the UP process was applied successfully include: Shipbuilding, Railway and Highway Bridges, Construction Equipment, Mining, Automotive, Aerospace. The results of fatigue testing of welded elements in as-welded condition and after application of UP are considered in this paper. It is shown that UP is the most effective and economic technique for increasing of fatigue strength of welded elements in materials of different strength. These results also show a strong tendency of increasing of fatigue strength of welded elements after application of UP with the increase in mechanical properties of the material used.

scholarly journals Fatigue Strength Analysis of S34MnV Steel by Accelerated Staircase Test

2020 ◽  
Vol 10 (1) ◽  
pp. 394-400 ◽  
Author(s):  
I. M. W. Ekaputra ◽  
Rando Tungga Dewa ◽  
Gunawan Dwi Haryadi ◽  
Seon Jin Kim
Keyword(s):  
Standard Deviation ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Fatigue Testing ◽  
Reliability Estimation ◽  
Test Method ◽  
Strength Analysis ◽  
Staircase Method ◽  
Staircase Test ◽  
Number Of Cycles

AbstractThis paper presents the reliability estimation of fatigue strength of the material used for crank throw components. The material used for crank throw components is forged S34MnV steel and subsequently heat-treated by normalising and tempering. High cycle fatigue testing under fully reversed cycling (R = −1) was performed to determine the fatigue limit of the material. The staircase test method is used to obtain accurate values of the mean fatigue limit stress until a number of cycles up to 1E7 cycles. Subsequently, the fatigue test results depend strongly on the stress step and are evaluated by the Dixon-Mood formula. The values of mean fatigue strength and standard deviation predicted by the staircase method are 282 MPa and 10.6MPa, respectively. Finally, the reliability of the design fatigue strength in some selected probability of failure is calculated. Results indicate that the fatigue strength determined from accelerated staircase test is consistent with conventional fatigue testing. Furthermore, the proposed method can be applied for the determination of fatigue strength and standard deviation for design optimisation of S34MnV steel.

FORMATION OF EXPERIMENTAL AND METHODICAL BASIS TO ESTIMATE STRENGTH CORRESPONDENCE OF DOMESTIC PASSENGER CAR BODIES TO EUROPEAN STANDARD BASIS

2021 ◽  
Vol 2021 (8) ◽  
pp. 67-76
Author(s):  
Sergey Korshunov ◽  
Aleksandr Skachkov ◽  
Sergey Samoshkin ◽  
Aleksandr Smirnov ◽  
Dmitriy Goncharov
Keyword(s):  
International Markets ◽  
The Body ◽  
Standard Basis ◽  
Rolling Stock ◽  
European Standard ◽  
Static Tests ◽  
Railway Infrastructure ◽  
Methodical Basis ◽  
Equipment Development ◽  
European Standards

The development of the international trade and the entrance of domestic car manufacturers into international markets required bench equipment development for tests in accordance with the requirements of the European standards. In this connection the purpose of this work is to develop an experimental and methodical basis for the estimation of the strength correspondence of export railway produce to the European standard basis. In the work there is shown a description of the bench developed for static tests of rolling stock for loads corresponding to the European standard basis. In the requirements mentioned there is used a more extended list of loads and combination of efforts and the necessity in the application of longitudinal loads to the elements of the end wall in three levels should be particularly emphasized. On the test bench there are carried out static tests of the car of model 61-4514 for Egyptian national railways and the body of the motor-rail car of model 2853 for the railway infrastructure of Serbia.

Assessment of Cryogenic Fatigue Strength of MARK-III LNG Carrier Insulation System

2009 ◽  
Author(s):  
Myung Hyun Kim ◽  
Yoon Pyo Kil ◽  
Min Sung Chun ◽  
Yong Suk Suh ◽  
Wha Soo Kim ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Dynamic Strength ◽  
Fatigue Loading ◽  
Limited Information ◽  
Insulation System ◽  
Fundamental Study ◽  
Design Guideline ◽  
Oil Companies ◽  
Containment System ◽  
Effective Manner

The importance of dynamic strength characteristics of LNG cargo containment system, various research efforts including dry-drop and wet-drop tests as well as sloshing test have been carried out by GTT, shipyards, oil companies, universities as well as classification societies. However, no explicit consideration with regard to the structural performance of insulation system toward the cryogenic environment is yet given. Besides only limited information regarding experimental procedure and analysis results is shared among stakeholders, and it acts as obstacles for the development of consistent CCS (Cargo Containment System) design criteria in an effective manner. Demand for LNG carriers with increased capacity requires further development of the design technology for LNG cargo tanks to meet the safety requirements due to the larger size LNG tanks. In this study, a systematic experimental research is required for the assessment of fatigue strength at cryogenic environment as well as impact strength of insulation system. The different sized mastic support has been adopted to compare the cryogenic fatigue performance. One of the main challenges in this work is to generalize the test results for use in case of other mastic support sizes. The aim of the study is to investigate the typical failure mode and obtain the S-N data under cryogenic fatigue loading. This study will be used as a fundamental study for the cryogenic fatigue assessment for the LNGC insulation system as well as a design guideline. The fatigue tests of Mark-III insulation system are carried out at room temperature and cryogenic temperature, and considered sloshing effect (R = −10). The load levels have been determined based on ultimate strength of reinforced polyurethane foam 12.2bar.

Fatigue Assessment of Welded Joints Taking Into Account Effects of Residual Stress

2010 ◽  
Author(s):  
Nur Syahroni ◽  
Stig Berge
Keyword(s):  
Residual Stress ◽  
Fatigue Strength ◽  
Welded Joints ◽  
Fatigue Testing ◽  
International Association ◽  
Hot Spot ◽  
Mean Stress ◽  
Element Analysis ◽  
Structural Rules ◽  
Fatigue Design

Residual stress may have a significant effect on the fatigue strength of welded joints. As a non-fluctuating stress, it has an effect similar to that of the mean stress. Recently the International Association of Ship Classification Societies (IACS) has issued Common Structural Rules (CSR) for respectively tankers (IACS 2006a) and bulk carriers (IACS 2006b). The effect of mean stress in fatigue design is taken into account in both sets of rules. However, the treatment is quite different, in particular with regard to residual stress and shakedown effects. In the present paper a comparative study of fatigue design procedures of the IACS rules is reported, with emphasis on residual stress effects. Testing was carried out with longitudinal attachment welds in the as-welded condition. The initial residual stress was measured by a sectioning method using strain gages. Hot spot stress was determined experimentally by strain gauges and numerically by finite element analysis using different types of elements. Fatigue testing was carried out and SN-curves were plotted according to the relevant stress as specified by the rules. In order to investigate the shake-down effect of residual stress, testing was performed for several pre-load conditions which could be taken to represent maximum load levels in a load history. The aim of the study is to contribute towards better understanding of the effect of residual stress and shakedown on fatigue strength of welded joints.

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