Development of a device for application of vertical and lateral forces on rail head for determination of scale of strain measurement circuits for measuring influence of rolling stock on track

2020 ◽  
pp. 50-55
Author(s):  
Darya Vladimirovna Rasshhepkina ◽  
◽  
Mariya Viktorovna Zimakova ◽  
Dmitriy Vladimirovich Beloborodov ◽  
◽  
...  

On the basis of analytical method of studying devices for the application of forces on a rail head and numerical method of calculating structural strength the authors have developed a new device for loading the rail head by vertical and lateral forces. The device that simulates force of wheel influence on rail allows applying vertical force on the axis of symmetry and with the offset of ±20 mm simultaneously with lateral force. Due to the lightened collapsible frame and the existence of roller bearings the device is comfortable in use, which contributes to the increase of speed of tests on the influence on track and researches in this sphere.

Author(s):  
М. А. АРБУЗОВ ◽  
Є. В. АРБУЗОВА

Abstract. The transportation process depends on the state of the technical systems involved. Technical systems depend on the organization of the transportation process. The paper considers the influence of operational parameters on the condition of the railway track. To study this problem, the most difficult section of the Slavsko-Lavochne-Beskid-Volovets track was chosen at the Lviv Railway regional branch. The influence of the missed tonnage, radius of the curve, longitudinal slope, speed and increase of the outer rail on the lateral wear of the rail head was investigated. It is established that all factors are influential. But the most influential - the longitudinal slope, in second place - speed, in third place - the radius of the curve. The effect of the slope on the rise was greater than the effect of the slope on the descent 3.3 times. A multiparametric mathematical law is established, which reflects the process of lateral wear of the rail head depending on the operational factors. This function allows you to predict the amount of lateral wear of the rail. Significant deviation of actual wear from the calculated, called excessive wear. From the analysis of data of the regional branch "Lviv Railway" it follows that 40% of the curved sections of the track with excessive wear are located on the section Slavsko-Lavochne-Beskid-Volovets. During the Lavochne-Beskid 1629 km pk9 race on the odd track, the test section of the track was equipped with strain gauges and prognometers, which were installed in the places of the smallest and largest lateral wear. There was an increase of 34% in lateral force in the cars in front of the pusher locomotive. No exceedance was detected. Observations at the Lavochne-Beskid race showed that the rolling stock was moving at a speed of 35 km/h. Thus, the established speed of movement of freight trains makes 60 km / h and during calculations is accepted as the minimum freight. That is, there is an under-realization of speed. Calculations show that this reduces the service life of the rails by 38%. Metal ingots in the shape of a wheel crest and a rolling surface were also found in the track. These ingots, formed from scales and drops of metal, are formed as a result of excessive braking in the pass sections, which is a consequence of the heavy weight of the train and steep descents. The paper develops recommendations for the transportation process in areas of complex plan and profile.


Author(s):  
M Adachi ◽  
A Matsumoto

Lateral forces between wheels and rails must be reduced in order that rolling stock runs safely and smoothly on curved tracks. The excessive lateral force will cause not only derailment of rolling stock but also destruction of tracks, rail corrugation, track irregularity, squeal noise and wear. It is important to reduce lateral force of wheels in curves, so new wheel-tread profiles and steerable bogie structures have been developed up to now, however, they cannot solve various problems in curving perfectly. In this article, the authors propose three methods for improvement of running performance on curves by using existing types of wheels and rails, and analyse the effects of three methods by numerical simulation. According to analytical results, the authors conclude that ‘expansion of gauge widening’, and ‘larger rail inclination angle of inner rail installation’ or ‘asymmetrically inclined grinding of inner rail head’ can get sufficient rolling radius difference, and are effective for improvement of running performance on curved tracks.


2019 ◽  
pp. 608-614
Author(s):  
A. Kuzyshyn

In the article the author notes that the horizontal forces arising in the process of pressing the wheel flanges to the working edge of the rail, under certain conditions can be very significant. These forces, in combination with the wheel unloading, caused by the geometric deviation of the track in the plan and profile, can lead to rolling the wheel of the wheelset onto the rail head and, as a consequence, to the stock derailment. Such pressing of the wheel to the rail head in the straight part of the track can occur when faults in the running gears of the wagons: non-parallelism of the axles of the wheel pairs of the bogie frame by the difference in the bases of the side frames, wear of the guide axle-box openings; the difference of the flanges on one wheel pair is more than permissible, wear of the body and bogie bolster center plates, step bearing; a significant difference in the diameters of the wheels of the wheelset caused by the intense wear of the rolling surface of one of them, etc. The article deals with the investigation of the influence of the wheels’ diameters difference of the wheelset on the amount of lateral force for the empty and loaded state of the rolling stock wagon. The results obtained made it possible to conclude that an increase in the wheels’ diameters difference of the wheelset of a loaded wagon of rolling stock leads to more intensive growth of the lateral force, as compared with the exhaust. This is caused by the linear dependence of the lateral force on the mass of the wagon of the rolling stock. However, for both the empty and the loaded wagon, the increase in the lateral force value has a negative effect. In conjunction with the unloading of the wheel it increases the probability of rolling in the wheel of the wheelset on the rail head. Also, an increase in the action of the lateral force from the wheelset on the rail, causes increased wear of the rail, the wheel flange, which is pressed. At the same time, rolling surfaces of an irregular shape are formed on the surface of the other wheel. Therefore, it is important to ensure the maintenance of the wheels of a wheel pair with the smallest difference in its diameters. Key words: rolling stock, diameter difference of wheels, quasi-dynamics method.


2018 ◽  
Vol 77 (4) ◽  
pp. 230-240
Author(s):  
D. P. Markov

Railway bogie is the basic element that determines the force, kinematic, power and other parameters of the rolling stock, and its movement in the railway track has not been studied enough. Classical calculation of the kinematic and dynamic parameters of the bogie's motion with the determination of the position of its center of rotation, the instantaneous axes of rotation of wheelsets, the magnitudes and directions of all forces present a difficult problem even in quasi-static theory. The paper shows a simplified method that allows one to explain, within the limits of one article, the main kinematic and force parameters of the bogie movement (installation angles, clearance between the wheel flanges and side surfaces of the rails), wear and contact damage to the wheels and rails. Tribology of the railway bogie is an important part of transport tribology, the foundation of the theory of wheel-rail tribosystem, without which it is impossible to understand the mechanisms of catastrophic wear, derailments, contact fatigue, cohesion of wheels and rails. In the article basic questions are considered, without which it is impossible to analyze the movement of the bogie: physical foundations of wheel movement along the rail, types of relative motion of contacting bodies, tribological characteristics linking the force and kinematic parameters of the bogie. Kinematics and dynamics of a two-wheeled bogie-rail bicycle are analyzed instead of a single wheel and a wheelset, which makes it clearer and easier to explain how and what forces act on the bogie and how they affect on its position in the rail track. To calculate the motion parameters of a four-wheeled bogie, it is represented as two two-wheeled, moving each on its own rail. Connections between them are replaced by moments with respect to the point of contact between the flange of the guide wheel and the rail. This approach made it possible to give an approximate estimation of the main kinematic and force parameters of the motion of an ideal bogie (without axes skewing) in curves, to understand how the corners of the bogie installation and the gaps between the flanges of the wheels and rails vary when moving with different speeds, how wear and contact injuries arise and to give recommendations for their assessment and elimination.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Fin O’Flaherty ◽  
Fathi Al-Shawi

AbstractThis study presents a detailed analysis of the lateral forces generated as a result of vertically applied loads to recycled plastic drainage kerbs. These kerbs are a relatively new addition to road infrastructure projects. When concrete is used to form road drainage kerbs, its deformation is minimum when stressed under heavy axle loads. Although recycled plastic kerbs are more environmentally friendly as a construction product, they are less stiff than concrete and tend to deform more under loading leading to a bursting type, lateral force being applied to the haunch materials, the magnitude of which is unknown. A method is proposed for establishing the distribution of these lateral forces resulting from deformation under laboratory test conditions. A load of 400 kN is applied onto a total of six typical kerbs in the laboratory in accordance with the test standard. The drainage kerbs are surrounded with 150 mm of concrete to the front and rear haunch and underneath as is normal during installation. The lateral forces exerted on the concrete surround as a result of deformation of the plastic kerbs are determined via a strain measuring device. Analysis of the test data allows the magnitude of the lateral forces to the surrounding media to be determined and, thereby, ensuring the haunch materials are not over-stressed as a result. The proposed test methodology and subsequent analysis allows for an important laboratory-based assessment of any typical recycled plastic drainage kerbs to be conducted to ensure they are fit-for-purpose in the field.


2005 ◽  
Vol 93 (9-10) ◽  
Author(s):  
Dorothea Schumann ◽  
R. Grasser ◽  
R. Dressler ◽  
H. Bruchertseifer

SummaryA new device was developed for the identification of several iodine species in aqueous solution using ion chromatography. Iodide, iodate and molecular iodine can be determined. (The equipment allows both conductivity and radioactivity detections.) The method is applicable for the determination of radioactive iodine contaminations in the cooling water of nuclear power plants.


1968 ◽  
Vol 5 (01) ◽  
pp. 63-71
Author(s):  
Philip J. Danahy

The paper presents a method for the determination of the critical minimum scantlings for small high-speed vessels. Particular attention is given to the shell plating strength for hydrodynamic impact loads. The suggested method uses an integrated approach involving assumed loads, suggested safety factors, and preferred stress-analysis method. The stress analysis uses plastic theory based partly on the works of J. Clarkson and Thein Wah. Included in the paper is a comparison of the relative structural strength of several commercial, military, and experimental hydrofoil vessels along with a few planing boats and a seaplane hull. This shows the variation of existing vessel structures and compares them to the results obtained by the suggested method. Most commercial, military, and recreational vessels exceed the minimum scantlings of the suggested method. The most significant deviation is the hull of the seaplane:


2018 ◽  
Vol 27 (4) ◽  
pp. 250-5
Author(s):  
Sultan A.M. Saghir ◽  
Amer A. Almaiman ◽  
Aishah K.A. Shatar ◽  
Norris Naim ◽  
Huda S. Baqir

Background: The fast and outpatient setting for a determination of the hemoglobin (Hb) level is a well-recognized prerequisite to detect anemia in blood donors. This study aimed to evaluate the performance of the HemoCue methods (HemoCue B-Hb and HemoCue-301) against Coulter LH-750 as a reference method for Hb determination.Methods: This study was an experimental cross-sectional study. It includes 455 blood samples that were collected from volunteer blood donors between January 15, 2010 and February 15, 2011. The performance of the three methods and their comparisons were assessed using the analysis of coefficients of variation (CV), linear regression, and mean difference. Correlation coefficient and Bland–Altman plots were drawn to compare the two HemoCue measurements and the automated cell analyzer against each other and to evaluate their results. The Hb concentrations were compared using the concordance correlation coefficient.Results: The findings exhibited that the CV for the three methods Coulter LH-750, HemoCue B-Hb, and HemoCue-301 were 0.60%, 0.72%, and 0.92%, respectively. A statistically significant difference was observed between the means of the Hb measurements for the three methods (p<0.001). The HemoCue B-Hb and HemoCue-301 methods showed the best agreement, and the Coulter LH-750 method gave a lower Hb value compared with the two HemoCue methods. The results showed a positive correlation of HemoCue Hb results compared with the reference method.Conclusion: All three methods provide a good agreement for Hb determination. The new device HemoCue-301 was found to be more accurate compared with HemoCue B-Hb and Coulter LH-750.


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