scholarly journals THERMAL CONTROL INVESTIGATION OF ROLLING-STOCK SHOE BRAKES BY SIMULATION METHOD

2020 ◽  
Vol 2020 (4) ◽  
pp. 31-42
Author(s):  
Pavel Shalupin

The development of heavy speed freight train communications in the Russian Federation results in the increased thermal loading of braking system elements of rolling-stock, in particular, in shoe brakes. Taking into account the requirements of branch program documents on wheel life increase, it is evident that the further development of freight communications requires a complex application of thermal diagnostics means for auto-brake equipment of rolling-stock during a train motion. The statistics shows that the fifth part of wheel pair failures is connected with thermal-mechanical damages and the situation goes on to be aggravated. In view of this hardware and software means for thermal diagnostics of shoe brakes require further improvement. The purpose of this paper is the process investigation of shoe brake thermal control by method of computer simulation and the estimate of infrared optics position impact upon control results. There is considered a model for the definition of a scanning path and computation of a signal level being part of a complex simulation model of wheel thermal control. The model offered is based on the methods of solid dynamics system investigations in the basis of which there is an application of theorems on mass center motion and changes of a solid kinetic moment. The model is used for finding a form and a spot area at every time moment of scanning by a solution of a problem on a dynamic spatial intersection of a wheel surface with the control area. There are considered different versions of optics orientation to an object of control for each of which for the first time there are obtained calculated thermal signals from the object under control. The analysis has shown that at the optics orientation to wheels from the outside a wheel tread appears to be in the control area that allows defining a maximum temperature of a wheel. But at the realization of emergency brake application a sharp short-time temperature increase of a tread is possible which indicates an improper operation of a brake unit. The optics orientation to a wheel from its inner side allows excluding false alarm indices at emergency brake application. The correctness of the results shown in the paper is confirmed by convergence with the results of wheel heating monitoring and environmental tests of experimental complexes of thermal control means of shoe brakes.

2006 ◽  
Vol 42 (8) ◽  
pp. 525-529
Author(s):  
Yu. G. Vasenev ◽  
V. E. Ermolov ◽  
V. I. Mel’nik

Author(s):  
Shaolin Chen ◽  
Hong Zhang ◽  
Liaoping Hu ◽  
Guangqing He ◽  
Fen Lei ◽  
...  

The fatigue life of turbine housing is an important index to measure the reliability of a radial turbocharger. The increase in turbine inlet temperatures in the last few years has resulted in a decrease in the fatigue life of turbine housing. A simulation method and experimental verification are required to predict the life of a turbine housing in the early design and development process precisely. The temperature field distribution of the turbine housing is calculated using the steady-state bidirectional coupled conjugate heat transfer method. Next, the temperature field results are considered as the boundary for calculating the turbine housing temperature and thermomechanical strain, and then, the thermomechanical strain of the turbine housing is determined. Infrared and digital image correlations are used to measure the turbine housing surface temperature and total thermomechanical strain. Compared to the numerical solution, the maximum temperature RMS (Root Mean Square) error of the monitoring point in the monitoring area is only 3.5%; the maximum strain RMS error reached 11%. Experimental results of temperature field test and strain measurement test show that the testing temperature and total strain results are approximately equal to the solution of the numerical simulation. Based on the comparison between the numerical calculation and experimental results, the numerical simulation and test results were found to be in good agreement. The experimental and simulation results of this method can be used as the temperature and strain (stress) boundaries for subsequent thermomechanical fatigue (TMF) simulation analysis of the turbine housing.


2011 ◽  
Vol 308-310 ◽  
pp. 2328-2333
Author(s):  
Li Fu Li

The thermal control indicators CAE methods of Space optical remote sensor are analyzed in the presented work. We sat up a thermal optical analysis model for space optical remote sensor. By assuming fully covered by in-orbit temperature load, and using the finite element method for thermal deformation analysis, we obtained the optical remote sensor surface deformation and displacement under various thermal loading. Using ZERNIKE polynomial, wave was fitted to obtain ZERNIKE polynomial coefficients which were incorporated into the optical system design. Using CODE V optical calculation software, heat-ray machines under elastic deformation of the system point spread function, transfer function (MTF), wave front differential (WFE) etc. were calculated. Image quality changes of remote sensors are discussed in variety assumed cases such as temperature loads of quality change. By repeated iteration, critical value of temperature fields meeting the design requirements are obtained for the optical system. Optical indicators were converged to the temperature field indicator, then reasonable indicators of thermal control for remote sensors were obtained. For the thermal control design, this method provided a reliable basis for design.


Author(s):  
Yuriy P. BORONENKO ◽  
◽  
Aleksandr V. TRET’YAKOV ◽  
Rustam V. RAKHIMOV ◽  
Mariya V. ZIMAKOVA ◽  
...  

Objective: To develop the method to monitor the technical condition of the railway track. Me-thods: A strain-gauge wheel pair is used for continuous recording of vertical and lateral interaction forces in a dynamic wheel–rail system. Results: Stability margin factors of a wagon relative to de-railment have been determined and the defective (prone to derailment) sections of a railway track have been identified with the exact identification of their location (GPS coordinates) on the map using navigation devices. Practical importance: The developed monitoring method makes it possi-ble to promptly re¬gister and eliminate railway track defects


2003 ◽  
Author(s):  
Anatoli Z. Venediktov ◽  
Vladimir N. Demkin ◽  
Dmitri S. Dokov ◽  
V. N. Tireshkin
Keyword(s):  

Author(s):  
Nikoloz Mgebrishvili ◽  
Guri Sharashenidze ◽  
Manana Moistsrapishvili ◽  
Sergo Sharashenidze ◽  
Liana Kuparashvili ◽  
...  

Development of modern railways largely depends on the control of intactness of the wheel pairs and rails. It is impossible to ensure safety and increase the speed of railway traffic without providing such control. Detection of the wheel pairs’ and rails’ wear and damage is one of the key problems of railway science. Many scientific works are accomplished and lot of devices are elaborated in this field, but the mentioned problem still remains urgent. In order to increase the traffic safety, the group of authors has proposed a constructional scheme of the mobile device for detection of wheel pairs’ and rails’ wear and damage, which will have increased accuracy of measurement. Increasing of accuracy of measurement is carried out on the basis of development of mathematical model, which provides the realization of equal wear of wheel pairs’ as well as ones no equal wear. By installation of the proposed device on each wheel pair of each railcar of the rolling stock, the automatic control of wheel pairs’ and rails’ condition will be achieved. Namely: -Detection of the worn out wheel pair and determination of wear degree; -Detection of the damaged wheel pair; -Identification of the worn out or damaged wheel pair. Besides, on the basis of elaborated mathematical model: -Detection of the worn out rail; -Detection of the damaged rail; -Identification of location of the worn out or damaged rail. The obtained information will be constantly connected to the locomotive computer system. Therefore, for checking rolling stocks, there will no longer be need to build expensive stationary systems, to move trains great distances for their inspection and in the result, the time lost for stoppage will be saved. So, with the help of proposed mobile device, the traffic safety increases and at the same time expenses for detection of wheel pairs’ wear and damage decrease, which results in significant economic effect.


1976 ◽  
Vol 98 (2) ◽  
pp. 292-296 ◽  
Author(s):  
D. C. Ross ◽  
K. R. Diller

The effects of thermal insult on living tissue have been studied by direct microscopic observation of the circulatory system’s response to a controlled trauma regimen. An experimental apparatus has been developed which utilizes a unique high and low temperature stage in conjunction with a precision thermal control system to examine the injury process in the microcirculation of the golden hamster cheek pouch. Unique features of this experimental apparatus are: (1) continuous monitoring of the injury processes at the cellular level, (2) capability for quantitative assay of thermal injury, (3) precise control over the thermal parameters that govern injury, (4) versatility in isolating the effects of these individual parameters. The important thermal parameters monitored using this experimental procedure are the time rates of change of temperature during burning and cooling, the maximum temperature reached, and the length of time the tissue was held at this temperature. With this type of experimental apparatus any portion of the burn protocol, such as the maximum temperature reached during burning, may be varied while holding all other parameters constant. It is well documented that the microvascular bed is a primary site for manifestation of burn wound injury. Burn injury occurs as a consequence of rate dependent physiochemical processes, and, therefore, develops over a finite period of time subsequent to trauma. The experimental technique is designed to determine the gross response of the microvascular system to burn trauma. Initial investigations on burn injury have demonstrated a direct dependency of the extent of damage upon both the maximum temperature attained and the duration of exposure. The minimum temperature required to produce stasis within 20 s after completion of the burn in 95 ±5 percent of the microcirculation decreased exponentially with burn duration between the extremes of 85°C for 1 s exposure and 60°C for 100 s exposure.


2019 ◽  
pp. 36-40 ◽  
Author(s):  
Alexander Anatolyevich Mironov ◽  
◽  
Dmitriy Nikolaevich Saltykov ◽  
Alexander Eduardovich Pavlyukov ◽  
Pavel Igorevich Shalupina ◽  
...  

2019 ◽  
pp. 580-588
Author(s):  
A. Batih

The countries of the European Union have a huge territory and a large number of objects of transport infrastructure and rolling stock. In these countries, various methods, complex systems and technologies are offered for the organization and management of the cargo transportation process and passengers with traffic safety. The acceptance and admission of rolling stock to operation is carried out in accordance with the requirements set out in document EN 14363. This document defines the main indicators of railway traffic safety, methods, means and conditions for conducting tests of rolling stock on the definition of its qualitative driving characteristics. In the author’s article, the following safety indicators were studied on the EU railways: the coefficient of stability from rolling the wheel flange of the wheel pair onto the rail head, the value of the turning of the trolley relative to the body of the rolling stock (index X), the indicator of the lateral action of the rolling stock on the rails. The stability of the rolling of the wheel of the wheel pair onto the rail head on the EU railways is investigated on the basis of the Nadal’s criterion. The value of the resistance of the trolley rotation relative to the body of the rolling stock is decisive for proving the safety condition against the derailment wheel pairs on the EU railways. With the help of the indicator of the lateral action of the rolling stock on the rails limited the size of the lateral forces to minimize the risk of shifts of rail-sleeper lattice. The article describes how a rolling stock test on EU railways is being conducted to determine the traffic safety indicators. The author notes that in order to determine the possibility of derailment of rolling stock under the norm EN 14363, it is necessary to have the value of the guiding force. However, determining the direction of the force is a complicated and time-consuming process, since it requires a large number of experimental studies. Key words: railways, rolling stock, indicators of sustainability, European Union.


2018 ◽  
Vol 234 ◽  
pp. 05003 ◽  
Author(s):  
Andriy Kuzyshyn ◽  
Andriy Batig ◽  
Sergei Kostritsa ◽  
Julia Sobolevska ◽  
Vitalii Kovalchuk ◽  
...  

The problem of the interaction of rolling stock with the rail track has been analyzed in the present paper. It has been established that in the process of transport science development a number of methods for determining the causes of wheel pairs derailment are developed, which, in a varying degree, take into account the peculiarities of their interaction. The problem of choosing the most accurate method for estimating the causes of rolling stock derailment becomes more complicated because of the lack of sufficient experimental data that would allow us to verify the adequacy of the models. The indicators of stability of the wheel against derailment, which are used on the railways of Ukraine and Europe, have been examined. Their dependences on the speed of movement were derived. It has been established that the increase of the speed of motion leads to the increase of the interaction power of the rolling stock with the rail track, which may, under certain operational parameters, provoke its derailment. As a result of the calculations, it has been shown that the use of norms for car design and calculation used on Ukrainian railways can lead to an inadequate estimation of traffic safety parameters, since it does not take into account the unevenness of the railway track. It has been established that the requirements of BS EN 14363: 2005 European norms are stricter in comparison with the norms for calculation and evaluation of the bearing elements strength and dynamic qualities of motor-vehicle rolling stock used on Ukrainian railways. A comparison of the experimentally and theoretically calculated values of the stability margin coefficient against wheel derailment of the first wheel pair of the diesel train car was carried out.


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