scholarly journals Dynamics of the Rolling Stock and the Choice of Parameters of Vibration Dampers

2022 ◽  
Vol 19 (4) ◽  
pp. 13-20
Author(s):  
L. A. Sladkova ◽  
A. N. Neklyudov

Modern railway rolling stock should meet requirements regarding comfort (maximum travel speed with minimum vibrations of wagons, noiselessness of movement, etc.).To eliminate the influence of dynamic loads, rolling stock is equipped with vibration dampers. The objective of the work is to select the parameters of the vibration dampers of rolling stock, depending on its characteristics, to ensure the due indicators of comfort and safety of transportation of passengers and goods by rail. To achieve this objective, applied methods of mathematical modelling were based on numerical programming of operation of dynamic systems. The indicators of vibration dampers are evaluated according to the results of studies of the dynamics of the rolling stock (in particular, of vibration protection rates).Assessment of dynamic state of the rolling stock implies application of methods of mathematical and physical modelling, which include the development of a physical and mathematical model, a calculation algorithm, and computer programming. The study of the mathematical model by numerical methods makes it possible to carry out a multifactorial experiment using a large number of input parameters (factors) and to select the characteristics of vibration dampers that are optimal for the conditions under consideration.To solve dynamic problems, the harmonic perturbation model, which is the most widespread, was specified in the form of a sinusoid with a period corresponding to the rail length.A quantitative assessment of the vibration process (frequency, amplitude) makes it possible to identify the main processes occurring in the system under consideration under various types of external load. The introduced assumptions related to rigidity, mobility and geometric immutability of the system allow determining the methods for obtaining a mathematical model and considering the vibrations as flat ones.The equations were solved in MathCad Prime 4.0 package using the Runge–Kutta method with automatic step selection. The subsequent study of the properties of the dynamic system was carried out by changing the resistance parameter of dampers of the first stage of spring suspension, while recording the values of the amplitude of the vibrations of the system and the period.The analysis of the results has shown that the vibration period of the body and bogies under any changes in the resistance parameter of the damper remains unchanged, while rational parameters of resistance of axle box dampers have been revealed for specified indicators. Hydraulic vibration dampers with the revealed parameters used on rolling stock help to reduce wear and damageability of running gears, improve ride comfort and traffic safety, as well as to reduce repair and maintenance costs. 

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.


2019 ◽  
Vol 294 ◽  
pp. 05005
Author(s):  
Marek Kaniewski ◽  
Michał Cichoński

The authors present a method of modeling pantograph cooperation with a catenary system by means of a computer program based on a pantograph discrete model with two degrees of freedom and a catenary system model as a focused mass that in the dynamic state has variable stiffness along the span. After performing the appropriate tests, the validation was carried out according to the proposed method in the PN EN 50318:2019-02 standard required in the Technical Specifications for the interoperability of the subsystem “Energy” and “Rolling stock -locomotives and passenger rolling stock” of the trans-European rail system in Europe.


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.


Author(s):  
A. O Lovska ◽  
O. V Fomin ◽  
A. V Rybin

Purpose. The work aims to investigate dynamic loading of the supporting structure of a gondola car with an elastic-viscous filler in the center sill by means of mathematical modeling. Methodology. Mathematical modeling of the dynamic loading of the supporting structure of a gondola car with a closed center sill filled with a filler with elastic-viscous properties has been carried out. The case of the highest load on the supporting structure of the gondola car in operation is taken into account – a shunting collision, taking into account the action of a load of 3.5 MN on the rear stop of the automatic coupler. To determine the dynamic loading of a gondola car, a mathematical model formed by prof. G. I. Bohomaz was used. However, within the framework of this study, the model was refined by adapting it to the determination of the dynamic loading of a gondola car. It also takes into account the friction forces arising between the center plates of the body and the center pivots of the bogies, as well as the properties of the energy-absorbing material. The solution of the mathematical model was carried out in the MathCad software package. In this case, the differential equations of motion were reduced to the Cauchy normal form, and then integrated using the Runge-Kutta method. Initial displacements and speeds are taken equal to zero. The calculation was carried out on the example of a universal gondola car model 12-757 built by Kriukivskyi Carriage Works PJSC (Kremenchug) on standard bogies 18-100. Findings. Accelerations are obtained as components of a dynamic load acting on a gondola car with a closed center sill structure filled with an elastic-viscous filler. It was found that with the stiffness of the center sill filler of 82 kN/m, as well as the viscous resistance coefficient of -120 kN∙s/m, the maximum accelerations of the gondola car supporting structure is about 37 m/s2 (0.37g). Originality. A mathematical model is proposed for determining the dynamic loading of a gondola car with a closed structure of a center sill filled with an elastic-viscous filler. The model makes it possible to obtain accelerations as the components of the dynamic loading acting on the supporting structure of the gondola car, taking into account the improvement measures during a shunting collision. Practical value. The results of the research will help to reduce the damage to the supporting structures of gondola cars in operation, reduce the cost of their maintenance, create developments in the design of innovative structures of rolling stock, as well as increase the efficiency of its operation.  


2019 ◽  
pp. 588-599
Author(s):  

The article noted that the speed of trains is one of the main quality indicators of the railway. It increases the throughput and carrying capacity of the railway. But it must be remembered that one of the main obstacles today in increasing the speed of movement is the curved sections of the path. The speed in such areas is limited by the requirements of traffic safety and the necessary level of comfort for passengers. Increasing the speed of trains leads to an increase in the forces of interaction between the track and the rolling stock and, accordingly, affects the probability of rolling stock derailment. The limitation of the speed of movement in the curved sections of the path is trying to reduce the horizontal transverse forces that are transmitted from the wheel to the rail. For passenger wagons, it also allows reducing lateral accelerations, which tire passengers and worsen the ride comfort. Restrictions in curved sections of the path are versatile, and they are unequal. Some of them allow relatively high speeds, other speed limits are significant. The permissible rolling stock speeds are set based on the outstanding horizontal acceleration, the growth rate of this acceleration, and the speed of raising (lowering) the wheel is normalized through the cant rail-speed tables. There are several criteria for limiting the speed of rolling stock in curves. In this article, the authors investigated the limitations of the speed of movement of rolling stock in a curved section of the track according to the coefficient of stability from racking or crawling the wheel flange of the wheelset onto the rail head. The article investigated the limitations of the speed in a curved section of the track in the case of a uniform, uneven loading of the wheel of the wheelset, with and without cant of external rail. The authors of the article notes that the study of the issue of the interaction of rolling stock and rail track allows to set factors and indicators that affect the safe movement of trains at appropriate speeds. Key words: maximum speed of movement, restriction of speed, trains, sections of the track.


Author(s):  
Beibei Liu ◽  
Lin Xu ◽  
Zhen Zhao ◽  
Mohamed A. A. Abdelkareem ◽  
Junyi Zou ◽  
...  

Active suspension can adapt itself to the rigidity and the damping characteristics based on the vehicle dynamic state and the road condition, making the suspension in the best state of shock absorbing, which can increase the handling stability, the ride comfort and the passing ability of vehicles. As for strikingly rugged roads like off-road conditions, the traditional active suspension can hardly balance the contradiction between the wheel adhesion and the vertical accelerated speed of the body. In this paper, an active suspension in which the position of the vehicle body can be adjusted is proposed. In the proposed suspension, a series of electric cylinders are installed, which can actively adjust the position between the vehicle body and the suspension in order to achieve the purpose of controlling the relative body-wheels position. In this manner, AMESim is used to set up three suspension designs which include suspension supporter adaptation equipment with different locations in the system. Through simulation analysis, the paper has explored the feasibility of the vehicle attitude control of the three suspension designs under off-road conditions. The results proved that the active suspension system with adjustable body position can restrain the body roll or pitch efficiently in which this technology can be applied to the body attitude control when ORVs are at high speed.


Author(s):  
Eduard Biloshytskyi ◽  
Alyona Oleksandrivna Lovska ◽  
Sergiy Myamlin

Passenger rolling stock is an important component of passenger transportation services, which should ensure not only traffic safety, but also comfortable transportation conditions. Studies on the energy saving of railway rolling stock have revealed shortcomings in the operating documentation that increase the unproductive consumption of thermal energy by passenger cars during the operation of a heating system with a combined electric-coal boiler in electric heating mode. Experimental measurements confirmed the presence of unproductive losses of thermal energy through the intake blinds of the ventilation system due to the infiltration of outside air during downtime at the points of formation and turnover of passenger cars. Also, experimental measurements showed that there is a leak of warm air through the deflectors to remove exhaust air from the car into the environment. This is their regular mode of operation, but as highlighted in the author's early publications there are two zones of temperature fields in the body of the passenger car with different temperature regimes, which are separated by a decorative ceiling. The results show that the leakage of warm air through the deflectors occurs from the temperature field zone with a higher temperature, which increases the unproductive consumption of thermal energy. Thus, by making appropriate changes to the operating documentation based on the study, the energy efficiency of passenger rolling stock will be greatly improved in its further operation. In particular, it is established that the proposed modernization in order to increase the energy efficiency of the heating system can be carried out at relatively low cost, in modern car repair depots during overhauls, and also needs to be considered when designing new passenger cars.


2018 ◽  
Vol 77 (1) ◽  
pp. 49-57 ◽  
Author(s):  
T. A. Antropova ◽  
M. I. Glushko

The rolling stock and the railway track are a single stant tendency of the development of rail transport in relation to mechanical system. The running parts of the rolling stock and the the interaction of the power wheel-to-rail friction pair consists in track are interacting under difficult dynamic conditions. The con-increasing the axle load on the rails for freight rolling stock and further increasing the speed of the passenger trains. It takes a qualified approach to traffic safety issues and special attention to the stability of rolling stock to achieve these goals. An analysis of the stability control of the car with an admission to the infrastructure was carried out based on the regulatory documents that establish the main provisions and procedures for the operation of railways and railway workers. Authors proposed the elimination of existing shortcomings and ensuring the stability of the carriage motion by optimizing parameters of the placement of goods in the car. Calculations were made on the rollover stability conditions (stability loss) of the body and the criterion of the critical speed at which the carriage derailed due to the loss of contact of the wheels with the internal rail line of the curve. A method for controlling the stability of a car with a load by means of two-position weighing is proposed. The results obtained also make it possible to determine the height of the common center of gravity (CG), the magnitude of the longitudinal and lateral displacement of the center of gravity of the freight.


2019 ◽  
Vol 20 (2) ◽  
pp. 340-350
Author(s):  
А. Batig ◽  
A. Kuzyshyn

The purpose of this article is to analyze the need to apply the methods of mathematical modeling when performing examinations of rolling stock derailment. The description of the dynamic behavior of rolling stock when moving on the track is a rather complicated, time-consuming process, which requires highly qualified expert and time-consuming. The presence of detailed mathematical models of the constituent units of the rolling stock would greatly facilitate the study of cases of their derailment. At present, a significant number of scientific papers are devoted to the study of the dynamics of rolling stock movement using mathematical models. In Lviv NDISE, investigations of such railway accidents as rolling stock derailment from the rails are performed by experts according to the methods developed by the doctor of technical sciences Sokol E. M., allowing to take into account a certain number of parameters of wagon running gears. At present, when experts examine the cases of rolling stock derailment, there is a need to develop new methods that would allow to take into account more parameters of the undercarriage parts of the wagons, such as: parameters of the damping system, spring suspension, bolster, node of the body-bogie bolster center plates, etc. P. There are also cases of railway accidents, in which one of the reasons may be the presence of defects on the rolling surface of the wheels of the rolling stock. In this regard, experts of Lviv NDISE to take into account the above-mentioned parameters of the running gears and to identify the most significant for rolling stock derailment, it was developed object-oriented programming in the computer environment Maple. At present, have developed a mathematical model of a passenger car of a diesel train, the DPKr-2, and an improved mathematical model of a freight wagon. The authors of the article came to the conclusion that the use of mathematical models and their computer solution can facilitate the process of researching rolling stock cases from the rails, as it allows automating and speeding up the study of dynamic indicators of rolling stock, facilitating the process of establishing the limiting values of its technical condition parameters and assessing the consequences changes in these parameters in certain working conditions.


2014 ◽  
Vol 590 ◽  
pp. 451-457
Author(s):  
Sen Nan Song ◽  
Fa Chao Jiang ◽  
Hong Shi

The present work is concerned with the rolling motion of the battery pack when EV travelling on the road. First McPherson suspension system was regarded as the research object with detailed analysis of its structural features and motion characteristics. Establish the mathematical model which could apply to calculating the rolling motion of the vehicle body. Through MATLAB/Simulink simulation software, we could calculate the rolling angle on passive suspension. On this basis, assume that the battery pack mounted on the vehicle body and make it passive connection and PID connection. When the body rolls, the battery pack will produce a certain angle then. Next establish the mathematical model to summarize the relationship between the two variables. Then we set the parameters and calculate the roll angle of battery pack in both cases for comparison. Simulation results show that road irregularities will make battery rotate an angle and PID controller can effectively reduce the angle, especially angular acceleration. This paper put forward a new idea that battery is connected with body by active control on EV, and proves the superiority in reducing the rolling angle.


Sign in / Sign up

Export Citation Format

Share Document