scholarly journals Effect of Rail Vehicle–Track Coupled Dynamics on Fatigue Failure of Coil Spring in a Suspension System

2021 ◽  
Vol 11 (6) ◽  
pp. 2650
Author(s):  
Sunil Kumar Sharma ◽  
Rakesh Chandmal Sharma ◽  
Jaesun Lee

In a rail vehicle, fatigue fracture causes a significant number of failures in the coil spring of the suspension system. In this work, the origin of these failures is examined by studying the rail wheel–track interaction, the modal analysis of the coil springs and the stresses induced during operation. The spring is tested experimentally, and a mathematical model is developed to show its force vs. displacement characteristics. A vertical 10-degree-of-freedom (DOF) mathematical model of a full-scale railway vehicle is developed, showing the motions of the car body, bogies and wheelsets, which are then combined with a track. The springs show internal resonances at nearly 50–60 Hz, where significant stresses are induced in them. From the stress result, the weakest position in the innerspring is identified and a few guidelines are proposed for the reduction of vibration and stress in rail vehicles.

Author(s):  
Sunil Kumar Sharma ◽  
Anil Kumar

In a railway vehicle, vibrations are generated due to the interaction between wheel and track. To evaluate the effect of vibrations on the ride quality and comfort of a passenger vehicle, the Sperling's ride index method is frequently adopted. This paper focuses on the feasibility of improving the ride quality and comfort of railway vehicles using semiactive secondary suspension based on magnetorheological fluid dampers. Equations of vertical, pitch and roll motions of car body and bogies are developed for an existing rail vehicle. Moreover, nonlinear stiffness and damping functions of passive suspension system are extracted from experimental data. In view of improvement in the ride quality and comfort of the rail vehicle, a magnetorheological damper is integrated in the secondary vertical suspension system. Parameters of the magnetorheological damper depend on current, amplitude and frequency of excitations. Three semi-active suspension strategies with magnetorheological damper are analysed at different running speeds and for periodic track irregularity. The performance indices calculated at different semi-active strategies are juxtaposed with the nonlinear passive suspension system. Simulation results establish that magnetorheological damper strategies in the secondary suspension system of railway vehicles reduce the vertical vibrations to a great extent compared to the existing passive system. Moreover, they lead to improved ride quality and passenger comfort.


Author(s):  
Rakesh Chandmal Sharma ◽  
Sono Bhardawaj ◽  
Mohd Avesh ◽  
Neeraj Sharma

This paper focuses to the parametric analysis of Indian Railway Rajdhani (LHB) coach. A suitable mathematical model of 40 degrees of freedom (DOF) is formulated by Lagrangian method. The mathematical model of rail-vehicle is modelled by considering eleven mass system containing of backseat support (without cushion), a seat, a car body, two (front and Rear) bolsters, two (front and Rear) bogie frame and four wheelaxles (front bogie front and rear wheel axles and rear bogie front and rear wheel axles. The vehicle is simulated to travel at speed of 100 km/hr on a tangent track. The results from the simulation are validated by comparing the same with the results from experimental data which is acquired from research designs and standards organization (RDSO), Lucknow (India). The parametric analysis is performed to estimate the effect of different parameters of rail-vehicle on the ride behaviour.


2014 ◽  
Vol 6 (5) ◽  
pp. 531-537 ◽  
Author(s):  
Rasa Žygienė ◽  
Marijonas Bogdevičius ◽  
Laima Dabulevičienė

A mathematical model of the system Railway Vehicle Wheel–Track with a wheel flat of a wheelset has been made. The system Railway Vehicle Wheel–Track has been examined on the vertical plane. The mathematical model of the system Railway Vehicle Wheel–Track has employed linear, nonlinear, elastic and damping discrete elements. Rail dynamics haves been described using the finite element method. The unevenness of the rail and the wheel of the wheelset have been evaluated considering the contact between the rail and the wheel flat of the wheelset. The analysis of dynamic processes taking place in a railway vehicle wheel with the wheel flat moving at speed V = 60 km/h has been accomplished. The results of mathematical modelling of the above introduced dynamic system have been presented along with graphically displayed research findings of the conducted research. Sukurtas sistemos „Geležinkelių vagono ratas – kelias“ su aširačio rato iščiuoža matematinis modelis. Sistema „Geležinkelių vagono ratas – kelias“ nagrinėjama vertikalioje plokštumoje. Sistemos „Geležinkelių vagono ratas – kelias“ matematiniame modelyje yra panaudoti tiesiniai ir netiesiniai tamprieji ir slopinimo diskretiniai elementai. Bėgio dinamika aprašoma baigtinių elementų metodu. Kontakte tarp bėgio ir aširačio rato su iščiuoža įvertinti bėgio ir aširačio rato nelygumai. Atlikta geležinkelio vagono rato su iščiuoža, judančio greičiu V = 60 km/val., dinaminių procesų analizė. Pateikti šios dinaminės sistemos matematinio modeliavimo rezultatai. Tyrimų rezultatai pavaizduoti grafiškai ir pateiktos tyrimų išvados.


2017 ◽  
Vol 260 ◽  
pp. 289-294 ◽  
Author(s):  
Marijonas Bogdevicius ◽  
Rasa Zygiene ◽  
Rimantas Subacius

Dynamic force that strains on the rail and the wheel occurs. In case of wheel flats, during wheel and rail interaction, exposure time of dynamic forces acting in contact is very short and depends on the railway vehicle speed and the length of flat.Results obtained from a method that uses mathematical model of a system “Railway Vehicle Wheel-Track” and the simplified method to determine a vertical impact force of wheel with flat and rail interaction are presented in this article.The results of the mathematical and physical results of this system are analysed and presented.


Author(s):  
Mortadha Graa ◽  
Mohamed Nejlaoui ◽  
Ajmi Houidi ◽  
Zouhaier Affi ◽  
Lotfi Romdhane

In this paper, an analytical reduced dynamic model of a rail vehicle system is developed. This model considers only 38 degrees of freedom of the rail vehicle system. This reduced model can predict the dynamic behaviour of the rail vehicle while being simpler than existing dynamic models. The developed model is validated using experimental results found in the bibliography and its results are compared with existing more complex models from the literature. The developed model is used for the passenger comfort evaluation, which is based on the value of the weighted root mean square acceleration according to the ISO 2631 standard. Several parameters of the system, i.e., passenger position, loading of the railway vehicle and its speed, and their effect on the passenger comfort are investigated. It was shown that the level of comfort is mostly affected by the speed of the railway vehicle and the position of the seat. The load, however, did not have a significant effect on the level of comfort of the passenger.


2012 ◽  
Vol 591-593 ◽  
pp. 1710-1714
Author(s):  
Wei Chen ◽  
Zhi Yao ◽  
Qing Bo Zhao ◽  
Tong Jian Wang

In order to make the active hydraulic suspension system to adaptive the ground. Taking the asymmetric valve controlled hydraulic cylinder as actuators, a six wheels hydraulic active suspension was designed. It is difficult to analysis of the six wheels system. So this paper established the single wheel’s mathematical model to instead analysis of the whole system, designed QFT (Quantitative Feedback Theory) controller which can be a solution to the system robustness, researched the hydraulic active suspension system. The results show that it is good for tracking performance of the hydraulic cylinder which taking the asymmetric valve controlled as actuators, system responses timely and the controller can meet the controlling requirements. This hydraulic active suspension system can improve off-road performance of engineering vehicles.


2020 ◽  
Vol 10 (15) ◽  
pp. 5220 ◽  
Author(s):  
Jianjun Wang ◽  
Jingyi Zhao ◽  
Wenlei Li ◽  
Xing Jia ◽  
Peng Wei

In order to ensure the ride comfort of a hydraulic transport vehicle in transportation, it is important to account for the effects of the suspension system. In this paper, an improved hydraulic suspension system based on a reasonable setting of the accumulator was proposed for a heavy hydraulic transport vehicle. The hydraulic transport vehicle was a multi-degree nonlinear system, and the establishment of an appropriate vehicle dynamical model was the basis for the improvement of the hydraulic suspension system. The hydraulic suspension system was analyzed, and a mathematical model of the hydraulic suspension system with accumulator established and then analyzed. The results revealed that installing the appropriate accumulator can absorb the impact pressure on the vehicle, while a hydraulic suspension system with an accumulator can be designed. Further, it was proved that a reasonable setting for the accumulator can reduce the impact force on the transport vehicle through simulation, and the optimal accumulator parameters can be obtained. Finally, an experiment in the field was set up and carried out, and the experimental results presented to prove the viability of the proposed method.


2018 ◽  
Vol 157 ◽  
pp. 03004 ◽  
Author(s):  
Ján Dižo ◽  
Miroslav Blatnický ◽  
Stasys Steišūnas ◽  
Blanka Skočilasová

In certain conditions rail vehicles wheels can be during operation damaged. Then, the profile of wheels is no longer circular, but it is changed depending on the type and severity of defects. When such rail vehicle with the damaged wheel operates, the quality of a ride comfort for passenger is degraded. This article is focused on the assessment of ride comfort for passenger based on results obtained from dynamic analyses. Simulations and calculations were carried out in commercial multibody software. In our research we considered one type of the railway wheel untrueness – wheel-flat. This type of wheel damaging is relatively common and has such influence on the ride comfort for passenger worsening, which needs to be detected and investigated.


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