An Analytical Study on Running Safety and Ride Comfort in Case of Superimposition of Vertical and Transition Curves

Abstract This article deals with computer analyses of output quantities of a railway vehicle depending on changing of parameters of suspension system. A passenger car was chosen for dynamic analyses. An analysed passenger railway vehicle uses two stage suspension system composed of coil springs and hydraulic dampers. Stiffness of coil springs of primary and secondary suspensions were defined for two states and its influence on output values in terms of quality and quantity was evaluated. As output variables, values of forces in a wheel/rail contact and accelerations in several locations on a wagon body floor were chosen. Values of forces in a wheel/rail contact indicate dynamic response of a railway vehicle running in terms of running safety and values of accelerations serve as important input for evaluation of passenger ride comfort.

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Influence of stiffness characteristics of a railway track on output parameters in a multibody model

MATEC Web of Conferences ◽

10.1051/matecconf/202031801003 ◽

2020 ◽

Vol 318 ◽

pp. 01003

Author(s):

Ján Dižo ◽

Miroslav Blatnický

Keyword(s):

Indirect Method ◽

Ride Comfort ◽

Direct Method ◽

Point Of View ◽

Railway Track ◽

Railway Vehicle ◽

Running Safety ◽

Multibody Model ◽

Stiffness Characteristics ◽

Stiffness And Damping

The article is aimed at the research of the influence of stiffness characteristics included in a model of a railway track, which is the part of a multibody system. The other part of the multibody model is a railway vehicle. Authors are focused on the investigation of response of some selected output parameters under various values of input of stiffness and damping coefficients. The interaction of a railway vehicle and a railway track is studied. A passenger railway vehicle has been chosen for presented research. Outputs parameters are chosen in the passenger ride comfort point of view and the running safety point of view. The passenger ride comfort can be evaluated either by the direct method, when a real vehicle runs on a track and passengers evaluate a vehicle by means of their feelings during the ride or by means of the indirect method, when accelerometers are used for measuring accelerations in various positions of a tested wagon and subsequently values of accelerations are processed in required way. Then, the ride comfort is calculated and indexed by means of ride comfort indices. In the presented work, the indirect method has been used. In the computer multibody model of the wagon accelerations on a floor have been detected and the mean ride comfort for a person is assessed. The ride safety is most often determined by waveforms of vertical wheel forces, lateral wheel forces and the derailment quotient.

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Development of multibody dynamical using MR damper based semi-active bio-inspired chaotic fruit fly and fuzzy logic hybrid suspension control for rail vehicle system

Proceedings of the Institution of Mechanical Engineers Part K Journal of Multi-body Dynamics ◽

10.1177/1464419320953685 ◽

2020 ◽

Vol 234 (4) ◽

pp. 723-744

Author(s):

Sono Bhardawaj ◽

Rakesh Chandmal Sharma ◽

Sunil Kumar Sharma

Keyword(s):

Fuzzy Logic ◽

High Speed ◽

Ride Comfort ◽

Mr Damper ◽

Fruit Fly ◽

Creep Model ◽

Ride Quality ◽

Response Analysis ◽

Running Safety ◽

Rail Vehicle

In this paper, the semi-active suspension in railway vehicles based on the controlled Magnetorheological (MR) fluid dampers is examined, and compared with the semi-active low and semi-active high suspension systems to enhance the running safety, ride quality and ride comfort for a high-speed rail vehicle. Fuzzy logic and chaotic fruit fly control techniques are used as system controllers to determine desired damping forces for front and rear bogie frame with force track-ability of system controllers. A 28 degrees of freedom (DoF) mathematical model of the rail vehicle is formulated using nonlinear vehicle suspension and nonlinear heuristic creep model. The Modified Dahl model is formulated to characterize the behavior of the MR damper. The simulation result is validated using the experimental results. Four different suspension strategies are proposed with MR damper i.e. passive, semi-active low, semi-active high and semi-active intelligent compound controller based on bio-inspired chaotic fruit and fuzzy logic hybrid controller. A comparison indicates that the semi-active controller gives the optimum performance based on frequency and time response analysis for comfort vibration actuation (9.088 to 15.33%), ride quality (14.81–20.73%) and comfort (24.91–27.81%) and it has little influence on derailment quotients, offload factors, as a result, it will not endanger the running safety of rail vehicle.

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Effect of Differential Ballast Settlement on Dynamic Response of Vehicle–Track Coupled Systems

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455418500918 ◽

2018 ◽

Vol 18 (07) ◽

pp. 1850091 ◽

Cited By ~ 11

Author(s):

Yu Sun ◽

Yu Guo ◽

Zaigang Chen ◽

Wanming Zhai

Keyword(s):

Dynamic Response ◽

Ride Comfort ◽

Coupled System ◽

Coupled Systems ◽

Track Structure ◽

Static Deflection ◽

The Finite Element Method ◽

Dynamics Model ◽

Running Safety ◽

Bed Changes

An improved vehicle-track coupled dynamics model that takes into account the differential ballast settlement is presented in this paper. Central to this formulation is an iterative method for acquiring the mapping relationship between the ballast settlement and the deflection of rail and sleepers. The proposed method is validated by comparing the results obtained with those of the finite element method (FEM) and the equilibrium state calculated for the track with the ballast settlement. Using the proposed method and dynamic model, numerical analyses have been performed for the static deflection of the rail and sleepers and for the dynamic response of the vehicle-track coupled system. The results indicate that the upper track structure will settle along with the ballast bed, and sleepers are likely to become unsupported when the settlement amplitude is large or when the settlement wavelength is small. The contact between the sleeper and the ballast bed changes dynamically when the vehicle passes through the settlement area. The ballast settlement has a significant effect on the deformation of the track and sleepers, thereby deteriorating the running safety and ride comfort of the vehicle.

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Analytical study of the transition curves in the bi-linear Mathieu equation

Nonlinear Dynamics ◽

10.1007/s11071-020-05884-0 ◽

2020 ◽

Vol 101 (4) ◽

pp. 2615-2627

Author(s):

K. R. Jayaprakash ◽

Yuli Starosvetsky

Keyword(s):

Analytical Study ◽

Mathieu Equation ◽

Transition Curves

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Impact of maintenance conditions of vehicle components on the vehicle–track interaction loads

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406217722803 ◽

2017 ◽

Vol 232 (15) ◽

pp. 2626-2641 ◽

Cited By ~ 7

Author(s):

Naim Kuka ◽

Riccardo Verardi ◽

Caterina Ariaudo ◽

João Pombo

Keyword(s):

Ride Comfort ◽

Dynamic Performance ◽

Rolling Stock ◽

Life Cycle Costs ◽

Railway Transport ◽

Structural Fatigue ◽

Running Safety ◽

Vehicle Component ◽

Vehicle Components ◽

Definition Of

To improve the efficiency and competitiveness of railway transport, passenger and freight trains should travel faster and have increased payload, without losing the necessary levels of running safety and ride comfort, as well as assuring low aggressiveness on track and minimising the life cycle costs. Hence, the manufacturer’s challenge consists of improving the dynamic performance of the railway vehicles and reducing the loads on the track as well as on the rolling stock components. These objectives can be achieved through optimizing the design of the vehicle, while taking into consideration that the characteristics of the vehicle and of the track may change over time and space, and that they depend on the maintenance conditions of the vehicle and of the infrastructure. This work proposes a computational methodology to study how the varying vehicle component characteristics, on normal and degraded conditions, impact on the vehicle/track interaction loads and on the track damage. The purpose of this study is to trace a path towards a realistic definition of a load mission profile for the structural fatigue dimensioning of the vehicle components. The assessment criteria and the evaluated quantities are defined according to the EN14363 regulation.

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Assessment of Train Running Safety, Ride Comfort and Track Serviceability at Transition between Floating Slab Track and Conventional Concrete Track

Journal of the Korean society for railway ◽

10.7782/jksr.2012.15.1.048 ◽

2012 ◽

Vol 15 (1) ◽

pp. 48-61 ◽

Cited By ~ 6

Author(s):

Seung-Yup Jang ◽

Sin-Chu Yang

Keyword(s):

Ride Comfort ◽

Conventional Concrete ◽

Running Safety ◽

Slab Track

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Running safety evaluation of high-speed train subject to the impact of floating ice collision on bridge piers

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/09544097211010001 ◽

2021 ◽

pp. 095440972110100

Author(s):

Penghao Li ◽

Zhonglong Li ◽

Zhaoling Han ◽

Shengyang Zhu ◽

Wanming Zhai ◽

...

Keyword(s):

High Speed ◽

Ride Comfort ◽

Dynamic Responses ◽

Impact Loads ◽

High Speed Train ◽

Train Track ◽

Railway Bridges ◽

Running Safety ◽

Track Bridge ◽

The Impact

In Northeast China and the areas along Sichuan-Tibet railway, collision between floating ice and piers of railway bridges seriously threatens the train operation safety. The safety of high-speed train running on the bridge subject to the impact of floating ice collision is rarely assessed considering the spatial interaction of the train-track-bridge-ice system. To evaluate the running safety and ride comfort of trains and the structural stability of railway bridges under the collision between floating ices and piers, a train-track-bridge (TTB) dynamic interaction model considering the impact of floating ice is established. Using the refined finite element model, the collision process of floating ice on bridge pier is simulated, and the impact loads are employed as the excitation input of the TTB dynamics model. Taking a 5 × 32 m simply-supported bridges as a case study, the influence of bridge structural parameters on the floating ice collision system is investigated, and then the dynamic responses of the TTB system induced by the floating ice impact loads are analyzed in detail. Finally, the effect of the ice impact loads on the running safety of the high-speed train is revealed. Results show that under the floating ice impact loads, the angle of the pier sharp-nose (APSN) and lateral stiffness of foundations are the key parameters that influence the dynamic responses of the bridge, and an improperly small lateral stiffness of foundation would lead to an instability of bridge structure. The influence of ice impact loads on the dynamic responses of the train is remarkable. The lateral vibration acceleration, derailment factor and lateral wheel rail force caused by the ice impact loads are all greater than those caused by the track irregularity, while the wheel unloading rate is slightly smaller. In addition, the running speed of train is also closely related to the running safety and ride comfort when the collision occurs. When the train speed exceeds 400 km/h, the train passing through the bridge would have the possibility of derailment.

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