Railway Vehicle Model Research Articles

Effect of Ovalization of High Speed Railway Wheels on Vehicle Dynamic Performance

A coupling dynamics model of railway vehicle with oval wheels and track is built and a corresponding numerical method is developed.The effect of ovalization of the wheels on the dynamical behavior of the vehicle system is analyzed in details.The numerical results regarding the misalignments of the vehicle and wheelset,the dynamical normal loads of the wheels and the rails and the reduction in the wheelset loading are presented under the conditions in which the wheels are in ovalization and the train speed is from 200 km/h to 350 km/h.The limit of the wheel ovalization is determined according to the traditional criterion of wheelset loading reduction for safely running estimation.The results show that the dynamical behavior of the vehicle are much related to the wheel ovalization status(the difference between the maximum diameter and the minimum diameter of the elliptical wheel),the phase between the elliptical shapes of the two side wheels and the train speed.The wheel ovalization under high speed greatly influences the vehicle behavior.The lateral motion ability and the running quality of the vehicle quickly reduce with an increasing in the wheel ovalization,and the dynamical normal load increases greatly.In such a situation,it is affirmed that the use lives of the parts of the vehicle and the track would be much reduced.And also the risk of derailment is increased largely.

2204 旅客乗車時の車両モデルと軸ダンパ減衰制御の制振効果 : 数値的検討と試験台での検証(OS1-1 鉄道車両の振動,OS1 交通・物流システムの高速化,利便性,快適性の向上,オーガナイズド・セッション(OS))

2204 旅客乗車時の車両モデルと軸ダンパ減衰制御の制振効果 : 数値的検討と試験台での検証(OS1-1 鉄道車両の振動,OS1 交通・物流システムの高速化,利便性,快適性の向上,オーガナイズド・セッション(OS))

Semi-active suspension systems for railway vehicles using magnetorheological dampers. Part I: system integration and modelling

In this paper, it is aimed to investigate semi-active suspension systems using magnetorheological (MR) fluid dampers for improving the ride quality of railway vehicles. A 17-degree-of-freedom (DOF) model of a full-scale railway vehicle integrated with the semi-active controlled MR fluid dampers in its secondary suspension system is proposed to cope with the lateral, yaw, and roll motions of the car body, trucks, and wheelsets. The governing equations combining the dynamics of the railway vehicle integrated with MR dampers in the suspension system and the dynamics of the rail track irregularities are developed and a linear quadratic Gaussian (LQG) control law using the acceleration feedback is adopted, in which the state variables are estimated from the measurable accelerations with a Kalman estimator. In order to evaluate the performances of the semi-active suspension systems based on MR dampers for railway vehicles, the random and periodical track irregularities are modelled with a uniform state-space formulation according to the testing data and incorporated into the governing equation of the railway vehicle integrated with the semi-active suspension system. Utilising the governing equations and the semi-active controller developed in this paper, the simulation and analysis are presented in Part II of this paper.

Dynamic Analysis of a 4-Axles Railway Vehicle Model

The paper deals with using dynamic simulations in fields of construction, production and operating of railway vehicles. It contained process of dynamics solution of choices referent vehicle by the help special solution software - MSC ADAMS. The creating of virtually model included creating model for railway vehicle and the model of track which is assigned for motion of railway vehicle. In the end of paper there are summary of obtained data from dynamic analysis which give us integrated view of railway vehicle behavior by the run on given track.

360497 STUDY ON DETECTION OF SIGNS OF WHEELCLIMB DERAILMENT FOR RAILWAY VEHICLES(Safety,Technical Session)

This paper presents study on the detection of signs of wheel climb derailment. The sensing method and detecting algorithm were examined. A 1/10-scale model of railway vehicle including one car body and two trucks as well as a special device that can simulate various climb-up derailments only for the chosen wheel are designed and made. Based on experimental derailment tests, sensing method and algorithm for detecting signs of derailment beforehand were proposed. It was found that the peak threshold of pitch angular rate and the integral threshold of roll angular rate of truck flame can be possible to detect of signs derailment.

Building a Railway Vehicle Model for Hardware-in-the-loop Simulation

We have developed a hardware-in-the-loop simulation (HILS) system as a virtual running-test environment to replace actual test runs. It is essential for the vehicle model in the HILS system to run under real-time conditions and for actual vehicle motion to be simulated accurately. In this paper, we introduce the HILS model and report on the results of amplitude-frequency response tests executed on a rolling stock motion stand to improve the model's performance by modifying its parameters.

A railway vehicle multibody model for real-time applications

Hardware in the loop (HIL) techniques are widely used for fast prototyping of control systems, electronic and mechatronic devices. In the railway field, several mechatronic on board subsystems are often tested and calibrated following the HIL approach. The accuracy of HIL tests depends on how the simulated virtual environment approximates the physical conditions. As the computational power available on real-time hardware grows, the demand for more complex and realistic models of railway vehicles for real-time application increases. In past research activities, the authors worked on the implementation of simplified real-time models for several applications and in particular for an HIL test rig devoted to the type approval of wheel slide protection systems. The activity has then been focused on the development of a three-dimensional model of the dynamics of a railway vehicle for more complex applications. The paper summarises the features and the results of the study.

Bifurcation approach to the influence of rolling radius modelling and rail inclination on the stability of railway vehicles in a curved track

This paper is devoted to the problems of stability of railway vehicles in a curved track. The applied method is well known as bifurcation approach, based on the analysis of bifurcation diagrams being the result of numerical simulations. Nevertheless, the original elements existing in the method enable the studies of stability in curved tracks. The main new content within this article is a study of influence of two factors on the stability of two-axle railway vehicle model in curved track, and straight track as well. These two factors are the variations in rail inclinations and the way of mean rolling radius determination. Four different values of the inclination for the three wheel–rail profile combinations and four different ways of determination of mean rolling radius are the case studies here. All of them are illustrated, discussed and supplemented with concluding remarks. At the end, more general conclusions are drawn, summarising all results.

Effect of sleeper pitch on rail corrugation at a tangent track in vehicle hunting

The effect of sleeper pitch on the initiation and development of rail corrugation at tangent track is investigated using a numerical method in vehicle hunting. The numerical analysis considers a combination of Kalker's rolling contact theory with non-Hertzian form, linear frictional work model and the dynamics model of a half railway vehicle coupled with a tangent track. Kalker's theory is modified. The half vehicle has a two-axle bogie and doubled suspension systems. It is treated as a full dynamic rigid multi-body model. In the tangent track model, an Euler beam is used to model each rail, and the backward moving discrete supports of the rails are considered to simulate the action of the discrete sleeper supports on the wheels/rails in rolling contact, when the train running on the track. The sleepers are treated as rigid bodies and the ballast bed is replaced with equivalent mass bodies. The effect of the discrete sleeper supports on the normal loads of the wheels/rails is analyzed at different speeds. The easily excited resonant frequencies of the wheelset and the track at different speeds are investigated in detail. In order to find the conditions necessary for rail corrugation occurring at the tangent track through numerical simulation, the vehicle hunting at higher speed is caused by setting the appropriate initial displacement condition of the vehicle system. The numerical results show that when the yaw angle of the wheelset reaches its maximum value in the vehicle hunting the lateral creepage of the wheel and rail oscillates at sleeper passing frequency and higher track frequencies. Therefore, rail corrugation due to wear initiates with several frequencies including sleeper passing frequency, and grouped near the peaks of the wheelset yaw angle. With increasing passage number of the vehicle in hunting, the corrugation became serious and also extended further along the rail.

Effect of discrete track support by sleepers on rail corrugation at a curved track

The paper investigates into the effect of discrete track support by sleepers on the initiation and development of rail corrugation at a curved track when a railway vehicle passes through using a numerical method. The numerical method considers a combination of Kalker's rolling contact theory with non-Hertzian form, a linear frictional work model and a dynamics model of a half railway vehicle coupled with the curved track. The half-vehicle has a two-axle bogie and doubled suspension systems. It is treated as a full dynamic rigid multi-body model. In the track model, an Euler beam is used to model the rail, and the discrete track support by sleepers moving backward with respect to the vehicle running direction is considered to simulate the effect of the discrete sleeper support on the wheels/rails in rolling contact when the vehicle moves on the track. The sleeper is treated as a rigid body and the ballast bed is replaced with equivalent mass bodies. The numerical analysis exams in detail the variations of wheel/rail normal loads, the creepages, and the rail wear volume along the curved track. Their variations are much concerned with the discrete track support. The numerical results show that the discrete track support causes the fluctuating of the normal loads and creepages at a few frequencies. These frequencies comprise the passing frequency of the sleepers and the excited track resonant frequencies, which are higher than the sleeper passing frequency. Consequently, rail corrugation with several wavelengths initiates and develops. Also the results show that the contact vibrating between the curved rails and the four wheels of the same bogie has different frequencies. In this way, the different key frequencies to be excited play an important role in the initiation and development of curved rail corrugation. Therefore, the corrugations caused by the four wheels of the same bogie present different wavelengths. The paper shows and discusses the depths of the initial corrugations caused by the four wheels of the same bogie, at the entering transition curve, the circle curve and the exit transition curve of the curved track, respectively.

Fault Detection of Railway Vehicle Suspension Systems Using Multiple-Model Approach

This paper demonstrates the possibility to detect suspension failures of railway vehicles using a multiple-model approach from on-board measurement data. The railway vehicle model used includes the lateral and yaw motions of the wheelsets and bogie, and the lateral motion of the vehicle body, with sensors measuring the lateral acceleration and yaw rate of the bogie, and lateral acceleration of the body. The detection algorithm is formulated based on the Interacting Multiple-Model (IMM) algorithm. The IMM method has been applied for detecting faults in vehicle suspension systems in a simulation study. The mode probabilities and states of vehicle suspension systems are estimated based on a Kalman Filter (KF). This algorithm is evaluated in simulation examples. Simulation results indicate that the algorithm effectively detects on-board faults of railway vehicle suspension systems.

Condition Monitoring and Fault Detection of Railway Vehicle Suspension using Multiple-Model Approach

This paper demonstrates the possibility to detect suspension failures of railway vehicles using a multiple-model approach from on-board measurement data. The railway vehicle model used includes the lateral and yaw motions of the wheelsets and bogie, and the lateral motion of the vehicle body, with sensors measuring the lateral acceleration and yaw rate of the bogie, and lateral acceleration of the body. The detection algorithm is formulated based on the Interacting Multiple-Model (IMM) algorithm. The IMM method has been applied for detecting faults in vehicle suspension systems in a simulation study. The mode probabilities and states of vehicle suspension systems are estimated based on a Kalman Filter (KF). This algorithm is evaluated in simulation examples. Simulation results indicate that the algorithm effectively detects on-board faults of railway vehicle suspension systems.

Influence of high speed railway wheels ovalization on vehicle lateral stability

The problem on out-of-round railway wheels in their service is analyzed and the wheel out-of roundness is made into categories.A new mathematical model is put forward numerically to simulate the wheel ovalization,which is called the second order periodic non-roundness of wheel.In the numerical simulation,the dynamic model of a half railway vehicle coupled with a tangent track is employed,in which elliptical railway wheels are considered in the calculation of the wheels and the rails in rolling contact. Using the new numerical method investigates the effect of the wheel ovalization on the dynamic behavior of the wbeelsets in the lateral direction,and determines the critical range of wheel ovalization at vehicle speed of 200 km/h.The numerical results show that the ovalization of high speed railway wheels has a great influence on the occurring of the vehicle hunting and the lateral stability.The situation of the wheelset hunting caused by the wheel ovalization depends greatly on the combinations of the wheel ovalization extent, the vehicle speed,and the phase angle of the ovalization of the two side wheels of the wbeelset.Increasing the wheel ovalization will cause a decrease in its lateral stability.

2202 フライホイールエネルギ貯蔵装置を用いた鉄道車両の車体傾斜制御システム(OS1-1 高速化と制御技術,OS1 交通・物流システムの高速化,利便性,快適性の向上,オーガナイズド・セッション)

Flywheel was considered as long life and high energy density auxiliary power source in hybrid traction system of railway vehicles. However, it is necessary to evaluate the gyro-dynamic interaction between current vehicle and additional flywheel. This paper proposes a new method on tilting control of railway vehicles using gyroscopic moment obtained from onboard flywheel primarily used as auxiliary power source. Uncontrolled pendulum railway vehicle cannot neutralize sensory lateral stationary acceleration in transient process. In order to prevent comfort deterioration in transient process, active control torque is necessary. Differing from conventional methods, we utilize gyroscopic moment of flywheel in hybrid powered railway vehicle. We developed a simulation model of railway vehicle considering onboard flywheel as a controllable gyroscope. Controller consists of feed-forward and energy needed for the control was calculated by numerical simulation.

2301 鉄道車両の地震時挙動に関する研究(OS4-1 接触問題とトライボロジ(その1),OS4 接触問題とトライボロジ,オーガナイズド・セッション)

The seismic behavior of railway vehicle was investigated to consider the mechanism of derailment by an earthquake. A scale of 1 to 10 railway vehicle model was vibrated by two types of seismic wave, which are Niigata Prefecture Chuetsu Earthquake and Iwate Miyagi Inland Earthquake. The speed of the vibrated model were 0km/h, 3km/h, 6km/h and 9km/h. For each condition, the model was vibrated ten times and derailment probabilities were found. By this study, it was shown that derailment probabilities tend to be higher when railway vehicle is running. Also, it was found that limits of effective value of input and response acceleration are different for stopping vehicle and running vehicle.

Effect of a scratch on curved rail on initiation and evolution of plastic deformation induced rail corrugation

A calculation model is put forward to analyze the effect of a scratch on the running surface of a curved rail on initiation and growth of plastic deformation induced rail corrugation when a wheelset is steadily and repeatedly curving. The numerical method considers a combination of Carter’s two-dimensional contact theory, a two-dimensional elastic–plastic finite element model and a vertical dynamics model of railway vehicle coupled with a curved track. A concept of feedback between the corrugation development and the vertical coupling dynamics of the wheelset and track is involved. The cyclic ratchetting effect of the rail material under repeated contact loadings is taken into account. The numerical results indicate that when a vehicle runs on rails with a scratch the contact vibration between the wheel and rail occurs at large amplitude, and rail corrugation due to plastic deformation initiates and develops. The corrugation has a tendency to move along the running direction and its evolution rate decays as wheelset passages increase. The passing frequencies of the plastic deformation induced corrugation depend on the natural frequencies of the track. The residual stresses stabilize after a limited number of wheelset passages. The residual strains increase at a reduced rate with increasing wheelset passages.

A New Dynamic Model of High-Speed Railway Vehicle Moving on Curved Tracks

A new dynamic model of railway vehicle moving on curved tracks is proposed. In the new model, the motion of the car body is considered and the motion of the truck frame is not restricted by a virtual boundary. Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of an eight degrees of freedom car system—considering the lateral displacement and the yaw angle of each wheelset, the truck frame, and the half car body—moving on curved tracks are derived completely. To illustrate the accuracy of the analysis, the limiting cases are examined. It is shown that the influence of the gyroscopic moment of the wheelsets on the critical hunting speed is negligible. In addition, the influences of the suspension parameters, including those losing in the six degrees of freedom system, on the critical hunting speeds evaluated via the linear and the nonlinear creep models are studied and compared.

Suppressing Vertical Vibration in Railway Vehicles through Air Spring Damping Control

To improve the riding comfort of railway vehicles equipped with the air suspension system now in widespread use, we tested a semi-active air suspension control system with a variable orifice. The system is installed between the air spring and the auxiliary air chamber, and is adjusted using a controller with a design based on the H∞ control algorithm. We carried out numerical simulations using a half railway vehicle model with a 4-element air suspension model, as well as performing excitation tests using a half carbody at a rolling stock test plant. The results show that the proposed system effectively reduces the power spectral density (PSD) of acceleration of the carbody floor. Additionally, little difference was observed between the vibration mitigation effectiveness of a reduced-order controller and that of the original one.

Bifurcation Analysis of Railway Vehicles

To identify the long-time behaviour of nonlinear dynamical systems with respect to the influence of one or more system parameters, numerical bifurcation analysis is an ideal computer-aided method. The objective of the paper is to describe a software environment for such an analysis that is based on the principles of path-following or continuation. A specific viewpoint is the application to ‘realistic’, i.e. detailed and complex simulation models of railway vehicles following a multibody system approach. Stationary as well as periodic behaviour is considered. Three major topics are of primary interest: The integration of a bifurcation software into a software package for the simulation of arbitrary mechanical systems; the direct calculation of periodic solutions (limit cycles); and the handling of differential algebraic equations (DAEs). The algorithms are applied finally to the ‘realistic’ simulation model of a high-speed railway passenger car.

Modelling Requirements for the Design of Active Stability Control Strategies for a High Speed Bogie

The paper presents the findings of a study on active stability control and simulation for a railway bogie vehicle. For control design a plan-view partial railway vehicle model is described. This is a simplified model derived from research experience and appropriate modelling, and a frequency domain analysis illustrates the problems associated with system instability. A multi-body dynamics software, SIMPACK is used to generate a detailed non-linear full vehicle model for simulation and control assessment. Model order reduction methods, both empirically and analytically based, are used to simplify the linear model generated from SIMPACK for further system analysis and control designs based upon the complex model. Comparisons between the simplified plan-view model and the exported reduced-order model are presented.