Stability Analysis of High-Speed Railway Vehicle Based on Multibody Dynamics Analysis (original) (raw)

High Speed Stability of a Railway Vehicle Equipped with Independently Rotating Wheels

2018

The paper is devoted to the study of lateral oscillation and the assessment of the motion stability of a four axle railway vehicle equipped with wheelsets with independently rotating wheels. First, a linear four degrees of freedom mathematical model of the unconstrained wheelset in a straight track has been built. The wheelset model was consequently utilized in a model of the whole vehicle representing typical railway passenger car. The model has 25 degrees of freedom and it is described by a system of 50 first order homogeneous differential equations. Linear algebra methods were used to assess the stability. The influence of a running velocity, the torsional stiffness of wheelsets and the viscosity of coupling element between wheels was studied. Results of this study shows that wheelsets with independently rotating wheels and viscous coupling element enable stable behaviour of a vehicle at speeds exceeding 500 km/h. Prospectively, this type of wheelset is applicable to high-speed r...

Study of the railway vehicle suspension using the multibody method

INCAS BULLETIN, 2009

The article presents a mathematical model for the study of a passenger coach hunting motion using the multibody approach. The model comprises the lateral displacement, rolling and yawing motions for the main constitutive elements: axles, bogies and case. The equation system is written applying energetic methods. The forced vibrations determined by the irregular profile of the tracks are considered. The wheel -rail contact forces are expressed using the creepage coefficients established according to Kalker's linear theory. The equations system is solved through numeric methods using specialized calculus programs. The response of the system -passenger coach on a tangent track, the critical speed and the influence of the constructive characteristics of the coach on its performances are determined.

Multibody Dynamics Models of Railway Vehicle Using Adams/Rail

This research is focusing on multibody dynamics modeling data and parameter comparison. The comfort and stability of railway vehicle suspension can be measured by using Ride Index Machine and other sensors. Complete model of EMU82 from KTMB is adapted to multibody software, ADAMS/Rail. With ADAMS/Rail, the behavior and characteristic of each suspension element can be determined. The accuracy of the simulation model is verified by comparing the result of body roll angle in Adams/Rail and the actual test. As for the experiment, certain test track will be chosen and simulated in ADAMS/Rail. The selection of track is based on the design and curvature characteristic. In experiment, data of roll angle and lateral acceleration are necessary. For that purpose selected sensors such as tri-axis accelerometer and gyro will be used. The running performance of the KTMB EMU82 suspension will be gathered from the simulation.

Analysis of generalized force and its influence on ride and stability of railway vehicle

Noise & Vibration Worldwide, 2020

Formulation of a rail vehicle model using Lagrange’s method requires the system’s kinetic energy, potential energy, spring potential energy, Rayleigh’s dissipation energy and generalized forces to be determined. This article presents a detailed analysis of generalized forces developed at wheel–rail contact point for 27 degrees of freedom–coupled vertical–lateral model of a rail vehicle formulated using Lagrange’s method and subjected to random track irregularities. The vertical–lateral ride comfort of the vehicle and the ride index of the vehicle are evaluated based on ISO 2631-1 comfort specifications and stability is determined using eigenvalue analysis. The parameters that constitute the generalized forces and critically influence ride and stability have been identified and their influences on the same have been analysed in this work.

Multibody Dynamic Stability Analysis of a Diesel-Hydraulic Locomotive

In the development stage of a rail vehicle, analyses to evaluate its dynamic stability are required. In this work, a newly designed Diesel-Hydraulic Locomotive is modelled as a multibody system consisting of several rigid bodies interconnected by elastic elements. Multibody dynamic analysis of the system is performed to obtain the dynamic response and stability evaluation. Stability on tangent and curve tracks as well as the Locomotive dynamic response is investigated. The stability on tangent track is limited by the locomotive critical speed, V cr , evaluated for various wheel conicity and primary suspension stiffness. Operation beyond this critical speed will result in hunting which could lead to wheel-climb. Stability evaluation on the curve track is conducted through simulation of the model negotiating a curve with rail irregularity for various radii. The maximum and minimum velocities for negotiating the curve are evaluated. To evaluate the derailment safety on the curve track, the wheel-rail contact force ratio in lateral and vertical directions (L/V), and the loading-unloading ratio of the primary suspension in the vertical direction are computed, and are compared to limiting criteria. The results are found to meet the safety criteria. The guiding lateral force on the wheel entering a curve track for various primary suspension stiffnesses is also evaluated because its effect on wear rate of the wheel and rail. While lower stiffness value of the primary suspension results in favourable L/V and lower guiding force, it yields lower critical speed on tangent track. Hence, a parametric study of the primary suspension stiffness is conducted to obtain optimum value which yield acceptable critical speed and guiding force, yet still meet the safety criteria.

Nonlinear Dynamic Characteristics of the Railway Vehicle

Nonlinear Engineering, 2017

The nonlinear dynamic characteristics of a railway vehicle are checked into thoroughly by applying two different wheel-rail contact model: a heuristic nonlinear friction creepage model derived by using Kalker ’s theory and Polach model including dead-zone clearance. This two models are matched with the quasi-static form of the LuGre model to obtain more realistic wheel-rail contact model. LuGre model parameters are determined using nonlinear optimization method, which it’s objective is to minimize the error between the output of the Polach and Kalker model and quasi-static LuGre model for specific operating conditions. The symmetric/asymmetric bifurcation attitude and stable/unstable motion of the railway vehicle in the presence of nonlinearities which are yaw damping forces in the longitudinal suspension system are analyzed in great detail by changing the vehicle speed. Phase portraits of the lateral displacement of the leading wheelset of the railway vehicle are drawn below and on...

Modeling, Simulation, and Results of Their Use in Railway Vehicle Dynamics Studies

Railway Research - Selected Topics on Development, Safety and Technology, 2015

This chapter focuses on problems related to building mathematical and numerical models of railway vehicle dynamics and then using these models in the process of vehicle dynamics simulation. Finally, the results of such simulations devoted to selected dynamical problems are presented, highlighting the importance of powerful tools such as both the modeling and the simulation. The dynamical problems selected for the presentation concern railway vehicle stability and importance of kinematics accuracy for the description of the dynamics. These selected problems focus on the vehicle dynamics in a curved track, both in the circular and transition sections. Type of the chapter should be defined as the review paper, however, based on the authors' own results in the main.

Modelling and linear analysis of high-speed articulated trainsets

International Journal of Vehicle Design, 2001

The success of high-speed rail systems in Europe and Japan has led to the consideration of deployment of such systems in the United States. Since operating conditions in the United States are different from those in Europe and Japan, questions arise as to the safety-related behaviour of such systems. To address questions of dynamic behaviour, linear simulation models have been developed to compute the lateral stability of articulated trainsets on tangent track. These models include the essential features of articulated trainsets such as shared trucks and suspension characteristics such as car-to-car connections and car-to-truck yaw dampers. Parameter studies have been conducted for a trainset consisting of ten vehicles and having a critical speed of approximately 310 km/h. The studies show that consist stability is sensitive to the yaw damping between the trucks and the carbody, the conicity of the wheel pro¢le, and the primary suspension. Other parameters affect the stability but to a lesser degree. The modal behaviour of the consist suggests that instabilities can occur in the form of whole consist modes, in some cases a wave-like motion, especially at low conicities.

Methods of Simulation of Railway Wheelset Dynamics taking into account Elasticity

2017

Two simulation techniques for analyzing flexible wheelset dynamics are presented. They are applied within multibody approach and implemented in "Universal mechanism" software. Equations of wheelset motion are derived using floating frame of reference and component mode synthesis methods. Modal analysis is carried out in external FEA software. Kinematics of a wheel profile is described taking into account flexible displacements of wheelset nodes. In the first techniques, Lagrangian approach is applied to obtain all terms of equation of motion including inertia forces. In the second one, Eulerian approach is simulated in the stage of integration of equation of motion. Non-rotating finite element mesh of the wheelset is considered using the interpolation of flexible displacements in the nodes. The first simulation results obtained using both approaches are presented. These results confirm correctness of the suggested techniques.

Effects of Rail-Wheel Parameters on Vertical Vibrations of Vehicles Using a Vehicle-Track-Coupled Model

Transport Problems

This paper presents an insight into mathematical analysis of dynamic models of the vehicle-track system. After identification of its advantages and disadvantages, an improved three-dimensional "vehicle-track" system of a mathematical model is presented. It not only assesses the influence of realistic track irregularities but also on all elements of the railway structure: rail, rail pads, sleepers, ballasts, and subballast parameters on the wagon's movement smoothness. Based on the expanded mathematical model of the "vehicle-track" dynamic system, the dynamic process of the wagon was theoretically studied, and the effect of track with irregularities on the vibrations of the wagon elements was studied. The final conclusions and recommendations are presented.