Curved Ballasted Track-Vehicle Dynamic Interaction: Effects of Curve Radius and Track Structural Nonlinearity

2021 ◽  
Author(s):  
Liu Pan ◽  
Lei Xu ◽  
Xianmai Chen ◽  
Zixu Zhu
Keyword(s):  
Dynamic Performance ◽  
Body System ◽  
Vehicle Dynamic ◽  
Lateral Resistance ◽  
Structural Nonlinearity ◽  
Ballasted Track ◽  
Statics And Dynamics ◽  
Curved Track ◽  
Nonlinear Performance ◽  
Curve Radius

Abstract In this work, a model for characterizing the ballasted track-vehicle interaction is presented. The vehicle is modelled as a multi-rigid-body system consisting of a car body, two bogie frames and four wheelsets, and the track is modelled by finite elements including the rail, the sleeper and the track bed. All bodies are connected by spring-dashpot elements. With novelty, the geometric nonlinearity of curved rail beam and mechanical nonlinearity of ballasted bed lateral resistance have been fully considered. Besides, numerical solution procedures including iteration and increment have been also developed to accurately clarify the dynamic nonlinear performance of vehicle-track systems. Apart from model validations in statics and dynamics, the influence of track nonlinearity and curved track radius on vehicle-track dynamic performance has been revealed in detail.

Three-Dimensional Vehicle–Curved Track Dynamic Model Based on FEM and DEM

2021 ◽  
Author(s):  
Xianmai Chen ◽  
Liu Pan ◽  
Lei Xu ◽  
Can Shi
Keyword(s):  
Dynamic Model ◽  
Three Dimensional ◽  
Beam Element ◽  
Body System ◽  
Numerical Studies ◽  
Ballasted Track ◽  
Curved Track ◽  
Engineering Practices ◽  
Continuously Welded Rail ◽  
Element Method

In this work, a systematic vehicle–curved track dynamic model is presented, in which the vehicle is modeled as a multi-rigid-body system. The track structure is modeled by finite element method with curved rail beam element considered in geometry. To obtain accurate dynamic behavior of railway ballasted track, the resistance characteristics of ballast bed are revealed by introducing the discrete element method. Besides, a two-step iterative-update method is improved to solve the multi-nonlinearity of the vehicle–curved track dynamic interaction. To improve the computational efficiency, and the improved infinite cyclic calculation method is introduced. Apart from the model validations, the application of this model in engineering practices, such as the vehicle-induced vibration of the continuously welded rail (CWR), has been revealed, and some conclusions are drawn from the numerical studies.

Dynamic Performance of High-Speed Electric Multiple Unit within Multi-Body System Simulation

2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Body System ◽  
High Speed Railway ◽  
Evaluation Indexes ◽  
Actual Operation ◽  
Multiple Unit ◽  
The Stability ◽  
Multi Body

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.

scholarly journals Multi-Objective Lightweight Optimization of Parameterized Suspension Components Based on NSGA-II Algorithm Coupling with Surrogate Model

Machines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 107
Author(s):  
Rongchao Jiang ◽  
Zhenchao Jin ◽  
Dawei Liu ◽  
Dengfeng Wang
Keyword(s):  
Ride Comfort ◽  
Lightweight Design ◽  
Dynamic Performance ◽  
Vehicle Dynamic ◽  
Multi Objective Optimization ◽  
Original Design ◽  
Dynamic Simulations ◽  
Nsga Ii ◽  
Torsion Beam ◽  
Multi Objective

In order to reduce the negative effect of lightweighting of suspension components on vehicle dynamic performance, the control arm and torsion beam widely used in front and rear suspensions were taken as research objects for studying the lightweight design method of suspension components. Mesh morphing technology was employed to define design variables. Meanwhile, the rigid–flexible coupling vehicle model with flexible control arm and torsion beam was built for vehicle dynamic simulations. The total weight of control arm and torsion beam was taken as optimization objective, as well as ride comfort and handling stability performance indexes. In addition, the fatigue life, stiffness, and modal frequency of control arm and torsion beam were taken as the constraints. Then, Kriging model and NSGA-II were adopted to perform the multi-objective optimization of control arm and torsion beam for determining the lightweight scheme. By comparing the optimized and original design, it indicates that the weight of the optimized control arm and torsion beam are reduced 0.505 kg and 1.189 kg, respectively, while structural performance and vehicle performance satisfy the design requirement. The proposed multi-objective optimization method achieves a remarkable mass reduction, and proves to be feasible and effective for lightweight design of suspension components.

Analysis of Vehicle Dynamic Performance Based on MATLAB

2013 ◽  
Vol 860-863 ◽  
pp. 1725-1728
Author(s):  
Fan Biao Bao
Keyword(s):  
Research Method ◽  
Dynamic Performance ◽  
Specific Model ◽  
Paper Analysis ◽  
Power Balance ◽  
Model Parameters ◽  
Vehicle Dynamic ◽  
Clear Physical Meaning ◽  
New Ideas ◽  
High Degree

This document focus on the car's dynamic performance characteristics.Because MATLAB has many advantages such as intuitive, clear physical meaning, a small amount of programming, data visualization and high degree of merit. This paper Computes and analysis with the introduction of an instance practice vehicle models.In light of the specific model parameters, this paper has analyzed car driver and driving resistance balance, power balance and power factor based on the application of Mat Lab's data analysis and graphics, and drawn the relevant graph, according to the mapping feature maps.The paper analysis of the car comprehensive power the car's dynamic graphing features calculation and research method are provided. The paper has provided new ideas of vehicle parameter selection and design.It has some practical value.

Analysis on the Dynamic Performance of Vehicles

2021 ◽  
Vol 42 ◽  
pp. 71-78
Author(s):  
Oana Victoria Oțăt ◽  
Ilie Dumitru ◽  
Laurenţiu Racilă ◽  
Dragoș Tutunea ◽  
Lucian Matei
Keyword(s):  
Initial Data ◽  
Analytical Method ◽  
Dynamic Performance ◽  
Automotive Sector ◽  
Vehicle Dynamic ◽  
Car Model ◽  
Dynamic Performances

The current accelerated developments within the automotive sector have triggered a series of performance, comfort, safety and design-related issues. Hence, oftentimes manufacturers are challenged to combine various elements so as to achieve an attractive design, without diminishing the vehicle’s dynamic performance. In order to determine the vehicle dynamic performances we carried out an analysis by two methods. In the first part of the paper, we have used the analytical method to establish the dynamic performances of a vehicle. The second part of our study addresses another method to determine the star performances of the vehicle by means of computerized simulations. The first test aimed to determine vehicle starting performances for two vehicle models, with similar technical configuration, but with the same initial data. In the second test, we aimed at determining the start performance for the same car model, with the same initial data, but for different adhesion coefficients

Suggestion for allowable additional compressive stress based on track conditions

2017 ◽  
Vol 232 (5) ◽  
pp. 1309-1325 ◽  
Author(s):  
Kyung-Min Yun ◽  
Beom-Ho Park ◽  
Hyun-Ung Bae ◽  
Nam-Hyoung Lim
Keyword(s):  
Compressive Stress ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Additional Stress ◽  
Analysis Model ◽  
Temperature Changes ◽  
Lateral Resistance ◽  
Ballasted Track ◽  
Continuous Welded Rail ◽  
Track Bridge

A continuous welded rail has immovable zones due to its structural characteristics. In an immovable zone, thermal expansion and contraction of rails are restricted when the temperature changes, thereby causing excessive axial force on the rail. When the immovable zone of the continuous welded rail is located on a bridge, additional stress and displacement occur through track–bridge interactions. Additional stress and displacement of the rail compared to the embankment area are restricted when constructing the bridge under the continuous welded rail track to prevent problems with the track–bridge interaction according to UIC 774-3R and Euro codes. According to the various codes, the maximum allowable additional compressive stress is 72 MPa, with the conditions of a curve with a radius (R) ≥ 1500 m, UIC 60 continuous welded rail (tensile strength of at least 900 MPa), ballasted track with concrete sleepers and 30 cm of deep for a well-consolidated ballast. However, the lateral resistance that has the greatest effect on track stability can depend on the conditions mentioned above. Therefore, an additional review of various track conditions is required. In this paper, an evaluation of the current criteria was performed using the minimum buckling strength calculation formula, and the allowable additional stress on the rail suggested by codes could only be used on tracks with a large lateral resistance above 18 kN/m/track. Thus, a three-dimensional nonlinear analysis model was developed and analyzed to calculate the allowable additional compressive stress considering various track conditions. According to the results of the analysis, the allowable additional compressive stress was reduced with a comparatively small lateral resistance. The freedom of design can be enhanced with respect to the parameters of various track and bridge conditions using this model.

On the Wheelset Vibration due to the Stochastic Track Vertical Irregularities

2015 ◽  
Vol 809-810 ◽  
pp. 1037-1042
Author(s):  
Mădălina Dumitriu ◽  
Ioan Sebeşan
Keyword(s):  
Spectral Density ◽  
Numerical Simulations ◽  
Power Spectral Density ◽  
Dynamic Performance ◽  
Maximum Level ◽  
Vehicle Dynamic ◽  
Power Spectral ◽  
Vertical Vibrations ◽  
Basic Features ◽  
Weak Damping

The track vertical irregularities are the originator of the vertical vibrations in the wheelset. These vibrations are further conveyed to the suspended masses of the vehicle, thus generating and maintaining their vibrations. The study of the vibrations behavior of the wheelset plays an important role in the research dealing with the improvement of the vehicle dynamic performance, mainly at high velocities. This paper examines the vibrations behavior of the wheelset during running at speed of up to 200 km/h on a track with stochastic vertical irregularities, which are mathematically represented via the power spectral density. As underlain on numerical simulations, a series of basic features of the wheelset vertical vibrations will stand out, in correlation with the velocity, track quality and its damping. The observations herein prove that the maximum level of vibrations is visible at the frequency resonance of the wheelset on the track. Similarly, it is evident that the wheelset vibrations behavior increases during the running at high velocities on a track with weak damping and low quality.

Study on Nonlinear Damping Properties of Hydro-Pneumatic Suspension System for XP302-Pneumatic Tyred Roller

2014 ◽  
Vol 945-949 ◽  
pp. 987-991
Author(s):  
Bang Sheng Xing ◽  
Ning Ning Wang ◽  
Le Xu
Keyword(s):  
Dynamic Performance ◽  
Nonlinear Damping ◽  
Suspension System ◽  
Nonlinear Stiffness ◽  
Damping Properties ◽  
Vehicle Dynamic ◽  
Nonlinear Mathematical Model ◽  
Computer Simulation Program ◽  
Pneumatic Suspension ◽  
Stiffness And Damping

The nonlinear stiffness and damping properties of the hydro-pneumatic suspension system are introduced, and the nonlinear mathematical model of it is established. Using MATLAB 2009b to establish the computer simulation program and draw out the nonlinear stiffness curve and damping properties curve of the hydro-pneumatic suspension system. Then, researching the influences of related parameters' changes on the nonlinear stiffness and damping properties of the hydro-pneumatic suspension system. The simulation of vehicle dynamic performance research's foundation is provided.

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