Hunting stability analysis of train system and comparison with single vehicle model

2008 ◽  
Vol 44 (04) ◽  
pp. 184 ◽  
Author(s):  
Ren LUO
Keyword(s):  
Stability Analysis ◽  
Vehicle Model ◽  
Single Vehicle ◽  
Hunting Stability ◽  
Train System

The stability analysis using Lyapunov exponents for high-DOF nonlinear vehicle plane motion

2021 ◽  
pp. 095440702110433
Author(s):  
Shuming Shi ◽  
Fanyu Meng ◽  
Minghui Bai ◽  
Nan Lin
Keyword(s):  
Stability Analysis ◽  
Quantitative Analysis ◽  
Lyapunov Exponents ◽  
Plane Motion ◽  
Vehicle Model ◽  
Motion Stability ◽  
Motion System ◽  
Nonlinear Vehicle Model ◽  
The Stability ◽  
Different Characteristics

The Lyapunov exponents method is an excellent approach for analyzing the vehicle plane motion stability, and the researchers demonstrated the effectiveness under 2-DOF vehicle model. However, whether the Lyapunov exponents approach can effectively reveal the characteristics of high-DOF nonlinear vehicle model is the key problem at present. In this paper, the Lyapunov exponents is applied to quantitatively analyze the stability of the nonlinear three and five degree of freedom vehicle plane motion system. The different characteristics between 2-DOF and high-DOF model are revealed and explained by using Lyapunov exponents. It illustrates the feasibility of using Lyapunov exponents to analyze the stability of high-DOF vehicle models, which supplements and perfects the existing quantitative analysis conclusion.

A New Method for Equilibria and Stability Analysis of Nonlinear Dynamical Systems

2014 ◽  
Vol 534 ◽  
pp. 131-136
Author(s):  
Long Cao ◽  
Yi Hua Cao
Keyword(s):  
Stability Analysis ◽  
Dynamical Systems ◽  
Nonlinear Dynamical Systems ◽  
Nonlinear Dynamical System ◽  
Numerical Continuation ◽  
Vehicle Model ◽  
Nonlinear Dynamical ◽  
Novel Method ◽  
Linearized System ◽  
Continuation Algorithm

A novel method based on numerical continuation algorithm for equilibria and stability analysis of nonlinear dynamical system is introduced and applied to an aircraft vehicle model. Dynamical systems are usually modeled with differential equations, while their equilibria and stability analysis are pure algebraic problems. The newly-proposed method in this paper provides a way to solve the equilibrium equation and the eigenvalues of the locally linearized system simultaneously, which avoids QR iterations and can save much time.

Hunting stability analysis of partially filled tank wagon on curved track using coupled CFD-MBD method

2019 ◽  
Vol 50 (1) ◽  
pp. 45-69 ◽  
Author(s):  
Ahmad Rahmati-Alaei ◽  
Majid Sharavi ◽  
Masoud Samadian Zakaria
Keyword(s):  
Stability Analysis ◽  
Curved Track ◽  
Hunting Stability

scholarly journals Investigation on aerodynamic characteristics of tailing vehicle hood in a two-vehicle platoon

2019 ◽  
Vol 234 (1) ◽  
pp. 283-299 ◽  
Author(s):  
Qiliang Li ◽  
Wentong Dai ◽  
Zhigang Yang ◽  
Qing Jia
Keyword(s):  
Wind Speed ◽  
Total Energy ◽  
Aerodynamic Characteristics ◽  
Blockage Ratio ◽  
Vehicle Model ◽  
Frequency Bands ◽  
Discernible Effect ◽  
Vehicle Platoon ◽  
Single Vehicle ◽  
Proper Orthogonal

Experimental and numerical methods were performed to study the hood aerodynamics of a 1:18 scale vehicle model in a two-vehicle platoon under different fixed intra spacing and dynamic intra spacing at the Reynolds number of 4.9 × 105 and 4.08 × 105 in a 1:15 scale wind tunnel. Blockage ratio was calculated to be 5.6% for experiments. The averaged and fluctuating pressures of the hood of the tailing vehicle are much higher than that of single vehicle, and stronger fluctuation occurs at the front and rear edges of hood. Pressure fluctuation over the tailing vehicle hood increases as the intra spacing diminishes but sharply declines within intra spacing of 0.2 L. The energy of fluctuation is concentrated in frequency bands from 50 to 110 Hz at wind speed of 30 m/s and 40–90 Hz at wind speed of 25 m/s. Energy at the main frequency bands and peak frequencies take up nearly 25% of total energy, respectively. The results of proper orthogonal decomposition show that total energy proportion is 49.6% for the first 11 modes and 67.0% for the first 30 modes, respectively. Relative motion at low speed has no discernible effect on hood behavior and peak frequencies have inclination to decline during the process of vehicle approaching.

scholarly journals Hunting Stability of High-Speed Railway Vehicles Under Steady Aerodynamic Loads

2018 ◽  
Vol 18 (07) ◽  
pp. 1850093 ◽  
Author(s):  
Xiao-Hui Zeng ◽  
Jiang Lai ◽  
Han Wu
Keyword(s):  
Stability Analysis ◽  
High Speed ◽  
Critical Speed ◽  
Railway Vehicle ◽  
Aerodynamic Load ◽  
High Speed Railway ◽  
Aerodynamic Loads ◽  
Railway Vehicles ◽  
Pitch Moment ◽  
Hunting Stability

With the rising speed of high-speed trains, the aerodynamic loads become more significant and their influences on the hunting stability of railway vehicles deserve to be considered. Such an effect cannot be properly considered by the conventional model of hunting stability analysis. To this end, the linear hunting stability of high-speed railway vehicles running on tangent tracks is studied. A model considering the steady aerodynamic loads due to the joint action of the airflow facing the moving train and the crosswind, is proposed for the hunting stability analysis of a railway vehicle with 17 degrees of freedom (DOF). The key factors considered include: variations of the wheel–rail normal forces, creep coefficients, gravitational stiffness and angular stiffness due to the actions of the aerodynamic load, which affects the characteristics of hunting stability. Using the computer program developed, numerical calculations were carried out for studying the behavior of the linear hunting stability of vehicles under steady aerodynamic loads. The results show that the aerodynamic loads have an obvious effect on the linear critical speeds and instability modes. The linear critical speed decreases monotonously as the crosswind velocity increases, and the influences of pitch moment and lift force on the linear critical speed are larger than the other components of the aerodynamic loads.

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