Track Irregularity Power Spectrum and Numerical Simulation

2021 ◽  
pp. 125-148
Author(s):  
Xiaoyan Lei
Keyword(s):  
Numerical Simulation ◽  
Power Spectrum ◽  
Track Irregularity

Shock and Sine Response of Rigid Structures on Nonlinear Mounts

1991 ◽  
Author(s):  
R. Dufour ◽  
J. Der Hagopian ◽  
M. Pompei ◽  
C. Garnier
Keyword(s):  
Numerical Simulation ◽  
Power Spectrum ◽  
Dynamic Behavior ◽  
Dynamic Environment ◽  
Rigid Bodies ◽  
Nonlinear Parameters ◽  
Large Power ◽  
Passive Damper ◽  
Highly Nonlinear

Abstract The dynamic environment of embarqued structures such as radars or more generally electronic equipments consists of impacts, sine and large power spectrum excitations. Under these real conditions and amongst different kinds of isolation, the passive damper with nonlinear parameters can provide good performances. This paper is concerned with the dynamic behavior of rigid bodies on highly nonlinear mounts. The numerical simulation and the experiment carried out, show that the load-deflection behavior of the dampers have to be slightly ajusted with respect to impact vibrations to obtain a well designed behavior.

Six-Dimensional Chaotic System and its Circuit Implementation

2011 ◽  
Vol 255-260 ◽  
pp. 2018-2022 ◽  
Author(s):  
Jian Liang Zhu ◽  
Yu Jing Wang ◽  
Shou Qiang Kang
Keyword(s):  
Numerical Simulation ◽  
Power Spectrum ◽  
Chaotic System ◽  
Time Domain ◽  
Circuit Simulation ◽  
System Simulation ◽  
Practical Significance ◽  
Chaotic Attractors ◽  
Circuit Implementation ◽  
Product Term

In order to generate complex chaotic attractors, a six-dimensional chaotic system is designed, which contains six parameters and each equation contains a nonlinear product term. When its parameters satisfy certain conditions, the system is chaotic. By Matlab numerical simulation, chaotic attractor and relevant Lyapunov exponents spectrum can be obtained, which validates that the system is chaotic. And, time domain waveform and power spectrum are shown. Finally, the implementation circuit of this system is designed, and circuit simulation can be done by using Multisim. Circuit simulation result is identical to system simulation completely. The circuit has a practical significance in secrecy communication and correlative fields.

Numerical Simulation and Mechanism Study of Two Level Partial Blocks Vibration Motor

2011 ◽  
Vol 396-398 ◽  
pp. 2463-2466
Author(s):  
Xiao Lan Yang ◽  
Ji Feng Liu ◽  
Jing Chao Zou
Keyword(s):  
Numerical Simulation ◽  
Power Spectrum ◽  
High Intensity ◽  
Mechanical Model ◽  
Mechanism Study ◽  
Lagrange Method ◽  
Special Operations ◽  
Chaotic Vibration ◽  
Vibrating System ◽  
Initial Sensitivity

In order to finish some special operations, the chaotic vibrating motor with two-level partial blocks is constructed. Mechanism principles are designed and dynamics of mechanical model is analyzed by using Lagrange method. Based on the initial sensitivity, non-repetition and complexity of phase-trajectory, many characteristics of chaotic vibration are verified in the vibrating system. It is found the vibrating system with wide power spectrum can achieve some special properties like transient high-intensity, super high-intensity and large vibrating amplitude. It is important to overcome some work barriers and solve some technological bottlenecks of vibrating machinery.

scholarly journals Vehicle Vibration Analysis in Changeable Speeds Solved by Pseudoexcitation Method

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Li-Xin Guo ◽  
Li-Ping Zhang
Keyword(s):  
Numerical Simulation ◽  
Power Spectrum ◽  
Traditional Method ◽  
Vibration Analysis ◽  
Random Vibration ◽  
Degrees Of Freedom ◽  
Rear Wheel ◽  
Front Wheel ◽  
Power Spectrum Density ◽  
Spectrum Density

The vehicle driving comfort has become one of the important factors of vehicle quality and receives increasing attention. In this paper, the mechanical and mathematical models of the half-car, five degrees of freedom (DOF) of a vehicle were established, as well as the pseudoexcitation model of road conditions for the front wheel and the rear wheel. By the pseudoexcitation method, the equations of transient response and power spectrum density were established. After numerical simulation to vehicle vibration response of changeable driving, the results show that the pseudoexcitation method is more convenient than the traditional method and effectively solves the smoothness computation problems of vehicles while the pseudoexcitation method is used to analyze vehicle vibration under nonstationary random vibration environments.

Improvement of curving performance by expansion of gauge widening and additional measures

2011 ◽  
Vol 226 (2) ◽  
pp. 203-215 ◽  
Author(s):  
M Adachi ◽  
A Matsumoto
Keyword(s):  
Numerical Simulation ◽  
Inclination Angle ◽  
Lateral Force ◽  
Rolling Stock ◽  
Running Performance ◽  
Rail Corrugation ◽  
Lateral Forces ◽  
Curving Performance ◽  
Track Irregularity ◽  
Squeal Noise

Lateral forces between wheels and rails must be reduced in order that rolling stock runs safely and smoothly on curved tracks. The excessive lateral force will cause not only derailment of rolling stock but also destruction of tracks, rail corrugation, track irregularity, squeal noise and wear. It is important to reduce lateral force of wheels in curves, so new wheel-tread profiles and steerable bogie structures have been developed up to now, however, they cannot solve various problems in curving perfectly. In this article, the authors propose three methods for improvement of running performance on curves by using existing types of wheels and rails, and analyse the effects of three methods by numerical simulation. According to analytical results, the authors conclude that ‘expansion of gauge widening’, and ‘larger rail inclination angle of inner rail installation’ or ‘asymmetrically inclined grinding of inner rail head’ can get sufficient rolling radius difference, and are effective for improvement of running performance on curved tracks.

scholarly journals Dynamics of the Bogie of Maglev Train with Distributed Magnetic Forces

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Yaozong Liu ◽  
Wenxi Deng ◽  
Pu Gong
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Dynamic Behavior ◽  
Magnetic Force ◽  
Control Parameters ◽  
Maglev Train ◽  
Electromagnetic Suspension ◽  
Frequency Responses ◽  
Magnetic Forces ◽  
Track Irregularity

A dynamic model of the bogie of maglev train with distributed magnetic forces and four identical levitating controllers is formulated. The vertical, pitching, and rolling degree of freedom of the electromagnet modules and their coupling are considered. The frequency responses of the bogie to track irregularity are investigated with numerical simulation. The results tell us that there are resonances related to the first electromagnetic suspension whose frequencies are determined by the control parameters. A comparative analysis has been carried out between the models with distributed or concentrated magnetic forces. The comparison indicates that simplifying the distributed magnetic force to concentrated one degenerates the dynamic behavior of the maglev bogie, especially resulting in overestimated resonances of the first electromagnetic suspension of maglev trains. The results also indicate that those resonances only occur on specific wavelengths of irregularity that relate to the length of the electromagnets.

Insight Into the Non Periodic Motion of the Knife Follower With a Polydyne Cam Mechanism

2020 ◽  
Author(s):  
Louay S. Yousuf ◽  
Yaakob K. H. Dabool
Keyword(s):  
Numerical Simulation ◽  
Fourier Transform ◽  
Lyapunov Exponent ◽  
Angular Velocity ◽  
Power Spectrum ◽  
Periodic Motion ◽  
Phase Plane ◽  
Power Spectrum Analysis ◽  
Cam Follower ◽  
The Impact

Abstract A polydyne cam and knife follower system are studied. The effect of cam angular velocity and follower guides internal dimensions on Lyapunov parameter is considered. Wolf algorithm is used to quantify largest Lyapunov exponent parameter. The impact between the cam, follower and the two guides is occurred due to the impulse and momentum phenomenon. Positive value of Lyapunov exponent parameter indicates to non-periodic motion and chaos for the follower. Non-periodic motion is examined using power spectrum analysis of Fast Fourier Transform (FFT) and phase plane diagram. The numerical simulation has been done using SolidWorks software. Follower movement is processed experimentally through an infrared 3-D camera device with a high precision optical sensor. A polydyne cam and knife follower system are studied. The effect of cam angular velocity and follower guides internal dimensions on Lyapunov parameter is considered. Wolf algorithm is used to quantify largest Lya-punov exponent parameter. The impact between the cam, follower and the two guides is occurred due to the impulse and momentum phenomenon. Positive value of Lyapunov exponent parameter indicates to non-periodic motion and chaos for the follower. Non-periodic motion is examined using power spectrum analysis of Fast Fourier Transform (FFT) and phase plane diagram. The numerical simulation has been done using Solid-Works software. Follower movement is processed experimentally through an infrared 3-D camera device with a high precision optical sensor. The simulation and experimental results are compared and verified for non-periodic motion of the follower. The follower motion is non-periodic when the orbit of phase-plane diagram diverges with no limit of spiral cycles.

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