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.

Numerical Simulation of Shock Wave in Air Based on FCT Method

2013 ◽  
Vol 397-400 ◽  
pp. 270-273
Author(s):  
Ying Li ◽  
Xiao Bin Li ◽  
Yu Wang ◽  
Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Comparative Analysis ◽  
Numerical Method ◽  
Blast Wave ◽  
Empirical Formula ◽  
Godunov Method ◽  
Numerical Accuracy

Blast wave is numerical simulated based on FCT method. According to the comparative analysis, taking Henrych empirical formula as a standard, FCT method is more accuracy than Godunov method. Moreover, it has been found that the numerical accuracy is insufficient when the distance is small, it is necessary to develop and modify the numerical method continuously.

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.

scholarly journals Numerical simulation of particles movement in cellular flows under the influence of magnetic forces

PAMM ◽  
2011 ◽  
Vol 11 (1) ◽  
pp. 573-574
Author(s):  
Matjaž Hriberšek ◽  
Paul Steinmann ◽  
Jure Ravnik ◽  
Franziska Vogel
Keyword(s):  
Numerical Simulation ◽  
Magnetic Forces ◽  
Cellular Flows

Various Types of Coexisting Attractors in a New 4D Autonomous Chaotic System

2017 ◽  
Vol 27 (09) ◽  
pp. 1750142 ◽  
Author(s):  
Qiang Lai ◽  
Akif Akgul ◽  
Xiao-Wen Zhao ◽  
Huiqin Pei
Keyword(s):  
Numerical Simulation ◽  
Dynamic Behavior ◽  
Chaotic System ◽  
Limit Cycles ◽  
Electronic Circuit ◽  
Strange Attractors ◽  
Bifurcation Diagrams ◽  
Coexisting Attractors ◽  
Signum Function ◽  
Multiple Coexisting Attractors

An unique 4D autonomous chaotic system with signum function term is proposed in this paper. The system has four unstable equilibria and various types of coexisting attractors appear. Four-wing and four-scroll strange attractors are observed in the system and they will be broken into two coexisting butterfly attractors and two coexisting double-scroll attractors with the variation of the parameters. Numerical simulation shows that the system has various types of multiple coexisting attractors including two butterfly attractors with four limit cycles, two double-scroll attractors with a limit cycle, four single-scroll strange attractors, four limit cycles with regard to different parameters and initial values. The coexistence of the attractors is determined by the bifurcation diagrams. The chaotic and hyperchaotic properties of the attractors are verified by the Lyapunov exponents. Moreover, we present an electronic circuit to experimentally realize the dynamic behavior of the system.

Numerical Simulation on Deformation Features and Filling Efficiency of Channel Goaf Foundation

2013 ◽  
Vol 353-356 ◽  
pp. 3707-3712
Author(s):  
Zhi Dong Zhou ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Hong Ya Yue
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Comprehensive Analysis ◽  
Obvious Effect ◽  
Before And After ◽  
Check Gate ◽  
Deformation Features ◽  
Natural Foundation ◽  
The Stability

For analyzing and evaluating the deformation features of channel goaf foundation and its effect on superstructure, according to the foundation reinforcement engineering of Ji-Liang Channel Check Gate, the comparative analysis on the differential settlement between the unfavorable foundation and natural foundation was performed by numerical simulation with FLAC3D. The computer results showed that the present foundation had obvious effect on the stability and security of the superstructure, so the engineering treatment are needed. Based on technical-economic comprehensive analysis among three treatment methods for strengthening the channel golf foundation with different kinds of filling, the reasonable method is put forward in this paper. By comparing mechanical characteristic of flashboard in channel goaf before and after strengthening, we confirmed the foundation stability of channel goaf and the security of the ground building which can satisfy the long term usage requirements.

scholarly journals Nonlinear Model and Dynamic Behavior of Photovoltaic Grid-Connected Inverter

2020 ◽  
Vol 10 (6) ◽  
pp. 2120 ◽  
Author(s):  
Zhi-Xian Liao ◽  
Dan Luo ◽  
Xiao-Shu Luo ◽  
Hai-Sheng Li ◽  
Qin-Qin Xiang ◽  
...  
Keyword(s):  
Bifurcation Diagram ◽  
Dynamic Behavior ◽  
Nonlinear Model ◽  
Nonlinear Dynamic ◽  
Optimization Design ◽  
Stable Operation ◽  
Control Parameters ◽  
Nonlinear Dynamic Behavior ◽  
Predictive Controller ◽  
Grid Connected Inverter

A photovoltaic grid-connected inverter is a strongly nonlinear system. A model predictive control method can improve control accuracy and dynamic performance. Methods to accurately model and optimize control parameters are key to ensuring the stable operation of a photovoltaic grid-connected inverter. Based on the nonlinear characteristics of photovoltaic arrays and switching devices, we established a nonlinear model of photovoltaic grid-connected inverters using the state space method and solved its model predictive controller. Then, using the phase diagram, folded diagram, and bifurcation diagram methods, we studied the nonlinear dynamic behavior under the influence of control parameters on both fast and slow scales. Finally, we investigated the methods of parameter selection based on the characteristics of nonlinear dynamic behavior. Our research shows that the predictive controller parameters are closely related to the bifurcation and chaos behaviors of the grid-connected photovoltaic inverter. The three-dimensional bifurcation diagram can be used to observe the periodic motion region of the control parameters. After selecting the optimization target, the bifurcation diagram can be used to guide the selection of control parameters for inverter design. The research results can be used to guide the modeling, stability analysis, and optimization design of photovoltaic grid-connected inverters.

Study on the Capacity Increasing and Dam Heighten of Plain Reservoirs

2013 ◽  
Vol 353-356 ◽  
pp. 2531-2536
Author(s):  
Xiu Guang Song ◽  
Zhi Dong Zhou ◽  
Hong Bo Zhang ◽  
Hong Ya Yue
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Site Investigation ◽  
Seepage Flow ◽  
Differential Settlement ◽  
Construction Technology ◽  
Dam Stability ◽  
The Stability ◽  
Design Construction

In order to solve the problem of differential settlement, seepage flow and stability between the new and old dam boundary in capacity increasing of the plain reservoirs, the comparative analysis on the stability of the dam slope with different methods on dealing with the new and old dam boundary was performed by numerical simulation with FLAC3D. The result shows that combining the new and old dam by using geogrid indicates superiority for reducing differential settlement, improving the dam stability and safety, etc. In the meantime, on the basis of actual site investigation and theoretical analysis, combined with the requirements of design, construction and management in capacity increasing of the plain reservoirs, the key construction technology was put forward and widely applied foreground, which can improve the quality of the construction, reduce engineering disease and provide references for capacity increasing engineering of in plain reservoirs.

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