Self-excited vibration problems of maglev vehicle-bridge interaction system

2014 ◽  
Vol 21 (11) ◽  
pp. 4184-4192 ◽  
Author(s):  
Jin-hui Li ◽  
Jie Li ◽  
Dan-feng Zhou ◽  
Pei-chang Yu
Keyword(s):  
Maglev Vehicle ◽  
Interaction System ◽  
Excited Vibration ◽  
Vibration Problems

scholarly journals The Modeling and Analysis for the Self-Excited Vibration of the Maglev Vehicle-Bridge Interaction System

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jinhui Li ◽  
Jie Li ◽  
Danfeng Zhou ◽  
Lianchun Wang
Keyword(s):  
Ride Comfort ◽  
Interaction Model ◽  
Control Unit ◽  
The Self ◽  
Modeling And Analysis ◽  
Maglev Vehicle ◽  
Interaction System ◽  
Excited Vibration ◽  
Vibration Problems ◽  
The Stability

This paper addresses the self-excited vibration problems of maglev vehicle-bridge interaction system which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the whole system. Firstly, two levitation models with different complexity are developed, and the comparison of the energy curves associated with the two models is carried out. We conclude that the interaction model with a single levitation control unit is sufficient for the study of the self-excited vibration. Then, the principle underlying the self-excited vibration is explored from the standpoint of work acting on the bridge done by the levitation system. Furthermore, the influences of the parameters, including the modal frequency and modal damping of bridge, the gain of the controller, the sprung mass, and the unsprung mass, on the stability of the interaction system are carried out. The study provides a theoretical guidance for solving the self-excited vibration problems of the vehicle-bridge interaction systems.

Experimental study on vertical vibration characteristics of medium-low speed maglev vehicle when standing still on steel beams

2021 ◽  
pp. 095440972110324
Author(s):  
Miao Li ◽  
Xiaohao Chen ◽  
Shihui Luo ◽  
Weihua Ma ◽  
Cheng Lei ◽  
...  
Keyword(s):  
Coupled System ◽  
Vertical Vibration ◽  
Vibration Characteristics ◽  
Steel Beams ◽  
Steel Beam ◽  
Air Spring ◽  
Low Speed ◽  
Maglev Vehicle ◽  
Excited Vibration ◽  
Eigen Frequencies

Levitation stability is the very basis for the dynamic operation of Electromagnetic Suspension (EMS) medium-low speed maglev trains (MSMT). However, self-excited vibration tends to occur when the vehicle is standing still above the lightweight lines, which remains a major constraint to the promotion of medium-low speed maglev technology. In order to study the vertical vibration characteristics of the coupled system of MSMT when it is standing still above lightweight lines, levitation tests were carried out on two types of steel beams: steel beam and active girder of the turnout, with a newly developed maglev vehicle using levitation frames with mid-set air spring. Firstly, modal tests were carried out on the steel beam to determine its natural vibration characteristics; secondly, the acceleration signals and the dynamic displacement signals of the air spring obtained at each measurement point were analyzed in detail in both the time and frequency domains, and the vertical ride comfort was assessed by means of the calculated Sperling index. Subsequently, theoretical explanations were given for the occurrence of self-excited vibration of coupled system from the perspective of the vehicle-to-guideway vibration energy input. Results show that the eigen frequencies of the vehicle on the steel beam and the turnout are 9.65 Hz and 2.15 Hz, respectively, the former being close to the natural frequency of the steel beam while the latter being close to the natural frequency of the air spring suspension system, thus causing the self-excited vibration of the coupled system. It is recommended to either avoid the main eigen frequencies of the coupled system or to increase the damping of the corresponding vibration modes to guarantee a reliable coupled system for its long-term performance. These results may provide valuable references for the optimal design of medium-low speed maglev systems.

scholarly journals An Experimental Validated Control Strategy of Maglev Vehicle-Bridge Self-Excited Vibration

2017 ◽  
Vol 7 (1) ◽  
pp. 38 ◽  
Author(s):  
Lianchun Wang ◽  
Jinhui Li ◽  
Danfeng Zhou ◽  
Jie Li
Keyword(s):  
Control Strategy ◽  
Maglev Vehicle ◽  
Excited Vibration

scholarly journals A Practical Control Strategy for the Maglev Self-Excited Resonance Suppression

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jinhui Li ◽  
Dong Fang ◽  
Ding Zhang ◽  
Ying Cai ◽  
Qi Ni ◽  
...  
Keyword(s):  
Control Strategy ◽  
Ride Comfort ◽  
Block Diagram ◽  
Current Feedback ◽  
Positive Effects ◽  
Maglev Vehicle ◽  
Interaction System ◽  
Electrical Damping ◽  
The Stability ◽  
Additional Feedback

This paper addresses the control strategy for the suppression of maglev vehicle-bridge interaction resonance, which worsens the ride comfort of vehicle and degrades the safety of the bridge. Firstly, a minimum model containing a flexible bridge and ten levitation units is presented. Based on the minimum model, we pointed out that magnetic flux feedback instead of the traditional current feedback is capable of simplifying the block diagram of the interaction system. Furthermore, considering the uncertainty of the bridge’s modal frequency, the stability of the interaction system is explored according to an improved root-locus technique. Motivated by the positive effects of the mechanical damping of bridges and the feedback channels’ difference between the levitation subsystem and the bridge subsystem, the increment of electrical damping by the additional feedback of vertical velocity of bridge is proposed and several related implementation issues are addressed. Finally, the numerical and experimental results illustrating the stability improvement are provided.

IDENTIFY PROBLEM ISSUES OF SELF-ORDERED DEVELOPMENT MECHANISMS IN THE PUBLIC ADMINISTRATION SYSTEM

2018 ◽  
Vol 1 (12) ◽  
pp. 250-259
Author(s):  
Igor Yurievich Rodchenko
Keyword(s):  
Public Administration ◽  
Separation Of Powers ◽  
Self Regulation ◽  
State Power ◽  
Administrative Reform ◽  
Administration System ◽  
The Public ◽  
Object Interaction ◽  
Interaction System ◽  
Power Hierarchy

The problematic issues of the development of self-ordering mechanisms in the public administration system are determined, with observance of their division into institutional, functional and evolutionary parts. The institutional part includes self-regulation mechanisms implemented in the models of subject-subject interaction at the levels of higher, central and local government bodies, as well as in models of object-object interaction between them. The most important in the institutional part of self-governing mechanisms are those that ensure: the separation of powers between branches of government; administrative reform of the government structure; separation of public spheres of government between central government bodies; administrative reform of the structure of central executive bodies; delimitation of territorial spheres of government between local authorities; administrative-territorial reform; formation and implementation of the structure of the power hierarchy; administrative reform of the structure of the power hierarchy. The functional part includes the mechanisms of self-regulation, realized in the model of object-object interaction “system of state power — social sphere, industry and relations”. The most important parts of the mechanisms of self-regulation are those that ensure: the formation and implementation of state policies in various spheres of society; formation and implementation of national projects; formation and implementation of state target programs; state budgeting. The evolutionary part includes the mechanisms of self-regulation, realized in the model of object-object interaction “system of state power — the creation of conditions for social development”. The most important parts of the evolutionary part of self-governing mechanisms are those that provide: strategic management and planning; realization of state programs of social and economic development; conducting constant economic and social reforms and transformations.

MODELING OF NONLINEAR VIBRATION PROBLEMS WITH FLUID FLOWS THROUGH PIPELINES

2018 ◽  
pp. 44-47
Author(s):  
F.J. Тurayev
Keyword(s):  
Differential Equations ◽  
Nonlinear Vibration ◽  
Viscoelastic Properties ◽  
Construction Material ◽  
Fluid Flows ◽  
Variable Coefficients ◽  
Algebraic Equations ◽  
Flowing Liquid ◽  
Vibration Problems

In this paper, mathematical model of nonlinear vibration problems with fluid flows through pipelines have been developed. Using the Bubnov–Galerkin method for the boundary conditions, the resulting nonlinear integro-differential equations with partial derivatives are reduced to solving systems of nonlinear ordinary integro-differential equations with both constant and variable coefficients as functions of time.A system of algebraic equations is obtained according to numerical method for the unknowns. The influence of the singularity of heredity kernels on the vibrations of structures possessing viscoelastic properties is numerically investigated.It was found that the determination of the effect of viscoelastic properties of the construction material on vibrations of the pipeline with a flowing liquid requires applying weakly singular hereditary kernels with an Abel type singularity.

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