Suspension Bounce Response of Canadian MAGLEV Vehicle Under Guideway Excitations—Part I: Deterministic Analysis

1983 ◽  
Vol 105 (1) ◽  
pp. 104-111
Author(s):  
M. Kotb ◽  
T. S. Sankar ◽  
M. Samaha
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Equations Of Motion ◽  
Vehicle Body ◽  
Ride Quality ◽  
Numerical Techniques ◽  
Deterministic Analysis ◽  
Maglev Vehicle ◽  
Main Emphasis

The dynamic bounce response of the Canadian designed high speed magnetically levitated vehicle is investigated when subjected to purely periodic excitations from the guideways. The equations of motion of the system are derived, on the basis of a realistic linear mathematical model, using d’Alembert’s principle of force and moment analysis. Solutions for the system responses in the time and frequency domain are obtained using numerical techniques. Although the main emphasis of this study is focused on the bounce response of the vehicle body as a measure of the ride quality of the vehicle, the vehicle pitching response as well as the bounce responses of the levitation magnets are also given appropriate attention.

scholarly journals Effect of the turning characteristics of underfloor wheel lathes on the evolution of wheel polygonisation

2018 ◽  
Vol 233 (5) ◽  
pp. 479-488 ◽  
Author(s):  
Dabin Cui ◽  
Boyang An ◽  
Paul Allen ◽  
Ruichen Wang ◽  
Ping Wang ◽  
...  
Keyword(s):  
Fourth Order ◽  
High Speed ◽  
Higher Order ◽  
Ride Quality ◽  
Sustained Use ◽  
High Speed Trains ◽  
Cut Quality ◽  
Multiple Unit ◽  
Component Failures

During both running and wheel cut operations, wheels of railway vehicles and the friction rollers that support and drive the wheelset on a typical wheel cut lathe are subject to wear and hence are likely to develop out-of-round characteristics after sustained use. The resulting out-of-round wheels can significantly affect the ride quality and can potentially increase the incidence of fatigue-related component failures due to the resulting higher intensity loading cycles. Furthermore, the corresponding out-of-round characteristics of the lathe's friction rollers will continue to degrade the subsequent cut quality of wheels. For the analysis of the out-of-round characteristics caused by an underfloor wheel lathe used for the high-speed trains in China, a mathematical model based on a typical electric multiple unit (EMU) vehicle's wheelsets and their interactions with the wheel lathe friction rollers was established. Factors influencing the cut quality of the wheels, including the number of cuts, eccentricity forms of the friction rollers and the longitudinal spacing of the two rollers, have been analysed. The results show that two cuts can effectively remove the higher order polygon on the wheel surface. The eccentricity and phase angle of the friction rollers have no influence on the cut quality of higher order polygons, whereas they are the primary cause for the fourth-order polygons. The severity of the fourth-order polygon depends on the level and the phase of the eccentricity of the friction rollers. The space of the two rollers can also significantly affect the cut quality. Obtaining the theoretical and practical value for the maintenance of polygonised wheels using the underfloor lathe is the main outcome of this study.

Guideway Camber and Three-Stage Passive Suspension for Improved Tracked Air Cushion Vehicle Ride Quality: Part II of a Parametric Study

1973 ◽  
Vol 95 (1) ◽  
pp. 86-91
Author(s):  
S. B. Biggers
Keyword(s):  
High Speed ◽  
Ride Quality ◽  
Attractive Alternative ◽  
High Quality ◽  
Passive Suspension ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Air Cushion ◽  
Passive Suspension System

Two means of providing a high quality air cushion ride at high speed using simple passive suspension systems are investigated. The inclusion of the proper amount of camber in guideway beams is shown to greatly reduce both low and high speed heave accelerations. A three-stage passively suspended vehicle including two degrees of pitching motion is shown to eliminate the high speed peak in accelerations present with two-stage vehicles. The effects of secondary and tertiary damping, of the vehicle to span length ratio, and of guideway camber on the ride quality of this vehicle are investigated. Coupled with cambered guideway beams, the three-stage passive suspension system appears to be an attractive alternative to active suspension systems.

Forced Wave Motion of Liquid Partially Filling a High-Speed Rotor

1985 ◽  
Vol 107 (4) ◽  
pp. 446-452
Author(s):  
J. Inoue ◽  
Y. Jinnouchi ◽  
Y. Araki
Keyword(s):  
High Speed ◽  
Wave Motion ◽  
Equations Of Motion ◽  
Governing Equations ◽  
Rotor Vibration ◽  
Liquid Motion ◽  
Large Wave ◽  
Main Emphasis ◽  
Two Dimensional Flow ◽  
Theoretical Results

Wave motion of a liquid in a partially filled hollow cylindrical rotor, which rotates at a high speed and is forced to vibrate, is theoretically and experimentally investigated. Main emphasis is placed on the analysis of a large wave motion in the liquid which may cause self-excited vibrations of the rotor. Assuming a thin liquid layer, simplified equations of motion are derived by integration of the governing equations for a two-dimensional flow. Nonlinearity and viscosity are taken into account in the analysis. A large wave motion with a broken wavecrest is analyzed by applying a theory of hydraulic jump. Illustrating typical examples of the theoretical results together with the experimental ones, the dynamic behavior of the liquid motion and the basic relations between the liquid force and the rotor vibration are discussed.

scholarly journals The longitudinal static stability of an aerodynamically alleviated marine vehicle, a mathematical model

2009 ◽  
Vol 466 (2116) ◽  
pp. 1055-1075 ◽  
Author(s):  
Maurizio Collu ◽  
Minoo H. Patel ◽  
Florent Trarieux
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Equations Of Motion ◽  
Static Stability ◽  
Mathematical Approach ◽  
Vehicle Concept ◽  
Longitudinal Stability ◽  
Aerodynamic Surfaces ◽  
Marine Vehicle ◽  
Longitudinal Static Stability

An assessment of the relative speeds and payload capacities of airborne and waterborne vehicles highlights a gap that can be usefully filled by a new vehicle concept, utilizing both hydrodynamic and aerodynamic forces. A high-speed marine vehicle equipped with aerodynamic surfaces is one such concept. In 1904, Bryan & Williams (Bryan & Williams 1904 Proc. R. Soc. Lond. 73 , 100–116 (doi:10.1098/rspl.1904.0017)) published an article on the longitudinal dynamics of aerial gliders, and this approach remains the foundation of all the mathematical models studying the dynamics of airborne vehicles. In 1932, Perring & Glauert (Perring & Glauert 1932 Reports and Memoranda no. 1493) presented a mathematical approach to study the dynamics of seaplanes experiencing the planing effect. From this work, planing theory has developed. The authors propose a unified mathematical model to study the longitudinal stability of a high-speed planing marine vehicle with aerodynamic surfaces. A kinematics framework is developed. Then, taking into account the aerodynamic, hydrostatic and hydrodynamic forces, the full equations of motion, using a small perturbation assumption, are derived and solved specifically for this concept. This technique reveals a new static stability criterion that can be used to characterize the longitudinal stability of high-speed planing vehicles with aerodynamic surfaces.

Modal Analysis of Ballooning Strings With Small Sag

1999 ◽  
Author(s):  
Rongjun Fan ◽  
Sushil K. Singh ◽  
Christopher D. Rahn
Keyword(s):  
Steady State ◽  
High Speed ◽  
Natural Frequencies ◽  
Rotation Speed ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Mode Shapes ◽  
Theoretical Predictions ◽  
Nonlinear Equations Of Motion

Abstract During the manufacture and transport of textile products, yarns are rotated at high speed and form balloons. The dynamic response of the balloon to varying rotation speed, boundary excitation, and disturbance forces governs the quality of the associated process. Resonance, in particular, can cause large tension variations that reduce product quality and may cause yarn breakage. In this paper, the natural frequencies and mode shapes of a single loop balloon are calculated to predict resonance. The three dimensional nonlinear equations of motion are simplified via small steady state displacement (sag) and vibration assumptions. Axial vibration is assumed to propagate instantaneously or in a quasistatic manner. Galerkin’s method is used to calculate the mode shapes and natural frequencies of the linearized equations. Experimental measurements of the steady state balloon shape and the first two natural frequencies and mode shapes are compared with theoretical predictions.

Mathematical modeling of articulated passenger train spatial vibrations

2021 ◽  
Vol 2021 (2) ◽  
pp. 91-99
Author(s):  
O. Markova ◽  
◽  
H. Kovtun ◽  
V. Maliy ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Ride Quality ◽  
Railway Transport ◽  
Passenger Train ◽  
Wide Range ◽  
Random Track Irregularities ◽  
The Mathematical Model

The problem of high-speed railway transport development is important for Ukraine. In many countries articulated trains are used for this purpose. As the connections between cars in such a train differ from each other, to investigate its dynamic characteristics not a separate car, but a full train vibrations model is necessary. The article is devoted to the development of the mathematical model for articulated passenger train spatial vibrations. The considered train consists of 7 cars: one motor-car, one transitional car, three articulated cars, one more transitional car and again one motor-car. Differential equations of the train motion along the track of arbitrary shape are set in the form of Lagrange’s equations of the second kind. All the necessary design features of the vehicles are taken into account. Articulated cars have common bogies with adjoining cars and a transfer car and the cars are united by the hinge. The operation of the central hinge between two cars is modeled using springs and dampers acting in the horizontal and vertical directions. Four dampers between two adjacent car-bodies act as dampers for pitching and hunting and are represented in the model by viscous damping. The system of 257 differential equations of the second order is set, which describes the articulated train motion along straight, curved, and transitional track segments with taking into account random track irregularities. On the basis of the obtained mathematical model the algorithm and computational software has been developed to simulate a wide range of cases including all possible combinations of parameters for the train elements and track technical state. The study of the train self-exited vibrations has shown the stable motion in all the range of the considered speeds (40 km/h – 180 km/h). The results obtained at the train motion along the track maintained for the speedy motion have shown that all the dynamic characteristics and ride quality index insure train safe motion and comfortable conditions for the travelling passengers.

Suspension Dynamics and Design Optimization of a High Speed Railway Vehicle

Joint Rail ◽  
2004 ◽  
Author(s):  
Kazuhiko Nishimura ◽  
N. C. Perkins ◽  
Weiming Zhang
Keyword(s):  
High Speed ◽  
Design Strategy ◽  
Vehicle Body ◽  
Ride Quality ◽  
Railway Vehicle ◽  
High Speed Railway ◽  
Design Objective ◽  
Lumped Parameter ◽  
Power Spectral ◽  
Suspension Dynamics

The design of suspension systems for high speed railway vehicles involves the simultaneous consideration of those requirements as suspension packaging, ride quality, stability, and cost. A design strategy is presented in this paper that enables an optimal design with respect to these competing requirements. The design strategy consists of four steps including the development of a lumped parameter vehicle model, the determination of vehicle parameters, the formulation of a design objective, and the minimization of the objective to optimize key suspension parameters. The design objective captures vehicle requirements including ride quality, suspension packaging, and wheel/rail holding. Power spectral densities (PSDs) are computed for the vertical vehicle body acceleration, suspension travel and dynamic wheel/rail interaction. The design objective function is calculated based on these PSDs and minimized to yield an optimum. An example suspension design is proposed that improves vehicle ride quality and wheel/rail holding without sacrificing other requirements.

scholarly journals Dynamic Simulation of High-Speed Induction Motor

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2713
Author(s):  
Maria Dems ◽  
Krzysztof Komeza ◽  
Jacek Szulakowski ◽  
Witold Kubiak
Keyword(s):  
Mathematical Model ◽  
Induction Motor ◽  
High Speed ◽  
Start Up ◽  
Modified Equations ◽  
Higher Power ◽  
The Mathematical Model ◽  
Dynamic Phenomena ◽  
Dynamic States

In the drives of high-speed devices, such as a blood centrifuge, dynamic states also play an important role in terms of the time and quality of the tests performed. The article presents the application of modified equations resulting from the mathematical model of an induction motor to model dynamic phenomena during motor start-up, both with mains supply and with frequency start-up. The applied solution considers the phenomenon of current displacement in the rotor bar and the phenomenon of saturation. The comparison of the obtained results with the experiment shows that the method is sufficiently accurate. The obtained results can also be extended to higher power machines and to modeling other dynamic states.

Study on Influences of Air Spring Failures on Ride Quality of High-Speed Railway Trains

2013 ◽  
Vol 420 ◽  
pp. 9-15 ◽  
Author(s):  
Dao Gong ◽  
Wen Jing Sun ◽  
Jin Song Zhou
Keyword(s):  
High Speed ◽  
Ride Quality ◽  
Railway Vehicle ◽  
Air Spring ◽  
High Speed Railway ◽  
Damping Characteristics ◽  
Secondary Support ◽  
Sudden Release ◽  
Straight Lines

A refined non-linear air spring model of railway vehicle model is established in this paper and the influences of different air spring failures on ride quality are studied. Results show that the orifice failure makes the air spring loses damping characteristics and deteriorates the vehicle ride quality; The failure of levelling valve has little influence on the ride quality when vehicle running on straight lines; The fracture of air spring diaphragm results in a sudden release of air, and car body secondary support disappears rapidly, excessive wheel unloading will happen and which can easily lead to derailment. In addition, the longer the leakage process, the less the influence on vehicle safety.

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