Dynamic Interactions Between Long, High Speed Trains of Air Cushion Vehicles and Their Guideways

1971 ◽  
Vol 93 (1) ◽  
pp. 16-24 ◽  
Author(s):  
James F. Wilson ◽  
Sherrill B. Biggers
Keyword(s):  
High Speed ◽  
Span Length ◽  
Static Deflection ◽  
Dynamic Interactions ◽  
Suspension Systems ◽  
Passenger Safety ◽  
High Speed Trains ◽  
Air Cushion ◽  
Vertical Accelerations ◽  
Air Cushion Vehicles

Trains of high speed air cushion vehicles traversing simple spans are modeled as uniform pressure segments traveling at arbitrary speeds over identical Bernoulli-Euler beams. Series solutions are found for the transient span and vehicle responses where the trains overlap several spans at a time. Elastic foundation, span tension, and span damping effects are included. Conclusions reached after studying some realistic numerical examples for constant-speed trains on elevated spans are: (a) for trains which are longer than one span length, the dynamic deflection factors (maximum ratios of dynamic to static deflection at midspan) approach 2.0 at speeds between 300 and 600 mph, and occur as the end of the train approaches, midspan; (b) these dynamic deflections may be reduced by the addition of damping, by a reduction of span length, by the addition of span tension, and by an increase in span stiffness; (c) the high vertical accelerations of the vehicles, which may approach 2 g’s at speeds of 300 mph, show the need for advanced suspension systems to insure passenger safety and comfort.

Dynamic Interactions of High Speed Tracked Air Cushion Vehicles With Their Guideways: Part I of a Parametric Study

1973 ◽  
Vol 95 (1) ◽  
pp. 76-85 ◽  
Author(s):  
S. B. Biggers ◽  
J. F. Wilson
Keyword(s):  
High Speed ◽  
Bending Moments ◽  
Passenger Compartment ◽  
Dynamic Interactions ◽  
Vehicle Load ◽  
Vehicle Mass ◽  
Air Cushion ◽  
Vehicle Motion ◽  
Frequency Ratios ◽  
Air Cushion Vehicles

The vehicle-guideway system is modeled as an arbitrary number of lumped, doubly-sprung vehicle mass systems traveling in tandem along simple supported beams. The vehicle load is transmitted to the guideway as a time-varying uniform pressure compatible with vehicle motion. Effects of the dimensionless system parameters on vehicle heave acceleration, and guideway deflections and bending moments at high vehicle speeds are evaluated. Results for a vehicle which includes pitching motion compare favorably with those for a vehicle without pitch where the front and rear masses are uncoupled. By proper choice of parameters, passenger compartment heave accelerations can be minimized, although to keep this acceleration below 0.05g for vehicles traveling 100–300 mph requires systems with low vehicle to beam mass and frequency ratios as well as low vehicle lower to upper mass ratios. The benefits of distributed air cushion pressure to vehicle and guideway design are shown. Also, if the ratio of lower to upper vehicle mass is low, a constant moving pressure conservatively predicts the guideway response.

scholarly journals Levitation Methods for Use in the Hyperloop High-Speed Transportation System

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4190 ◽  
Author(s):  
Eric Chaidez ◽  
Shankar P. Bhattacharyya ◽  
Adonios N. Karpetis
Keyword(s):  
Speed Of Sound ◽  
High Speed ◽  
System Size ◽  
Magnetic Suspension ◽  
Air Bearings ◽  
Commercial Aviation ◽  
Simple Theories ◽  
Suspension Systems ◽  
Air Resistance ◽  
High Speed Trains

The Hyperloop system offers the promise of transportation over distances of 1000 km or more, at speeds approaching the speed of sound, without the complexity and cost of high-speed trains or commercial aviation. Two crucial technological issues must be addressed before a practical system can become operational: air resistance, and contact/levitation friction must both be minimized in order to minimize power requirements and system size. The present work addresses the second issue by estimating the power requirements for each of the three major modes of Hyperloop operation: rolling wheels, sliding air bearings, and levitating magnetic suspension systems. The salient features of each approach are examined using simple theories and a comparison is made of power consumption necessary in each case.

Determination of the optimal span length for a railway bridge crossed by various types of high-speed trains

2014 ◽  
Vol 230 (2) ◽  
pp. 531-543
Author(s):  
Jeong-Rae Cho ◽  
Kilje Jung ◽  
Keunhee Cho ◽  
Jong-Won Kwark ◽  
Young Jin Kim ◽  
...  
Keyword(s):  
High Speed ◽  
Span Length ◽  
Railway Bridge ◽  
High Speed Trains ◽  
Optimal Span

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.

Two-Dimensional Dynamics of Tracked Ram Air Cushion Vehicles With Fixed and Variable Winglets

1979 ◽  
Vol 101 (4) ◽  
pp. 321-331
Author(s):  
L. M. Sweet ◽  
H. C. Curtiss ◽  
R. A. Luhrs
Keyword(s):  
Active Suspension ◽  
Suspension System ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Air Cushion ◽  
Linearized Model ◽  
The One ◽  
Air Cushion Vehicles

A linearized model of the pitch-heave dynamics of a Tracked Ram Air Cushion Vehicle is presented. This model is based on aerodynamic theory which has been verified by wind tunnel and towed model experiments. The vehicle is assumed to be equipped with two controls which can be configured to provide various suspension system characteristics. The ride quality and dynamic motions of the fixed winglet vehicle moving at 330 km/hr over a guideway described by roughness characteristics typical of highways is examined in terms of the rms values of the vertical acceleration in the foremost and rearmost seats in the passenger cabin and the gap variations at the leading and trailing edges of the vehicle. The improvement in ride quality and dynamic behavior which can be obtained by passive and active suspension systems is examined and discussed. Optimal regulator theory is employed to design the active suspension system. The predicted rms values of the vertical acceleration in the one-third octave frequency bands are compared with the vertical ISO Specifications. It is shown that marked improvements in the ride quality can be obtained with either the passive or active suspension systems.

scholarly journals OUTLOOK CONSTRUCTION SPRING SUSPENSION VEHICLES

2015 ◽  
Vol 2 (158) ◽  
Author(s):  
Vyacheslav Masliev ◽  
Sergey Kravchenko ◽  
Anton Masliyev
Keyword(s):  
High Speed ◽  
Compressed Air ◽  
Static Deflection ◽  
Two Stage ◽  
Spring Suspension ◽  
High Speed Trains

A study of the prospects for the development of construction spring suspension vehicles. It was foundthat high-speed trains, where the requirements for smoothness of motion is significantly higher than inpassenger cars, used a two-stage spring suspension with static deflection of 0.3 to 0.5 m, which is achievedthrough the use of air springs, where an elastic member is compressed air.

Paper 2. Problems and Requirements of Directional Stability, Control and Manoeuvrability; High-Speed Craft

1972 ◽  
Vol 14 (7) ◽  
pp. 6-13
Author(s):  
M. C. Eames
Keyword(s):  
High Speed ◽  
Stability Control ◽  
Paper Briefly ◽  
Planing Craft ◽  
Stability And Control ◽  
Directional Stability ◽  
Air Cushion ◽  
And Control ◽  
Air Cushion Vehicles

The problems of stability and control of high-speed craft are somewhat different for the various vehicle types. The first part of this paper briefly compares characteristics of air-cushion vehicles and planing craft. This is followed by a more detailed discussion of the problems and requirements of hydrofoil craft.

Mechanical Assessment of Maglev Vehicle: A Proposal for Implementing Maglev Trains in Iran

2010 ◽  
Author(s):  
Hamid Yaghoubi ◽  
M. Sadat Hoseini
Keyword(s):  
High Speed ◽  
Magnetic Levitation ◽  
Rapid Development ◽  
Suspension System ◽  
Magnetic Suspension ◽  
Response Characteristics ◽  
Suspension Systems ◽  
Maglev Vehicle ◽  
High Speed Trains ◽  
Live Loads

Rapid development of transportation industries worldwide, including railways and the never ending demand to shorten travel time during trade, leisure, etc. have caused planning and implementation of high-speed railways in many countries. Variety of such systems including magnetic levitation (maglev) has been introduced to the industry. Contrary to traditional railway vehicles, there is no direct contact between maglev vehicle and its guideway. These vehicles travel along magnetic fields that are established between the vehicle and its guideway. Therefore, these vehicles can travel at very high speeds. The replacement of mechanical components by electronics components overcomes restrictions of conventional railway. Manned maglev vehicles have recorded speed of travel equal to 581km/hr. This has practically paved the way to manufacture super high-speed trains. Currently, there are ElectroMagnetic Suspension (EMS) and ElectroDynamic Suspension (EDS) systems available to the industry. There are also varieties of vehicles that are manufactured based on these two types of systems. Mechanical engineering plays vital roles in design and analysis of suspension systems and corresponding vehicles. In this research, different types of maglev suspension systems and vehicles are studies. It is the purpose of this research to design a model for magnetic suspension system and a model for maglev vehicle. Static and dynamic live loads due to the maglev vehicle are investigated and mathematical model of maglev loading is presented. The proposed model for maglev vehicle is thoroughly analyzed for its static and dynamic loading. This study is focused on the dynamics of maglev vehicle. Modeling vehicle/guideway interactions and then explain the response characteristics of the maglev system for a five-car vehicle traveling on a single-span guideway, with emphasis on vehicle/guideway coupling effects are accomplished. Design of maglev vehicle with finite element method is also considered. Results justify practicality of the proposed suspension system and vehicle for Tehran-Mashhad maglev project.

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