Conventional Versus Self-Steering Radial Trucks for High-Speed Passenger Trains

1982 ◽  
Vol 104 (4) ◽  
pp. 290-296 ◽  
Author(s):  
G. R. Doyle
Keyword(s):  
Steady State ◽  
High Speed ◽  
Analytical Study ◽  
The Self ◽  
Lateral Stability ◽  
Rail Head ◽  
Passenger Trains ◽  
Design Speed ◽  
Wear Index

The performance of self-steering, articulated, and nonarticulated trucks for high-speed passenger trains was compared to a conventional passenger truck. Lateral stability and steady state curving analyses were used to evaluate a design speed of 200 km/h (125 mi/h), and a wheel tread/rail head wear index in curves. Based on the results of this analytical study, the self-steering articulated truck would reduce the wear index in curves by a factor of two. However, the use of a “relaxation” device in the secondary yaw suspension of the conventional nonarticulated truck would reduce the wear index in curves by a factor of four.

Synthesis and Steady State Analysis of High-Speed Elastic Cam-Follower Linkages With Concentrated Masses: Part I — Theory

1991 ◽  
Author(s):  
Hsin-Ting J. Liu ◽  
Donald R. Flugrad
Keyword(s):  
Steady State ◽  
Iterative Procedure ◽  
High Speed ◽  
Linear Ordinary Differential Equations ◽  
Periodic Linear ◽  
Cam Follower ◽  
Cam Profile ◽  
Concentrated Masses ◽  
Design Speed ◽  
Steady State Solutions

Abstract A cam driving a lumped inertia through a massless, elastic, slider-crank follower linkage with two concent rated masses located at the pin joints is considered. An iterative procedure taking the elasticity, damping, and changing geometry of the linkage into account is developed for synthesizing the cam profile to produce a desired output motion at a given design speed. The steady state solutions for the inhomogeneous, periodic, linear, ordinary differential equations are solved numerically by Hsu’s method.

COMPUTER SIMULATION OF STEADY STATE CURVING PERFORMANCE OF HIGH SPEED ARTICULATED TRAIN SETS

1996 ◽  
Vol 20 (4) ◽  
pp. 365-389 ◽  
Author(s):  
A.K.W. Ahmed ◽  
C. Liu ◽  
I. Haque
Keyword(s):  
Steady State ◽  
Parametric Study ◽  
High Speed ◽  
Railway Vehicle ◽  
Lateral Stability ◽  
High Speed Rail ◽  
Trade Off ◽  
Stability Performance ◽  
Minimum Number ◽  
Curving Performance

This study focuses on the steady state curving performance of articulated High Speed Rail (HSR) train sets. The models incorporate the essential features of an articulated train system such as shared trucks, and suspension characteristics such as car-to-car and car-to-truck connections. As one of the first studies on the curving performance of articulated HSR train sets, linearized steady state curving models for ten-car, five-car, and three-car consists have been developed. Steady state curving performance of the three models has been evaluated and compared to determine the minimum number of cars required in a consist for effective simulation of curving performance. The models are further used for parametric study to examine the influence of selected parameters on the steady state curving performance. The results are compared with those of a parallel study on lateral stability performance in view of stability-curving trade-off. The results show that a baseline articulated train set corresponding to lateral stability critical speed of 310 km/h is capable of negotiating a standard curved track with 0.43 degree curvature, maximum 4 degree unbalance and 12.5 mm flange clearance without wheel flanging or slip. The parametric study showed that the trade off between stability and curving is less extensive than it is known for a conventional railway vehicle. It is found that there is no conflict for wheel conicity less than 0.035 where both curving and stability performance improves with increase in wheel conicity.

Stability and Steady-State Vibrations in a High-Speed Slider-Crank Mechanism

1970 ◽  
Vol 37 (4) ◽  
pp. 1069-1076 ◽  
Author(s):  
P. W. Jasinski ◽  
H. C. Lee ◽  
G. N. Sandor
Keyword(s):  
Steady State ◽  
Small Parameter ◽  
High Speed ◽  
Analytical Study ◽  
Elastic Stability ◽  
Connecting Rod ◽  
Concentrated Mass ◽  
Transverse Vibrations ◽  
Steady State Solutions ◽  
Crank Mechanism

The research presented in this paper is an analytical study of the vibrations associated with planar mechanical linkages. Specifically, the vibrations of a high-speed slider-crank mechanism with a uniform elastic connecting rod and a rigid crank are studied. The elastic connecting rod, with distributed mass, is taken to be externally, viscously damped with a concentrated mass present at its sliding end. The equations governing the longitudinal and transverse vibrations of the elastic connecting rod are derived, a small parameter is found, and the solution is developed as an asymptotic expansion in terms of this small parameter with the aid of the Krylov-Bogoliubov method of averaging. The elastic stability is studied and the steady-state solutions for both the longitudinal and transverse vibrations of the connecting rod are obtained.

Experimental Study on the Dynamic Deformation of Simply Supported Beam in Chinese High-speed Railway

2018 ◽  
Author(s):  
Gonglian Dai ◽  
Meng Wang ◽  
Tianliang Zhao ◽  
Wenshuo Liu
Keyword(s):  
High Speed ◽  
Structure Design ◽  
Dynamic Coefficient ◽  
Bridge Structure ◽  
High Speed Railway ◽  
Simply Supported Beam ◽  
Vertical Stiffness ◽  
Simply Supported ◽  
Speed Up ◽  
Design Speed

<p>At present, Chinese high-speed railway operating mileage has exceeded 20 thousand km, and the proportion of the bridge is nearly 50%. Moreover, high-speed railway design speed is constantly improving. Therefore, controlling the deformation of the bridge structure strictly is particularly important to train speed-up as well as to ensure the smoothness of the line. This paper, based on the field test, shows the vertical and transverse absolute displacements of bridge structure by field collection. What’s more, resonance speed and dynamic coefficient of bridge were studied. The results show that: the horizontal and vertical stiffness of the bridge can meet the requirements of <b>Chinese “high-speed railway design specification” (HRDS)</b>, and the structure design can be optimized. However, the dynamic coefficient may be greater than the specification suggested value. And the simply supported beam with CRTSII ballastless track has second-order vertical resonance velocity 306km/h and third-order transverse resonance velocity 312km/h by test results, which are all coincide with the theoretical resonance velocity.</p>

Analysis of Transient Two-Phase Flow in Pressure Safety Valve Outlet Headers

2018 ◽  
Author(s):  
Maral Taghva ◽  
Lars Damkilde
Keyword(s):  
Steady State ◽  
Shock Waves ◽  
High Speed ◽  
Two Phase Flow ◽  
Safety Valve ◽  
Strong Shock ◽  
Flow Property ◽  
Phase Flow ◽  
Transient Pressure ◽  
Two Phase

To protect a pressurized system from overpressure, one of the most established strategies is to install a Pressure Safety Valve (PSV). Therefore, the excess pressure of the system is relieved through a vent pipe when PSV opens. The vent pipe is also called “PSV Outlet Header”. After the process starts, a transient two-phase flow is formed inside the outlet header consisting of high speed pressurized gas interacting with existing static air. The high-speed jet compresses the static air towards the end tail of the pipe until it is discharged to the ambiance and eventually, the steady state is achieved. Here, this transient process is investigated both analytically and numerically using the method of characteristics. Riemann’s solvers and Godunov’s method are utilized to establish the solution. Propagation of shock waves and flow property alterations are clearly demonstrated throughout the simulations. The results show strong shock waves as well as high transient pressure take place inside the outlet header. This is particularly important since it indicates the significance of accounting for shock waves and transient pressure, in contrast to commonly accepted steady state calculations. More precisely, shock waves and transient pressure could lead to failure, if the pipe thickness is chosen only based on conventional steady state calculations.

Associative Behaviors of a Novel Series of Amphiphilic Statistical Tripolymers

2014 ◽  
Vol 472 ◽  
pp. 603-606
Author(s):  
Xu Wu ◽  
Hong Hua Xiao ◽  
Ji Juan Wang ◽  
Xiao Xuan Xie ◽  
Jia Wei Lin ◽  
...  
Keyword(s):  
Steady State ◽  
Self Assembly ◽  
Sulfonic Acid ◽  
The Self ◽  
Steady State Fluorescence

A novel series of brush-like amphiphilic statistical tripolymers were designed and prepared by polymerization of amphiphilic macromonomer 2-(acrylamido)-dodecane sulfonic acid (AMC12S, 10 to 90 mol %), with hindrance units sodium p-styrenesulfonate (SSS, 0 to 5 mol %), and 2-(acrylamido)- 2-methylpro-panesulfonic acid (AMPS). The self-assembly behaviors of these tripolymers were investigated using steady-state fluorescence, and the increase of amphiphilic units results in a decrease of microdomain polarity and polymer concentrations for assembly, while the increase of hindrance units leads little change of microdomain polarity.

Research on Control Power and Self-Sensing Technology for GMM Self-Sensing Actuator

2010 ◽  
Vol 34-35 ◽  
pp. 1314-1318
Author(s):  
Xin Hua Wang ◽  
Shou Qiang Hu ◽  
Qian Yi Ya ◽  
Shu Wen Sun ◽  
Xiu Xia Cao
Keyword(s):  
Real Time ◽  
High Speed ◽  
Dynamic Balance ◽  
The Self ◽  
Time Dynamic ◽  
Scheme Design ◽  
Control Power ◽  
Sensing Technology ◽  
The Cost ◽  
Micro Controller Unit

Structure and principle of a new kind of diphase opposition giant magnetostrictive self-sensing actuator (SSA for short) is introduced, for which a kind of double outputs high-precision NC stable voltage power is designed. With the method of combining with the hardware design and the software setting, the controllability and reliability of the actuator are greatly improved. And the whole design becomes more reasonable, which saves the cost and improves the practicability. In addition, based on the micro controller unit (MCU) with high-speed control, the scheme design of the real-time separation circuit for dynamic balance signal can effectively identify out and pick up the self-sensing signal which changes from foreign pressure feed back. Then the SSA real-time, dynamic and accurately control is realized. The experiment results show that the voltage power can high-speed and accurately output both output voltages with high current, and that the self-sensing signal decoupling circuit can isolate the self-sensing signals without distortion

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