Evaluation and analysis approach of wheel–rail contact force measurements through a high-speed instrumented wheelset and related considerations

2019 ◽  
Vol 58 (8) ◽  
pp. 1189-1211
Author(s):  
Xincan Jin
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Analysis Approach ◽  
Force Measurements

Force Reduction by Motion Design in Spring-Loaded Cam Mechanisms

1984 ◽  
Vol 106 (3) ◽  
pp. 278-284 ◽  
Author(s):  
R. C. Johnson
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Critical Force ◽  
Inertia Force ◽  
Motion Synthesis ◽  
Spring Force ◽  
Force Reduction ◽  
Motion Design

A strategy of motion synthesis is developed for reducing critical forces in relatively rigid high-speed spring-loaded cam mechanisms. A special motion is specifically presented to illustrate application of the developed strategy, for the dwell-rise-dwell displacement case. Critical force graphs are presented for a numerical industrial probelm in three examples, comparing the developed special motion with the commonly used cycloidal and modified trapezoidal motions. Maximum values of cam contact force, inertia force, and spring force are all appreciably reduced by the special motion.

Thigh–calf contact force measurements in deep knee flexion

2007 ◽  
Vol 22 (7) ◽  
pp. 821-826 ◽  
Author(s):  
J. Zelle ◽  
M. Barink ◽  
R. Loeffen ◽  
M. De Waal Malefijt ◽  
N. Verdonschot
Keyword(s):  
Contact Force ◽  
Knee Flexion ◽  
Force Measurements

A Study on Speed Elevation Possibility at the Connection between High Speed Lines and Conventional Lines with Korean High Speed Train

2006 ◽  
Vol 326-328 ◽  
pp. 635-638 ◽  
Author(s):  
Young Sam Ham ◽  
Jai Sung Hong
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Integrated System ◽  
Communication Line ◽  
Mass Transportation ◽  
Test Results ◽  
High Speed Train ◽  
Safety Standards ◽  
Derailment Coefficient ◽  
Train Speed

Railways are a mass transportation system with high safety and punctuality. These strengths have been well proved by tests and evaluations. Railways are an integrated system with cars, power, signal, communication, line structures and operation. Among many safety standards of these systems, contact force between wheels and lines can be chosen since a derailment coefficient evaluated by contract force is the most important fact that decides the safety of railways. Especially regarding express trains, since they run twice faster than conventional ones, the evaluation of a derailment coefficient is more important than any other criteria. Currently, Korean express trains between Seoul and Pusan use the same stations as conventional trains in Daejeon and Dong-Daegu; therefore, express trains run on conventional lines from express lines. This paper describes test results acquired by increasing the train speed where express lines and conventional lines are connected. Test results tell that it is safe with under 0.8 derailment coefficient and running time is reduced by 10~30 seconds in each section.

scholarly journals Functional morphology of suction discs and attachment performance of the Mediterranean medicinal leech ( Hirudo verbana Carena)

2016 ◽  
Vol 13 (117) ◽  
pp. 20160096 ◽  
Author(s):  
Tim Kampowski ◽  
Laura Eberhard ◽  
Friederike Gallenmüller ◽  
Thomas Speck ◽  
Simon Poppinga
Keyword(s):  
Functional Morphology ◽  
High Speed ◽  
Substrate Surface ◽  
Surrounding Medium ◽  
Medicinal Leech ◽  
Force Measurements ◽  
High Speed Video ◽  
Hirudo Verbana ◽  
Substrate Surface Roughness ◽  
Medicinal Leeches

Medicinal leeches use their suction discs for locomotion, adhesion to the host and, in the case of the anterior disc, also for blood ingestion. The biomechanics of their suction-based adhesion systems has been little understood until now. We investigated the functional morphology of the anterior and posterior suckers of Hirudo verbana by using light and scanning electron microscopy. Furthermore, we analysed the adhesion qualitatively and quantitatively by conducting behavioural and mechanical experiments. Our high-speed video analyses provide new insights into the attachment and detachment processes and we present a detailed description of the leech locomotion cycle. Pull-off force measurements of the anterior and posterior suction organs on seven different substrates under both aerial and water-submersed conditions reveal a significant influence of the surrounding medium, the substrate surface roughness and the tested organ on attachment forces and tenacities.

scholarly journals Active Control of Contact Force for a Pantograph-Catenary System

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jiqiang Wang
Keyword(s):  
Active Control ◽  
Contact Force ◽  
High Speed ◽  
Large Scale ◽  
Vibration Suppression ◽  
Numerical Study ◽  
Primary Objective ◽  
Geometric Framework ◽  
High Speed Trains ◽  
Catenary System

The performance of the high speed trains depends critically on the quality of the contact in the pantograph-catenary interaction. Maintaining a constant contact force needs taking special measures and one of the methods is to utilize active control to optimize the contact force. A number of active control methods have been proposed in the past decade. However, the primary objective of these methods has been to reduce the variation of the contact force in the pantograph-catenary system, ignoring the effects of locomotive vibrations on pantograph-catenary dynamics. Motivated by the problems in active control of vibration in large scale structures, the author has developed a geometric framework specifically targeting the remote vibration suppression problem based only on local control action. It is the intention of the paper to demonstrate its potential in the active control of the pantograph-catenary interaction, aiming to minimize the variation of the contact force while simultaneously suppressing the vibration disturbance from the train. A numerical study is provided through the application to a simplified pantograph-catenary model.

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