Wear of Titanium and Titanium Alloys Under Conditions of Rolling Stress

1978 ◽  
Vol 100 (2) ◽  
pp. 199-207 ◽  
Author(s):  
H. Krause ◽  
J. Scholten
Keyword(s):  
Titanium Alloys ◽  
Weight Reduction ◽  
High Speed ◽  
Laboratory Tests ◽  
Total Weight ◽  
Wear Behaviour ◽  
Light Weight ◽  
High Speed Railway ◽  
Railway Traffic ◽  
Positive Results

One of the most important conditions necessary for high-speed railway traffic is a clear reduction of the unsprung masses. The fact that even with light-weight wheelsets, the steel tires still constitute over 50 percent of the total weight, shows that it is here, by utilizing the lightweight materials, that the most promising possibility of weight reduction lies. For this reason, the frictional and wear behaviour of various titanium alloys was investigated and compared with that of normal steels. From the positive results, it would appear worthwhile carrying out further investigations under practical conditions as an adequate assessment cannot be obtained on the basis of the laboratory tests alone.

Research on High Speed Railway Evaluation of the Sustainable Competitive Advantage

2014 ◽  
Vol 505-506 ◽  
pp. 43-48
Author(s):  
Zhong Yang Lv ◽  
Kang Ning Zheng
Keyword(s):  
Competitive Advantage ◽  
High Speed ◽  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Fuzzy Comprehensive Evaluation ◽  
Sustainable Competitive Advantage ◽  
High Speed Railway ◽  
Systematic Analysis ◽  
Railway Traffic ◽  
Positive Externality

In this paper, in order to improve the high speed railway sustainable competitive advantage as the research objective, systematic analysis of the high-speed railway to obtain sustainable competitive advantage evaluation index, including high-speed railway traffic function advantage, competitive advantage, advantage of positive externality, the Delphi method is used to scientific empowerment of these factors, by constructing fuzzy comprehensive evaluation model, the research conclusion is highway and air passenger is higher than that in high speed railway of competitive advantage

Real-Time Database System Implementation of Railway Signal Power Source Remote Monitoring

2011 ◽  
Vol 128-129 ◽  
pp. 961-964
Author(s):  
Zhi Jian Qu ◽  
Li Liu
Keyword(s):  
Power Supply ◽  
Remote Monitoring ◽  
High Speed ◽  
Low Voltage ◽  
Signal Power ◽  
High Speed Railway ◽  
Railway Traffic ◽  
Power Failure ◽  
Railway Signal ◽  
Real Time Database

Railway signal is a key technology for high-speed railway，which is the foundation to keep the high-speed train line. Railway signal power is the automatic blocking of railway lines and 10kV lines transform into 380V power through after the power supply for railway signals. Signal power as the railway traffic signal of the power supply, it belongs to the first level of power system load. Its 10kV high voltage side stik up by the major of electric, 380V low voltage side maintenance by the signal major. When the signal power failure, often occur shirk responsibilities between the different majors, in order to define the responsibilities of the accident better, which need automation remote monitoring for main railway lines of the railway signal power and scheduling control as soon as possible[1-3].

A New Monitoring Method of Wheel/Rail Contact Forces Caused by Out-of-Round Railway Wheels

2012 ◽  
Vol 178-181 ◽  
pp. 1125-1130
Author(s):  
Zhi Chen Wang ◽  
Ying Song ◽  
Ying Ming Shen
Keyword(s):  
Traffic Safety ◽  
High Speed ◽  
Test System ◽  
Simulation Software ◽  
Contact Forces ◽  
Strain Gauges ◽  
Monitoring Method ◽  
High Speed Railway ◽  
Railway Traffic ◽  
Railway Wheels

Traditional methods of wheel-rail contact forces measurement all need strain gauges on wheel sets or rails. The shortcomings of strain gauges such as zero-drift, poor anti-interference property and instability of test system can’t meat wheel/rail force test requirements in high-speed railways. A method based on PVDF piezoelectric sensing technology is presented for the test of wheel/rail contact force. Firstly, on the basis of the theory of vehicle-track coupling dynamics and by means of simulation software ADAMS/Rail, a three-dimensional train-track simulation model is established. Secondly, the modes and characteristics of wheel/rail impact vibrations due to non-roundness of railway wheels are investigated in high-speed railway operation. The relationship between the range for acceptable roundness values and vehicle speed is determined. Finally, the view that it is of important significance to establish wheel/rail force real-time monitoring system is expanded, so that abnormal conditions caused by out-of-round wheels can be detected in time, to ensure high-speed railway traffic safety. The study is very important for enhancing the stability and economy signification of rail transmission.

SiR Insulation for Outdoor Insulator

2017 ◽  
pp. 57-113
Keyword(s):  
Discharge Current ◽  
High Speed ◽  
Laboratory Tests ◽  
Electrical Strength ◽  
Surface Discharge ◽  
Contact Method ◽  
Light Weight ◽  
Hydrophobic Properties ◽  
Acoustic Characteristics ◽  
Accurate Evaluation

Silicone rubber (SiR) insulators were employed in power system due to its light weight, high electrical strength and excellent contamination performance. Much attention has been paid on the accurate evaluation of the insulator hydrophobicity. In this chapter, the acoustic characteristics of surface discharge were investigated to evaluate the hydrophobic properties of SiR insulator at different ageing degrees. The obtained results indicate that the acoustic characteristic of discharge is sensitive to the hydrophobic properties in the laboratory tests, which can be applied as a non-contact method for hydrophobicity evaluation of SiR insulator. Besides, the surface charge behaviors considering the hydrophobic properties of SiR insulator were discussed. The droplet experiment was carried out to investigate the maximum value, cumulative charge and energy eigenvector of discharge current. Finally, considering the strong airflow for SiR insulators employed in high-speed railway, the hydrophobic properties and corona discharge properties were investigated in this chapter.

Mud pumping in the roadbed of ballastless high-speed railway

Géotechnique ◽  
2021 ◽  
pp. 1-49
Author(s):  
Xuecheng Bian ◽  
Zhangbo Wan ◽  
Chuang Zhao ◽  
Yujun Cui ◽  
Yunmin Chen
Keyword(s):  
High Speed ◽  
Laboratory Tests ◽  
Fine Particles ◽  
Water Source ◽  
Vicious Cycle ◽  
High Speed Train ◽  
High Speed Railway ◽  
Mud Pumping ◽  
Favorable Conditions

Mud pumping intendedly avoided in the design of a ballastless high-speed railway still occurred and induced extraordinary track vibrations. In this study, in situ investigations and laboratory tests were performed to disclose the initiation and development of mud pumping detected in the field. The in situ investigations indicated that mud pumping principally appeared at both ends of the concrete base up to a maximum distance of 2 m. Precipitation, instead of groundwater, was found to be the water source triggering mud pumping, which infiltrated into the graded gravel roadbed through the detachments of the ends of the overlying concrete bases due to the whipping effect. Once mud pumping occurred, the vibrations of concrete bases were aggravated and caused severe track settlements under train loads. The results of laboratory tests indicated that the infiltrated rainwater was retained in the roadbed above the less permeable subgrade, and the roadbed contained an unstable particle skeleton with excessive plastic fine particles, both of which provided favorable conditions to form mud pumping under dense high-speed train loads. Soil particles less than 7.1 mm in diameter migrated during mud pumping, which first accumulated at the lower roadbed, then gradually migrated to the upper roadbed actuated by generated hydraulic gradient, and finally pumped out through the detachments around the expansion gaps, thereby resulting in large amounts of voids in the roadbed and a vicious cycle if not timely treated. These features of mud pumping in ballastless tracks differ from those of ballasted tracks and will benefit the development of remediation measures and improvement of slab track designs.

A Modified Davidenkov Model for Stiffness and Damping Characteristics of Saturated Clayey Soils due to Low-Amplitude Small-Strain Vibrations

2013 ◽  
Vol 680 ◽  
pp. 166-171 ◽  
Author(s):  
Peng Fei Jia ◽  
Ai Wu Yang
Keyword(s):  
High Speed ◽  
Small Strain ◽  
Clayey Soils ◽  
High Speed Railway ◽  
Railway Traffic ◽  
Damping Characteristics ◽  
Non Linear ◽  
Stiffness And Damping ◽  
Low Amplitude ◽  
Linear Softening

Railway track and nearby structures in the vicinity of high-speed railway are exposed to low-amplitude small-strain vibrations as high-speed railway traffic construction activities arise. These low-level dynamic events can lead to a non-linear softening behavior of the “elastic” stiffness and a considerable amount of energy dissipation in soils with a gradually increasing strain. The modelling of these non-linear behaviours are an important to predict lifetime and serviceability of existing structures in the vicinity of high-speed railway. An objective of this study is to develop validated computational models that can be used to perform stiffness and damping characteristics of saturated clayey soils due to low-amplitude small-strain vibrations. This paper provides an insight in the normalized shear modulus G/Gmax and damping ratio D in relation with shear strain amplitude γ through free-vibration column test, and proposes a modified Davidenkov model.

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