Experimental study on the temperature of the contact strip in sliding electric contact

2017 ◽  
Vol 231 (10) ◽  
pp. 1268-1275 ◽  
Author(s):  
GX Chen ◽  
Y Hu ◽  
BJ Dong ◽  
HJ Yang ◽  
GQ Gao ◽  
...  
Keyword(s):  
Electric Current ◽  
Normal Force ◽  
Experimental Tests ◽  
Wear Volume ◽  
Test Results ◽  
Electric Contact ◽  
Sliding Speed ◽  
Factors Affecting ◽  
Contact Wire ◽  
Sliding Electric Contact

Using a ring-on-block tester with AC, the authors accomplished several experimental tests on the temperature of the contact wire and strip in sliding electric contact. In the test, the temperature of the samples, arc voltage, electric current, and wear volume of the strip were collected. Influences of the normal force, sliding speed, and electric current on the temperature of the contact wire and strip were studied. Test results show that the temperature of the carbon strip increases with the increasing of sliding speed and electric current or the decreasing of normal force. The strip wear rate is linearly related with the temperature of the strip. Moreover, the factors affecting the strip temperature were also discussed.

The Influence of the Temperature in Severe Wear of Copper Contact Wire/carbon Strip under Electric Current

2011 ◽  
Vol 71-78 ◽  
pp. 3653-3656
Author(s):  
Tao Ding ◽  
Guang Xiong Chen ◽  
Zeng Gang Xiong ◽  
Li Xie ◽  
Chuan Xue Wu
Keyword(s):  
Friction Coefficient ◽  
Electric Current ◽  
Experimental Tests ◽  
Electrical Current ◽  
Severe Wear ◽  
Contact Wire ◽  
Thermal Wear ◽  
Current Passage ◽  
Pin On Disc ◽  
Contact Couple

A series of experimental tests were carried out using copper contact wire rubbing against carbon strip under electric current on a pin-on-disc test. The aim to experiment can be understand the roles of the thermal wear in severe wear of copper/carbon strip under electrical current passage. During testing, the contact temperature and friction coefficient were recorded. The wear volumes of carbon strip specimens were measured. The results indicate that the temperature rise of contact couple with and without electric current is distinctly different. And the friction coefficient increases firstly due to the accumulation of wear debris, and then decreases with the increasing of electric current due to the accumulation of electric heat and friction heat on contact interface. It can be found that the wear volumes of carbon strip samples with electric current are larger than those without electrical current. Several thermal wear tests were conducted to study the influence of the temperature on the wear of carbon strip samples. The result indicates that thermal wear, oxidation wear and abrasive wear are a main mechanism for the severe wear of carbon strip samples.

Selection of Pantograph Strip/Contact Wire Couples in Catenary/Pantograph System

2011 ◽  
Vol 347-353 ◽  
pp. 647-650
Author(s):  
Tao Ding ◽  
Guang Xiong Chen ◽  
Shu Fen Xiao ◽  
Li Xie
Keyword(s):  
Stainless Steel ◽  
Friction And Wear ◽  
Pure Copper ◽  
Wear Volume ◽  
Test Results ◽  
Contact Wire ◽  
Pure Carbon ◽  
Pin On Disc ◽  
Properties Of Materials ◽  
Selection Of

A serials of experiments were carried on the pin-on-disc friction and wear tester. The friction and wear behaviors of on four materials couple with electric current were studied on in different conditions. The result indicates that properties of materials couple have a significant influence on the test results. The friction coefficient is the highest in process of the copper-impregnated metallized carbon rubbing against pure copper couple, and its wear volume of carbon strip material is also the largest. However, the friction and wear volume of copper-impregnated metallized carbon/stainless steel and pure carbon/pure copper couples are lower. Therefore, both friction couples are appropriate for pantograph strip/contact wire couple.

Experimental Investigation of the Time Delay Between a Varying Applied Normal Force and the Resulting Friction Force

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Guangxiong Chen ◽  
Xiaolu Cui
Keyword(s):  
Time Delay ◽  
Friction Force ◽  
Normal Force ◽  
Excitation Frequency ◽  
Experimental Tests ◽  
Generation Mechanism ◽  
Test Results ◽  
Test Apparatus ◽  
Force Measurements ◽  
Force Signal

Recently, one of the present authors proposed a new model to explain the generation mechanism of brake squeal based on the time delay between a varying applied normal force and the resulting friction force. The present work conducts a series of experimental tests examining the behavior of this time delay using a special test apparatus. The test apparatus suppresses the effect of interference in the time delay owing to the excitation normal force to the greatest extent possible. Several calibration tests of the test apparatus are conducted to ensure the validity of the normal force and friction force measurements. The varying friction force is extracted from the overall friction force signal without phase distortion using a zero-phase filter. The test results demonstrate a time delay between the varying normal force and the resulting friction force under various testing parameters. The time delay is found to increase with increasing excitation frequency. The generation mechanism of the time delay is also discussed.

Electric Contact Stability and Wear Durability at a Nanoscale Sliding Electric Contact

2013 ◽  
Vol 133 (6) ◽  
pp. 229-236
Author(s):  
Yasushi Tomizawa ◽  
Yongfang Li ◽  
Akihiro Koga ◽  
Hiroshi Toshiyoshi ◽  
Yasuhisa Ando ◽  
...  
Keyword(s):  
Electric Contact ◽  
Contact Stability ◽  
Sliding Electric Contact

On axial compressive behavior of steel fiber reinforced concrete confined by FRP

2021 ◽  
pp. 136943322098165
Author(s):  
Hossein Saberi ◽  
Farzad Hatami ◽  
Alireza Rahai
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Steel Fiber ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Frp Confinement

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-confined specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

scholarly journals Methodology for Selecting the Operating Conditions of a Vibration Generator Used in the Hot-Dip Galvanizing Process

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2042
Author(s):  
Wojciech Kacalak ◽  
Igor Maciejewski ◽  
Dariusz Lipiński ◽  
Błażej Bałasz
Keyword(s):  
Simulation Model ◽  
Asynchronous Motor ◽  
Experimental Tests ◽  
Suspension System ◽  
Operating Conditions ◽  
Test Results ◽  
Forced Simulation

A simulation model and the results of experimental tests of a vibration generator in applications for the hot-dip galvanizing process are presented. The parameters of the work of the asynchronous motor forcing the system vibrations were determined, as well as the degree of unbalance enabling the vibrations of galvanized elements weighing up to 500 kg to be forced. Simulation and experimental tests of the designed and then constructed vibration generator were carried out at different intensities of the unbalanced rotating mass of the motor. Based on the obtained test results, the generator operating conditions were determined at which the highest values of the amplitude of vibrations transmitted through the suspension system to the galvanized elements were obtained.

Improving the Strength of Abrasive Wheels and Optimizing the Control over the Strength of Composite Abrasive Materials

2019 ◽  
Vol 946 ◽  
pp. 380-385
Author(s):  
Boris A. Chaplygin ◽  
Viacheslav V. Shirokov ◽  
Tat'yana A. Lisovskaya ◽  
Roman A. Lisovskiy
Keyword(s):  
Mechanical Properties ◽  
Test Results ◽  
Key Factors ◽  
Special Equipment ◽  
Material Density ◽  
Factors Affecting ◽  
Control Factors ◽  
Reinforcing Material ◽  
Special Studies ◽  
First Time

The strength of abrasive wheels is one of the key factors affecting the performance of abrasive machining. The paper discusses ways to improve the strength of abrasive wheels. The stress-state mathematical model presented herein is a generalization of the existing models. It is used herein to find for the first time that there are numerous optimal combinations of the elastic modulus and reinforcing material density, which result in the same minimum value of the objective function. It is found out that increasing the radius of the reinforcing component while also optimizing the mechanical properties of its material may increase the permissible breaking speed of the wheel several times. We herein present a regression equation and a nomogram for finding the optimal combination of control factors. Conventional methods for testing the mechanical properties of materials, which have been proven reliable for testing metals and alloys, are not as reliable for testing abrasive materials, as the test results they generate are not sufficiently stable or accurate. We therefore propose an alternative method that does not require any special equipment or special studies.

scholarly journals Evaluation of Bleeding Resistance in Chip Seal and Asphalt Emulsion Residue Rheology

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 670
Author(s):  
Preeda Chaturabong
Keyword(s):  
Influence Factors ◽  
Application Rate ◽  
Test Methods ◽  
Test Results ◽  
Asphalt Emulsion ◽  
Aggregate Gradation ◽  
Factors Affecting ◽  
Promising Tool ◽  
Chip Seal ◽  
Asphalt Emulsions

Chip seal bleeding is influenced by many factors, including design inputs, material properties, and project-specific conditions. It reduces the surface texture of the pavement and thus compromises the safety of the traveling public. Even though factors that bring about premature bleeding are known, currently, no laboratory test methods for evaluating bleeding in chip seals have been specified. The objective of this paper is to present the results of an investigation of the influence factors of asphalt emulsion residue properties measured by the ASTM D7405 multiple stress creep and recovery (MSCR) test, as well as other factors related to chip seal bleeding resistance as measured by the modified loaded wheel test (MLWT). In this study, the MSCR test was used as a tool for evaluating the performance of asphalt emulsions because it has been identified as a potential test related to bleeding in the field. In addition, MLWT was selected as a tool for evaluating chip seal bleeding performance in the laboratory. The results of the MLWT showed that the emulsion application rate (EAR), aggregate gradation, and emulsion properties were significant factors affecting bleeding. The MSCR test was found to be a promising tool for the performance evaluation of asphalt emulsion residue, as the test was able to differentiate between emulsion chemistries and modifications in terms of sensitivity to both temperature and stress. In relation to chip seal bleeding resistance, only the creep compliance (Jnr) obtained from the MSCR test results was identified as a significant property affecting potential for bleeding.

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