Thermal Modelling and Experimental Comparison for a Moving Pantograph Strip
This paper proposes a thermal study of the catenary/pantograph interface for a train in motion. A 2.5D complex model of the pantograph strip has been defined and created by a coupling between a 1D and a 2D model. Experimental and simulation results are presented and with a comparison allow validating the 2.5D model. Some physical phenomena are described and presented with the help of the model such as the stagger motion thermal effect, particular heats and the effect of the material characteristics. Finally it is possible to predict the critical thermal
configuration during a train trip.
Effect of temperature and arc discharge on friction and wear behaviours of carbon strip/copper contact wire in pantograph–catenary systems
Abstract A series of tests on friction and wear performance of pure copper rubbing against carbon strip under electric current have been carried out on a modified pin-on-disc friction and wear tester. The results indicate that there are temperature rise and arc discharge in the electrical sliding processes. The temperature rise of contact pairs and the intensity of arc discharge increase with the increasing of electric current. However, 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. The increase in wear volume of the carbon strip is mainly caused by high temperature of contact pairs and arc discharge phenomenon. The test results also show that the wear volume of pin specimen with arc discharge is much greater than that without arc discharge under the same temperature. Therefore, the thermal wear due to high temperature has a distinct influence on the service life of pantograph contact strip and arc erosion even has more significant influence. Cooling measures should be applied in pantograph/catenary systems. Especially, off-line arc discharge of the contact couple should be suppressed to the maximum extent to extend the service life of pantograph contact strip.
A study of the adhesion of copper using the twist compression technique in vacuum
Abstract The results of an investigation of the adhesion of 99.999% copper in vacuum using the twist compression technique are presented. The adhesion coefficient was found to increase with increasing abrasion until a constant value of the adhesion coefficient was achieved. After the surface was abraded the adhesion coefficient could be measured without further twisting. Data is presented showing the dependence of the adhesion coefficient upon contact area and load.