Experimental study on thermal shock damage characteristics of pantograph strip

Abstract

The thermal shock damage of the pantograph strip was unavoidable during the long run of the train. Long term thermal shock may harm the health of the strip. Therefore, it was necessary to study the thermal shock damage characteristics of pantograph strip. In this paper, the thermal shock damage experiment was carried out by simulating the cold and hot alternating conditions of pantograph strip during train operation, the evolution law of the porosity and compressive strength of the pantograph strip were analyzed, and the influence of thermal shock on the surface topography of pantograph strip was discussed, the mechanism of thermal shock effect on damage of the pantograph strip was studied, and the damage degree of the strip was characterized by ultrasonic velocity. The results showed that thermal shock would increase the porosity of the pantograph strip, and caused the changes in compressive strength, the ultrasonic velocity can well characterize porosity and characterize the thermal shock damage degree of the strip. But once thermal shock damage was reversible, and repeated thermal shock damage was irreversible. The research results were of great significance for prolonging the service life of the pantograph strip material and ensuring the safe and stable operation of the high-speed train.