Evaluation of Material Properties of Pantograph Contact Strip by Microscopic Structure Model

Abstract

Most frictional materials used in railways are made of composite material, and their macroscopic material properties are largely affected by their microscopic structure. It is useful to clarify the relationship between microscopic structure and material properties by numerical simulation for effective improvement or development of the materials. In this study, we developed an image-based microscopic model by using X-ray computed tomography for a metalized carbon pantograph contact strip material and evaluated its Young’s modulus, thermal conductivity and electrical resistivity based on the homogenization method. The calculated material properties were more consistent with the experimentally measured values than the estimated values based on the classical Voigt model. We also introduce the analysis result of the stress, temperature and cur rent density distribution in the microscopic model. There is growing demand for high energy efficiency railway vehicles which do not emit CO 2 and NOx. To meet this demand, we have been developing railway vehicles powered by a hybrid configuration of fuel cells (FC) and batteries (Bat). In the previous development stage, we installed FC and power converters in passenger areas on the train, because of their size. In addition, acceleration of the vehicle was limited to that of a conventional DMU. For this paper, using passenger areas was not necessary, because downsized FC and power converters were installed under the vehicle floor. Furthermore, we improved tractive performance to reach that of a standard EMU, by increasing the power capacity of each FC and Bat.