Sensitivity Analysis of Flexible Upper Frame of Pantograph with a Novel Simplified Method

Optimization design for pantograph-catenary system is of great significance to keep the good current collecting quality. As the main parameters of pantograph’s upper frame, stiffness and damping need to be well designed, especially in the high speed operation condition. Based on the relative coordinate theory in multibody dynamics, this paper proposed a new simplified method to simulate the flexible characteristic of the upper frame in pantograph-catenary interaction. In this method the upper frame is divided into several segments, which are articulated with torsion springs. The flexibility change of the upper frame is described by the key parameter variation of these torsion springs. In the pantograph-catenary coupling system, finite element method (FEM) is applied to establish the model of catenary, Hertz contact theory is adopted and the standard deviation (STD) of the contact force is used as an evaluation index. Sensitivity of the upper frame’s flexibility to current collecting quality is given, which will effectively support for the structural design and material selection of the upper frame of pantograph adapting to different train operation speeds.