Validation of a Low Fidelity Catenary Model Developed Using a Novel Optimization Algorithm

Abstract

Contact wire pre-sag directly impacts the current quality collection in a high-speed railway catenary. Due to this, the initial configuration of the catenary geometry plays an important role on the dynamic performance of the railway. Therefore, accurately representing the initial equilibrium state of the catenary based on specific design requirements is crucial to obtain accurate dynamic results. Despite its importance, there are only a few publications in this area that present methods that can accommodate desired amount of presag in the contact wire and are computationally efficient. The goal of this paper is to present a catenary system that has been modelled using a novel optimization method and validate its dynamic response from its interaction with a pantograph system against the reference model results in BS EN 50318. The novel optimization methodology presented in this paper employs a gradient-based algorithm with a modified finite difference method to solve the initial equilibrium geometry of the catenary. The pantograph and catenary systems are modelled using a commercial finite element software and the post-processing of the results is done using in-house code. A penalty contact-force model is used to represent the contact behavior between the pantograph-catenary system and a threestep simulation procedure is used to achieve better convergence of results. The results from the simulation demonstrated good accordance with the reference model results in BS EN 50318. Keywordscatenary modelling; initial equilibrium problem; pantograph-catenary dynamic interaction; finite element analysis