Keywords: railway dynamics, multibody systems, finite elements, contact mechanics, co-simulation.

High-speed railway overhead systems are subjected to tight functional requirements to deliver electrical energy to train engines, while their reliability and maintenance periods have to be increased. The quest for interoperability of different pantographs in existing and projected catenary systems puts an extra level of demand on the ability to control their dynamic behaviour. Also the quality of the current collection, the loss of contact and consequent arching, not also limit the top velocity of high-speed trains but have implications in the deterioration of the functional conditions of these mechanical equipment. To address such important aspects for the design and analysis of the pantograph-catenary system, it is necessary to develop reliable, efficient and accurate computational procedures that allow capturing all the relevant features of their dynamic behaviour.

In this paper a computational methodology is proposed enabling the dynamic analysis of pantograph-catenary interaction. The finite element method is used for the dynamic analysis of the catenary and a multibody dynamics approach is used for the dynamic analysis of the pantographs, regardless of being lumped or multibody models. A co-simulation environment is setup to run the interference between the independent catenary and pantograph dynamic analyses. A contact model, based on a penalty formulation, is selected to represent the interaction between the two codes.

It is shown that the use of linear finite elements are sufficient to allow for the correct representation of the catenary provided that the wire tension forces are accounted for in the stiffness formulation and that the droppers slacking is properly represented. Also the use of multibody dynamics methods allows the capture of all the important dynamic features of the pantographs. Advantages and shortcomings of the use of either a full multibody approach or a lumped mass model of the pantograph are presented.

The methods proposed in this work are demonstrated in a study case of multiple pantograph operation in high-speed trains between a generic catenary and a high speed pantograph. This case addresses one of the limiting factors in high-speed railway operation that is the need to use more than a single pantograph for current collection. The application of the procedures allowed the identification of the important quantities of the dynamic response that are required for the pantograph homologation and for the operational decisions. The catenary damping plays a fundamental role in the pantograph-catenary contact quality. This parameter leads to higher maximum contact forces, lower minimum contact forces, eventually to contact losses, and to higher standard deviations of the contact forces. All these characteristics of the contact force lead to the rejection of the operation of multiple pantograph units at the required speed of 300 km/h in lightly damped catenaries.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £65 +P&P)