A new nonlinear displacement-dependent parametric model of a high-speed rail pantograph hydraulic damper

A new fully parametric model revealing the nonlinear displacement-dependent characteristics of a high-speed rail pantograph damper has been developed in this study. In the multi-disciplinary physical modelling, the key pressure-flow characteristics of a displacement-dependent resistance network and a compression shim-stack valve are formulated, considerable agreement between computer simulation and experiment has validated the damper model. Extensive pantograph-catenary dynamics simulation and experiments were carried out to compare the pantograph dynamic responses when separately using the conventional linear and the new nonlinear damper models, the results show that when designed with the nonlinear damper model, the pantograph would have a softer contact with the catenary when it is raised without prolonging the whole raising time, the operating contact quality of the pantograph and catenary is also significantly improved, and the lowering time of the pantograph is considerably reduced. The new nonlinear damper model is more complete and adaptive to working conditions of the pantograph than the conventional linear damper model, so it is more effective for modern high-speed problem analysis and parameter optimisation of the pantograph-catenary system.