Dynamic Analysis of High-Speed Railway Bridges with Application to Vehicle-Bridges Interaction

Dynamic effects of high speed trains on railway bridges have been analyzed in many research works. Two major approaches have been used widely: in the first approach represented by a constant load that crosses the bridges and thus dynamic properties of the vehicle itself are ignored. There are also more complex methods that incorporate dynamic properties of both the structure and the vehicle. In these models primary and secondary suspension systems the bogie and the wheels are incorporated into the model by their individual & commercial ad mechanical properties. In this paper, two and three dimensional finite element models of a high speed trains crossing bridges susceptible to resonance effects are developed. In order to model dynamic interaction of the vehicle and the bridge, differential equation of second order is solved for both the vehicle and the bridge. The equating differential equations of the 2 systems are coupled by forces exerted on the vehicle and on the structure in rail wheel contacts. An explicit time advancement scheme is used to drive the model in time. It was necessary to regenerate reprehensive matrixes of the system in each time step, resulting it considerable computational cost.
Using the developed numerical model, a parametric study is done, revealing importance of damping and stiffness of primary suspension system, damping and stiffness of secondary suspension systems, damping and stiffness of ballast, interaction effects of vehicle and bridge simultaneously on dynamic behavior of bridge-vehicle system for high speed trains. The range of parameters for which a full dynamic model of the vehicle would be necessary is derived on the parametric study.