Effective Mode Shapes of Viaducts Subjected to High-speed Train

The high-speed railways require more viaducts than conventional railways. The dynamic interactioneffect between train and viaduct are important issue due to the risk of derailment, structural safetyand deterioration of the passenger comfort. In this study, viaduct is modelled as a multi-bay frame.The multi-bay frame is modelled by finite element method. The train is idealized as a two-axle systemwith 4 degrees of freedom. The equations of motions of the coupled vehicle-structure system aredetermined via generalized Lagrange's equation. The Wilson-theta time integration method isemployed to determine the dynamic response of the system. The effective mode shapes areinvestigated using 3D frequency-velocity-amplitude graphs. The resonant response has beendetermined at first and second modes of 1 and 2-bay frames.