This work package develops a novel excitation model accounting for non-linearity of elements of conventional tracks, i.e. railpads, ballast, slab and trough tracks. The model utilises the dynamic stiffness and Finite Element (FE) methods considering both discretely and continuously supported tracks. Time-domain analysis is followed to allow taking into account the non-linear track stiffness and damping values.
The main tasks of WP1 are:
- Characterising the non-linearity of track components by reviewing non-linear elements for railway tracks from the literature, and investigating field measurements of ISVR in Track21 and Pandrol in Worsop. The measurements include the stiffness and damping of resilient elements of tracks.
- Developing numerical models based on the dynamic stiffness and FE methods for discretely and continuously supported tracks under static and dynamic moving loads.
- Accounting for moving trains on a track with a given rail irregularity and joints, including quasi-static load component and the effects of sleeper passing and axle spacing within the train.
- Conducting a series of field measurements in Birmingham with the support of Centro (now Transport for West Midlands) to validate the models and identify track parameters and vibration due to running trains.
- Developing a linearisation technique to feed into WP3.