Vehicle-track interaction and ground propagation of vibrations for urban railway vehicles

One of the main concerns for a light rail transport system manoeuvering in urban areas is the reduction of acoustic and vibratory nuisances on the neighborhood. In order to take this aspect into account in the first step of the design process, this paper proposes a framework intended to predict the level of ground vibrations induced by tramways rolling on discontinuities at the wheel-rail interface. The paper first presents the modelling process, which is based on multibody and finite element approaches for vehicle and track while the propagation of vibrations is computed from Green's functions. The experimental methodologies, leading to the main track and ground parameters are also described. The validity of the model is finally illustrated, through experimental measurements involving tramway vehicles passing on discontinuities. The influence of tramway velocity and wheel resilience is also shortly outlined.