Numerical study on the influence of primary suspension damping upon the dynamic behaviour of railway vehicles

The paper deals with a numerical study on the dynamic behaviour of the railway vehicle while running on a track with vertical irregularities in a particular case of a damper failure in the primary suspension. The study is based on model of rigid-flexible coupled vehicle, with seven degrees of freedom, where the carbody is modelled as an Euler-Bernoulli type equivalent beam. The dynamic behaviour of the vehicle is evaluated based on the dynamic response of the carbody bogie, expressed as the power spectral density of the vertical acceleration, and on the root mean square of the acceleration for various cases of reduction in the damping constant of the primary suspension in an axle, compared with the reference value. The results of the numerical simulations highlight the significant increase in the level of bogie vibration at decreasing the damping of the primary suspension of an axle. In the carbody, the level of vibrations is less influenced, mainly at its centre. (paper)