Influence of Underbody Suspended Equipment on Rail Ride Comfort

This paper illustrates a methodology that, by means of laboratory and on-track tests, allows for an appropriate design of the connection elements between the suspended equipment and the carbody in order to enhance the rail ride comfort. In particular at first the connection elements are tested in laboratory to assess their visco-elastic behaviour simulating the common operating conditions. Subsequently on-track tests and experimental modal analysis are carried out to identify the interaction between underframe equipment motions and carbody modes. In the experimental tests, starting from the laboratory test results, it is possible to define the connection elements in order to minimise the negative influence on vehicle ride comfort. Two different solutions are proposed: the “TMD solution” (the suspension is tuned on the natural frequency of the carbody mode most relevant from the comfort point of view) and the “suspended solution” (the suspension system aims to decouple the two subsystems).