Investigation of adhesion recovery phenomenon using a scaled roller-rig

When high creep values occur on a braked/trailing wheelset running on a contaminated track, changes in the friction conditions take place. In fact, the work of the friction forces gradually removes the contaminant from the wheel and rail surfaces. Therefore, lower levels of adhesion are present on the leading wheelsets, while better conditions are restored on the following ones. A deep understanding of this phenomenon is needed to develop new algorithms for WSP and antiskid systems, in order to maximise the tractive/braking performances of railway vehicles. The research group of the Politecnico di Torino has recently designed an innovative multi-axle roller-rig to investigate the adhesion recovery phenomenon. First, the paper briefly shows the configuration of the new roller-rig, then focus is given to the experimental results obtained from adhesion recovery tests performed on the test bench.