On the Time-Dependent Spin Creep of a Railway Wheel

This paper describes two theoretical calculations of the fluctuating spin creep of a railway wheel rolling on straight track. The first calculation is of the transient spin moment which occurs when a constant spin creep angular velocity is applied suddenly to a rolling wheel. This may occur, for example, when a wheel passes over a discontinuity in the rail and rolling contact is resumed suddenly. The second calculation is of the fluctuating spin creep moment which occurs when a coned railway wheel rolls along a slightly corrugated rail.The analysis is highly idealized, using the approximations of the simplified theory of Kalker and assuming that the area of slip is limited to a negligible proportion of the area of contact. In the first calculation, the area of contact is assumed to be circular; in the second calculation, it is assumed to be rectangular.Subject to these far-reaching assumptions, the results of the calculations suggest that oscillatory fluctuations in spin creep may be initiated by rail dis...