TY  - JOUR
PY  - 2012//
TI  - On the use of second-order derivatives of track irregularity for assessing vertical track geometry quality
JO  - Vehicle system dynamics
A1  - Li, Martin
A1  - Persson, Ingemar
A1  - Spännar, Jan
A1  - Berg, Mats
SP  - 389
EP  - 401
VL  - 50
IS  - Suppl 1
N2  - This paper studies the use of second-order derivatives of track irregularities (longitudinal level, LL) for assessing vertical track geometry quality. Both a single-degree-of-freedom and a three-DOF vehicle-track model are investigated in order to explain theoretically why from the aspect of vehicle-track dynamic interaction it is relevant to consider not only the amplitudes of LL but also their second-order derivatives (LL2). Simulation results are then presented to demonstrate that dynamic vertical track forces are more correlated with the second-order derivatives (LL2) than to the amplitudes (LL) themselves. A comparison of the power spectral density (PSD) spectra for typical track reveals that it is more convenient to use the PSD spectra for the second-order derivatives than for the amplitudes, as the curves for the second-order derivatives are flat within the short wavelength range. Finally, the practical use of derivatives within the maintenance management system in order to achieve improved assessment of track geometry quality is also discussed.<p />
LA  - en
SN  - 0042-3114
UR  - http://dx.doi.org/10.1080/00423114.2012.671947
ID  - ref1
ER  -