Maria Molodova, Alfredo Núñez, Rolf Dollevoet
the International Symposium on Dynamics of Vehicle on Roads and Tracks, IAVSD2013
Location: Qingdao, China
axle box acceleration, squats
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This paper presents a new methodology to support the early detection of short wave anomalies which causes high frequency dynamic wheel-rail contact force. The method is based on axle box acceleration (ABA) measurements and a three-dimensional finite element (FE) model. For the investigated tracks, the power spectrum in the frequencies between 1060-1160Hz and around 300Hz indicate existence of a squat. Moreover, the power spectrum density of the frequency around 300Hz is proved to be highly related with the squat’s geometry, so it is used to assess its severity. In summary, the major novelties of the methodology comprises: (1) A three-dimensional FE model is validated with real-life ABA measurements and used to gain insight of the vibration characteristics of the wheel-track system. The useful vibration frequency for detection is extended to up to 2000 Hz and higher, (2) A longitudinal ABA measurement is employed to complement the vertical one. This significantly enhances the sensitivity and signal-to-noise ratio, (3) Features which are unique of the anomalies are identified through numerical simulation of the wheel-track interaction, and are calibrated and validated with laboratory and field testing.