A laboratory test method has been described for measuring the high frequency dynamic stiffness of resilient rail fasteners in the region 100-1000 Hz. The stiffness is found to be virtually independent of frequency in the range studied apart from the occurrence of internal resonances in two-layer systems. Dynamic-to-static stiffness ratios of between 2 and 8 have been found. The stiffness is also strongly dependent on the preload in many cases, increasing by factors up to 3 under a 40 kN load. Comparisons with stiffness values derived from field measurements of track frequency responses show good agreement once the effect of preload has been allowed for. The damping loss factors apparent in the field measurements, from the width of resonance peaks and the decay of vibration along the track, are generally higher than those measured in the test rig. However, this may be related to variations between pad stiffnesses, sleeper spacings, etc. introducing variations in resonance frequency and additional spatial attenuation in the rail vibration.
The dynamic behaviour of rail fasteners at high frequencies
Applied Acoustics ; 52 , 1 ; 1-17
1997
17 Seiten, 7 Bilder, 5 Tabellen, 11 Quellen
Article (Journal)
English
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