Dopravní stavby - Fakulta stavební - Vysoké učení technické v Brně

12th International Scientific Conference, April 20-22, 2009 Brno, Czech Republic 79DYNAMIC NATURE OFVEHICLE-TRACK INTERACTIONMoravčík MilanThe paper is devoted dynamic measurements on un-sprung wheelsets of the locomotive andcorresponding in situ measurements on the track structure. Briefly are presented someexperimental measurements approaches in order to appreciate the dynamic behaviour ofthe track structure. The vertical acceleration of wheelsets are compared with the verticalvibration of rails, sleepers, and ballast field and are analysed in the time and frequencydomain.IntroductionAn increasing need for detailed knowledge of how a track structure behaves under appliedloads follows from the technological demands requiring more exact understanding of the structuralbehaviour under load. A convenient means of identification the track structure conditions anddeterioration in track is measuring the resultant vibrations levels on the axle box of locomotives andcoaches. Railway track is not perfectly smooth and with time its surface roughness increases. Alongwith other forms of deterioration (the sleeper settlement, ballast deterioration) this leads to anincrease in the vibration generated as the un-sprung wheels rolling along the track.The dynamic interaction between moving vehicle and the rail can be investigated anddescribed reasonably well in the vertical direction using suitable mathematical models, see fig 1, oran suitable experimental analysis based on an experimental measurement in the vehicle and in thetrack, see Fig. 2. Problems arising from the vehicle track interaction may be simply expressed infrequency domain, see Tab.1. In [1, 2] several mathematical models of varying complexity forcalculation the vertical dynamic response of the track is examined.Prof. Ing. Milan Moravčík, CSc, Katedra stavebnej mechaniky, Stavebná fakulta ŽU v Žiline. e-mail:momo@fstav.uniza .sk