An analysis of longitudinal vibration for bogie car. The lasting vibration of a constant frequency excited by track irregularity.

When the new Shinkansen train set, the Series 100 EC train, came into service, lasting longitudinal vibration with a constant frequency arose frequently near the maximum operation speed. The vibration was of a sort not experienced before. This paper describes the calculation analysis for the longitudinal vibration if the Shinkansen bogie cars. The results are summarized as follows. The lasting vibration is the 1st modal one caused by vertical track irregularities through the pitching motion of bogie trucks. It becomes marked in the speed range where the pitch phase of the front truck is close to that of the rear one. The bolster-anchor height has an optimum value against the 1st mode, but it is so narrow that the vibration grows rapidly as the real height differs from the optimum one.