PSI - Issue 17

Paulo Morais et al. / Procedia Structural Integrity 17 (2019) 419–426 Paulo Morais et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 6. Continuous condensed spectral amplitude spectrum on the vertical channel of a cabin accelerometer (Peaks in yellow).

Regarding the on-site accelerometers, in order to determine vertical displacements, it was necessary to perform double integration of the signals. In this case, in order to avoid the error propagation, typical of this operation, an approach was used that consisted on doing double integration of the signals in the frequency domain. The results obtained made it possible to verify that there is a significant and gradual peak deflection reduction, with an increase of stiffness between accelerometer 1 and accelerometer 8 (Fig. 7). This result was expected due to fact, as mentioned above, that this railway section was equipped with USP that significantly change its vertical stiffness profile.

Fig. 7. Average peak vertical displacements values in the positions of each on-site accelerometer (1 to 8).