Title of article :
Application of the continuous wavelet transform on the free vibrations of a steel–concrete composite railway bridge
Author/Authors :
ـlker-Kaustell، نويسنده , , Mahir and Karoumi، نويسنده , , Raid، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2011
Abstract :
In this article, the Continuous Wavelet Transform (CWT) is used to study the amplitude dependency of the natural frequency and the equivalent viscous modal damping ratio of the first vertical bending mode of a ballasted, single span, concrete–steel composite railway bridge. It is shown that for the observed range of acceleration amplitudes, a linear relation exists between both the natural frequency and the equivalent viscous modal damping ratio and the amplitude of vibration. This result was obtained by an analysis based on the CWT of the free vibrations after the passage of a number of freight trains. The natural frequency was found to decrease with increasing amplitude of vibration and the corresponding damping ratio increased with increasing amplitude of vibration. This may, given that further research efforts have been made, have implications on the choice of damping ratios for theoretical studies aiming at upgrading existing bridges and in the design of new bridges for high speed trains. The analysis procedure is validated by means of an alternative analysis technique using the least squares method to fit a linear oscillator to consecutive, windowed parts of the studied signals. In this particular case, the two analysis procedures produce essentially the same result.
Keywords :
Train induced vibrations , Continuous wavelet transform , Steel–concrete composite bridge , Railway bridges , System identification
Journal title :
Engineering Structures
Journal title :
Engineering Structures