APPLICATION OF HILBERT-HUANG TRANSFORM TO IDENTIFY MODAL PARAMETERS FOR LARGE BRIDGE

摘要

For identifing the modal parameters from the bridge vibration response under the abient excitation, a method based on Hilbert-Huang Transform(HHT) is discussed in this paper. The method of HHT includes expirical mode decompostion(EMD) and Hilbert Transform(HT). Firstly,The EMD is used to filter the mesasured data, which can reduce the effect of high freqency noise and identify the main intrinsic mode function(IMF). The resulting IMF, however, consisted of free vibration and forced vibration. Then, the theory that the autocorelation function of the signal is thought of a free vibration under static random excitation is studied to get the s free vibration and use it as the input data for identifing the modal parameters. Finally, this method is applied on the GPS dynamic monitoring data of the Wuhan Baishazhou Bridge. The results show that the mode parameters can be identify effectively.