Identification of Bridge Mode Shapes from a Two-Axle Test Vehicle by Wavelet Transform

Wavelet transform (WT) is theoretically investigated to recover bridge mode shapes from a passing two-axle test vehicle by using the correlation between the front and rear contact points.In this study, closed-form solutions for the dynamic responses of the bridge and front and rear contact points are derived.To overcome the masking effect by vehicle's self frequencies on bridge frequencies in the vehicle's spectra, the procedure for calculating contact responses of a two-axle test vehicle considering the suspension effect was derived.Next, the procedure for constructing bridge mode shapes using the WT is proposed and theoretically investigated.The efficacy of the proposed procedure is validated by numerical studies.