Extracting the bridge frequencies indirectly from a passing vehicle: Parametric study

Previous studies on the extraction of the bridge frequencies indirectly from the dynamic response of a passing vehicle were focused primarily on the feasibility of the technique. Few investigations have been conducted to study the effects of key dynamic parameters of the system on the vertical response of the passing vehicle. To fill such a gap, the key parameters will be studied not only for evaluating their relative influence, but for increasing the probability of successfully identifying the bridge frequencies of concern. Various amplitude ratios will be defined and expressed in terms of the key parameters, serving as useful indicators for evaluating the probability of successful identification of the bridge frequencies from the passing vehicle. For the two cases studied, in which either one or two bridge frequencies are to be identified, it was shown that the initial amplitude ratio plays a role that is more important than the others in successful identification of the bridge frequencies. Suggestions are made for application of the technique in the field.