ABSTRACT
Identifying vehicle loads by the dynamic characteristics of vehicle-bridge system is a widely concerned inverse problem. In recent years, researchers have proposed many new methods for accurately identifying moving loads. Related studies show that the type of bridge and the form of support constraints have influence on the accuracy of moving force identification (MFI). In this work, the influence of vehicle-bridge interaction (VBI) on the accuracy of MFI will be studied. Two kinds of moving force pass over a simply supported bridge to simulate different vehicle-bridge systems. The bending moment responses and acceleration responses of the bridge are measured and some random noise is added to evaluate the identification accuracy of MFI. Simulation results show that the type of force not only leads to different bridge dynamic responses but also has obvious influence on the noise contamination of dynamic responses. In other words, the VBI has significantly influence on the identification accuracy of MFI. In order to reveal the influence of VBI on the accuracy of MFI, the fast Fourier transformation (FFT) is introduced to analysis the dynamic responses caused by different vehicle types. The simulation results show that the narrow effective frequency band and the simple frequency domain component of dynamic responses cause it to be susceptible to noise contamination, which directly leads to poor identification results. To summarize, it is not the type of dynamic response influences the accuracy of MFI, but the VBI influences the accuracy of MFI.
