Abstract
This paper shows the estimation method of bridge m ode shapes based on dynamic responses of passing vehicles on a bridge and its verification by numerical simulation. The proposed method includes four steps: (1) estimation of input displacement to a mon itoring vehicle, (2) dedu ction of a ro ad roughness from the estimated displacement to obtain a bridge displacement, (3) transfor mation of the bridge displacements obtained by moving vehicl es to those assumed to be measured at the fixed locations on the bridge, and (4) mode estimation from the transformed displacements by singular value decomposition. To verify the estimation method, measurement errors, velo cities and masses of the vehicles, types of road roughness, and mode shapes were varied in numerical simulations. As a result, it was found that using three monitoring vehicles the first mode shape can be detected with high accuracy in all assumed cases, but, much improvement should be done to estimate the higher mode shapes.
