Comparative studies on moving force identification from bridge strains in laboratory

Force identification from dynamic responses of bridges is an important inverse problem. The parameters of both the vehicle and the bridge play an important role in the force identification. Based on the bending moments measured in the laboratory and the four identification methods developed, this paper aims to investigate the effect of various parameters on the four methods. For this purpose, a bridge-vehicle system model has been designed in the laboratory. The bending moments and acceleration responses of the model bridge are simultaneously measured when the model vehicle moves across the bridge at different speeds. The moving forces are identified from the bridge strains using the four methods, and the rebuilt responses are calculated from the identified forces for comparative studies on the four methods. Assessment results show that all four methods are effective and acceptable with higher accuracy to some extent. The TDM is the best and is strongly recommended for incorporation into a moving force identification system (MFIS)