A novel reduced model for damage detection of frame structures

When performing damage detection for frame buildings, a shear structure model is frequently employed to model the dynamic responses of the frame. The estimated parameters of the shear model are then utilized to determine the damage status of the frame. However, it was pointed out in many studies that, due to the existence of modeling error, the shear model cannot very well represent the true dynamic behavior of the frame; hence, the damage detection results are often inaccurate. In this paper, a novel reduced model of frame structures is proposed for the damage detection of frame structures, which has two important characteristics: 1) compared with shear model, the new model can reflect the true interstory shear forces of the frame buildings, thereby significantly reducing the modeling error and improving damage detection accuracy; 2) the parameters of the new model have a clear relation with the physical parameters of the frame, facilitating using the estimated parameters of the new model to determine the damage status of the frame. Moreover, based on this new model, an iterative substructure identification method is proposed to identify the parameters of frame structures. Finally, a numerical example of a frame structure is utilized to demonstrate the effectiveness of the new model. The results show that using the new model greatly improve the accuracy of the damage detection of the frame structure, compared with using a shear structure model.