Indirect structure damage identification with the information of the vertical and rotational mode shapes

In this paper, a robust method is proposed to detect damage extent and location of structural elements focusing on data type and acquisition method and aiming to the promotion of model updating tools. The novelty of this method is rotational mode shape acquisition, which provides valuable information on the damage. In this method, the damaged elements are indirectly identified by detecting the healthy elements and eliminating them from searching space. This method requires to minimize the modal strain energy difference between the damaged model and numerical model via an optimization algorithm, then an improved genetic algorithm (IGA) is used. In this study, four numerical and two experimental damage scenarios are applied on a simply supported beam to examine the performance of the proposed method. Modal data acquisitions have been made by vision-based method and accelerometer sensors. The results demonstrate that this method could accurately figure out the location and severity of damage using just the first mode shape since rotational mode shapes are more sensitive than vertical mode shapes in damage detection.