Direct damage diagnosis of structural component using vibration response

摘要

This study proposes a semi-model-based method for detecting, locating and quantifying damages that may exist in a structure after a seismic event. The basic concept of the proposed method is to design a monitor for each structural component that needs to be monitored. The monitor is designed based on a residual generator technique and is sensitive only to the damage of the targeted component. The input signals to this monitor are the structural dynamic responses and the excitation. The monitor produces zero or close to zero output when there is no damage in the corresponding component. It produces an obvious nonzero output when the condition of that component has changed. The occurrence and the location of the structural damage can be determined by the display of nonzero output. Furthermore, the severity of the damage can be assessed by using a time-domain system identification technique on the input-output data of the monitor. The proposed method requires some prior knowledge about the structure being monitored. However, as the method can be used to assess and update the structural property of the components, precise modeling of the structure prior to the implementation of the technique is not necessary. A three-story lumped mass shear beam model under a seismic excitation was chosen as a numerical example. Results show that the proposed method can accurately detect, locate and quantify structural damages.