THESIS
2004
1 v. (various leaves) : ill. ; 30 cm
Abstract
A simple damage assessment technique based on the proper orthogonal decomposition (POD) is proposed in this study for identifying damage in buildings subjected to earthquake excitation. It is shown that the POD can be achieved through performing an eigenvalue analysis on the auto-correlation matrix of modulated structural responses measured at distributed locations of a building. For a building with distinct natural frequencies and small dampings, the eigenvectors obtained from the POD can be shown to be related to the mode shapes of the building. These mode shapes can be used to calculate the flexibility matrix for assessing the occurrence and the location of damage. The proposed technique is tested on two numerical shear-beam building models. Results show that the POD can accurately e...[
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A simple damage assessment technique based on the proper orthogonal decomposition (POD) is proposed in this study for identifying damage in buildings subjected to earthquake excitation. It is shown that the POD can be achieved through performing an eigenvalue analysis on the auto-correlation matrix of modulated structural responses measured at distributed locations of a building. For a building with distinct natural frequencies and small dampings, the eigenvectors obtained from the POD can be shown to be related to the mode shapes of the building. These mode shapes can be used to calculate the flexibility matrix for assessing the occurrence and the location of damage. The proposed technique is tested on two numerical shear-beam building models. Results show that the POD can accurately extract the mode shapes of the buildings under both simulated and actual nonstationary earthquake ground excitation. The flexibility matrix obtained from these estimated mode shapes can correctly locate damages which are modeled as stiffness reduction. Results also show that the mode shape estimations and damage identification are virtually unaffected under the presence of 10 dB noise. The proposed technique is a simple yet rather accurate method that can potentially be used for on-line real-time damage assessment for line-like buildings immediately after the seismic event.
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