| The objective of this study is to develop a practical vibration-based nondestructive damage evaluation method to detect, locate, and size damage in a beam-like structure and in a plate-like structure. Most uncertainties in vibration-based nondestructive damage evaluation methods can be traced to incompleteness of modal measurements such as limited number of modes, finite number of measured degrees of freedom, and incomplete sensor resolutions. Using the concept of modal flexibility, damage index equations for the selected classes of structures (beams and plates) are derived, numerically verified, and experimentally verified. Finally, the feasibility and practicability of the proposed NDE scheme are studied using the results of an existing on-line health monitoring system of a reinforced concrete bridge. The damage indices for the bridge have been monitored for about three months giving a total of 183 sets of acceleration-time responses caused by normal traffic. The results of this study reveal that the modal flexibility approach proposed here may circumvent the existing problems of local damage detection with incomplete measurements. |
