Structural health monitoring for flexible bridge structures using correlation and sensitivity of modal data

This study investigates the use of correlation-based damage detection methods for long-span, cable-stayed bridges. The proposed approach is based on the multiple damage location assurance criterion (MDLAC), which combines a correlation-based technique with a forward-type estimation of damage-sensitive structural parameters. Observing the level of correlation between the variations in the measured and analytically synthesized natural frequencies enables damage localization. The sensitivity matrix, developed from the finite element model, further accommodates multiple damage detection. The locations of damage are determined by iteratively searching for the combination of structural parameters that maximizes the correlation coefficient through the application of genetic algorithms. It is demonstrated that correlation-based modal analysis is successful for damage detection and localization using a numerical model of a full-scale cable-stayed bridge.