Localization and Degree of Damage Based on Relative Curvature Difference and Frequency Perturbation

This study proposed a damage identification method compared with the existing ones, based on relative curvature difference and frequency perturbation theory, showing sensitivity to local damage by changes in the curvature mode and high recognition accuracy of frequencies. Considering the relative curvature difference as a damage index, numerical simulation is used for a simply supported beam under single and multiple damage conditions for different damage degrees. The damage is located according to the curvature mode curves, and the damage degree is qualitatively determined. Based on the perturbation theory, the damage equations are established by the changes between frequencies before and after damage, and the damage localization and degree are verified and determined. Effectiveness of the proposed method for identifying damage at different conditions is numerically investigated. This method potentially promotes the development of damage identification of beam structures.