Structural damage detection based on natural frequency vector

Based on the new conception of natural frequency vector (NFV) and natural frequency vector assurance criterion (NFVAC), a new damage detection method using the natural frequencies as damage character is described in detail. For a specific structure, a series of small damage states can be simulated and the NFVs of these damaged structures can be calculated and used to build the damage feature database of the structure. Then, the values of natural frequency vector assurance criterion (NFVAC) which are calculated between the damage states in the damage feature database and the actual structure are used as damage index. An 8-story shear frame model is adopted as an example to show the feasibility and validity of the proposed method. Both numerical simulations and model experiments for damage detection are performed, the results demonstrate that using NFVAC, the damage location can be identified correctly and the damage extents can be estimated as well.