A mode shape sensitivity-based method for damage detection of structures with closely-spaced eigenvalues

A new optimisation problem is proposed to facilitate a fast and reliable damage detection of structures with closely-spaced eigenvalues. The first stage of the proposed method identifies the most probable defective elements resulting in the elimination of healthy members from further investigation. This will further reduce the computational efforts of computing damage indices regarding the defective elements. The second stage of the proposed method exploits the proposed objective function to update the damage indices of the identified defective elements from the first stage. Two truss structures with multiple damaged elements in different damage scenarios are studied where measurements with different levels of noise are used as input to the proposed algorithm. Numerical results and comparison with previous studies demonstrate the superiority of the proposed method in damage detection of structures with closely-spaced eigenvalues.