Structural damage identification based on the sensitivity technique of structural flexibility is studied. Using the Neumann series expansion

the flexibility sensitivity of the structure is firstly derived to obtain the damage detection equation. Then all the elemental damage parameters can be easily calculated by manipulating the matrix equation into a set of linear equations. Two significant advantages of the proposed flexibility sensitivity method are pointed out. The first one is that the computation of structural flexibility sensitivity is very simple and then the presented method is easily to implement. The second one is that the number of independent linear equations of the proposed method is greater than that of the previous eigenparameter sensitivity technique in most case. So damage detection results obtained by the proposed scheme will be more accurate than that obtained by the eigenparameter perturbation method. A 31-bar structure is used as a numerical example to validate the presented flexibility sensitivity method and the results are satisfactory even if noise is present. It has been shown that the proposed approach is more effective than the eigenparameter sensitivity technique and may be a promising method for structural damage detection.