This paper presents modal-based structural damage detection. Specifically, we focus on localized flexibility properties that can be deduced from the experimentally determined global flexibility matrix.
We present the underlying theory that can be viewed as a generalized flexibility formulation in three different generalized coordinates, namely, localized or substructural displacement-basis, elemental
deformation-basis and element strain-basis. Then, the present methods are applied to CFRP pipes and shells having interior damage and the numerical and experimental results show that the elemental strain-basis
method is quite useful for detecting the damage inside CFRP filament winding pipes.