Damage detection of CFRP pipes and shells by using localized flexibility method

Abstract 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. Keywords: CFRPDAMAGE DETECTIONLOCALIZED FLEXIBILITYINVERSE PROBLEMFEM FILAMENT WINDING