A Flexibility-Based Damage Identification Method Using Ambient Modal Data

Structural damage identification using ambient vibration modes has become a very important research area in recent years. The main issue surrounding the use of ambient vibration modes is the mass normalization of the measured mode shapes. This paper presents a promising approach that extends the flexibility sensitivity technique to tackle the ambient vibration case. By introducing the mass normalization factors, manipulating the flexibility sensitivity equation, the unknown damage parameters and mass normalization factors can be computed simultaneously by the least-square technique. The effectiveness of the proposed method is illustrated using simulated data with measurement noise on a steel truss structure. The results show the good efficiency and stability of the proposed method on the identification of damage on more than one element. It has been shown that the proposed procedure is simple to implement and may be useful for structural damage identification under ambient vibration case.