DAMAGE ASSESSMENT USING MODE SHAPE SENSITIVITIES

In this paper, a method for the localisation and assessment of damage is presented. The method is based on the use of mode shape sensitivities to changes in mass or stiffness in the test structure. With these sensitivities, differences in the dynamical behaviour of the structure in its undamaged and damaged conditions can be translated into damage information (location and amount of changes in mass or stiffness). Since the sensitivities are calculated on the basis of the experimentally determined mode shapes, there is no need for a prior finite element model of the test structure. The applicability of this technique is discussed on the basis of damage detection experiments performed on a beam-like structure (laboratory conditions) as well as data from the experiments on the I-40 highway bridge in Albuquerque, New Mexico. A comparison is made with a variety of existing damage detection techniques which do not require a finite element model.