Damage detection with auxiliary subsystem

Among Non-Destructive Evaluation, vibration-based methods respond to the current tendency which is to integrate into the structure identification and monitoring systems; to this aim transducers and sensors are embedded with the mechanical system and driven by suitably designed electronic controllers. The major limit of this and the other indirect identification techniques based on frequency response measurements turns out to be the small sensitivity to local variations of mechanical characteristics: it reflects on a uncertainty on the identified parameters, since it implies a small curvature of any reasonable identification functional build on these quantities. An enlightening example for the application of the proposed technique is given through a beamlike structure coupled to a network of piezoelectric patches. Although the forces exerted by the piezoelectric transducers are not large, the choice of such a kind of actuators/sensors implies the remarkable advantage of dealing with highly sensitive and easily tunable devices. © 2008 Trans Tech Publications.