Damage Identification in Composite Plates by Dynamic Displacement Measurements

Assessing structural health from vibration measurements appears as an advantageous approach to monitor the conditions and performances of mechanical systems. An accurate knowledge of the dynamic behavior of the structure can be considered as a prime source of basic information for the detection of possible damages occurring in the structure and, above all, the evaluation of this behavior from operating conditions represents the potential gain this approach can offer since structures can be monitored continuously during their operative life. In this paper, two different experimental techniques for structural damage identification, based both on the changes of modal and response characteristics, have been considered and compared. The identification of an "acceptance criterion" to be considered not only when the structure is being manufactured, but also during its working life, represent the main topics of this work, together with an investigation among the different approaches considered in evaluating the health of the structure via dynamic measurements.