Damage Detection and Mitigation of Composite Structures using Smart Materials

This paper reports the results of an ongoing experimental program for damage assessment and mitigation of composite structures using smart materials. One consequence of all damage to a composite structure is a change in its stiffness. This change in stiffness is measured by modal analysis which can be carried out using piezoelectric films as both sensor and actuator on the structure member. It is shown that the presence of damage can be detected by the change in natural frequencies and the location of the damage can be detected from the ratio of changes in frequencies between two successive modes. Experiments are now being carried out using healthy and damaged composite beams of rectangular cross section with piezoceramic sensors and actuators. In this paper experimental results of damage detection will be described in detail.