Damage detection of fiber-reinforced polymer honeycomb sandwich beams

In a framework of developing a structural health monitoring for civil infrastructure, the damage identification procedure based on dynamic response for fiber reinforced polymer (FRP) sandwich composites is evaluated. In this paper, an experimental damage identification procedure based on structural dynamic responses and using smart sensors is conducted. Damage identification is estimated from comparison of dynamic responses of healthy and damaged FRP sandwich beams. Correspondingly, based on the relationship between the changes of mechanical properties and the related changes of dynamic responses (i.e., the curvature mode shapes in this study), damage magnitude is quantified. The composite sandwich beams are made of E-glass fiber and polyester resin, and the core consists of the corrugated cells in a sinusoidal configuration. Artificial damage is created between the interface of core and faceplate and also in the core of sandwich beam to simulate core–faceplate debonding and core crushing, respectively. Using piezoelectric smart sensors, dynamic responses data is collected and dynamic characteristics of the sandwich structure are extracted, from which the location and magnitude of the damage are evaluated. As demonstrated in this study, the present dynamic response-based procedure using smart sensors can be effectively used to assess damage and monitor structural health of FRP honeycomb sandwich structures.