A new fiber optic based method for delamination detection in composites

The early detection of closed delamination is important for ensuring the safety of laminated composite structures. In this article, an approach for delamination detection using fiber-optic interferometric technique is introduced. The integral strain along a fiber that is surface-attached to the composite is measured as a function of load position. By comparing the integral strain versus load position curve (or its first or second derivatives) for the undamaged and delaminated cases, the delamination location and size can be determined. To demonstrate the feasibility of the technique, numerical and experimental investigations have been carried out. The results of the study indicate that the proposed technique is applicable for delamination detection in both simply supported beams and beams on elastic foundation.