A novel fiber optic delamination detection scheme: Theoretical and experimental feasibility studies

Delamination detection is important in ensuring the safety and timely repai r of structures. In this paper. a novel technique for detecting delaminatio n is proposed. By embedding an optical fiber inside a structural component, the integrated strain along the fiber can be determined. With a load movin g along the component, a plot of integrated strain vs load position can be obtained. By correlating changes in the plot with the presence of delaminat ions, a simple loading test can be employed for delamination detection. The objective of the present investigation is to assess the feasibility of the proposed technique. Experimentally, to ensure the measurement of small len gth changes as a result of delamination, a highly sensitive interferometer is developed. Laboratory tests are carried out on simply supported beams an d beams on elastic foundation. To compare with experimental measurements, f inite element analysis is carried out to obtain numerical results. The expe rimental and numerical results correlate reasonably well with one another. The findings of this investigation demonstrate the potential of the techniq ue and warrant further developments for practical applications.