Microinteraction of optical fibers embedded in laminated composites

The mechanical interaction between an embedded optical fiber sensor and its host laminated composite is investigated in this paper with a combination of moire' interferometry and Fourier transform fringe interpretation in order to achieve sub-micron spatial resolutions. Typical strain distributions are presented for several coated and uncoated optical fibers embedded at the mid-plane of a 9012 graphite/epoxy laminated composite compression specimen. Descriptors indicating the effect which the fiber has on the host, such as ellipse of influence and strain concentrations, are presented. Instances of residual strain devolvement and total collapse of interfaces are also documented.