Determination of cantilever plate shapes using wavelength division multiplexed fiber Bragg grating sensors and a least-squares strain-fitting algorithm

An algorithm has been developed to determine the full deformation field of a cantilever honeycomb plate under arbitrary loading conditions. The algorithm utilizes strain information from a set of sixteen fiber Bragg grating sensors mounted on the plate so that all sensors measure strains along the clamped-free direction. The sensors were interrogated using a wavelength division multiplexing scheme. A two-dimensional polynomial function which represents the strain field was created using a least-squares surface-fitting algorithm. This function was integrated twice with the known boundary conditions applied to yield the deformation field for the plate. Finite-element comparisons were performed to test the accuracy of the strain-displacement algorithm. Single-point loading tests were also experimentally performed to further verify the accuracy of the algorithm.