Within the EC Clean Sky - Smart Fixed Wing Aircraft initiative concepts for actuating morphing wing structures were under development. In order for developing a complete integrated system including the actuation, the structure to be actuated and the closed loop control unit a hybrid deflection and damage monitoring system was required.

The aim of the proposed project ""FOS3D"" was to develop and validate a fibre optic sensing system based on low-coherence interferometry for simultaneous deflection and damage monitoring. The proposed system used several distributed and multiplexed fibre optic Michelson interferometers to monitor the strain distribution over the actuated part. In addition the same sensor principle was used to acquire and locate the acoustic emission signals originated from the onset and growth of defects like impact damages, cracks and delaminations.