Phase-based FBG detectors for self-diagnosis of marine vehicles structures N. Roveri & A. Carcaterra Department of Mechanics and Aeronautics, University of Rome, ‘La Sapienza’, Rome, Italy M. Platini ACE System Snc, Rome, Italy ABSTRACT: In the context of a new project named SEALAB, aimed at conceiving an innovative high speed marine vehicle, a new system for monitoring the structural response and potential damages in the ship structures is under development. This system permits the real-time self-monitoring of the structure using a new system of sensor based on optical fibers equipped with FBG (fiber-Bragg-gratings) sensors. These fibers are applied using different technologies. For traditional materials, like aluminum made structures, the fibers are simply glued along the system. For composite materials, the fibers are embedded directly into the matrix. A novel HHT-based method (Hilbert-Huang transform) for damage detection of panel structures under impulsive or travelling load is proposed. The technique is able to identify the presence and the location of the damage along the panels. The measured data are processed by the HHT technique, and none a priori information is needed about the response of the undamaged structure. Damage location is revealed by direct inspection of the first instantaneous frequency, which presents a sharp crest in correspondence of the damaged section. 1 INTRODUCTION This paper proposes a new technology for continuous structural monitoring and damage detection in ships structures. Namely the system combines a novel algorithm for damage identification together with a new optical sensors based on FBG (fiber Bragg grating). The system is particularly appealing when using the optical fibers directly embedded into the composite material. The development of this new technology is part of a larger project developed at the University “La Sapienza” named SEALAB focused on the concept design and building of an innovative high speed marine vehicle. The new challenging vehicle is a technology platform with many new technologies hosted on board. The vehicle presents innovation in several field, involving the whole architecture of the vehicle, the propulsion, transmission and control systems, the shock attenuation devices and the structural real-time monitoring and damage detection system based on optical technology. A new architecture of the vehicle has been developed, being it equipped with three types of control surfaces closed in the same loop: submerged foils, aerodynamic surfaces and a special interface system equipped with an electromechanical suspension device that contributes to the vehicle lift, large mitigation of the of water-impact phenomena, and to the trim-keeping at high speed (about 200km/h). IX HSMV Naples 25 - 27 May 2011 1