Application of an FBG sensors system for structural health monitoring and high performance trimming on racing yacht

Abstract

Real time Structural Health Monitoring (SHM) is a requirement in all fields of engineering and is aimed at assuring the safety of the structures themselves and of the people who use them or move around them. This leads to the need for a monitoring system, stable and effective, which allows long term measurement campaigns, even throughout the whole lifetime of a structure; such a system, integrated with the structure to be monitored in real time, shall be invisible, durable (more of the structure itself), but should not interfere with the physical characteristic being measured (strain, acceleration, temperature, etc). The same requirements are also present in many sports: motor racing (cars and motorbikes), aerobatics and also yacht racing (regattas), where a monitoring system helps checking the status of the structure (car, bike, airplane, boat), for the safety of people on board, and for improving performance by making real time variation on aerodynamic and mechanical components (such as spoilers, wings, winglets, brakes, suspension), as it is now being done for over thirty years with the telemetry. Telemetry has been a key factor in modern motor racing: engineers analyze the vast amount of data collected during a test or a race (accelerations, temperature, speed of the wheels and displacement of suspensions) and use them to tune the car for optimizing performance. In this paper a monitoring and trimming system for racing yachts based on fiber optic FBG sensors integrated inside the structure itself is presented. Several applications are described where sensing system has been installed on the boat mast, either glued externally or embedded inside the material (carbon fiber reinforced composite, CFRC) during manufacturing, and on the sails. The same system can be used to monitor hull, keel, rudder, etc. Prevention of serious damage on a racing yacht might be achieved by monitoring the loading conditions and by inspecting the structural integrity, but if it is not easy to estimate loads (generally due to waves and winds) it could be easier to check the structural integrity in real time.