Monitoring composite materials during their manufacturing process is very important to achieve a good quality. At the same time, a monitoring system, able to continuously identify the stress state and the possible incoming of micro-cracks during the component operative life, may increase the safety levels.
Fibre optics, instrumented with FBG (Fibre Bragg Gratings) and embedded in composite materials can be a key sensor system for structural health monitoring, minimally intrusive.
In this work, the calibration of a FBG-based sensorial system has been carried out with static and dynamic strain tests and compared with measurements, made with traditional strain gage and piezoelectric sensors.
Tests demonstrate that these devices, embedded in a composite laminate, can monitor static and dynamic strains with the same accuracy level of traditional ones.
Fiber optic may be also used as refractometer to monitor the advancement of the resin front and the curing reaction during an RTM manufacturing process. In a near future these two fibre optics-based sensor systems could be both applied in operative structures so to increase their reliability level.