Life cycle monitoring of large-scale CFRP VARTM structure by fiber-optic-based distributed sensing

This study demonstrated fiber-optic-based life cycle monitoring of a representative carbon fiber reinforced plastic (CFRP) stiffened panel manufactured by vacuum assisted resin transfer molding (VARTM). A single optical fiber was embedded between the stiffeners and the skin during the laminate lay-up process and the formed fiber-optic network was then utilized to monitor the manufacturing process and subsequent impact tests. A Brillouin-based system with a spatial resolution of 10 cm was utilized for distributed strain measurement. Strain changes induced during the manufacturing process and the impact tests were comprehensively presented and discussed. The internal state of the panel was successfully monitored throughout its life, confirming the effectiveness of life cycle monitoring by fiber-optic-based distributed sensing for developing highly-reliable composite structures.