Embedding Fiber Optical Sensors in FRP-Hybrid Materials

The presented work includes development and verification of techniques for embedding fiber- optical sensors in Fiber Reinforced Polymers (FRP) and Aluminum hybrid materials for Structural Health Monitoring (SHM) purposes. The fiber-optical sensors both survive the manufacturing process of the FRP-Hybrid material and achieve sufficiently strong bonding to the material matrix. Mechanical tests have been performed to characterize the performance of embedded fiber-optical sensors for obtaining strain data under both static- and cyclic loading. Further, the fiber-optically read strain data is comparable with the strain readings from surface-mounted extensometers and strain gauges. Embedded fiber-optical sensors could monitor up to 1,5 – 2% strain in quasi-static tensile tests. During cyclic tests at low load, within the linear elastic region, the embedded sensors provided strain data for the entire testing cycle (18 000 cycles). At high cyclic loading, above the linear elastic region (300 MPa, 5 Hz), the embedded sensors provided strain data for 5000 cycles. This work has shown that embedded fiber-optical sensors can be used for Structural Health Monitoring of mechanical components.