Fig. 1. OFDR system with polarization analysis. (a) Schematic diagram of system structure; (b) schematic diagram of the internal structure for PSG; (c) schematic diagram of the internal structure for PSA

Fig. 2. Bending stress results of composite materials. (a) Stress cloud image and (b) internal fiber stress of the composite material embedded with 250 μm fiber when the bending radius is 6 cm, illustration is local enlargement; (c) stress cloud image and (d) internal fiber stress of the composite material embedded with 165 μm fiber when the bending radius is 3 cm, illustration is local enlargement

Fig. 3. Simulated equivalent stresses of embedded fibers at different bending radii of the composite materials. (a) Embedded fiber with cladding diameter of 250 μm; (b) embedded fiber with cladding diameter of 165 μm

Fig. 4. Experimental system of deformation monitoring for carbon fiber composite plate

Fig. 5. Results of linear birefringence. (a) Measured linear birefringence of 250 μm fiber under different bending radii; (b) variation in linear birefringence of 250 μm fiber with bending radius; (c) measured linear birefringence of 165 μm fiber under different bending radii; (d) variation in linear birefringence of 165 μm fiber with bending radius

Fig. 6. Fitting curves of fiber linear birefringence with different bending radii. (a) Embedded fiber with cladding diameter of 165 μm; (b) embedded fiber with cladding diameter of 165 μm