| Bragg gating sensors are evaluated as tools to determine crack growth in structures repaired with bonded patches. Linear elastic fracture mechanics theory, as well as the 1-dimensional theory of bonded joints are incorporated into a computer model which simulates crack growth in thin plates loaded in plane stress. The model suggests an elegant method of tracking crack length regardless of load magnitude based on the location of the peak strain measured along an axis perpendicular to the crack. This strain can be theoretically measured using short Bragg grating sensors positioned perpendicularly 2 mm away from a 4 cm long crack in a 7 cm wide, thin aluminum plate subject to loads of 2000 to 5000 N. |
