Experimental Tracking of Helicopter Rotor Blade Hidden Crack Development Using Fiber-Optic-Based Sensing Technology

An optical-fiber-based SHM concept for the detection of a hidden damage in a helicopter rotor blade was proposed, and demonstrated in a cyclic loading test. Not only could the sensing network detect the hidden cracks in the rotor root structure, it could also follow their growth at a stage where the damage was too small to compromise the blade ability to sustain the test cyclic loading.