Abstract
A surface-mounted CFBG sensor has been used to monitor disbond growth of a CFRP platebonded reinforcement of a structural box-section beam, bonded using a room-temperature cure structural adhesive. These tests are part of a programme to determine whether disbonding of such a plate could be monitored by ambient thermal fluctuations alone with the aid of thermal mismatch strains. Disbonds were introduced by physically cutting the structural adhesive and a range of different disbond lengths and temperatures have been investigated. When monitoring the disbond growth using the CFBG sensors, a distinct peaktrough perturbation in the reflected spectra was indicative of the location of the disbond front during the test. A prediction of the reflected spectrum was in good agreement with the experimentally-determined results, enabling the disbond lengths to be measured using the CFBG sensor technique to within about 3 mm.