Initial studies of glued wood joints using FBG strain sensors

This work addresses the experimental work of characterization of wood (P. pinaster) bonded joints by means of pure mode I using the double cantilever beam (DCB) configuration test. The approach combines fracture mechanical testing with embedded fiber Bragg grating (FBG) sensors in the glue line. A method for the determination of the FBG reflection spectra shift based on the spectral geometric mean determination is used. The load-displacement (P-δ) curve and wavelength-displacement (λ-δ) curve are acquired and related to each other. An quantification of a global internal equivalent uniform strain applied to the FBG was then calculated.