Monitoring the Structural Integrity of Wind Turbine Blades Subcomponents using Advanced Signal Processing Techniques

This paper presents a methodology, based on advanced signal processing, to monitor the damage evolution and to identify the structural failure modes in two composite I-beams. The composite I-beams with different geometrical configuration were subjected to cantilever tests. The I-beams represented the shear web-to-the spar caps connection of a wind rotor blade. Acoustic Emission technique was used to monitor the cantilever tests while Digital Image Correlation technique measured the displacement fields of the bond-lines and shear webs. The aim of the exercise was to investigate the influence of the geometry to the structural failure pattern, failure in the bond-line that connects the shear web to the spar caps and/or buckling of the shear web, and to monitor the failure process.