Comparison and analysis of non-destructive testing techniques suitable for delamination inspection in wind turbine blades

Wind turbine blades are one of the key components of a complete wind turbine system due to their significant effect in the overall performance of the system. They are fabricated with composite materials with polymeric matrices and the current manufacturing processes are still highly manual resulting in different types of defects. Thus, non-destructive testing (NOT) techniques that provide surface and internal information of the blade are necessary. In this paper, the detection capabilities and performance of ultrasonic, shearography, thermography and X-ray CT techniques for the inspection of wind turbine blades with delamination defects have been analyzed. To this end, two specimens of E-glass/polyester and E-glass/epoxy with several teflon inserts have been fabricated and the necessary inspections with the NDT techniques under study have been performed. Finally, the efficacy of each NDT technique has been analyzed and a comparison among their capabilities for such application has been carried out. (C) 2011 Elsevier Ltd. All rights reserved.