Relative Thermal Contrast Analysis in the Inspection of Wind Turbine Blades Using Pulsed Thermography

Abstract:

The rotor blade is an important component in wind turbine generator, it consists of glass fiber reinforced plastics (GFRP) and sandwich areas containing wood or plastic foam, different defects may be generated because of manufacturing problem. To improve the safety of wind turbine blades, pulsed thermography is being investigated in this study. Surface defects, such as air bubbles, edge bonding, etc. were easily and clearly detected on several full scale blades. Several specimens were manufactured to simulate the adhesive conditions between supporting spar and GFRP shells. The direct analysis of the original, 1^st or 2^nd derivatives was normally applied to judge any possible defects in the measured sample, and also used in quantitatively calculation. This study compared the relative thermal contrast (RTC) of the original and 1^st derivative for air bubbles at shallow depth and deficiency adhesive bonding at deep depth, the calculation of the RTC could give us the approximate best time to analysis defects of different depth and types. The comparison also indicated that it is better to use the 1^st derivative than the original to analysis the deep defects, however, there is no significant advantage in the analysis of shallow defects between the original and 1^st derivative.

• Periodical: Advanced Materials Research (Volumes 301-303)
• Pages: 591-596
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.301-303.591
• Online since: July 2011
• Authors: Zhi Zeng, Ning Tao, Li Chun Feng, Ye Shu Li, Cun Lin Zhang
• Keywords: Glass Fiber Reinforced Polymer (GFRP), Nondestructive Testing (NDT), Pulsed Thermography, Wind Turbine Blade

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