Eddy current pulsed thermography of CFRP for wind turbine blades

Wind turbine blades suffer from relatively high failure rates resulting in long downtimes. The motivation of this research is to improve the reliability of wind turbine blades via non-destructive evaluation (NDE) for the early warning of faults and condition-based maintenance. Failure in wind turbine blades can be categorised as three types of major defect in carbon fibre reinforced plastic (CFRP), which are cracks, delaminations and impact damages. To detect and characterise those defects in their early stages, this work proposes eddy current pulsed thermography (ECPT) NDE method for CFRP-based wind turbine blades. Directional excitation is applied to overcome the problems of non-homogeneous and anisotropic properties of composites in both numerical and experimental studies. Through the investigation of the multiple-physical phenomena of electromagnetic-thermal interaction, defects can be detected, classified and characterised via numerical simulation and experimental studies. The defect detection, characterisation and classification along with comprehensive transient feature extraction at the three different levels of the pixel, local area and pattern are introduced in details.

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Liang Cheng was born in Beijing in 1985. He received the B.Sc. degree in electronics from Peking University, China in 2007; the M.Sc. degree in communications and signal processing from Imperial College London, UK in 2008, and the Ph.D. degree in failure models and life cycle assessment of wind turbine systems with Newcastle University, UK in 2013.