Quantitative non-destructive evaluation of CFRP components by sampling phased array

Continuous improvements in microelectronics performance and signal processing techniques have positively impacted development in NDE techniques specifically also with regard to aeronautical applications. Composite materials such as carbon fibre reinforced polymers (CFRP) have gained increasing application in aerospace over the past years and decades. Their primary advantage is their strength to-weight ratio. It is of parallel importance to ensure the quality of structures made from CFRP in production as well as in service. Ultrasonic non-destructive testing of CFRP is not always easy due to the anisotropic properties it exhibits. This can result in faulty defect sizing and image artefacts while ultrasonic testing. This paper intends to describe and discuss some of the applications and results using the Sampling Phased Array (SPA) technique with Reverse Phase Matching for the purpose of inspecting CFRP components without compromising the testing speed in real time quantitative imaging. The Principle of SPA is briefly described followed by a comparison of results with the state-of-the-art techniques, e.g. phased array method. CFRP samples with built-in defects have been used for measurements and the results prove the potential advantages of the SPA technique with Reverse Phase Matching.