Investigation and development of a combined nondestructive evaluation measurement laboratory for aerospace composites

Conventional ultrasonic systems are commonly used in the industry for the non-destructive evaluation (NDE) investigation of carbon fiber reinforced polymer (CFRP). These systems are widespread and very efficient, but they require contact with the structure to be analyzed, which induces long measurement times. Moreover, major problems arise when the shape of the element to be investigated is complex (peak, valley, small radius of curvature…). During the last decade, multiples optical metrology techniques have been proposed and studied, as alternative or complement. Techniques such as thermography, shearography, or CT-scan have now achieved good maturity. Additionally, laser ultrasonic systems can be used and the recent developments show promising results. All these techniques allow detection to be carried out in a faster, cheaper and just as effective manner. Furthermore, the combination of all these measurement techniques could widen the range of detectable defects and the field of applications. They could also allow an increase in inspection rates, and therefore production speed. In this paper, we present the comparison of the result obtain on multiple CFRP samples specially manufactured with different type of defect such as insert, impact damage, or porosity with all these techniques. We discuss the complementarity of multiple measurements for industrial NDT. We also show the current development of an independent laboratory, with its complete range of CND techniques and capable of managing complex geometries and in a robotic way for future industrial NDE.