Ultrasonic and thermographic studies for CFRP inspections with real and simulated defects

This paper deals with an overview of improved UT control procedures, related to defect investigation on advanced CFRP composite elements for aeronautical structures; the inspection procedures were evaluated with different frequency probes, employing direct contact, water stream and immersion methods. In this work, ultrasonic and thermographic controls of CFRP components are presented for detection of different types of defects (real and artificial) in order to evaluate sensitivity and detectability techniques. This work presents a preliminary ultrasonic study on CFRP components employing different probes and tools. For these aims, inspections of CFRP plates with artificial defects are optimized and compared to thermographic acquisitions with active pulsed technique, in order to calibrate Ultrasonic Technique tools and verify procedures for suitable results. In a second stage, improved ultrasonic scanning investigations are applied on real parts, containing real production defects in terms of small delamination and diffused porosity of T-shape stringer and resin/matrix excesses between layers, localized in the thin cap and web of structural civil aircraft stringers.