Phased Array Transducer for Non-Destructive Testing of Sandwich Honeycomb: C-scan Imaging, Skin Thickness Measurement and Detection of Delamination

Composites are nowadays increasingly used in industries such as aerospace, shipbuilding, automotive ... They are lightweight and have a very high specific stiffness, but defects such as delamination, inclusions may occur during their life cycle. Samples of sandwich honeycomb are tested using a 10 MHz central frequency phased array transducer constituted of 128 elements. Different defects are localized at the interface composite/honeycomb. These defects are due to the joint bond. Teflon inclusions are voluntary introduced in composite plate to evaluate the effectiveness of the experiment. The experiments illustrate that laminate defects are easily localized through a signal processing of all A-scans given by the phased array transducer. The concatenation of these A-scans processing gives a C-scan image where defects are clearly visible. In this work, we show the efficiency of phased array transducer for delamination detecting, thickness measurement and Cscan imaging of sandwich honeycomb composites.