Real-time nondestructive testing of composite aeronautical structures with a self-adaptive ultrasonic technique

In the aeronautical industry, composite structures under testing often have complex and variable geometries. In such cases, an optimal use of ultrasonic transducer arrays requires specific algorithms in electronic systems in order to achieve rapid and reliable inspections. To fulfil such requirements, a new real-time and adaptive technique is presented. The surface adaptive ultrasound (SAUL) technique is based on an iterative algorithm that does not require a prior knowledge of the geometrical properties of the inspected domain. All different parts of a given component can be controlled using the same transducer array, such as a conventional linear array with a flat shape. In this paper, the adaptive processing is demonstrated through acquisitions performed with different typical aircraft composite structures. In addition, we present a new surface reconstruction algorithm. This fast algorithm is efficient and can be coupled with the real-time adaptive processing to reconstruct SAUL images and, then, to improve the characterization of flaws in composite materials.