Laser Ultrasound Scanning of Coumpound Curved Aerospace Composite Structures

The introduction of advanced design methods using composite materials in the aerospace industry, that started out decades ago in the military environment, has now fully reached civil aviation. All current and future airframe designs will employ such materials to a very high degree, enabling the construction of lighter, stronger and more streamlined airplanes.

While this material revolution brings with it huge benefits, it also forces manufacturers to come up with novel inspection methods, that are better suited to the task. At the moment, most of the surfaces are scanned with conventional or phased array contact ultrasonic probes. Water coupling enables the use of these techniques to efficiently scan surfaces with moderately curved geometries.

Because of the geometric flexibility of composite designs, airframe possess numerous subparts that pose substantial challenges to traditionnal ultrasound inspection. This paper gives a short introduction of laser ultrasound testing and discusses the potential benefits of using small, agile, laser ultrasonic probes for these tasks.