LASER-GENERATED LAMB WAVES TO DETECT HIDDEN INTERFACIAL CORROSION IN THIN-SKIN AIRCRAFT COMPONENTS

Abstract One of the major challenges in extending the life of ageing aircraft is to develop improved nondestructive inspection techniques for the rapid large-area detection of various types of hidden corrosion in aircraft components. In this paper, a new one-sided ultrasonic technique is proposed to solve the generic problem of detecting hidden corrosion in thin metallic aircraft skins, where the corrosion has originated at the interface between the skin and a second layer in an aircraft component. The technique involves the use of laser-generated ultrasonic Lamb modes whose attenuation in a thin skin is increased by the presence of corrosion. This paper presents a successful demonstration of the technique on a thin-skin elevator component. The potential of the Lamb wave technique for rapid large-area scanning for hidden corrosion is also described.