Ultrasonic investigation of disbonds in thin aluminium plates for aircraft applications

A new approach to using acoustic plate waves for large area disbond detection is investigated. Plate models of sound waves are generated between a transmitter and receiver transducer pair, which is mounted at a fixed distance on the surface of bonded aluminum plates. By changing the boundary condition of the plate surface between transducers, the resultant amplitude variation of the received signals can be examined to locate disbond areas between the plates. Mode conversions involved in the propagation of plate waves also show interesting applications for structure inspection