Imaging technique enables thin & light aircraft design

Although it has long been understood that acoustic nonlinearity is sensitive to many physical properties, the lack of effective imaging has held back this technique. Currently, engineers use ultrasound to produce images of interior of components, however, this can only detect large problems such as cracks.

To achieve imaging of acoustic non-linearity, differences in the propagation of fields produced by the parallel and sequential transmission of elements in ultrasonic arrays are utilised. While increasing the safety of engineering structures, the imaging technique enables the design of thinner and lighter aircrafts.

The non-linear technique is published in the current issue of 'Physical Review Letters' together with an accompanying article in 'Physics'.

Dr Jack Potter, Research Assistant in the Department of Mechanical Engineering, said: “Imaging acoustic non-linearity not only provides sensitivity to smaller defects than is currently possible but may have the potential to detect damage before macroscopic material changes occur. “This would enable intervention before cracks have even begun to form, as well as predicting the remaining life of an engineering structure. Crucially the technique has been achieved using standard inspection equipment, which will allow for the rapid implementation of the technique in numerous applications.”