The development of a new imaging technique by researchers from the University of Bristol’s Ultrasonics and Non-destructive Testing (NDT) research group promises to be able to detect damage previously invisible to acoustic imaging systems which could lead to aircraft off the future being thinner and lighter.
Acoustic nonlinearity is
sensitive to many physical properties including material microstructure
and mechanical damage. The lack of effective imaging has, however, held
back the use of this important method. Engineers are currently able to
produce images of the interior of components using ultrasound, but can
only detect large problems such as cracks.
Imaging
of acoustic nonlinearity is achieved by exploiting differences in the
propagation of fields produced by the parallel and sequential
transmission of elements in ultrasonic arrays.
Commenting
on the project, study lead, Dr Jack Potter, research assistant in the
Department of Mechanical Engineering said: “Imaging acoustic
nonlinearity 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.”
Such
advances in non-destructive evaluation not only increase the safety of
engineering structures but can help future design, for example, allowing
the next generation of aircraft to be built thinner and lighter.
The study was supported by the UK Research Centre in Non-destructive Evaluation (RCNDE).
(source)