Waves can be guided by structural features for the detection of defects, such as cracks or corrosion, in or near the features.  The idea is supported by practical observations that a butt weld between two plates has a significant guiding effect, clearly tending to retain the energy of the fundamental extensional wave in and near the weld.  We are developing modelling capability to study and understand the nature of guided waves in welds and other structural features. You can view a presentation here.

Detection of cracks simulation

 

References

Z Fan, MJS Lowe, "Elastic waves guided by a welded joint in a plate", Proc R Soc Lond A, vol. 465, pp. 2053-2068, 2009.

Z Fan, MJS Lowe, "Scattering of weld guided modes from defects located around the weld”, Review of Progress in Quantitative NDE, eds. D.O. Thompson and D.E. Chimenti, American Institute of Physics, New York, vol. 30, pp. 153-160, 2011.