Refracted Shear Waves
If the angle of the wedge is sufficient (around 38° for example) it is possible to produce shear waves into the part.
- A pulse is sent to the piezoelectric element, the element expands and produces a longitudinal wave into the wedge
- The longitudinal wave propagates in the wedge and, at the interface wedge/steel, is refracted and becomes a shear wave
It is worth remembering that the wave in the wedge always propagate in longitudinal mode. It is only at the interface wedge/steel that, depending on the angle of the wedge, it becomes a shear wave or remains a longitudinal wave