In this part we consider echoes generated by Flat Bottom Holes (FBH) at different depths with different contact and immersion probes. The interaction between beam and FBH is simulated with the Kirchhoff model.

The FBH study is divided into three parts. First, specimens containing several vertical or 45° tilted FBH, of different diameters (1 mm, 3 mm or 6 mm) at different depths are inspected with varying probe apertures. Then the probe disorientation effect on echoes obtained in L0° at different frequencies is analyzed. Finally, the simulated results are compared to DGS/AVG curves of Krautkrämer, as well as DGS/AVG curves reproduced experimentally.

A discussion about the limitations due to the near field and small flaws concludes this part.


FBH at different depths

Influence of the tilt of the probe

DGS curves

Conclusion and discussion about the limitations


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