Total Focusing Methods (TFM) for Nondestructive Testing. Full Matrix Capture (FMC). Principles, examples and work in progress

1. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM imaging for NDT
g.neau@m2m-ndt.com
f.reverdy@m2m-ndt.com
l.leber@m2m-ndt.com

2. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
1. Data collection: FMC
• Transmission: each element of the phased-array probe, one by one
• Reception: all elements of the phased-array probe
• Each signal is buffered/stored into a matrix

3. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Transmitting element
Receiving element
Data collection: FMC

4. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Aluminum block
with 4
Side-drilled holes
5MHz IMASONIC probe
64-element linear array
+
MULTIX64 M2M System
T1 Rall T32 Rall T48 Rall T64 Rall
Data collection: FMC

5. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Imaging: TFM
Point selection in the zone●
Zone specification●
phased-array probe
specimen

6. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Imaging: TFM
Point selection in the zone●
Zone specification●
location with respect to the probe
and dimensions of the zone

7. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Imaging: TFM
Point selection in the zone●
Zone specification●

8. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Imaging: TFM
Point selection in the zone●
Zone specification●
TOF measurement according to
selected mode (e.g., LW, SW)
and sound path (e.g., direct,
after reflection)

9. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Imaging: TFM
Point selection in the zone●
Zone specification●
Example: TOF measurement LL

10. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Imaging: TFM
Point selection in the zone●
Zone specification●

11. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Σ
Imaging: TFM
Point selection in the zone●
Zone specification●

12. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Iteration on all points of the considered zone●
Amplitude extraction of each FMC signal●
TOF measurement to focus at that point, for the selected mode●
Summation of all amplitudes●
Σ
Imaging: TFM
Point selection in the zone●
Zone specification●

13. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Imaging: TFM
LL
LL
T
T
T
TTT
T
L
T
TTL
10 mm
LLT
T
L
L
LL
Imaging a 10mm crack using half-skip modes
depending on location and back-wall geometry

14. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Σ
Imaging: TFM
• Valid for all coupling methods (direct contact, wedge, bubbler, immersion)
• Valid for linear and matrix probes (e.g., off-the-shelf commercial probes)
• Valid for dual linear and dual matrix arrays (DLA and DMA probes)

15. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM examples
8” pipe, ½” thick, V-prep weld

16. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM examples
8” pipe, ½” thick, V-prep weld

17. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM examples
Screw thread inspection

18. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM examples
Corrosion mapping

19. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM comparison with traditional PAUT
5mm-lack of fusion – middle weld line
TFM sector scan

20. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM comparison with traditional PAUT
5mm-vertical notch – weld root
TFM sector scan

21. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM comparison with traditional PAUT
notch + pin-hole
TFM sector scan

22. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM comparison with traditional PAUT
“porosity” (cluster of 0,3mm –diameter SDHs)
TFM sector scan

23. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM comparison with traditional PAUT

24. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM comparison with traditional PAUT

25. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
TFM benefits and limitations
▲ TFM data structure identical to sector scanning data structure
▲ Resolution less sensitive to positioning than sector scanning
▲ Wider high-resolution range than sector scanning
▲ Easier and better defect characterization than sector scanning
▼ Requires precise geometry knowledge for 2+ legs modes
▼ Imaging dedicated to specific type of defect

26. p h a s e d - a r r a y t e c h n o l o g i e s | w w w . m 2 m - n d t . c o m
Next
• Adaptive TFM for complex-shaped interface (2016)
• Multi-group real-time TFM
• Real-time back wall measurement for 2+legs imaging modes
• Multi-group real-time ATFM