This presentation from ECNDT 2018 reviews the following topics: Ultrasonic Phased Array Benefits Coherent Adaptive Focusing (CAF) Capabilities of CAF Results Conclusions

1. 1
Coherent Adaptive Focusing
Technology for the Inspection
of Complex Geometry
Olympus Scientific Solutions Americas
ECNDT 2018, Gothenburg, Sweden June 2018
Etienne Grondin

2. Introduction

3. Ultrasonic Phased Array (UTPA)
Benefits
UTPA technology benefits for composite
laminate inspection:
1. Faster inspection
- Scalability and parallel firing
2. High resolution
3. Improved coverage
4. Better repeatability
- Flat and radius

4. Ultrasonic Phased Array
Limitations
1. Predefined focal laws unable to
adapt to geometry variations
- Poor uniformity radius
- Weighted radius
Uniform Radius
Poor Uniformity Radius Weighted Radius

5. Ultrasonic Phased Array
Limitations
2. Linear phased array probe
alignment vs. the part
- Bad probe positioning
- Rounded parts
3. Curved phased array probe
alignment vs. the part
- Bad probe positioning
(out of concentricity)
- Variation of the radius
along the scan axis
Curved array good alignment
(concentric)
Curved array bad alignment
(non-concentric)
Linear array good alignment Linear array bad alignment
R1 = 9.0mm
R2 = 16.0 mm
R1
R2

6. Coherent Adaptive Focusing (CAF)

7. Coherent Adaptive Focusing
CAF is an iterative process that
enables the transmission of a wave
front parallel to the part
Delay
0dB
-3dB
-6dB
BeamWidth
PA probe
Wave front
Part
FW
BW?
0dB
-3dB
-6dB
BeamWidth
PA probe
Delay
Part
Wave front
FW
BW
n iterations

8. Objectives

9. 1. Adapt the ultrasonic wave front to the real inspection scenario
2. Improve and simplify the inspection of a radius
- Twisted parts
- Nonconstant radius (varying, nonuniform, and weighted)
3. Compatible with:
- Linear PA probe on a pseudo flat surface
- Linear and curved PA probe on a radius (inside and outside)
4. Performance equivalent to phased array
- Inspection speed must be similar to ultrasonic phased array
5. Reliable and robust
- No data loss or convergence issues
Objectives

10. Results – Inner Radius

11. Results – Inner Radius
Test configurations
1. Curved array probe alignment
- Out of concentricity
- Misalignment Inner Radius – Out of Conc. (-) Inner Radius – Out of Conc. (+)
Misalignment

12. Results – Inner Radius
Part and Scan Parameters
1. Geometry: L shape
2. Radius: 9.0 mm to 15.0 mm
3. Max. out of concentricity: +15.0 mm
4. Probe: 3.5CC25-32R4

13. Results – Inner Radius

14. Results – Other Configurations
FlatOuter Radius

15. Results – Other Configurations

16. Capabilities

17. Capabilities
Name Results
Maximum out of
concentricity
(+) 30.0 mm
(-) 2.0 mm
Maximum misalignment
(horizontal)
(±) 6.0 mm
Maximum misalignment
(vertical)
(±) 6.0 mm
Coverage 90.0°
Detection
(reliability & stability)
All flaws
detected &
no data loss
Name Results
Maximum out of
concentricity
(+) 9.5 mm
(-) 10.0 mm*
Maximum misalignment
(horizontal)
(±) 6 mm
Maximum misalignment
(vertical)
(±) 6 mm
Coverage 90.0°
Detection
(reliability & stability)
All flaws
detected &
no data loss
Name Results
Maximum tilt 25.0°
Coverage
at max. tilt
d = L*cos(alpha)
d: coverage
L: probe length
alpha: tilt angle
Detection
(reliability & stability)
All flaws
detected &
no data loss
Case 1: Inner Radius Inspection Case 2: Outer Radius Inspection
* Until the probe touches the part
Case 3: Tilted Probe/Part
§ Boundaries

18. Capabilities
§ Productivity
Parameters
Number of elements 32
Aperture size 4
Aperture steps 1
Water path 25 mm
Material thickness 8.5 mm
Material velocity 2700 ms
Number of iterations 5
PRF with CAF PRF without CAF
300 Hz* 517 Hz
Optimization is still possible to improve
productivity

19. Conclusions

20. Conclusions About Coherent Adaptive Focusing
§ Enables the beams (focal laws) to adapt to the real inspection configurations
§ Relaxes the need on the mechanics to be perfectly aligned
§ Is compatible with linear and curved phased array probes
§ Makes the inspection of components easier with changing configurations
(varying radius, varying aperture, pseudo flat)
§ Detection and speed performance is comparable to phased array
§ Easy to use by the operator

21. Thank You
For more info please contact
Etienne.grondin@olympus-ossa.com