1. Quantification of the reliability of flaw detection (NDT) using probability of detection (POD) based on synthetic data - Validation of the ultrasonic phased array model Håkan Wirdelius Advanced NDT /SCeNDT Chalmers

2. Applications of NDE
To monitor, improve or control manufacturing processes
Structure and Microstructure Characterization
Estimation of Mechanical and Physical Properties
Dimensional Measurements
To inspect for in-service damage
Flaw Detection and Evaluation
Leak Detection

3. Reliability of used NDE method
NDE reliability is the degree that an NDE system is capable of achieving its purpose regarding detection, characterization, sizing and false calls.
Performance demonstrations
A systems reliability can be quantified by its:
capability (POD or Qualification)
reproducibility (calibration)
repeatability (NDE process control in application)
Unknown Defect Situation in
Testsample or Real Component
Non-Destructive Test
Report
Black Box
True Data
Test Result
Comparison

4. NDE capability by POD Defect size Signal magnitude
Probability of detection (POD)
Response
Experiments or simulation a â

5. Quantitative NDE
What is the critical flaw size that will cause failure for a given component subject to service stress and temperature conditions?
How long can a pre-cracked structure be safely operated in service?
What inspections must be performed to prevent catastrophic failure?
Redundant design, i.e. how can a structure be designed to prevent catastrophic failure from pre-existing cracks?

6. Definitions by signal response
Nondestructive Testing (NDT).
UT, ET, RT UT, ET, RT (technique, method)
Nondestructive Evaluation (NDE).
UT, ET, RT Hit/Miss (procedure, calibration)
Quantitative Nondestructive Evaluation (QNDE).
UT, ET, RT Characterization, (capability, reproducibility
size, position & repeatability)
Integrity and quality assessment by NDE (IqNDE).
UT, ET, RT residual life, KIC, (math. models of NDE
da/dN, nodularity & meta-modeling)

7. Mathematical modelling of UT
simSUNDT
The simSUNDT program (freeware) consists of a Windows®-based pre-processor and postprocessor
UTDefect used as a mathematical kernel
Model of ultrasonic backscattering due to grain growth in a welded region
The result can be read by a number of commercial analysis software
Reduce number of test pieces and synthetic defects

8. Quantification of the reliability of flaw detection
for phased array techniques
WP 1 Development of simulation model:
WP 2 Experimental verification of the model:

9. WP 1 Development of simulation model
Phased array UT
E.A. Ginzel1 and D. Stewart2 , PHOTO-ELASTIC VISUALISATION OF PHASED ARRAY ULTRASONIC PULSES IN SOLIDS, Proc WCNDT 2004

10. WP 2 Experimental verification of the model
Dimensions of used test specimen 20 40 60 10 80
300
5 Side-Drilled Holes 6 Flat- Bottom Holes all f = 2.4 mm 35 5
Depth 20, 40 and 60
Depth 10, 30 and 50

11. Initial experimental validation of the set-up

12. Initial experimental results

13. Validation of energy divergence (number of elements)

14. Validation of energy divergence (number of elements)

15. B & C-scan validation (amplitude)

16. Quantification of the reliability of flaw detection for non-destructive techniques using probability of detection (POD) based on synthetic data
WP 3 Procedure for synthetic data based POD:
Develop a technique that uses mathematical models in order to develop a data base that will be used as the basis for a POD curve. The procedure shall be for a specific NDT task based on experiences made in WP1 and 2.
WP 4 Experimental validation of the synthetic POD:
Experimentally validate the above evolved POD curve. This in order to optimize the inspection procedure and also to make it as a convention tool in the development of POD characteristics.

17. Academic SME Industry H T S
PICASSO imProved reliabIlity inspeCtion of Aeronautic structure through Simulation Supported POD
H T S
Hoch Technologie Systeme
World Centre for Materials Joining Technology
Industry
Academic
SME