Validation of simulation software for NDE applications in utility industry - NDT.net · Validation of simulation software for NDE applications in utility industry Thiago Seuaciuc-Osorio,

Validation of simulation software for NDE applications in utility industry

Thiago Seuaciuc-Osorio, George Connolly, Feng Yu and Mark Dennis Electric Power Research Institute

The 5th International CANDU In-Service Inspection Workshop in conjunction with the NDT in Canada 2014 Conference

June 16-18, 2014 Eaton Chelsea Hotel

Toronto, ON (Canada)

Outline

• Background

• NDE Simulation Software: CIVA

• Validation of CIVA Simulation Results

• Summary

2© 2014 Electric Power Research Institute, Inc. All rights reserved.

Our History…

• Founded by and for the electricity i d t i 1973industry in 1973

• Independent, nonprofit center for public interest energy andpublic interest energy and environmental research

• Collaborative resource for theCollaborative resource for the electricity sector

• Major offices in Palo Alto, CA; j , ;Charlotte, NC; Knoxville, TN– Laboratories in Knoxville,

Charlotte and Lenox MAChauncey StarrEPRI Founder


Charlotte and Lenox, MA EPRI Founder

Our Members…

• 450+ participants in more than 40 t icountries

• EPRI members generate more than 90% of the electricity in thethan 90% of the electricity in the United States

• International funding of more thanInternational funding of more than 15% of EPRI’s research, development and demonstrations

• Programs funded by more than 1,000 energy organizations


Challenges & Opportunities Associated with NDE Modeling &Simulation

• Increasing scope of NDE – Long Term Operation/License renewal– Buried piping; Concrete, etc.

Ph i l d t ti f NDE t h i• Physical demonstrations of NDE techniques are increasingly expensive.

• Modeling can be used as a training tool for new work force.

• Theoretical justification through modeling is considered as a possible acceptable way of meeting the regulatory requirements.


NDE simulation codes must be validated against experimental data to determine their suitability for industrial application!

CIVA: Software Dedicated to NDE Simulation

– Developed by Commissariat à l’Energie Atomique (CEA), France

– Multiple techniques and modulesUT Ult d• UT : Ultrasound

• RT : X Rays• ET : Eddy Currents• Analysis tool (signal processing data reconstruction )Analysis tool (signal processing, data reconstruction…)

– Generic Simulation Procedure of ET• Specimen• Probe • Inspection• Flaws

A i iti• Acquisition• Run• Analysis


Off-axis Detection• This study observes detection of reflectors away from the central

axis of ultrasonic beam (skewing)• A circular 0.5” 2.25MHz conventional probe is used; scanning

f d i t t 45° ( t l) i l i lperformed using transverse waves at 45° (steel) via a plexiglass wedge

GE SE1057

• Data collected by Zetec Omniscan MX 16-128– controlling software: Zetec Ultravision 1.2R7

• ATCO LPS-1000 encoder used for motion control along two axes


g

Experimental Apparatus• A 304 SS reference block is used for experimentation and simulation

– Overall dimensions 101.6mm×76.2mm×304.8mm (H×D×W)– Nine side-drilled holes as reflectors (Ø1.5875mm), ranging in depth from

6.35mm to 88.90mm (the ninth is not used)– Side-drilled holes are not though-holes; they are drilled ⅔ of the way

through– x is the scan direction and y is the index direction


Experimental Procedure• Calibration for wedge delay, exit point from

wedge front and shear wave velocity• Raster scanning is performed in 1mm steps g p p

in both scan (x) and index (y) directions– Five different skew angles are used,

varying from 135° to 195°– two cases are shown here: 150° and

indexscan

– two cases are shown here: 150 and 195°


195° negative skew150° positive skew

Comparison at 150° Positive Skew• CIVA simulations are run in “Direct” mode; no reflections nor mode conversions are

included– cumulated side views:

150° 150°

43

4321

4

5

6

4

5

6

7

EXPCUMULATED SIDE VIEW

SIMCUMULATED SIDE VIEW

7

7

8

• Comparison is favorable; third through seventh SDHs detected experimentally• Differences

– first two SDHs are not detected experimentally but are strongly present in the simulationCIVA predicting response along the length of the hole (was also the problem at the


– CIVA predicting response along the length of the hole (was also the problem at the negative skew) instead of only at the corner

Comparison at 195° Negative Skew

• Cumulated side views:

195°195°

4

5

321

EXP SIM

5

6

7

8

• No SDH is detected experimentally; though there are blurred indications for upper SDHs

EXP SIMCUMULATED SIDE VIEW CUMULATED SIDE VIEW

• Simulated data show strong detection of every SDH

S f f


• Simulated results need further investigation to determine the reason for these signals

Notched Block• Notched block is modelled as homogeneous isotropic steel

– Dimensions: 255.6mm×152.4mm×25.298mm (10”×6”×1”)N t h f 1 27 (5% TWT/TWE) t 22 86 (90%– Notches vary from 1.27mm (5% TWT/TWE) to 22.86mm (90% TWT/TWE) in height from back surface

• Probe is 0.5” 1.5MHz transverse; wedge at 45°

10 9 8 7 6SHALLOW NOTCHES

5 4 3 2 1


DEEP NOTCHES

Experimental and Simulated Results• (top) cumulated VC top view, filtered

by time to remove backwall reflections and (bottom) cumulated VC side view

• CIVA simulations performed using single contact element at 1.5 MHz

Si l t d f d i 8 (15and (bottom) cumulated VC side view• Responses from notches 1, 9 and 10

not discernible due to interference

– Simulated scan performed in 8 rows (15 mm apart); in each row, 456 data are collected (0.5 mm apart)

565

4

3

6

7

8

5

4

3

6

7

83

2

3

2

1

8

EXPSIMCUMULATED TOP VIEWCUMULATED TOP VIEW

54

32

1

54

32

76

EXPCUMULATED SIDE VIEW SIM

CUMULATED SIDE VIEW


78

6 58

Comparison Summary• Normalized echodynamic curves of cumulated top view normalized

by (left) amplitude of response from second notch and (right) amplitude of response from sixth notchamplitude of response from sixth notch– Simulation tends to overestimate amplitudes of subsequent

notches

6

23

45

SHALLOW NOTCHESDEEP NOTCHES

7

8


Comparison Summary

• Comparison of measured and actual depths of notches– Both simulation and experiment tend to overestimate notchBoth simulation and experiment tend to overestimate notch

depth i.e., the notch TWT/TWE is slightly underestimated– Error slightly worsens for shallowest notches

6

75

2

3

4

5

6

23

46

7

2


Austenitic Stainless Steel Piping Sample

• Piping sample from 10.0” NPS pipe– contains two circumferential flawscontains two circumferential flaws

whose CL are at θ=30.0° and θ=78.1°


Experimental Procedure• A circular 0.25” 3.5MHz conventional probe is used; scanning performed using

transverse waves at 45° (steel) via a plexiglass wedge– coupling between probe and wedge achieved by mineral oilp g p g y– coupling between wedge and part achieved by running water

• Data collected by Zetec Omniscan MX 16-128– controlling software: Zetec Ultravision 1.2R7

• ATCO LPS-1000 encoder used for motion control along two axes


Experimental and Simulated Results• (top) cumulated VC top view,

filtered by time to remove b k ll fl ti d (b tt )

• CIVA simulations performed using single contact element at 3.5 MHz

– Simulated scan performed in 89 rows (0 8°backwall reflections and (bottom) cumulated VC end view

– Simulated scan performed in 89 rows (0.8apart); in each row, 35 data are collected (1.0 mm apart)

22

1

1

EXPCUMULATED TOP VIEW SIM

CUMULATED TOP VIEW

2

1

12 EXP

CUMULATED END VIEW SIMCUMULATED END VIEW


1

Comparison Summary• Flaws are well located by both experiment and simulation• Differences

– CIVA overestimates length of first flaw; experimentally it is underestimatedg ; p y– Both methods underestimated length of second flaw– CIVA underestimates strength of reflection from first flaw relative to the

second flaw

flaw 1 CL flaw 1 length flaw 2 CL flaw 2 length

actual 30.0° 10.6° 78.1° 14.8°

experimental 30.1° 8.9° 77.4° 12.2°

simulated 30.0° 11.8° 78.4° 12.9°

1 2


UT Simulation Summary

• Three comparisons have been observed:– Quality of CIVA off-axis predictions from SDH– Relative reflection strengths and depth estimations from notches

cut into steel block– Quality of experimental and CIVA-estimated location of

i f ti l fl i t iti t i l t l i i lcircumferential flaws in austenitic stainless steel piping sample• Good qualitative and visual agreement between simulation and

experiment given the main limitations:no noise present in CIVA simulations– no noise present in CIVA simulations

– user must be aware of CIVA simulation options, particularly those controlling number of modes and reflectionsoptions are available to account for structural noise and other– options are available to account for structural noise and other simulation phenomena but computation time is greatly increased

• CIVA simulation performed adequately when compared against experimental measurements for notched block and austenitic


experimental measurements for notched block and austenitic stainless steel piping sample

Eddy Current Inspection of Steam Generator Tube w/ Holes


CIVA ET simulation

400 kHz bobbin coil, differential mode, ASME standard, IN 600, OD: 0.875” , WT: 0.05”


CIVA ET simulation vs. experimental Results

400 kHz bobbin coil, differential mode, ASME standard, IN 600, OD: 0.875” , WT: 0.05”

Simulation results


Experimental resultsRed: 100% thru; Black: 69%; Blue: 19%

CIVA ET Simulation vs. Experimental Results

400 kHz bobbin coil, absolute mode, ASME standard, IN 600, OD: 0.875” , WT: 0.05”

Red: 100% thru; Black: 69%; Blue: 19%


CIVA RT Screen DumpTube Voltage: 220 kV; Tube Current 2 mA; focus-to-film distance : 25”: Exposure Time: 30 s


CIVA RT Simulation vs. Experimental Results

Carbon steel (0.125, 0.25” thick) Experimental

( )Analytical, optical density (0-4) Analytical+ Monte-Carlo, optical density (0-4)


Bimetallic Welds Specimen


CIVA RT Simulation vs. Experimental Results: Bimetallic Welds

SimulatedExperimental


Summary• General good qualitative agreement was achieved between experimental

and CIVA results for the simulations performed in this study.useful to interpret the underlying physics and signal observed in NDE– useful to interpret the underlying physics and signal observed in NDE measurements;

– provide a useful tool when training inspectors;determine the influential parameters thru parametric studies– determine the influential parameters thru parametric studies.

• Like any simulation tools for engineering applications, CIVA represents simplified and idealized NDE inspections.

– critical to obtain the accurate information of the input parameters needed in CIVA simulation;

– Critical to validate CIVA models against experimental data for generic inspection or on a case-by-case basis for complex inspections with respect to technique justification and demonstration for plant operation.


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Validation of simulation software for NDE applications in utility industry - NDT.net · Validation of simulation software for NDE applications in utility industry Thiago Seuaciuc-Osorio,