Advanced imaging for non-destructive control of pressure vessels

Henri WALASZEK

Pôle Equipement sous Pression et Ingénierie de l’Instrumentation (EPI)

33 344673324

henri.walaszek@cetim.fr

www.cetim.fr sqr@cetim.fr

Governed by articles L342.1 to L342.13

of the French research code

Technological institute of mechanicsSteered by mechanical industrialists under the State’s supervision

Industrialand sustainable

performance

Metallic materialsand surfaces

Noise and vibration engineering

Mechatronics, power transmissions

and sensors

Pressurisedequipment

and instrument engineering

Mechanicalcomponent fatigue

Analysis of failuresand expert’s

analyses

Training and skills

management

Software

Sealingtechnologies

Innovative and powered processes

Polymer and composite material

engineering

Fluids and flow technique

InnovationDesign

Simulation

Joiningtechnologies

Metrologycalibration expertise

Businessintelligence

Breakdown into divisions

Page 4

Applied research and services in NDTCETIM offer

o Detection of defects in metal and composites : welds, cracks, porosities, thickness, delamination..

o Caracterization of materials : grade, stresses (residual, pre-load), thermal and thermochemical treatments

o Qualification / requalification of pressure equipments (AT, UT…)

oAcoustic emission monitoring (defects, leaks…)

oSimulation of NDT with CIVA software

• Feasibility studies,

• Improvement of existing NDT solutions

• Development of new solutions

• Expertise, NDT services

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Some « traditional » NDT have limitations

Visual :•Lack of traceability•Dependance of operator

MPI, Dye penetrant:•Lack of traceability•Dependance of operator

•Use of polluants•Automatisation difficult

•Time of operation

X-ray testing:

•Ionizing radiation

exposure

•Time of operation

Conventional UT :•Lack of traceability•Local response

•Interpretation

� Thanks to technological evolutions

� Digital and data processing techniques are more powerfull

� Transposal of medical and military technology

� These technologies are implemented in NDT equipment and affordable

� Many NDT equipment integrate image display and processing

� Enable global view of the component being inspected

� Make easier result interpretation

� Traceability and data storage are enhanced

� Communication about NDT results is improved

� Simulation softwares are available and help to save time and efficiency

� Signal processing applications

Technological context

11/2012

Page 7Page 7

28 octobre 2009 – ITT09

Tofd ultrasonics as alternative to X-ray testing

Wall

thickn

ess

trans

mitte

r

rece

iver

1

2 2

12

3 4

3

4

TOFD Image

X-ray Image

Standardised method

Page 8

Tofd Weld testing on site: alternative to X-Ray testing

Comparaison TOFD/RX

� « V » weld

X rays

porosities

Bscan - TOFD

Page 10Page 10

28 octobre 2009 – ITT09

Tofd ultrasonics for fatigue crack growth imaging

Application to a transmission

shaft

11/2012

TOFD Corrosion assesment on Trans-Channel tunnel

pitting

Receiving probe

Transmitting probe

Incident beam Diffracted beam

Conventional ultrasonic probe

No reflection

11/2012

TOFD Corrosion assesment on Trans-Channel tunnel

� Advantages: quick imaging,

� traceability, portability

� Limitations: same as in conventional UT, size of the probe

� Advantages of TOFD ultrasonic technique� Fast mapping of the corrosion� Unsensitive to orientation of corroded area

� Reduce of time for inspection� Global view of the corrosion

� Large surface inspected

� Limits the risk of missing the maximum corrosion depth

� Limitations of TOFD ultrasonic technique� Data volume storage

� Skill of operators higher than with conventional UT

� Acoustic coupling, measurements difficult on rough surfaces

TOFD ultrasonics advantages

11/2012

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28 octobre 2009 – ITT09

Phased array ultrasonic imaging

� Principle� Several piezo elements

� Delay laws:

� Electronic steering

� Electronic focusing

Advantages� Time to operate

� Traceability

� Easier interpretation

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28 octobre 2009 – ITT09

Xrays

Carbon steel

Thickness 35mm

Phased array ultrasonics as an alternative to X-rays

Page 16

Traditional thickness measurement on penstock pipe

Thickness measurement on site

Page 17

Now: thickness cartographies with PA

ultrasonic transducers

Phased array transducer on the pipe wall

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Phased array testing of cracks on shaft

� Shaft having length more than 1 meter and dia 180mm

� End acess only

� Potential cracks on filets

CIVA Simulation

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Phased array testing of cracks on shaft

� Experimental validation

0 dB

-∞ dB

-6

dB

-12 dB

Part with porosities

Electronic Phased array equipment : M2M MultiX-128 parallel channels

Total acoustic aperture: 96 mm (128 éléments, pitch 0,75 mm).

Avec FMC

Full matrix capture for defect sizing

Caracterization with PA ultrasonics

Sans focalisation

� Improvement of spatial resolution

�Reduction of shadow effect

Without focusingWith Full Matrix

Capture

Focusing

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Transfer of studies on advanced ultrasonics:

� Training of operators on TOFD and Phased array

� Certification through COFREND

� Rédaction of guide CETIM / IS « alternativeà la radiographie iridium »

Applications on compositestructures

� 3D ultrasonic imaging

� Requirements

� Wide structure testing (tanks, double curvature panels,…)

� Alternative to tank immersion

� Prototype parts, limited series,…

Applications sur structures composites

� 3D imaging on double curvature panel

� Contrôle de grandes structures composites

� imagerie 3D Vue d’ensemble

Zoom au niveau d’un délaminage

Pastilles

Scotchs

Délaminage

1 m1,3

m

Page 24

Ultrasonic waves

Halogen lamp

Flash lamps

Source

Active thermal infrared

Source:

Page 25Active thermal infrared on composite plates

� Testing of impact damaged composites

15J impact on opposite side/camera

Flash excitation on

camera side

Phase diagram

Other applications of active thermal

infrared on metallic materials

� Testing of welds (flaws open to the surface)

28 mm

18 mm

5 mm22 mm

Magnetic particle testing

Infrared thermography (induction)

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� Drawbacks of active infrared thermography� Inspection depth is limited according to thermal diffusivity of the material

� A few millimeters for monolithic material, more for honeycomb

� Surface properties affect the inspection

� Interpretation of data requires knowledge of thermal behaviour of the material

� Advantages of active infrared thermography� Global, non intrusive, contact-less and eco-friendly inspection

� In some cases, IT could replace Penetrant Testing for example

� Applicable to many material and kind of defects� Composite, metallic� Delamination, disbonding, crack, water infiltration, …

� Wide range of excitation sources� Feasibility study is required to choose the best one

� Allows to determine the shape and the depth of the defect� Temporal or frequency analysis

Active infrared thermography

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X-Ray Computed TomographyPrinciples

Real ObjectX-Ray Images

around 360°

Reconstruction of

transversal slices3D

Reconstruction of

the object

� Computed Tomography � Representation of an object with reconstructed slices from deported

measurement achieved outside of the object

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Computed tomographyEquipment characteristics

Medical applications

Type Nanofocus CT system

Microfocus CT system

Macrofocus CT systemMedical CT

systemCharacteristics

Energy max 180 keV 240 keV 150 to 600 keV 1 to 15 MeV 160 keV

Dmax object 120mm 200mm 1m >> 1m 1m

Resolution 0,5 to 10µm 1 to 50µm 0,1 to 0,5mm 0,5 to 1mm 0,1 to 0,5mm

Cost 250 – 500 k€ 250 – 500 k€ 250 – 800 M€ 0,8 – 1,5 M€* 1 – 3M€

NDT applications

Courtesy of VJ Technologies

Tomography: applications to crack caracterisation

Fatigue crack detection in metallic components

Vidéo

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Computed tomographyExample of application

� Composite pipe

Sagittal slice

Axial slice

3D View

Page 32

� Drawbacks of X-ray Computed Tomography� Non-portable system� Final resolution depending on the object size

� Acquisition and reconstruction duration (from 0,25 to 12h)� Amount of data to analyse (from 2 to 20Go)

� Advantages of X-ray Computed Tomography� Non-sensitive to the defect orientation and material

� 3D defect reconstruction and location in the volume� Complex shape inspection

� Comparison with CAD or others scans

� Dimensional measurement

� R&D applications, expertise, retro-engineering

Computed Tomography

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Application of NDT methods to detection and sizing of delamination in an impact damaged

part

Testing of impact-damagedcomposite plates

Page 34

�In aircraft industry

� Many structural composite parts are dimensioned through impact tests

– Impact tests trials on standardized parts

� CETIM equipment: Impact machine dedicated to these tests

– Trials meeting standard AITM 1-0010 requirements

Testing of impact-damaged composite plates

Impact machine

available in CETIM

L = 150mm

l =

10

0m

m

Monolythic epoxyde resin –carbon fiber

Unidirectionals plies oriented 0°,+/- 45° or

90°

Total thickness 3,0mm

Page 35Testing of impact-damagedcomposite plates

NDT means

used

Thermal camera

Flash location for front side excitation

Flash location for back side

excitation

Sample under test

20cm 50cm

Active thermal infrared with flash excitation

X ray computed Tomograph

(CETIM/MONTUPET project Tomopic)

• Thermal infrared

• Computed X ray tomography

Page 36

� delamination signature evolution versus depth in the part

30J

Sample test

Impacted side Opposite side /impact

Testing of impact-damaged composite plates

X r

ay

com

pute

d

tom

ogra

phy

Act

ive

ther

mal

infr

are

d*

*- phase at different frequencies , front face flash

Page 37

� Non Destructive Inspection using imaging technique have many advantages� Global eyesight of the inspected component

� Easier interpretation � Improvement of traceability and storage of the data� Facilitates the communication between NDT provider and customer

� Imaging techniques may sometime represent an “clean” alternative to traditional

techniques� Ultrasonic TOFD and Phased array imaging /X-ray testing (Standardization?)� Increase of the sensitivity/conventional UT� Next future: imaging improvement with matrix transducers� In the future: Thermal infrared-metallic component /MPI and Dye penetrant?

� The signal processing is now integrated in advanced equipment (Saul/M2M…..)

� Ultrasonic inspection would benefit of the simulation:� Optimization of the part at conception stage

� Reduction of the need of prototype parts� 3D computed Tomography - internal view of the component

Conclusions & Perspectives

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Thank you for your attention

Do you have some questions?