Post on 31-Mar-2015
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
New Standards. Together
Presented byKeith Phillips / Head of NDT & Mechanical Testing - UK September 2013
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Contents
• Developments on Flexible UT Arrays to optimize curved surface testing
• Single Side Omega Stringer Integrity Check• Advanced Simple to Use Quick Check Methods
• Line Tool• DolphiCam
• Paint thickness measurement on CFRP• Eddy Current with adapted probe (if LSP is present)• Microwave for all cases
• Advanced new wheel probe for curved surfaces• Fast CFRP-Nomex-Sandwich inspection with PAUT
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Flexible UT Array to access narrow curved surfaces
Objective:• Optimised and improved capability for inspection
of radius components • Using a new flexible probe coupling technology • combined with a linear transducer array based on
a flexible foil with sensors
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Flexible Array
First 8 element flex array
Next a 64 element flex array
Finally coupling and housing are key elements in the design for easy handling
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Flexible Array – Demo on Wing panel
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Single Side Omega Stringer Integrity Check
Objective:• Fast inspection method to check a hidden and for
direct NDT inaccessible structure part, which might be damaged with out any detectable/visible impact at the outer skin.
• Use of an advanced commercially available PAUT approach with an advanced PAUT system
• No need to know the exact position of the hidden structure
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Single Side Omega Stringer Integrity Check A Conventional Single Transducer Approach
A-Scan, Stringer with delamination
A-Scan, Stringer no damage
Conventional Transducers – it works but:awful to perform this inspection!
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Different Array Approaches
Optimized Aperture and Angle of Incidence
Guided Wave approach to becomeindependent from stringer position
Most simple –perpendicular - approach
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
PAUT – a simple direct inspection approach
- B-Scan configuration with pitch/catch
- Linear scanning with optimized angle of incident
- 1 MHz probe in contact (water delay line possible)
Indication of the
UT signal
travelling along the
Omega-STRG
64 Elements 1 MHz probe
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
PAUT – Approach with beam steering (Guided Wave)
Sector-Scan configuration with pitch/catch , with beam steering from 0° - 80°.
Combining a PAUT instrument and a 64 Element 1 MHz Probe
with water box delay line for easy coupling.
Use of Wheel probe to be checked later
current wheels too narrow
(wheel internal delay too big at current systems)
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Advanced Simple to Use Quick Check Methods
• Line Tool (EADS IW (Innovation Works)) for AIRBUS based on UT Array in a Wheel ProbeTraffic Light Human InterfaceTo be used by Non NDT mechanicsUsing wheel probe offering fast scanning
• DolphiCam (DolphiTech (N) & EADS IW / TESTIA support)2D Array with volume scan capabilityReduced and simplified controlsCustomized inspection APPs on Tablet PCFull A, B & C-Scan Display Dry coupling 30 x 30 mm field of view
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Line Tool-Concept for Quick Damage Assessment
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
DolphiCam – simple UT imaging method (2D)
Full PAUT inspection system Simple user interface (APP-Style)
Uses simple Tablet PC. Features dry coupling.Full A-,B-,C-scan, all volume data stored (if required)
Gate to slice voxel data setFull post processing with NDT-Kit-Software (Airbus Standard)Fits with OMA (remote inspector)
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
DolphiCam – simple UT imaging method (2D)
DolphiCam uses a novel crossbar approach to excite moving sound fields for areal scanning128 x 128 columns/rows can be switched generating an image 30 x 30 mm with ~16000 pixel4.27 points/mm lateral resolution, recording a full A-scan (CFRP: now 8mm deep – 16 mm follows soon)
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Paint thickness measurement on CFRP
For metallic structures paint thickness measurement is a simple task:
Just take Eddy Current and the lift/off effect.Or Ultrasound – as the acoustical impedance difference is high
For CFRP the conductivity is extremely low, paint has similar acoustical impedance to resin, lot of paint layers give confusing echo pattern.
How to proceed?
Now 2 new successful solutions for a long unsolved task:
• Eddy current with large probe diameter if a copper lightning strike protection is present (the cheaper solution)
• Microwave, in all cases (only a little more costly)
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Lightning strike protection by surface master
• An Expanded Copper Foil“ (ECF) dissipates the electrical energy in case of a lightning strike.
• It is a slit and expanded foil which forms as a net.
External surface protection
Pigmented resin with ECF
CFRP
Expanded Copper Foil (ECF)
< limit !
Paint above ECF must not exceed a maximum thickness !!Must be checked!
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Check of layer thickness above Expanded Copper Foil
EDDY Current Thickness measuring
works only on CFRP containing
metallic LPS / ECF
Typical Thickness Meter has a small ball pen sensor –
result has a high inaccuracy dependig where you hit the surface: on top of a copper cross point or in the hole of the net
Consequence:
A large sensor diameter is the key to reliable measurement.
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Check of layer thickness above Expanded Copper Foil
Together with commercially available equipment suppliers an appropriate sensor was found, which fits to standard gauges:
A 10mm diameter Sensor
Result: It increased the accuracy by more than a magnitude
The bigger sensor now integrates over a larger area with always a sufficient averaging of Copper and CFRP
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Microwave for Paint Thickness measurement
CFRP has a conductivity which rises with frequency. Carbon fibres itself are good conductors, resin is a dielectric medium in between, which lets the fibres act as a capacitor. This is for micro waves a perfect reflector having a very small penetration depth.
Challenge:
• the fibres of the top layer reflect anisotropic
• Specific permittivity of different paint layers(Resin above the first layer of carbon fibres (or ECF LSP) adds to the measured thickness – but this does not matter if checking the LSP quality)
Solution: An advanced and specific microwave antenna design and the well adapted detector unit, which is completely insensitive to permittivity changes and anisotropy (fiber orientation in surface layer)
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
µ wave Paint thickness gauge for CFRP
Microwave is applicable on ECF as well as on the CFRP substrate without ECF.
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
µ-wave paint thickness gauge - accuracy
• Equipment suppliers realised a device with measurement results being independent of permittivity of (non-conductive) layer composition.
• Diagrams show measurement results of layers being partly paint and partly foils.
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Advanced Wheel Probe for Large Area Inspection
• Portable device, quick and easy deployment
• rapid scanning of large areas of even thick CFRP structures
• New hand held approach with easier ergonomics for use under wing or other difficult areas - for vertical or overhead inspection
• Lighter: e.g. simple trolley design for lower weight – approx 1.9 kg
• For curved and geometrically challenging surfaces
• Fixed array height
• Simple guide wheels (could be rollers etc as required), wheel diameter ~ 35 mm, Wheel alignment flexible in scan and index axis, Flexible thin tyre
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
New wheel probe – design challenges
Different Normalization Tasks
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
The new Airbus Wheel Probe
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
General Procedure UT for Sandwich, NTM 51-10-24
A - delamination between plies of outer CFRP skin
B - disbond between outer skin and honeycomb core
C - cracked honeycomb core
D - crushed honeycomb core
E - disbond between inner skin and honeycomb core
F - fluid ingress in honeycomb core
It’s a kind of guided wave approach tuned to core height (membrane length = ½ λ) with equipment fulfilling specific needs:
• Square wave pulse excitation (preferred)• good filter capabilities to tune the receiverTransducer runs best with tuned bandwidth: Debonding causes resonance shift to ¼ λ = octave down. Debonding echoes have > 6db less amplitude
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
1 ... 16 48 ... 6410 ... 25
96 mm probe length (64 Elements)
~ 72 mm Scan (Index) - Axis
1. 5 mm Pitch
1 . . . 64
Back wall echo (BE)
Front surface echo (FSE)
Wasservorlaufstrecke
1L64E96-221L64E96-22
Water Delay Water Delay
1L64E96-22PHASED ARRAY – probe; 1MHz 64Elements (Array: 96mm x 22mm)
Setting for linear electronic scanning for sandwich
The linear scan is achieved by multiplexing of a single, constant Focal Law along a Linear-Array
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
UT Array for CFRP-Nomex-Sandwich Inspection
Method for single transducer to cover even non parallel areas using an average tilt angle – limited to non steep ramp structures - with PAUT also very steep ramp structures can be accessed
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
UT Array for CFRP-Nomex-Sandwich Inspection
A4A Sept 2013Recent developments in NDT from Airbus Engineering
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
UT Array for CFRP-Nomex-Sandwich Inspection
Typical screen setup with TCG, Gates and B & C scan of de-bonded area
Three areas of rear side disbond – C-scan & B scans
Probe configurations:• Direct contact• Water box /water delay• Wheel Probe (1MHz or 0.5 MHz
necessary – not available yet)
A4A Sept 2013Recent developments in NDT from Airbus Engineering