- 1. FML impact damage characterisation Fabien Lonard
Introduction FML background Damage characterisationImpact damage
characterisation of bre metal laminates by X-ray computed
tomographyExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damageFabien Lonard1 Yu Shi2
Costantinos Soutis3 Philip J. Withers1 Christophe Pinna2Composite
damageSummary Discussion1 Henry Moseley X-ray Imaging Facility, The
University of Manchester 2 Department of Mechanical Engineering
(Aerospace), The University of Sheeld 3 Aerospace Research
Institute, The University of Manchester5 th Conference on
Industrial Computed Tomography Upper Austrian University of Applied
Sciences Wels, Austria, February 26 th 20141/18FML impact damage
characterisationForward
2. FML impact damage characterisationFibre Metal LaminatesFabien
Lonard Introduction FML background Damage
characterisationExperimentalDenition Fibre Metal Laminates or FMLs
are multi-layered materials based on a stacked arrangement of
aluminium alloys and bre-reinforced composite materials.Material
and testing X-ray computed tomographyResults 2D data Metal
damageFMLs take advantages of metal and bre-reinforced composites,
providing superior mechanical properties to the conventional lamina
consisting only of bre-reinforced lamina or monolithic aluminium
alloys.Composite damageSummary DiscussionFML lay-up.1 1TU Delf
website http://www.lr.tudelft.nl 2/18FML impact damage
characterisationBackForward 3. FML impact damage
characterisationFML for aerospace applicationsFabien Lonard
Introduction FML background Damage characterisationExperimental
Material and testing X-ray computed tomographyResults 2D data Metal
damage Composite damageSummary DiscussionMetal/bre applications in
Airbus A380 airplane.2 2 A. Vlot & J.W. Gunnink; Fibre Metal
Laminates, Kluwer Academic Publishers, Dordrecht, The Netherlands,
2001. 3/18FML impact damage characterisationBackForward 4. FML
impact damage characterisationImportance of impact damage
characterisationFabien Lonard IntroductionImpacts are a relevant
source of damage for aircraft throughout their life. Mainly:FML
backgroundhigh velocity impacts: mainly in-ight, like bird strikes
and hail impactsDamage characterisationlow velocity impacts:
related to airport and maintenance operations like dropping tools,
cargo containers handling and crashes with airport
vehiclesExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
Discussion3TU Delf website http://www.lr.tudelft.nl 4/18FML impact
damage characterisationBackForward 5. FML impact damage
characterisationImportance of impact damage characterisationFabien
Lonard IntroductionImpacts are a relevant source of damage for
aircraft throughout their life. Mainly:FML backgroundhigh velocity
impacts: mainly in-ight, like bird strikes and hail impactsDamage
characterisationlow velocity impacts: related to airport and
maintenance operations like dropping tools, cargo containers
handling and crashes with airport vehiclesExperimental Material and
testing X-ray computed tomographyResults 2D data Metal damage
Composite damageSummary DiscussionLeading edge of an horizontal
stabilizer dented by hail.3 3TU Delf website
http://www.lr.tudelft.nl 4/18FML impact damage
characterisationBackForward 6. FML impact damage
characterisationImportance of impact damage characterisationFabien
Lonard IntroductionImpacts are a relevant source of damage for
aircraft throughout their life. Mainly:FML backgroundhigh velocity
impacts: mainly in-ight, like bird strikes and hail impactsDamage
characterisationlow velocity impacts: related to airport and
maintenance operations like dropping tools, cargo containers
handling and crashes with airport vehiclesExperimental Material and
testing X-ray computed tomographyResults 2D data Metal damage
Composite damageSummary DiscussionHeavy damage on a stabiliser
produced by bird strike.3Leading edge of an horizontal stabilizer
dented by hail.3 3TU Delf website http://www.lr.tudelft.nl 4/18FML
impact damage characterisationBackForward 7. FML impact damage
characterisationFML and X-ray CTFabien Lonard Introduction FML
background Damage characterisationExperimental Material and
testingLiterature Impact damage mainly characterised by sectioning
or C-scan. X-ray tomography mentioned4 but used only as detailed
cross-section analysis technique, no 3D information extracted.X-ray
computed tomographyResults 2D data Metal damage Composite
damageSummary Discussion4 K. Dragan, J. Bienia, et al.; Inspection
methods for quality control of bre metal laminates (FML) in
aerospace components. Composites, 12(4), 272-278, 2012. 5/18FML
impact damage characterisationBackForward 8. FML impact damage
characterisationFML and X-ray CTFabien Lonard Introduction FML
background Damage characterisationExperimental Material and
testingLiterature Impact damage mainly characterised by sectioning
or C-scan. X-ray tomography mentioned4 but used only as detailed
cross-section analysis technique, no 3D information extracted.X-ray
computed tomographyResults 2D data Metal damage Composite
damageSummary DiscussionChallenge To have enough X-ray energy to
penetrate fully the metal layers whilst still obtaining a good
contrast between the low density materials, i.e. polymer composite
matrix and cracks/voids.4 K. Dragan, J. Bienia, et al.; Inspection
methods for quality control of bre metal laminates (FML) in
aerospace components. Composites, 12(4), 272-278, 2012. 5/18FML
impact damage characterisationBackForward 9. FML impact damage
characterisationFML and X-ray CTFabien Lonard Introduction FML
background Damage characterisationExperimental Material and
testingLiterature Impact damage mainly characterised by sectioning
or C-scan. X-ray tomography mentioned4 but used only as detailed
cross-section analysis technique, no 3D information extracted.X-ray
computed tomographyResults 2D data Metal damage Composite
damageSummary DiscussionChallenge To have enough X-ray energy to
penetrate fully the metal layers whilst still obtaining a good
contrast between the low density materials, i.e. polymer composite
matrix and cracks/voids. This study We demonstrate how CT can be
employed to successfully assess impact damage in FML in a
three-dimensional non-destructive manner; and obtain information
conventional techniques cannot provide. 4 K. Dragan, J. Bienia, et
al.; Inspection methods for quality control of bre metal laminates
(FML) in aerospace components. Composites, 12(4), 272-278, 2012.
5/18FML impact damage characterisationBackForward 10. FML impact
damage characterisationMaterial and testingFabien Lonard
Introduction FML backgroundSpecimens:Damage
characterisationExperimental Material and testingCARALL: CARbon bre
reinforced polymer/ Reinforced ALuminium Laminate carbon bre/epoxy
layers (HTS40/977-2) with aluminium Al1050 layersX-ray computed
tomographyResults 2D data2 dierent structures: CARALL 3-3/2-0.5 and
CARALL 5-3/2-0.5 FML used as primary structures in aerospace
applicationsMetal damage Composite damageSummary DiscussionImpact
testing: impact testing following ASTM D7136/D7136M-07 standard5
impact energies of 9.8 J, 19.6 J, and 29.4 J simulates low velocity
impact thin laminates experience during service5 ASTM
D7136/D7136M-07; Standard test method for measuring the damage
resistance of a bre-reinforced polymer matrix composite to a
drop-weight impact event, Philadelphia: American Society for
Testing and Materials, 2007. 6/18FML impact damage
characterisationBackForward 11. FML impact damage
characterisationSpecimen structuresFabien LonardTwo CARALL
structures are under investigation: Introduction FML
backgroundImpact directionDamage
characterisationExperimentalStructure 3-3/2-0.5
includes:AluminiumMaterial and testing X-ray computed tomography3
layers of Al each layer is 500 m thickMTA 240Results0 ply2D data90
plyMetal damage Composite damage2 bre/epoxy layers each ply is 250
m thick 0 /90 bre orientationMTA 240SummaryAluminiumDiscussion MTA
240MTA 240 used as adhesive between metal and polymer90 ply 0 plyAl
rolling direction aligned with 0 pliesMTA 240AluminiumCARALL
3-3/2-0.5 7/18FML impact damage characterisationBackForward 12. FML
impact damage characterisationSpecimen structuresFabien LonardTwo
CARALL structures are under investigation: Introduction FML
backgroundImpact directionDamage characterisationExperimental
Material and testingStructure 5-3/2-0.5 includes:AluminiumX-ray
computed tomographyResults 2D data3 layers of Al each layer is 500
m thickMTA 240 0 ply 90 ply 90 ply 0 plyMetal damage Composite
damageSummary Discussion2 bre/epoxy layers each ply is 125 m thick
0 /90 /90 /0 bre orientationMTA 240 Aluminium MTA 240 0 ply 90 ply
90 ply 0 plyMTA 240 used as adhesive between metal and polymer Al
rolling direction aligned with 0 pliesMTA 240AluminiumCARALL
5-3/2-0.5 7/18FML impact damage characterisationBackForward 13. FML
impact damage characterisationSpecimen structuresFabien LonardTwo
CARALL structures are under investigation: Introduction FML
backgroundImpact directionImpact directionDamage
characterisationExperimental AluminiumMaterial and
testingAluminiumX-ray computed tomographyMTA 240ResultsMTA 240 0
ply 90 ply 90 ply 0 ply0 ply2D data90 plyMetal damage Composite
damageMTA 240SummaryMTA 240AluminiumAluminiumDiscussion MTA 240MTA
240 0 ply 90 ply 90 ply 0 ply90 ply 0 ply MTA 240MTA
240AluminiumAluminiumCARALL 3-3/2-0.5CARALL 5-3/2-0.5Both panels
have the same total thickness. 7/18FML impact damage
characterisationBackForward 14. FML impact damage
characterisationData acquisitionFabien Lonard Introduction FML
backgroundScanning was performed at the Henry Moseley X-ray Imaging
Facility on the Nikon Metrology 225/320 kV Custom Bay system:Damage
characterisationExperimentalSample dimensions: 45 45 3.5 mm (9.8 J)
and 70 70 3.5 mm (19.629.4 J)Material and testing X-ray computed
tomographyResults 2D dataVoxel size: 22.5 m (9.8 J) and 34.7 m
(19.6 J and 29.4 J)Metal damage Composite damageSummaryTarget:
MoDiscussionVoltage: 90 kV Current: 110 A Filtration: 1 mm Al
Exposure time: 1000 ms 3142 projectionsNikon Metrology 225/320 kV
Custom Bay.6Acquisition time: 53 6Henry Moseley X-ray Imaging
Facility website http://www.mxif.manchester.ac.uk/ 8/18FML impact
damage characterisationBackForward 15. FML impact damage
characterisationData processingFabien Lonard IntroductionThe data
visualisation and processing was performed with Avizo Fire version
7.17 .FML background Damage characterisationThe segmentation was
based on manual seeding followed by a watershed
algorithm.Experimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
DiscussionThe methodology of through-thickness impact damage
characterisation has been adapted from the work of Lonard et al.8 ,
used for assessing impact damage in composite panels. It is based
on the damage distance transform by regards to a reference surface.
7Avizo Fire specications, Visualization Sciences Group website
http://www.vsg3d.com/avizo/fire F. Lonard, J. Stein, et al.; 3D
damage characterisation in composite impacted panels by laboratory
X-ray computed tomography. 1st International Conference on
Tomography of Materials and Structures, Ghent (Belgium), July 1-5,
2013. 89/18FML impact damage characterisationBackForward 16. FML
impact damage characterisationRaw dataFabien Lonard Introduction
FML backgroundSlices show that the several damage modes relevant to
FMLs can be identied: 1aluminium yieldingDamage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
Discussiona) 3-3/2-0.5 XY planeb) 5-3/2-0.5 XY planec) 3-3/2-0.5 XZ
planed) 5-3/2-0.5 XZ planeExamples of slice showing damage (impact
face on top) for 10 J impact energy. 10/18FML impact damage
characterisationBackForward 17. FML impact damage
characterisationRaw dataFabien Lonard Introduction FML
backgroundSlices show that the several damage modes relevant to
FMLs can be identied: 1aluminium yielding2shear-induced polymer
matrix crackingDamage characterisationExperimental Material and
testing X-ray computed tomographyResults 2D data Metal damage
Composite damageSummary Discussiona) 3-3/2-0.5 XY planeb) 5-3/2-0.5
XY planec) 3-3/2-0.5 XZ planed) 5-3/2-0.5 XZ planeExamples of slice
showing damage (impact face on top) for 10 J impact energy.
10/18FML impact damage characterisationBackForward 18. FML impact
damage characterisationRaw dataFabien Lonard Introduction FML
backgroundSlices show that the several damage modes relevant to
FMLs can be identied: 1aluminium yielding2shear-induced polymer
matrix cracking3interlaminar cracking (or delaminations)Damage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
Discussiona) 3-3/2-0.5 XY planeb) 5-3/2-0.5 XY planec) 3-3/2-0.5 XZ
planed) 5-3/2-0.5 XZ planeExamples of slice showing damage (impact
face on top) for 10 J impact energy. 10/18FML impact damage
characterisationBackForward 19. FML impact damage
characterisationRaw dataFabien Lonard IntroductionSlices show that
the several damage modes relevant to FMLs can be identied:
1aluminium yielding2shear-induced polymer matrix
cracking3interlaminar cracking (or delaminations)4FML
backgroundbending-induced tensile polymer matrix crackingDamage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
Discussiona) 3-3/2-0.5 XY planeb) 5-3/2-0.5 XY planec) 3-3/2-0.5 XZ
planed) 5-3/2-0.5 XZ planeExamples of slice showing damage (impact
face on top) for 10 J impact energy. 10/18FML impact damage
characterisationBackForward 20. FML impact damage
characterisationDamage in metal layersFabien Lonard Introduction
FML backgroundMetal impact damageDamage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
DiscussionDent deepens and global permanent plate exure increases
with impact energy.a) 3-3/2-0.5 at 10 JDamage always maximum for
bottom Al layer Necking appearing from 10 J and cracking developing
along the Al rolling direction above 20 J.a) 3-3/2-0.5 at 20 JNo
quantitative data yet.a) 3-3/2-0.5 at 30 JEvolution of damage in
metal layers. 11/18FML impact damage characterisationBackForward
21. FML impact damage characterisationDamage in metal layersFabien
Lonard IntroductionEach Al layer can be assessed individually in
3D:FML background Damage characterisationExperimental Material and
testing X-ray computed tomographyResults 2D data Metal damage
Composite damageSummary Discussion3-3/2-0.5 at 10 J. 12/18FML
impact damage characterisationBackForward 22. FML impact damage
characterisationDamage in metal layersFabien Lonard
IntroductionEach Al layer can be assessed individually in 3D:FML
background Damage characterisationExperimental Material and testing
X-ray computed tomographyResults 2D data Metal damage Composite
damageSummary Discussion3-3/2-0.5 at 20 J. 12/18FML impact damage
characterisationBackForward 23. FML impact damage
characterisationDamage in metal layersFabien Lonard
IntroductionEach Al layer can be assessed individually in 3D:FML
background Damage characterisationExperimental Material and testing
X-ray computed tomographyResults 2D data Metal damage Composite
damageSummary Discussion3-3/2-0.5 at 30 J. 12/18FML impact damage
characterisationBackForward 24. FML impact damage
characterisationDamage in composite layersFabien Lonard
Introduction FML background Damage characterisationThe 3D rendering
of the damage illustrates the dierent damage morphologies obtained
for the two structures:Experimental Material and testing X-ray
computed tomographyResults 2D data Metal damage Composite
damageSummary Discussiona) 3-3/2-0.5 (250 m plies)b) 5-3/2-0.5 (125
m plies)3D rendering of impact damage in composite layers for 10 J
impact energy.13/18FML impact damage characterisationBackForward
25. FML impact damage characterisationSpecimen proleFabien Lonard
Introduction FML backgroundThe full specimen prole is obtained to
understand the location of the damage within the bre/epoxy
layers:Damage characterisationExperimental Material and testing
X-ray computed tomographyResults 2D data Metal damage Composite
damageSummary Discussiona) 3-3/2-0.5 (250 m plies)b) 5-3/2-0.5 (125
m plies)Full specimen prole for a 10 J impact energy.14/18FML
impact damage characterisationBackForward 26. FML impact damage
characterisationSpecimen proleFabien Lonard Introduction FML
backgroundThe full specimen prole is obtained to understand the
location of the damage within the bre/epoxy layers:Damage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
Discussiona) 3-3/2-0.5 (250 m plies)b) 5-3/2-0.5 (125 m plies)Full
specimen prole for a 10 J impact energy. Most of the damage lies
within the second composite layer, with clear dierences between the
two structure. 14/18FML impact damage characterisationBackForward
27. FML impact damage characterisationDamage prole of second
composite layerFabien Lonard Introduction FML backgroundA more
accurate location of the damage within the second composite layer
is obtained by taking the second Al layer as a reference for the
distance transform:Damage characterisationExperimental Material and
testing X-ray computed tomographyResults 2D data Metal damage
Composite damageSummary Discussiona) 3-3/2-0.5 (250 m plies)b)
5-3/2-0.5 (125 m plies)Damage volume prole with second (central)
aluminium layer as reference.15/18FML impact damage
characterisationBackForward 28. FML impact damage
characterisationDamage prole of second composite layerFabien Lonard
Introduction FML backgroundA more accurate location of the damage
within the second composite layer is obtained by taking the second
Al layer as a reference for the distance transform:Damage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummary
Discussiona) 3-3/2-0.5 (250 m plies)b) 5-3/2-0.5 (125 m
plies)Damage volume prole with second (central) aluminium layer as
reference. The damage proles can be used to automatically segment
the damage volume based on the damage type (crack vs delamination).
15/18FML impact damage characterisationBackForward 29. FML impact
damage characterisationSeparation of segmented impact damageFabien
Lonard Introduction FML background Damage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damage Composite damageSummarya)
3-3/2-0.5 (impact face on top)b) 5-3/2-0.5 (impact face on
top)Discussionc) 3-3/2-0.5 (impact face on bottom)d) 5-3/2-0.5
(impact face on bottom) 16/18FML impact damage
characterisationBackForward 30. FML impact damage
characterisationSummaryFabien Lonard Introduction FML
backgroundThis paper presents the rst 3D CT assessment of impact
damage in coupon size CARALL bre metal laminates.Damage
characterisationExperimental Material and testing X-ray computed
tomographyResults 2D data Metal damageCT was applied to provide
novel 3D insights as to the impact damage produced in both metal
and polymer layers of FML: metal: presence of yielding/cracking can
be assessed, visualised and localised in 3DComposite damageSummary
Discussioncomposite: impact damage can be segmented and rendered in
3D, showing the dierent damage mechanisms involved (cracking and
delamination) The distance transform methodology9 was employed to
obtain through thickness damage proles. These proles can be used to
automatically separate the segmented impact damage based on damage
type. 9 F. Lonard, J. Stein, et al.; 3D damage characterisation in
composite impacted panels by laboratory X-ray computed tomography.
1st International Conference on Tomography of Materials and
Structures, Ghent (Belgium), July 1-5, 2013. 17/18FML impact damage
characterisationBackForward 31. FML impact damage
characterisationDiscussionFabien Lonard Introduction FML
backgroundThank you!Damage characterisationExperimental Material
and testing X-ray computed tomographyResults 2D data Metal damage
Composite damageSummary Discussionhttp://www.nickveasey.comFabien
Lonard [email protected]/18FML impact damage
characterisationBack
