Upload
others
View
13
Download
0
Embed Size (px)
Citation preview
© Fraunhofer
Nondestructive Characterization and Evaluation of Adhesive Bondings
- R&D and Applications -
European Adhesive Engineer © [email protected] Fon +49 9302 / 3610Fraunhofer IZFP | Campus E3 1 | 66123 Saarbrücken, Germanywww.izfp.fraunhofer.de
Prof. Dr. Bernd Valeske
AIST Tsukuba, TIA-Fraunhofer Workshop, Oct. 5th 2017
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de2
Fraunhofer IZFP : R&D for Applied Research
Fraunhofer Mission
New Business Models
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de3
OUTLINE
Objectives and Philosophy (NDT Strategy)
Classical NDT for Defect Detection
Extended NDT (E-NDT) for Characterization ofAdhesive‘s & Adhesion Properties
Summary & Conclusions
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de4
Nondestructive Monitoring & Testing throughout the complete Process Chain
Original Materials:joining components + surfaces + (bulk) adhesive
Bonding Process:application of adhesive,joining,curing
„Finalized“ Joint:(before delivery)
completely set-upand cured bonded joint
Pre-Process:integrity of all materials,residual stresses in joining materials, surface state ofsubstrates, viscosity of adhesive/ state of storage
In-Process:rheological properties, change of viscosity, application of adhesive(geometry, position, thickness of bondline), cavities, inclusionsunsufficient wetting, curing
Post-Process:cohesive / adhesive failure, „defects“ (delaminations, disbonds, pores, „weak bonds“)thickness & geometry ofbondline, degree offilling
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de5
Adhesion
Cohesion
Microstructure
Molecularmobility
Geomety
Substrates
Properties
PoresInclusions
DelaminationsCorrosion
Cracks
Defects
In-service
& usage
Processing,
production
intrinsic stresses
, , t, T
Stresses/loads
chemical, physical,Perfor-
mance
Fields of application of non-destructive quality assurance
Classical NDT(Defect Detection)
Extended NDT(E-NDT)
Design
ProcessControl
aging, degradation
Monitoring
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de6
Development
Approval
Production
Quality Control(SPC ↔ 100%)
OperationIn-Service Inspection,
Predictive Maintenance, Repair
ultrasonicsTHz, videoscopy …
Xray CTshearography ,thermography
thermal waveselectro-magneticfields and waves
elasticvibrations & waves
NDT physical interactions (absorption, reflection) of „signals“ withmaterial inhomogeneities („defects“) and appropriate 2D or 3D visualization
Fields of application of classical NDT (defect detection)
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de7
OUTLINE
Objectives and Philosophy (NDT Strategy)
Classical NDT for Defect Detection
Extended NDT (E-NDT) for Characterization ofAdhesive‘s & Adhesion Properties
Summary & Conclusions
Classical NDT(Defect Detection)
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de8
Specimens / master samples withrepresentative artificial defects („reference defects“)
Cap Profile
Flat Sandwich
o Xray CTo Thermographyo Air Coupled Ultrasound
Phased Array Ultrasoundo Shearographyo …
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de9
cavitiesproper bonding
kissing bonds lack of adhesive restriction / retraction
NDT validation with more than 100 investigation programs
Different EP and PU adhesives (bond thickness: 1,5 … 3 mm)
Various material combinations: Steel, Aluminium, Glass, CFRP, GFRP, Polymers
500 mm
50 mm
top side
50 mm
bottom side~ 20 mm ~.50 mm
bondline
Specimen / master sample withrepresentative artificial defects („reference defects“)
wormholes
( 1 und 2mm)
bondline
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de10
wormholesrestriction / retraction
of adhesive cavities, d 3,5 mm
restriction / retractionof adhesive
cavities, d 0,5 mm cavities, d 0,5 mm
squeezingexcesss adhesive
lack ofadhesive
squeezingexcesss adhesive
CFRP / EP / St
Xray CT
Air coupledultrasound
CFRP / EP / Al
NDT for post-process defect detection – Examples ofextensive validation and selection of best suitable inspection methodfor more than 30 material and adhesive combinations
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de11
Air Coupled Ultrasound (contactless)
cavities
restriction ofadhesive
lack ofadhesive
wormholes
cavities
restriction ofadhesive
lack ofadhesive
wormholes
Kissing Bonddetection
unstressed state
sample under load
KissingBond
Bondline 2
Bondline 1
Bondline 1
Bondline 2
top views
Al / EP / St
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de12
NDT for post-process defect detection – Examples ofextensive validation and selection of best suitable inspection methodfor more than 30 material and adhesive combinations
Thermography
Phased ArrayUltrasound
St / EP / GPRP
St / EP / CPRP
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de13
Automated Evaluation (specific signal & image processing) automated detection of bond line + defects / suspicious RoI‘s
no defects defects & border artefacts defects
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de14
Advanced Algorithms and NDT Analysis Software to automatically evaluate the statistics of defect indications specialized segmentation & blob analysis
Feature extraction andclassification of essential defect and bondline parameters
advanced signal& image processing
specialized featureextraction & analysis
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de15
Input DataRaw Data byrobotizedThermographicInspection Output
Feature Extractionby Advanced Signal
Processing and Pattern Recognition
Bonding & Bondline Okay
Missing Adhesive, Debondg
Defect in Bondline(pores, wormholes…)
Advanced Algorithms and NDT Analysis Software to automatically evaluate the statistics of defect indications specialized segmentation & blob analysis
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de16
Results of test program (exemplary)
Benchmark Results of Different NDT methods / Capability
Test program + NDT Capability Benchmark
Datasheets: Capability for quantitative defect detection
Kanäle
Anzahl Anzahl Anzahl Anzahl
Kanal 1 2 3 4 5 6 7 8 Kanal 1 2 3 4 5 6 7 8 Kanal 1 2 3 4 5 6 7 8 Kanal 1 2 3 4 5 6
Länge / mm 21,5 21,5 20,8 21,1 20 13,9 18,5 21,1 Länge / mm (21,5) (21,5) (20,8) (21,1) (20,0) (13,9) (18,5) (21,1) Länge 17,3 17,2 17,8 17,2 17,4 12,9 17,6 17,5 Länge ca. 20 ca. 20 ca. 20 ca. 20 ca. 20 ca. 20
Breite / mm 2,4 3,0 2,5 2,5 1,2 1,4 1,5 1,6 Breite / mm 2,4 3,0 2,5 2,5 1,2 1,4 1,5 1,6 Breite 2,4 2,4 2,3 2,4 1,6 2,3 1,6 1,6 Breite
Tiefenlage / mm 3,3 3,3 3,3 3,3 3,8 3,3 3,9 3,9 Tiefenlage / mm Tiefenlage Tiefenlage
Nachweis Nachweis Nachweis Nachweis
Styropor‐Einschlüsse
Anzahl Anzahl Anzahl Anzahl
Größe von: bis: Größe von: bis: Größe von: bis: Größe von: bis:
Tiefenlage von: bis: Tiefenlage Tiefenlage Tiefenlage
Nachweis Nachweis Nachweis Nachweis
Klebnahtunterbrechung
Länge Länge Länge Länge
Nachweis Nachweis Nachweis Nachweis
Klebnahtrückfall
Ausführung Ausführung Ausführung Ausführung
Rückfalltiefe 1 Rückfalltiefe 1 Rückfalltiefe 1 Rückfalltiefe 1
Bereichslänge 1 Bereichslänge 1 Bereichslänge 1 Bereichslänge 1
Rückfalltiefe 2 Rückfalltiefe 2 Rückfalltiefe 2 Rückfalltiefe 2
Bereichslänge 2 Bereichslänge 2 Bereichslänge 2 Bereichslänge 2
Fehlender
Flächenanteil
Fehlender
Flächenanteil
Fehlender
Flächenanteil
Fehlender
Flächenanteil
Nachweis Nachweis Nachweis Nachweis
Werkstoffkombi 5 ‐ CFK auf Alu ‐ Probe P06 H‐AlKT‐CFPr‐2P‐01
FehlerRöntgen‐CT Radiographie Luft‐US
Verfahren
Thermografie
7 7 von 7 8 von 8
keine Aussage möglich (Transmission) keine Aussage möglich (Transmission)
100% 100% 100%
19 19
11 Anzeigen von 19 Einschlüssen (teilweise
Überdeckung/Überlagerung/Verschmelzung, 19
Einschlüsse nicht getrennt nachweisbar)
0,4 mm 2,9 mm 0,4 mm 2,9 mm 10,6 mm1,1 mm
2,1 mm 4,7 mm keine Aussage möglich (Transmission) keine Aussage möglich (Transmission)
100% 100% 85% (allerdings nicht einzeln nachweisbar)
46 mm 46 mm 46,5 mm
100% 100% 100%
zweiseitig zweiseitig zweiseitig
5 mm 5 mm 4,2 mm
ca. (438 + 666) mm²
134 mm 130 mm 132,7 mm
5 mm Abschattung Hutprofil 5,9 mm
6 von 8
keine Aussage möglich (integraler Wärmefluss)
80%
ca. 2
‐ ‐
nicht auswertbar
keine Aussage möglich (integraler Wärmefluss)
10%
ca. 40 mm
100%
einseitig
Anmerkung: Die Länge der Kanäle kann bei Radiographie nur unter
Zuhilfenahme der geometrischen Abmessungen der Probe
(Abschattungskanten) sowie Vorkenntnissen aus der Röntgen‐CT
exakt bestimmt werden. Daher stehen die Werte in Klammern.
Anmerkung: Das Vermessen von Merkmalen in thermographischen Aufnahmen stellt eine verfahrensbedingte
Schwierigkeit dar und ist derzeit auch kein qualifiziertes Verfahren zur Bestimmung von Fehlergrößen. Infolge des
lateralen Wärmeflusses kommt es zur "Verschmierung" von klaren Kanten, so dass die bestimmten Werte der
Merkmale oft deutlich von den wahren Fehlergrößen abweichen können (unscharfe Randausbildung). Es ist zu
beachten, dass aus prüfphysikalischen Randbedingungen, die Anzeigengröße der Merkmale nicht mit der wahren
Fehlergröße gleichzusetzen ist.
50%
nicht detektierbar
nicht detektierbar
ca. 9 mm
ca. 150 mm
ca. 1060 mm²
100% 100% 100%
161 mm Abschattung Hutprofil 143,7 mm
(540+700) mm² (430+???) mm²
Concept for implementation of NDT test set-ups
windshieldspare wheel
well
liftgate
roof
NDT supportedby robots
Sh
ea
rog
rap
hy
Th
erm
og
rap
hy
Air
-co
up
led
Ult
raso
nic
X-r
ay
-CT
Ph
oto
gra
ph
ic P
ictu
re
Rating matrix of defect detection
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de17
R&D / Contract Research for the German Automotive Consortium
Validation of Prototypes
Analysis of capability for different NDT Technologies
System selection and specific development
NDT System prototypes
Reference Samples
spare wheel well
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de18
Video clip: Spare wheel well (GFRP / PU / Al)
Video clip: Windshield (VSG / PU / St)
New:Fully automated non-destructive testing of real vehicle structures
Lab-Prototypes: NDT test set-up at real components
Long-term strategic R&D partnership
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de20
OUTLINE
Objectives and Philosophy (NDT Strategy)
Classical NDT for Defect Detection
Extended NDT (E-NDT) for Characterization ofAdhesive‘s & Adhesion Properties
Summary & ConclusionsExtended NDT
(E-NDT)
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de21
One Sided Access Nuclear Magnetic Resonance Technique (OSA-NMR)
NMR Inspect © NMR-Technique for components andmaterials inspection In-Process E-NDT
Resonance excitation of H1-Spins by suitablepulse sequencies
Informations concerning therelaxation behaviour in polymers(e.g. T2-relaxation time)
in the fluid state of adhesivesin the solid statein the visco-elastic state
Characterization of molecular dynamicsin polymer adhesives
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de22
Comparison of different types of NMR for Imaging vs. NDT
“Classical“ NMR (lab method, MRI)
NMR one-sided access technique (NDT for components)IZFP
Magnet
Magnet
Spu
le
Spu
le
Spule
Magnet
MagnetMagnetic field B0
HF field B1
Measurement layer (sensitive volume)Total measurement areaTest “object”
Magnetic field B0
HF field B1
Measurement layer (sensitive volume)Total measurement areaTest object
coil
coil
coil
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de23
Example: Curing of Araldit 2014 (2K EP) Process Control
Signal Ratio of Hahn-Echo / Solid-Echo („liquid / solid“ – dynamics)
3
5
7
9
11
13
15
0 50 100 150 200 250 300Aushärtungszeit, t A [min]
Spin
ech
o-S
ign
al,
SH
E u
nd
SS
E in
[V
]
1
1,5
2
2,5
3
3,5S
SE/S
HE in
[V
/V]
DSC: 52 % Aushärtung
curing time [min]
OSA-NMR In-Process NDT of Polymer Properties (Curing Process)
DSC: 52 % degree of cure
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de24
OSA-NMR for characterization of adhesive curing
security glass (wind screen) bonded with 2-part PU onto
Al-Sheet or Polymer Plate
dimensions of samples: ~ 10 cm x 10 cm, thickness of bonding: ~ 3 mm
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de25
OSA-NMR for monitoring the Curing in Adhesive Joints
appropriate mixing ratio (50:50)
excess of curing agent (70:30)
Adhesive Curing
curing time [min]0 min 300 min
pro
cess
ed
measu
rem
en
tsi
gn
al
[a.u
.]
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de26
New Approach for Testing of the Bond Performance:Laser Bond Inspection / Laser Proof Testing
Laser Bond Inspection Ph.D. Bastien Ehrhart (in cooperation with Fraunhofer IFAM and CNRS-ENSMA, Poitiers)
testing principle: generationof small defects by LASER shock waves for weak bonds(strength below criticalthreshold value)
new approach forclassification of degrees ofbond quality (bond strength)
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de27
Systematic correlation of critical LASER threshold values necessaryfor debonding (opening of weak bonds) compared to G1C - value
Examples for inspection of weak bonds in CFRP samples [source: Ph.D. Bastien Ehrhart, 2015]
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de28
OUTLINE
Objectives and Philosophy (NDT Strategy)
Classical NDT for Defect Detection
Extended NDT (E-NDT) for Characterization ofAdhesive‘s & Adhesion Properties
Summary & Conclusions
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de29
Summary & Conclusions
Nondestructive inspection of bond quality & bond performance needs both:
necessarily the detection of defects by classical NDTand
additionally the evaluation of adhesive‘s polymer properties (correct cure,degradation / aging), i.e. performance of adhesion E-NDT
In many cases: defect detection is sufficient for rejection of bad quality advanced NDT developments with automated evaluation / signal processing succesful validation of NDT methods, selection of best NDT technology
for a broad variety of material combinations and adhesives
New approaches for structural adhesive bonding or where „safe life“ design philosopy needs full evaluation of bond performance / nondestructivemonitoring of adhesive bonds in construction components & assemblies promising E-NDT methods
(e.g. OSA-NMR, upscaling of spectroscopic methods) sensing of bond strength e.g. by shock waves or advanced ultrasound
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de30
Summary & Conclusions
Nondestructive Quality Control of Adhesive Bonding
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de31
Acknowledgements
To all my colleagues at Fraunhofer IZFP for contributions inR&D works and in the recent projects
Dr. Bastien Ehrhart, and the corresponding partner institutions Fraunhofer IFAM, CNRS-ENSMA (Poitiers, France) and AIRBUS (Bremen, Germany)
To the research partners from industry over the last years, mainly the GERMAN Automotive OEMs (Porsche, AUDI, Volkswagen, BMW andDaimler /Mercedes-Benz)
To the European Commission for R&D Fundingmainly for the FP7-Project „ENCOMB“ and the CORNET-Project „ZeDeMAB“
© Fraunhofer
Tsukuba / JAPANOct 3rd – 5th 2017
[email protected] Fon +49 9302 / 3610
www.izfp.fraunhofer.de
Non-Destructive Monitoring of Adhesive Bonding
by Smart Sensors and NDE 4.0
Prof. Dr. Bernd [email protected] Fon +49 9302 / 3610Fraunhofer IZFP | Campus E3 1 | 66123 Saarbrücken, Germanywww.izfp.fraunhofer.de