Post on 11-Apr-2018
NARI NJlSA . ' ··•.
NASA AERONAUTICS RESEARCH INSTITUTE
Self-Repairing Fatigue Damage in Metallic Structures for Aerospace Vehicles Using
Shape Memory Alloy Self-Healing {SMASH) Technology
Investigators: M. Clara Wright, NASA KSC1
Michele Manuel, University of Florida2
Terryl Wallace, NASA LaRC3
Andy Newman, NASA LaRC Gate Brinson, Northwestern University4
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Team members: Hunter Henderson2 , Mike Kessler2 , Alanna Eilenberg2• Oscar Figueroa 1112•3,
Jeff Sampson1 , Thad Johnson1 , Fernando Reyes-Tirado1 , Ping ping Zhu4
NASA Aeronautics Research Mission Directorate (ARMD)
2015 LEARN/Seedling Technical Seminar
March 18 & 19, 2015
https://ntrs.nasa.gov/search.jsp?R=20150005789 2018-06-01T05:49:33+00:00Z
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March 18 & 19, 2015
Outline
•The innovation: SMASH technology
•Liquid-assisted self-healing approach
•Impact of the innovation
•Results of the Seedling Phases I and II efforts
•Distribution/dissemination
•Next Steps
... .... NASA A!!ronau! ics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar
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SMASH Technology • Proof of concept: healing em-long cracks with
retention of mechanical properties 95% recovery of ultimate tensile strength
original
healed
Time-lapse video showing actual healing of two overload cracks on a Sn-Bi dog bone specimen.
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Healing continues when the specimen is held at temperature and partial matrix liquefaction fills in any remaining gaps in the crack faces.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 4
Technical Approach
• Liquid-assisted healing of fatigue cracks
• Thermodynamic design of matrix
Binary and Ternary alloy design
Optimization of healing parameters
Optimization or microstructure and mechanical properties
• Complex specimen fabrication
- Multi-layer specimens
• Numerical modeling
At.omtC" P•rC"f'nt. l~tmut.h
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80 Virgin 70
60
l so ~ i 40
~ 30 Post-heal
"' 20
10
0
Bo
0 0.02 004 006
Model validation
Reinforcement architecture
Sttaln
Proof of concept material (top) and mechanical properties of cast AI-Si
material (bottom)
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 5
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Impact of Innovation NJlSA . ' .. ...
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Wrought and cast AI alloys used throughout aircraft
Fatigue and fatigue crack growth at high cycles is concern.
Improve damage tolerance and fatigue life of metals at critical structural locations
Integrated self -repairing approach would improve durability and sustainability of the aerospace material to ensure vehicle safety
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Blue = Under Development
Heinimann eta/, Alcoa, "Advanced Metallic and Hybrid Structural Solutions for Ught-Weight, Long-Uved Aerospace Structures
Aircraft Airworthiness & Sustainment Conference 2012
M arch 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technica l Seminar 6
Results from Phase I NJlSA . ' .. ...
• Self-repair of AI matrix materials
• Fatigue crack repair
Before: Post-Fatigue Testing at KSC ---...
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• 90% recovery of UTS after healing After :Post-HealatUF
• Multiple healing cycles achieved
Fatigue crack healed in POC
Adequate A l-Si microstructure for healing treatment Small-scale multi-ply AI-Cu-Si specimen
March 18 & 19, 2015 NASA Aeronautics Research M ission Directorate 2015 LEARN/Seedling Techn ica l Seminar
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Phase I Fatigue Testing Results • Fatigue testing of matrix
material after various healing cycles to study liquid-assisted portion of healing.
0 .30
-tn <I> ~ u 0.25 c -
After first t est
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After second test After second heal ~
:5 0 .20 0') c <I> -~ u 0.15
~ u
A e Before healing .& After 1st healing D After 2"d healing
0.10 ...____----' __ ___._ __ _.__ _ ____.
0 1000 2000 3000 4000
Cycle count, N (x 1 ,000)
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 8
Phase II Results: Fabrication Technique
• Improved upon diffusion bonding technique developed during Phase I by consolidating using
vacuum hot pressing (VHP)
- Larger scales
- Alignment fixtures
- Multi-step processing
Optimized pressures and temperatures 25 mm
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• Allowed for fabrication of more complex test VHP specimens
. spec1mens
• Ensured adequate SMA reinforcement by X-ray
and computed tomography (CT)
EDM of VHPdogbone CT scan of VHP dog bone
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 9
Phase II Results: Fabrication Technique NJlSA . ' .. ...
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• VHP samples had a similar microstructure to the cast samples with a decrease in porosity.
• Diffusion bonding interface around wires and between "slices" of matrix material were adequate.
Slight bonding line visible, but no contaminants were identified at the interface.
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March 18 & 19, 2015
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Phase II Results: Healing overload cracks
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Comparison of cast and healed mechanical properties
• Increase in ductility 100
when compared to cast - 80 VHP, pre-heal
samples from Phase I ~ 60 ~ -Resulted in necking of (/\
(/\
40 ~
test specimen I.. .w
"' Healing treatment
20
showed filling of crack 0
a 0 _2% = 39.2 Mpa EvHP =9.1 %
0 2 4 6 8 10
Cast overload VHP overload sample pre-healing sample pre- and
post -healing
Strain(%)
VHP overload sample pre- and post-healing Post-Healed Crack
1 II 'Ill 'lq ' 1'' ' 1' ''1''' 1 '~ '1'''1'''1'''1'" 1'''1'''1'''1" 1' 111''" ''I'' '1'''1 o 1 2 3 4 s·
March 18 & 19, 2015 NASA Aeronautics Research M ission Directorate 2015 LEARN/Seedling Techn ica l Seminar 11
Phase II Resu Its: Driver for treatment optimization
• CT stills showing diffusion front of wire within healed overload composite
VHP overload sample post-healing (SMA reinforcements) VHP overload sample post-healing
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar
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Phase II Results: Driver for treatment optimization
• Non-destructive CT vs. destructive metallography showing diffusion of SMA constituents into matrix.
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CT of VHP overload sample post-healing Metallographic specimen of VHP overload sample post-healing
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 13
Phase II Resu Its: Driver for treatment optimization
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• Sacrificial damage of SMA with original healing treatment
X-ray dot map of VHP sample after 24-hr healing treatment. Red = Ni, Green = Si
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X-ray dot maps of VHP sample after 24-hr healing treatment. AI, Si, Ti, and Ni shown
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar
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Phase II Results: Healing Treatment Optimization
• Optimization of:
Microstructure
Mechanical properties
Healing treatment
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VHP specimens after healing treatment for various time periods.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 15
Phase II Results: Healing Treatment Optimization
• Optimization of:
Microstructure
Mechanical properties
Healing treatment
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VHP specimens after healing treatment for various time periods.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 16
Phase II Results: Healing Treatment 0pti m ization
• Optimization of:
Microstructure
Mechanical properties
Healing treatment
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VHP specimens after healing treatment for various time periods.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 17
Phase II Results: Healing Treatment Optimization
• Optimization of:
Microstructure
Mechanical properties
Healing treatment
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VHP specimens after healing treatment for various time periods.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 18
Phase II Results: Healing Treatment Optimization
• Optimization of:
Microstructure
Mechanical properties
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VHP specimens after healing treatment for various time periods.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 19
Phase II Results: Healing Treatment Optimization
• Optimization of:
Microstructure
Mechanical properties
Healing treatment
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VHP specimens after healing treatment for various time periods.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 20
Phase II Results: Healing Treatment Optimization
• Optimization of: Microstructure
Mechanical properties
Healing treatment
• Grain growth and diffusion vs. mechanical properties
1110 _ ____ ___ _l 90·
~ < RO .. .... Percent \VtN Area Rcnliining
e ~ 70 · ... AlSi (MPoJ uncorrected ~ i ~ (,() c.." a.~~o-
-s ~ olO • 5' bl 30 ~ ..:! 20-.l!
10 -
o------------~--~-----------10 100 1000
lluhna 'lome Inion)
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Optimization of healing treatment VHP specimens after healing treatment for various time periods.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 21
Phase II Results: Fatigue Crack Growth NJlSA . ' .. ...
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• Edgewise single edge notch tension ESE(T) specimens tested by compliance control to grow and heal a small fatigue crack. - Surface strain measurements via visual image correlation (VIC-3D)
• FCG specimens were pre-cracked, tested, healed, and re-tested. High-temperature speckle pattern was used to continue strain
measurements after healing treatment.
ESE(T) specimen with speckle paint and relative location of SMA reinforcements.
ESE(T) specimen during FCG test with VIC data superimposed.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 22
Phase II Results: Fatigue Crack Growth N~SA . ' .. ' . .
• Pre-healing treatment CT
CT movies of ESE(T) FCG specimen pre-healing treatment.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 23
Phase II Results: Fatigue Crack Growth NJlSA . ' .. ...
• Strain fields during first fatigue test, after healing, and at the end of the second fatigue test.
VIC strain field data of ESE(T) FCG specimen pre- and post-healing treatment.
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar
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10
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Phase II Results: Modeling NJlSA . ' .. ...
• Modeled composite using various loading scenarios, SMA compositions, wire placement, continuous vs. discontinuous wire lengths, and wire pre-strain .
Evaluated plasticity induced on the matrix and wires from loading, unloading, and heating to healing temperatures.
Evaluated ability of SMA wires to force crack closure in the SMASH materials system.
Three-Point Bend Tensile Rectangular Plate
Roller constrain
Pinned Pinned
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar
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Phase II Results: Validation of Model NJlSA . ' .. ...
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• Empirical and model of metal matrix composite 3-point bend tests were in agreement
True test data, including material properties at different temperature regimes, was used in the model.
Simulation of crack opening displacement {COD} after unloading is in good agreement with the test measurements.
Final COD after loading: • Model: 0.17 mm
• Experimental : 0.15 mm
Crack length = 7.6 mm
Crack Opening Displacement (model)
0.3 -r-----------------,
0 5
0.25 mm
10 15 Time (s)
20
E = 65 GPa for Sn-Bi matrix
25 30
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 26
Phase II Results: FEA NJlSA . ' .. ...
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• FEA showing stress evolution (von-Mises, MPa) upon loading, unloading, and heating.
Step 1: Load Step 2: Unload Step 3: Heat
SMA
Matrix
March 18 & 19, 2015 NASA Aeronautics Research M ission Directorate 2015 LEARN/Seedling Technical Seminar
S. Mice:c
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•1 7 00hC2 -.1 A92C+C2 .. 1074s.C2 .. t .l SOC+Cl .. 3!59DuC1 1-DOOOhCO
Mal(: - 4 275t.02 Eliir1' : PA~T~9· I .5 NOQI ! :IC!
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Applying FEA to Fabrication of Complex Specimens
• 3-D model
Matrix SMA
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10· I ._ _ _,._ _ _____c
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 28
Applying FEA to Fabrication of Complex Specimens
• FEA was used to model two multi-ply hot pressed specimens: - -45/0/+45
- -30/0/+30
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar
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c (}.) (}.)
s +-' (}.)
...0 (}.) () c m +-' (/) ·-0
Phase II Results: Using FEA for
Extending the Realm of possibilities • The best wire placement in relation to the crack is
perpendicular (0° in figures below)
• Pre-stra ining re inforcements aids in crack closure
0.6
0.5
...--....
E 0.4
E ...__....
N 0. ~
o6 .._-(/) O..J (}.) -o 0 c 0.1
0
l
4
I
Unload Heat
n . ..;
- l ">rk;; 0.1
- ..J' Ct';-i O.l
l\ 1
Load Unload Heat
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-odeg
- 1sdeg
30deg
- 4Sdeg
{l ),1 25 30
Time (s) Time (s)
March 18 & 19, 2015 NASA Aeronautics Research M ission Directorate 2015 LEARN/Seedling Technical Seminar 30
Phase II Results: Using FEA for
Extending the Realm of possibilities • Short vs. Long fibers
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Continuous vs. discontinuous wire reinforcements were modeled.
The best case for crack closure is continuous reinforcements near the crack tip. Case 1 -discontinuous wires parallel
j ....,::.-- ------
- ease1 0.06 mm - easel - easel Case 2: discontinuous wires, offset by 12 mm
0 10 15 25 30
Case 3: discontinuous wires, offset by 20 mm
~' node1 node2 20mm
March 18 & 19, 2015 NASA Aeronautics Research M ission Directorate 2015 LEARN/Seedling Technical Seminar 31
Phase II Results: Matrix Alloy Design
• AI-Cu and AI-Cu-X systems
• Liquid-assisted step in healing:
- Eliminates work hardening and grain refinement
- Leaves precipitation hardening and solid solution strengthening
• Candidates:
- AI-Cu-Mg alloys that can precipitate the high-strength S-phase and its metastable precursors
• Heat treatment:
Cast, solution treat, quench, and age to peak strength.
Healing treatment performed on diffusion couples
Perform heat treatment again.
M arch 18 & 19, 2015 NASA Aeronaut ics Research M ission Directorate 2015 LEARN/Seedling Technical Seminar 32
Distribution/Dissemination NJlSA . ' .. . ..
• Patents: - A provisional patent application titled "Self-Repairing Metal Alloy Matrix Composites, Methods of
Manufacture and Use Thereof" was fi led in June 2014 with the Patent and Trademark Office.
• NASA Technical Memoranda
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Fatigue Resistance of Liquid-Assisted Self-Repairing Aluminum Alloys Reinforced with Shape Memory Alloys
Assessment of Fatigue Crack Damage and Mitigation in Self-Repairing Metallic Materials
• Invited Talks: - TMS 2015 Annual Meeting and Exhibition, March 2015 in Orlando, FL "Investigating the Fatigue Behavior of
Aluminum-Based Shape Memory Alloy Self-Healing (SMASH) Technology".
• Other Conference Talks: Aerospace Materials (AeroMat) Conference in June 2014 in Orlando, FL. " Amending Fatigue Damage Using Shape Memory Alloy Self-Healing {SMASH) Technology" .
International Conference of Self Healing Materials, Ghent, June 2013, "Design Methodology for LiquidAssisted Self-Healing Metals".
• Media, Articles and Public Relations: Central Florida Fox 35 News, January 2014
NASA web article I september 2 013 I http://www.nasa .gov /content/smash-alloys-being-designed-to-improve-aerospace-safety-margins/
NASA video highlight: http://www.youtube.com/watch?v=VBgGpkesHQo
Professor Michele Manuel was deemed as one of three top researchers with ground breaking research at the University of Florida in part because of the SMASH research, UF Alumni Magazine "Shaping the Future", Spring 2014.
March 18 & 19, 2015 NASA Aeronautics Research M ission Directorate 2015 LEARN/Seedling Techn ical Seminar 33
Next Steps NJlSA . ' .. ...
• Currently planning on 7 peer-reviewed journal articles - 1 high-level (in work), 2 modeling papers, 2 materials journals, 2
mechanics of materials.
• No-cost extensions granted to universities to complete experimental and modeling work for next 3 to 9 months.
- Includes testing of multi-ply specimens and precipitation hardened matrix alloys.
• Interest from the Space Technology Mission Directorate to continue work on embedded crack detection and surface or non-contact heating.
• Potential collaboration with JPL to further enhance matrix design.
• Continue to market technology to other NASA Principal Investigators
March 18 & 19, 2015 NASA Aeronautics Research M ission Directorate 2015 LEARN/Seedling Technical Seminar
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Summary/Conclusions
• Proved healing of fatigue and overload cracks in proof-ofconcept and aluminum matrix composites
• Performed fatigue crack growth tests before and after healing
• Experimentally optimized the processing parameters, healing treatment, matrix heat treatment
• Finite element model optimized the SMA reinforcement geometry, length, and pre-strain conditions
• Validated computer model using experimental data.
THANK YOU ARMD and NARI!
March 18 & 19, 2015 NASA Aeronautics Research Mission Directorate 2015 LEARN/Seedling Technical Seminar 35