An Integrated Approach to Corrosion Damage Management

1
An Integrated Approach to Corrosion Damage
Management

• Tobey Cordell
• SK Technologies
• 11 March 2003

2
Corrosion Effects on Structural Integrity

• AF Contract Number F09650-00-D-0018
• AF Program Manager
• Dr. Deborah Peeler
• AFRL/ML Liaison to ASC/AA
• AF IPT Members
• Richard Kinzie, AF CPCO
• Maj. Scott Fawaz, USAFA Structures
• Charles Buynak, AFRL NDE
• Thanks to Dr. Bill Abbott, Battelle Dr. Rob
  Kelly, RD Assoc.
• Laura Simon, SKT and Dr. Jill Ullett, SKT

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AATT Surveys 2001Major Needs Identified by ASIP
Managers

• Establish the Economic Service Life / Cost of
  Ownership Models
• Determine the onset of Widespread Fatigue Damage
  (WFD)
• Prevent, Assess and Control Corrosion
• Reduce the Inspection Burden and Improve
  Inspection Capability
• Standardize Bonded Repair

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AATT SurveysMajor Needs Identified by ASIP
Managers

• Establish the Economic Service Life / Cost of
  Ownership Models
• Determine the onset of Widespread Fatigue Damage
  (WFD)
• Prevent, Assess and Control Corrosion
• Reduce the Inspection Burden and Improve
  Inspection Capability
• Standardize Bonded Repair

Damage Management Toolkit Analysis and
Decision Software Addl Prevention and Repair
Options
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For Lack of a Comprehensive Damage Management
Tool..

• Corrosion is identified but not quantified
• Structural Impact of Current Corrosion Damage is
  not a metric that can be used to make disposition
  decisions- maintenance or condemnation
• Time is wasted and Structural Life REDUCED by
  doing some corrosion repairs

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For Lack of a Comprehensive Damage Management
Tool..

• Structural Impact of Corrosion Damage cannot be
  Projected to a Future Date / next PDM to allow
  cost effective A/C management
• Inability to anticipate and manage maintenance
  schedule / costs
• Some Aircraft prematurely removed from service
  due to projected cost and schedule impact of
  managing structurally insignificant corrosion
  damage

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AEPO Structures Strategy
Enhanced Depot Field Decision Making
Prevention
NDI and Health Monitoring


AFRL ASC/EN ASC/AA

Repair and Replacement
Multiple degradation mechanisms
Integrated Approach AFRL, ASC/EN, and ASC/AA
working together with warfighter customers and
depot maintainers
Aging A/C Analysis















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Integrated ApproachFour Focus Areas

• Prevention PREVENT
• NDI and Health Monitoring DETECT
• Aging Aircraft Analysis ASSESS
• Repair and Replacement MANAGE

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Prevention

• Exposure racks
• ESI basing strategies
• Enhanced CPCs and processes
• Web-based enhanced materials selection

• Maintain safety
• Increase availability
• and mission capability
• Decrease O S cost

NDI and Health Monitoring
INTEGRATED APPROACH
Repair and Replacement
Fatigue Corrosion Material Degradation Wear
Aging A/C Analysis















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New Specimen Racks Basing Environment

• Typical field installation
• Runway environment
• Base personnel install and remove
• 4 Test Cards per Sample Package
• Quarterly sample removals
• 1 Year Kinetic Data

• Ag (Chloride Sensor)
• Cu
• 7075 Al
• 6061 Al
• 1010 Steel

Prevention and Control Office
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Corrosion Exposure In Aircraft

• C-141 Flight Tests
• C-130 Flight Tests Coast Guard
• Clearwater, FL (3)
• Elizabeth City, NJ
• Sacramento, CA
• Kodiak, AK
• Hawaii

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Enhanced Materials Selection

• New alloys identified via supplier discussions
• Granta about to demo new web-based selection tool

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Proven Newer Materials already flying
Body skin Alclad 2524-T3
Upper wing surface 7055-T7751 skin 7055-T77511
stringers 7150-T77511 spar chords
Lower wing surface 2324-T39 skin 2224-T3511
stringers
Floors 7150-T77511 seat tracks
Body stiffeners 7150-T77511 keel
beam 7150-T77511 body stringers, upper lower
lobe
BOEING 777
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CESI - Virtual Collaboration
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NDI and Health Monitoring

• Enhanced NDI methods (As Is)
• Corrosion sensors
• Tracking methods
• Data management map by platform

• Maintain safety
• Increase availability
• and mission capability
• Decrease O S cost

Prevention



INTEGRATED APPROACH
Repair and Replacement
Fatigue Corrosion Material Degradation Wear
Aging A/C Analysis















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Enhanced NDI Methods

• Depot level NDI methods being used to evaluate
  corrosion exposure specimens
• Results to be correlated with inspection records
  from depot inspection of legacy fleet

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MAUS IV Scan of LWRU2OB1
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SKT Dayton is continuing to build and use a
structural component inventory
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Multi-Component Inventory
http//missioncontrolonline.com/Wacis/main.cfm See
Reports aircraftpartslist.xls
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Structural Health Monitoring

• Late 2002 start of flying corrosion sensors on
  C-141s
• Extensive lab and field analysis of various
  structural health sensors slated for 2003
• F-15 flight testing underway

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Aging A/C Analysis

• Maintain safety
• Increase availability
• and mission capability
• Decrease O S cost

Prevention



NDI and Health Monitoring
INTEGRATED APPROACH
Repair and Replacement
Fatigue Corrosion Material Degradation Wear

• Corrosion prediction software (To Be)
• Damage state knowledge / morphology
• Structural integrity analysis software (ASIP)
• Cost of corrosion tools

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Corrosion Growth Prediction
Structural Integrity Module
Framework
Environmental Severity Index
Structural State at time (t) area out, pit
depth, morphology, etc.
Corrosion Growth Module
Repair Selected
NDI- Inspection of Condition
Corrosion Growth Rate
Cost Assessment
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Predict To Be Condition
?t
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Corrosion Growth Model Summary

• Lap Joint
• Supporting Database population, validation
  testing continue
• Additional Materials Characterization data being
  leveraged internationally, industrially, and
  among services
• Wing
• Significant synergism among other 6.5, NDI devt
  tasks
• Will transition with Data mapping capability,
  mining
• Supports optimized maintenance decisions
• See DEMO in the SK Technologies booth!

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Repair and Replacement

• Maintain safety
• Increase availability
• and mission capability
• Decrease OS cost

Prevention



NDI and Health Monitoring
INTEGRATED APPROACH

• MATerials SUBstitution
• Composite patches
• RRA

Fatigue Corrosion Material Degradation Wear
Aging A/C Analysis















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Repair Summary

• Materials Substitution
• Key data development for limited promising alloys
• Initial considerations for C-130, C-5
• Defense Logistics Agency involved
• Retrogression and Re-Aging
• Promising process on and off aircraft
• Kinetics Understood, easily managed, monitored
• Process demonstrated on full-scale components
• Additional repair options unfunded
• composite patches, mechanical suppression, etc.

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Corrosion Damage ManagementStatus

• Management of Aging Aircraft is a long term
  problem
• Current young fleets and new designs will see
  extended operation
• Environmental (time-dependent) degradation under
  cyclic and /or sustained stress
• High potential to degrade flight safety
• Significant impact on life cycle costs and
  availability

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Corrosion Damage ManagementStatus

• Components which can become critical to both
  airworthiness and life cycle cost due to
  environmental degradation must be managed in the
  same robust manner as structurally significant
  fatigue critical components
• The ability to anticipate damage for the next PDM
  would be a significant step toward managing the
  cost of repairs and readiness of our aging fleet