Abschlussworkshop CFK-Rumpf NG · Leitprojekt CFK Rumpf NG 15.02.2011 von 09:00 Uhr – 17:00 Uhr...

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Leitprojekt CFK Rumpf NG 15.02.2011 von 09:00 Uhr – 17:00 Uhr Golden Tulip Hamburg Abschlussworkshop CFK-Rumpf NG Infusion Technology for Bonded CFRP Repairs (for Aircraft Primary Structures) Dr. Christian Hühne, Dirk Holzhüter, B. Kujak, Arne Hindersmann, Jens Bölke, Olaf Steffen
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Transcript of Abschlussworkshop CFK-Rumpf NG · Leitprojekt CFK Rumpf NG 15.02.2011 von 09:00 Uhr – 17:00 Uhr...

  • Leitprojekt CFK Rumpf NG

    15.02.2011 von 09:00 Uhr – 17:00 Uhr Golden Tulip Hamburg

    Abschlussworkshop CFK-Rumpf NG

    Infusion Technology for Bonded CFRP Repairs (for Aircraft Primary Structures)

    Dr. Christian Hühne, Dirk Holzhüter, B. Kujak, Arne Hindersmann, Jens Bölke, Olaf Steffen

  • 2Leitprojekt CFK Rumpf NG

    Topics

    Repair Environment

    State-of-the Art CFRP-Patch Repair

    Repair ConceptsDesign and Automation Infusion Repair

    Summary

    Outlook

    Boeing Demonstration of Patch

    Repair

    Damage

    by

    Lightning

    Strike

  • 3Leitprojekt CFK Rumpf NG

    Repair EnvironmentTemporary Conservation

    Protection

    of damaged

    structure

    against

    moisture. Application

    of waterproof

    cover

    immediately

    after

    detection

    Only

    temporary!

    Repair with Temporary Life Time: „Field Repair“Structural

    recovery

    for

    full

    use

    of part. This

    repair

    has to be

    redone

    at every

    major

    maintenance

    check!

    Permanent Repair: „Depot Repair“Full Repair

    of Structure. Structure

    is

    equivalent

    to original one

    (Level of Equivalent

    Safety)

    http://www.martinaire.com/Hangar1.jpg

    http://aviationdave.files.wordpress.com/

    http://www.aviation.technomuses.ca

    (Repair

    Level) [nach Baker und Raymond]

    http://aviationdave.files.wordpress.com/http://www.aviation.technomuses.ca/

  • 4Leitprojekt CFK Rumpf NG

    Repair Environment (EASA)Primary Structure

    Safety

    relevant, Failure

    causes

    total losse.g. Centre Wing

    Box, VTP Bearings, Rudder, Fuselage

    Secondary StructureStructure

    relevant for

    normal operation, Failure

    does

    not

    cause total Losse.g. aerodynamic

    Fairings

    / Flaps, Slats

    Tertiary StructureReimaing

    Structure, Failure

    has low

    impact

    on operatione. g.Maintenance

    covers

    Repaired by OEM or certified Company

    Redesign

    and Certification

    of Repair

    necessarrye. g. new

    Framecoupling

    Repaired by OperatorBy

    Structural Repair Manual (SRM)

    No immediate Repair necessaryPart may

    be

    temporarily

    removedFailure

    Cascade

    has to be

    prevented

  • 5Institute of Composite Structures and Apaptive Systems

    State-of-the-art (Bolted Repair)

    Bolted

    Repair

    Bypass

    of Original Load

    Path

    by

    Riveting

    of One or

    Two

    Doublers

    Advantage•

    Good Recovery

    of Strength•

    Slight•

    Fast Application•

    Easy Certification

    because

    of Fail-Safe-Concept

    Disadvantage•

    Minimum Skin Thickness

    necessary•

    Steps

    in Aerodynamic

    Shape•

    Complex

    at edges

    and pressure

    vessels•

    High Weight, Two

    Sided Access necessarry

    Examples•

    Thick

    aircraft

    structures

    (>3mm)

    1. Damage Detection by NDT

    2. Removal of Damage (Drilling, Grinding, Milling)

    3. Riveting of Doublers

    4. NDT

  • 6Institute of Composite Structures and Apaptive Systems

    State-of-the-Art CFRP-Patch Repair

    Scarf

    Repair

    NDT, Removal of Damage, Manual Grinding

    of Scarf, Cocuring

    of Wet

    Prepreg

    Layup

    or

    conbonding

    of Hard Patch

    (separate Tooling

    necessary), Prepreg

    Technology favoured.•

    Ramp

    of Scarf

    1:20 –

    1:40

    Adavantage•

    Original Structural

    behaviour

    nearly

    restored•

    Flushrepair•

    Excellent

    mechanical

    Performance

    Disadvantage•

    Extremely

    complex

    and time consuming•

    Qualitymanagement

    complex

    (Travellorcoupons)•

    A lot of healthy

    Material has to be

    removed

    by

    the

    scarf

    Weakening

    of Structure? Examples•

    Repair

    of Flaps (A320)

    1. Damage Detection by NDT

    2. Removal of Damage by Grinding or Milling

    3. Filmadhesive and Filler Plies cobonded or bonding of Hard Patch

    4. NDT

  • 7Leitprojekt CFK Rumpf NG

    DLR - Concepts

    ChallengesReduction

    of Maintenance

    Time

    Reduction

    of Maintenance

    CostsCertification

    of Bonded

    Repairs

    Reproducibility

    / Human FactorStructural

    Performance

    AimDepot Repair

    Method

    for

    Primary

    Structures

    SolutionsAutomated

    Repair

    Process

    Robust Repair

    ProcessFail-Safe

    Repair

    Process

    Repairs

    done

    todayRepairs

    done

    tomorrowDemonstration of Boeing 787 Repair

  • 8Leitprojekt CFK Rumpf NG

    DLR - Concepts

    Machining

    of Scarf

    -

    Laserscanning

    of Surface- Surface

    Reconstruction

    of Real-Geometry- Design of Scarf- Generation of Machining

    Data- Milling

    of Scarf

    (3-Axis or

    7-Axis)

    Design and Machining

    Concept

    Advantages

    -

    Digitized

    Geometry

    for

    Automation

    of Repair

    Process

    -

    Digitized

    Geometry

    for

    Tooling

    Generation (Hard Patch)

    - Digitized

    Geometry

    for

    Documentation

    -

    Automated

    Milling/Grinding

    of Scarf

    for

    Minimization

    of Human Factor

    - Automated

    Milling/Grinding

    of Scarf

    forMaintenance

    Time Reduction

  • 9Leitprojekt CFK Rumpf NG

    DLR - Design Concept

    Removal of Damage / ScarfingLaserscanning

    of 3D-Surface

    Scanning

    by

    Perceptron

    V5 Laserscanner:Absolute Precision: ~45μm

    ATOS 3D-Scanning System

    Manufacturer: GOM

    *

    *Source: EADS

    or

  • 10Leitprojekt CFK Rumpf NG

    DLR - Design Concept

    Virtual Design of RepairSurface

    reconstruction

    in CATIA V5

    Design of Scarf

    by

    parameterized

    Construction

    Pointcloud Triangulation Real-Surface

    Scarf-DesignParameter Input Machining

    Data

  • 11Leitprojekt CFK Rumpf NG

    Aligning

    of 3D-Data

    Preparation of Damaged Area for Bonded Repair

    Focussing

    of 3D Data on relevant RegionReduction

    of 3D-Data DensityTriangulation

    of 3D-Point CloudReconstruction

    of real GeometryChecking

    of deviationDesign of Tapered

    Repair

    based

    on real 3D-Shape

    DLR – Machining Concept

    Damage

    Removal by

    Milling

    of StructureStructure

    prepared

    for

    Patchrepair

    Process

    demonstrated

    on unstiffened

    Panel

    Automated

    Positioning

    andBonding of Repairpatches

    Process

    demonstrated

    on unstiffened

    Panel

  • 12Leitprojekt CFK Rumpf NG

    Hard-Patch

    Repair

    Characteristik- Bonded

    repair- Cured

    Patches- Automation of Process- One Sided Access only

    Hard Patch RepairRepair

    Concepts

    Machining

    of Scarf

    -

    Laserscanning

    of Surface- Surface

    Reconstruction

    of Real-Geometry- Design of Scarf- Generation of Machining

    Data- Milling

    of Scarf

    (3-Axis or

    7-Axis)

    Design and Machining

    Concept

    Advantages

    - Assembly

    Possible

    from

    One Side

    -

    Improved

    Mechanical

    Performance via Double Lap

    Joint

    - Improved

    Safety

    via Double Lap

    Joint

  • 13Leitprojekt CFK Rumpf NG

    Hard Patch Repair

    Hard Patch Repair ConceptMaximum of 3 Repair

    Patches

    (outer

    Patch

    optional)

    Inner Patch

    Inserted

    via Elliptic

    RepairholePositioning

    of Centre and Outer

    Patch

    Aligning

    by

    Middle

    Patch

    and Two

    Drill HolesClosing

    of Drill Holes

    by

    Two

    Blind Rivets

  • 14Leitprojekt CFK Rumpf NG

    Hard Patch Repair

    Hard Patch Repair3D-Demonstrator

    CNC-milled

    Scarf

    Based

    on Scanned

    Surface

    Hard Patch

    Repair

    with

    Inner

    and Centre Patch

    Hard Patch

    Repair

    withInner, Centre, and

    Outer

    Patch

  • 16Leitprojekt CFK Rumpf NG

    Infusion Repair

    -

    Infusion of Positioned

    Preform- Cobonding

    of Patch

    and Adhesive- One Sided Access only- Low Assembly

    Tolerances

    Infusion-Patch

    Repair

    Repair

    Concepts

    Machining

    of Scarf

    -

    Laserscanning

    of Surface- Surface

    Reconstruction

    of Real-Geometry- Design of Scarf- Generation of Machining

    Data- Milling

    of Scarf

    (3-Axis or

    7-Axis)

    Design and Machining

    Concept

    Advantages

    -

    Easy Repair

    Process

    via Infusion

    of Patch

    - No Patch

    Tooling

    necessary

    -

    Flexible Patch

    for

    Repair

    of Double Curved

    Structures

    - High mechanical

    Performance

    - One Sided Access only

    necessary

  • 17Leitprojekt CFK Rumpf NG

    Cobonding Infusion Repair ConceptBonding of Filler

    Plate

    Insertion of Film AdhesiveInsertion der Preform

    (with

    Overplies)

    Single Sided VacuumbaggingInfusion of PreformCo-Curing

    of Adhesive

    and Patch

    Infusion Repair

    Preform

    Grundplatte(AL oder GFK)

    StructurePatch

  • 18Leitprojekt CFK Rumpf NG

    Infusion Repair

    Evaluation of Mechanical PerformanceCoupon Specimen

    EN6066

    Easy ManufacturingEasy Testing

    (1-Axis Tension)

    Testing

    of Scarf

    not

    AdhesiveQuantative

    Evaluation of Joint

    Surface

    Analytic

    of Break Surface

    Patch

    Parent

    Adhesive

    Void

    Overply End of Adhesive

    Parent

    Standard Set of

    En6066 Coupons

  • 19Leitprojekt CFK Rumpf NG

    Infusion Repair

    Evaluation of mechanical PerformanceARAMIS

    Evaluation of Surface

    StrainfieldStrain

    Gauges

    for

    Local

    Strains

    0°/90°

    0°/90°90°

    /0°

    90°

    /0°+45°/-45°

    +45°/-45°

    -45°/+45°

    -45°/+45°

    -45°/+45°

    25kN 35kN

  • 20Leitprojekt CFK Rumpf NG

    Infusion Repair

    Detail TestingQuantification

    of Geometry

    Influence

    Scarf

    Angle, Elliptic

    RepairsEvaluation of Repair

    Process

    Verification

    of Doubler

    ConceptsValidation of Patch

    Lay-Up

    Ply-by-Ply

    / Cupped

    MaterialsDry

    Fabrics

    e.g. G0926, G1157 (Hexel)

    Dry

    NCF from

    Saertex

    (Biax)Resin: RTM6 (Hexel), LY (Huntsman) Adhesive: FM300 (Cytec), Hysol

    EA 9596 (Henkel)

  • 21Leitprojekt CFK Rumpf NG

    Infusion Repair

    Microscopic EvaluationCobonding

    Good Bond Line, no VoidsHard Patch

    (State-of-the-Art)

    Good Bond Line, some

    Voids

    Mechanical Evaluation (Coupon)Infusion Repair

    has equal

    Mechanical

    Performance compared

    to Hard Patch

    About

    80% total Load Recovery

    has been

    achievedundamaged

    State-of-the-Art

    DLR-Concepts

    Load Recovery

    ParentBond Line

    Patch

    Bond LinePatch

    Parent

  • 22Leitprojekt CFK Rumpf NG

    Infusion Repair

    3D-Infusion Repair Process Demosntration

    Cocured

    Patch

    CNC-milled

    Scarf

    based

    on Scanned

    Surface

  • 23Leitprojekt CFK Rumpf NG

    Summary

    DLR is certified for changes on our own aircrafts (EASA part 21,25) e.g. on our Do228, Dassault Falcon, Airbus A320

    State-of-the Art lacks a Bonded Repair Solution for Primary Structures to overcome „Designed for Bolted Repair“- Design-Rule

    Repair ist strongly driven by Certification Requirements

    Design and Machining Concept improves Repair Quality, Documentation and allows Process Automation as well as new Geometries

    Infusion Repair reduces Process Complexity for curved Parts drastically by equivalent mechanical Performance

  • 24Leitprojekt CFK Rumpf NG

    Outlook

    Development of Repair Method for Certification Process

    Development of Process Chain for Automated Repair Process

    Demonstration of a Full Automated Repair Process on a CertifiedAircraft Structure

    Inflight Testing of Repair

  • 25Leitprojekt CFK Rumpf NG

    Thank you for your Attention!

  • 26Leitprojekt CFK Rumpf NG

    Contact Data

    Expert Repair: Dirk Holzhüter

    Phone: 0531 295 2319

    Email: [email protected]

    Expert Joining: Dr. Axel Fink

    Phone: 0531 295 2308

    Email: [email protected]

    Expert Manufacturing: Michael Hanke

    Phone: 0531 295 2303

    Email: [email protected]

    Head of Department Composite Design: Dr. Christian Hühne

    Phone: 0531 295 2310

    Email: [email protected]

    15.02.2011 von 09:00 Uhr – 17:00 Uhr Golden Tulip Hamburg�Abschlussworkshop CFK-Rumpf NG��Infusion Technology for Bonded CFRP Repairs�(for Aircraft Primary Structures)��Dr. Christian Hühne, Dirk Holzhüter,�B. Kujak, Arne Hindersmann, Jens Bölke, Olaf Steffen� TopicsRepair EnvironmentRepair Environment (EASA)�State-of-the-art (Bolted Repair)State-of-the-Art CFRP-Patch RepairDLR - ConceptsDLR - ConceptsDLR - Design ConceptDLR - Design ConceptDLR – Machining ConceptHard Patch RepairHard Patch RepairHard Patch RepairInfusion RepairInfusion RepairInfusion RepairInfusion RepairInfusion RepairInfusion RepairInfusion RepairSummaryOutlookFoliennummer 25Contact Data