A Composite NDI Training Course To Address The Growing Need For .

A Composite NDI Training Course to Address theGrowing Need for Composite Laminate InspectionsAirlines for America NDT – September 2016Filament DiametersStephen Neidigk, Dennis Roach,Tom RiceSandia National LabsFAA Airworthiness Assurance CenterAlex MeltonDelta Air LinesDavid Westlund, Rusty JonesFAA

Presentation OverviewIntroduction and BackgroundClass Modules andObjectivesHands-On Training andProficiency Specimen SetFirst Deployment of theComposite NDI TrainingClass

Motivation for Composite NDI Training ClassMotivation - Extensive/increasing use of solid laminatecomposites on commercial aircraft and need for inspectors tomaintain a level of proficiency via training and hands-on practice.Composite Structures onBoeing 787 AircraftCarbon laminateCarbon sandwichFiberglassAluminumAluminum/steel/titanium pylonsAirbus A350 XWBaltairenlighten.com

Motivation for Composite NDI Training ClassBoeing 7871,161 Ordered455 DeliveredAll Nippon Airways – 83, 50United – 49, 30American – 42, 17Delta – 18, 0Airbus A350810 Ordered36 DeliveredQatar Airways – 80, 10United – 35, 0American – 22, 0Delta – 25, 0"Boeing 787: Orders and Deliveries (updated monthly)". The BoeingCompany. August 31, 2016. Retrieved September 8, liveries/

Solid Laminate Flaw Detection ExperimentProbability of Detection (POD) ExperimentThickness Range:12 – 64 pliesSimple TapersComplex tapersSubstructure FlawsCurved SurfacesArray of flaw typesEvaluate the performance of conventional ultrasonicinspection methods for flaw detection in solid laminatestructures. 70 inspectors from 14 airlines participated.

POD Curves for 12-20 Ply SolidLaminate FamilyIndividual and Cumulative ComparisonsOverall:POD[90/95] 1.29” dia.Probability of DetectionConstant Thickness(12, 20, 28 plies):POD[90/95] 0.86” dia.Complex Geometry(tapered, ] 1.49” dia.Flaw Size (Diameter in Inches)False Calls: Constant thickness 0.4/inspectorComplex Geometry 4.0/inspector34 ft.2 inspection area

Composite NDI Training SurveyIn addition to the POD experiment, a Composite NDITraining Survey was conducted.Airline and MRO NDI SurveyOnly 25% of responders currentlyhave special composite NDI training inplace

Recommendations – How to move inspectors from“average” to “good” to “outstanding”The POD experiment and NDI Training Survey led to several keyrecommendations resulting in the Composite Inspector Training Class. Increased exposure to representative composite inspections – commonindustry NDI Proficiency Specimens Increased, focused composite NDI training Enhanced NDI procedures – deployment, signal interpretation, clearschematics showing structural configuration Use of inspection coverage aids Divide large area inspections into a number of smaller regions Follow proceduresIdentified need for specific training that specifically addresses compositeinspection Unique challenges associated with composites Additional routine exposure to composite laminate inspections

Composite Laminate NDI Training ClassClass Definition – General Training Content (cont.) Target Class Length – 2 days (1/2 classroom, 1/2 hands-on) Format – stand-alone course but assumption is minimum ofLevel I student Instructor modifies for specific needsGoal of training is to enhance aircraft safety & optimizeaircraft utilization by improving NDI flaw detectionperformance in composite aircraft structure.

Composite Laminate NDI Training ClassClass Modules1. Introduction, Objectives & Expected Outcome fromClass2. Composite Awareness – Materials, Design,Fabrication and Use3. Composite NDI – Theory and Practice4. Special Cases - Challenges & Lessons Learned5. NDI Proficiency Specimens6. Hands-On Exercises

2. Composite Awareness – Materials,Design, Fabrication and UseWhat are Composites?Common Materials usedTypes of DamageAutoclave andVARTM ProcessingIntroduction to Repairs

3. Composite NDI – Theory and Practice Visual inspection of compositesBasic ultrasonic inspection theoryUltrasonic deployment and optionsUltrasonic equipment set upMapping damageUltrasonic signals from normal and damaged structurePhased array inspection C-Scan generation Solid laminate inspection methods and sample resultsTransducers and Delay LinesReference StandardsTCG CurvesSetting GatesDeployment Options

3. Composite NDI – Theory and PracticeA-Scan, B-Scan, C-Scan“Go” / “No-Go” DevicesSizing DamgeScan Indexing, Tapersand Substructure

3. Composite NDI – Theory and PracticeBrief introduction and sample results from: Various phased array systems CT Scanning DolphiCam Thermography Roller Probes LaserUT Digital Acoustic Video

4. Special Cases – Challenges &Lessons Learned Examples of operational damage and field inspection results Read and Follow the Procedures Caution using saved settings Embrace New Technology – It Can Be Helpful Follow OEM DocumentationAccidentalDamage fromGround HandlingEquipmentLightning StrikeDamage

5. NDI Proficiency SpecimensInitial design guidelines were assembled at the 1st (August 2014) project kick-offmeeting with industry partners and the FAA. Thickness, materials, flaw types, structural configurations etc.Development Considerations: Support hands-on training exercises Support recurrent training and composite NDI exposure Can be used in “blind mode” to demonstrate inspector proficiency Multiple flaw profiles and configurations designed so that end users can puttogether a set that fits their specific training needs and budget All lessons and teaching points will be encompassed in a limited number ofpanel configurations (minimize cost) Specimen geometry designed for ease of construction

5. NDI Proficiency SpecimensPanel Configuration Summary - 8 total panelsConfiguration 1 Configuration 1 - 3 variations Configuration 2 - 2 variations Configuration 3 - 3 a24"x18" Panel withcomplex taper (10:1Configuration 1and 20:1) andsecondary bond24"x18" Panel withpads, fasteners, cocured bonds,Configuration 2sealant, sounddampersConfiguration 316 ply solid lamianteskinRepair Panel20 Ply solid laminate1bPrimary VariationStandardconfiguration 1AdditionalSecondary bondand more subtleflaws (differentflaw profile)1cAdditionalthickness (up to 64plies) and differentflaw profile2aStandardconfiguration 22bDifferent flawprofile3a3b3cRep. Panel 1Standardconfiguration 3Subtle impactLarge impactStandard repairpanelConfiguration 2Configuration 3Flat solidlaminate skin

5. NDI Proficiency SpecimensExample Engineered Flaws in Proficiency SpecimensEmbedded in the panelsPillow insert*DelaminationGrease*ContaminationPaper Backing in thebond line*Foreign objectdamagePaper backing in thelaminate*Foreign objectdamageCarbospheres*Localized porosityGrafoil insert*Tight delaminationPillow insert in thebond line*Disbond

5. NDI Proficiency SpecimensExample Engineered Flaws in Proficiency SpecimensAdded to the panels after fabricationConcentric flatbottom holes*Impact damageMissing SealantFlat bottom holes*Significant delaminationGrinder Cut*Cracked or brokensubstructureGrinder Disk Grove*Gouge or deep scratchSealant*Raised material, not a flaw

5. NDI Proficiency SpecimensSpecimen Design 1c – Flaw ProfileStructure: Thick Specimen - Taper (10:1 and 20:1) and secondary bond32 Ply main skin32 Plybondedstrips64 Ply maxthicknessFabrication support from NORDAM Interiors and StructuresDarryl Graham and Jeff Harper

5. NDI Proficiency SpecimensSpecimen 1c – Inspection ResultsStructure: Thick Specimen - Taper (10:1 and 20:1) and secondary bondTeaching Points:Follow procedures to setproper gates and detectsecond layer defects

5. NDI Proficiency SpecimensTeaching Points: Defect detection usingPA can requirecombination of Amp.,TOF and A-Scan. dB drop criteria

5. NDI Proficiency SpecimensConfiguration 2Structure: Uniform thickness skin, pads, fastened shear tie flanges, co-cured stiffeners, sealant18”Built-up padsection (8 plies)Sound damper(acoustic tiles)16 Plythick skinCo-cured stiffenerflanges (8 plies)Shear tie flange24”Sealant betweenflange and padFastened sheartie flange

5. NDI Proficiency SpecimensSpecimen Design 2a – Flaw Profile

5. NDI Proficiency SpecimensSpecimen 2a – Inspection ResultsStructure: Uniform thickness skin, pads, fastened shear tie flanges, co-cured stiffeners, sealantOmniScan 3.5L64 (3.5 MHz)BackAmplitudeTOF

6. Hands-On ExercisesA-Scan ExercisesGeneral A-Scan Inspection Procedure1 - Calibration - Set Material Velocity and TCG Curve2 - Mark substructure on surface3 - Defect detection in uniform thickness skin4 - Defect detection in tapered skin5 - Inspection of bonded substructure6 - Inspection of co-cured substructure7 - Defect detection around other aircraft elementsPanelsAll panelsRef 2a,2b2a,2bPA ExercisesGeneral C-Scan Inspection Procedure1 - PA Calibration2 - Set up TCG Curve3 - Setting gates4 - Analyzing C-Scan resultsPanelsAll panelsRef StdST8872All panelsAll panels

6. Hands-On Exercises Students follow inspectionprocedure and exercises toconduct inspections on theProficiency Specimens Templates are used to checkinspection results Immediate instructor feedbackto identify hits, misses and falsecalls Markings on panel arecompared to C-Scan inspectionresults

First Deployment of the Composite NDITraining Class - July 2016 Conducted the class at Delta Air Lines 20 inspectors, engineers, and FAA participants Presented the full class and conducted hands-on exercises using theProficiency SpecimensFeedback from the first class deployment: Helpful background on composite materials and NDI refresher TCG, inspection over acoustic tiles, C-Scan data analysis, set up andcalibration of phased array transducer, new appreciation for setup files,immediate hit/miss feedback Comfort level increased

Outcome and Path Forward Development of NDI training class is complete Successful completion of first class deployment with an airline Class will provide: A general understanding of composite materials An in-depth understanding of the nondestructive testingmethods used to inspect carbon fiber parts An overall inspection proficiency on composite aircraft partsmade up of a variety of structural configurations Airlines/users customize for their particular needsIn the process of making the class materials available to the public: Class modules Proficiency specimen drawings and specifications Generalized A-Scan and C-Scan inspection procedures Hands-on exercises Grading and instructor materials

Questions?If you are interested in obtaining the CompositeInspector Training materials, contact me:Stephen Neidigksneidig@sandia.gov

3 - Defect detection in uniform thickness skin 1a,1b,1c,3a,3b,3c 4 - Defect detection in tapered skin 1a,1b,1c 5 - Inspection of bonded substructure 1a,1b,1c 6 - Inspection of co-cured substructure 2a,2b 7 - Defect detection around other aircraft elements 2a,2b PA Exercises Panels General C-Scan Inspection Procedure All panels 1 - PA .