improved methods for measurement of extension-twist coupling in composite laminates
DESCRIPTION
Improved Methods for Measurement of Extension-Twist Coupling in Composite Laminates. Michael D. Schliesman. F. +a. s. s. -a. F. In-Plane Extension-Shear Coupling. Extension-Twist Coupling. Introduction. Coupling in Off-Axis Laminates. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
Georgia TechSchool of Aerospace Engineering
January 10, 2000
Improved Methods for Improved Methods for Measurement of Measurement of Extension-Twist Extension-Twist
Coupling in Composite Coupling in Composite LaminatesLaminates
Michael D. SchliesmanMichael D. Schliesman
January 10, 2000 Georgia TechSchool of Aerospace Engineering
IntroductionIntroductionCoupling in Off-Axis Coupling in Off-Axis LaminatesLaminates
In-Plane Extension-Shear In-Plane Extension-Shear CouplingCoupling
F
F
Extension-Twist Extension-Twist CouplingCoupling
January 10, 2000 Georgia TechSchool of Aerospace Engineering
IntroductionIntroductionWant to Use Extension-Twist Coupling in Want to Use Extension-Twist Coupling in DesignDesign
Experimental Validation of Analytical MethodExperimental Validation of Analytical MethodRequires Precise Experimental DataRequires Precise Experimental Data
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Existing Testing MethodsExisting Testing MethodsThrust-Bearing Thrust-Bearing ApparatusApparatus
Rotating-Frame Rotating-Frame ApparatusApparatus
Air-Bearing ApparatusAir-Bearing Apparatus
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Improving the Rotating-Frame Improving the Rotating-Frame ApparatusApparatus
BenefitsBenefitsHigh Fidelity to Rotor Blade High Fidelity to Rotor Blade EnvironmentEnvironment
Investigation of Aeroelastic Investigation of Aeroelastic CharacteristicsCharacteristics
Problems to OvercomeProblems to OvercomeRestoring MomentRestoring MomentPoor Method of Data Poor Method of Data AcquisitionAcquisition
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Restoring MomentRestoring MomentCylindrical End MassCylindrical End Mass
DeflectedDeflectedNot DeflectedNot Deflected
POR
POR
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Data AcquisitionData Acquisition
Laser Twist MeasurementLaser Twist Measurement
BaseBase
WindoWindoww
LaseLaserr
End End MassMass
PapePaperr
hh
2
tan 1
h
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Improved Rotating-Frame Improved Rotating-Frame ApparatusApparatus
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Symmetric Testing MethodSymmetric Testing Method
[+[+/-/-]] [-[-/+/+]]
Symmetric Test SpecimenSymmetric Test Specimen
Net Twist of SpecimenNet Twist of Specimen
+
F
0°
F
-
Twist of Specimen Twist of Specimen ComponentsComponents
F
+
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Symmetric Testing MethodSymmetric Testing MethodTesting SetupTesting Setup
January 10, 2000 Georgia TechSchool of Aerospace Engineering
PredictionsPredictionsAnalytical MethodAnalytical Method
Finite Displacement AnalysisFinite Displacement AnalysisClosed Form SolutionClosed Form SolutionGeometric Nonlinear EffectsGeometric Nonlinear Effects
Numerical Method Numerical Method Finite Element Analysis (ABAQUS)Finite Element Analysis (ABAQUS)2200 S4R Elements2200 S4R ElementsGeometric Nonlinear EffectsGeometric Nonlinear Effects
January 10, 2000 Georgia TechSchool of Aerospace Engineering
PredictionsPredictionsAnalytical and Finite Element PredictionsAnalytical and Finite Element Predictions
0
2
4
6
8
10
12
14
16
18
20
0 200 400 600 800 1000 1200Axial Load (N)
En
d T
wis
t (d
eg)
FEA
Analytical
Axial Load (N)
End
Tw
ist (
deg)
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Testing ResultsTesting ResultsRectangular vs. Cylindrical End MassRectangular vs. Cylindrical End Mass
0
2
4
6
8
10
12
14
16
18
20
0 200 400 600 800 1000 1200
Axial Load (N)
En
d T
wis
t (d
eg
)
Rectangular
Cylindrical
Analytical
FEA
Axial Load (N)
End
Tw
ist (
deg)
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Testing ResultsTesting ResultsAeroelastic EffectAeroelastic Effect
0
2
4
6
8
10
12
14
16
0 10 20 30 40 50
Angular Speed (rps)
En
d T
wis
t (d
eg)
Rectangular
Cylindrical
0
2
4
6
8
10
12
14
16
0 10 20 30 40 50
Angular Speed (rps)
En
d T
wis
t (d
eg)
Rectangular
Cylindrical
End
Tw
ist (
deg)
End
Tw
ist (
deg)
Angular Speed (rps) Angular Speed (rps)
Chamber EvacuatedChamber Evacuated Chamber Not EvacuatedChamber Not Evacuated
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Testing ResultsTesting ResultsScatter in Symmetric Testing MethodScatter in Symmetric Testing Method
0
5
10
15
20
25
30
0 200 400 600 800 1000 1200
Axial load (N)
En
d T
wis
t (d
eg
)
1A - 1B
1A - 2B
2A - 1B
2A - 2B
Analytical
End
Tw
ist (
deg)
Axial Load (N)
January 10, 2000 Georgia TechSchool of Aerospace Engineering
ConclusionsConclusionsIsolation of Extension-Twist RelationshipIsolation of Extension-Twist Relationship
Cylindrical End Mass Eliminated Restoring Cylindrical End Mass Eliminated Restoring MomentMoment
Symmetric Method Provided Inconclusive ResultsSymmetric Method Provided Inconclusive ResultsDependent on Accuracy of Specimen ManufacturingDependent on Accuracy of Specimen ManufacturingSimple Method Shows PromiseSimple Method Shows Promise
Vibration VisualizationVibration Visualization1P Sampling of Twist Provides Dynamic 1P Sampling of Twist Provides Dynamic MeasurementMeasurement
Investigation of Aeroelastic CharacteristicsInvestigation of Aeroelastic Characteristics
January 10, 2000 Georgia TechSchool of Aerospace Engineering
Future WorkFuture WorkRefine Symmetric Testing MethodRefine Symmetric Testing Method
Accurate Specimen ManufacturingAccurate Specimen ManufacturingAccurate Twist MeasurementAccurate Twist Measurement
Submit Method to ASTMSubmit Method to ASTM