Structural Mechanic Aspects of CFRP Fuselage Structures · Structural Mechanic Aspects of CFRP...
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Institute of Composite Structures and Adaptive Systems Structural Mechanic Aspects of CFRP Fuselage Structures ESAComp User‘s Meeting 2007, April 24th – 25th, „Advances in Design and Analysis of Composite Structures“ Alexander Kling DLR Braunschweig Institute of Composite Structures and Adaptive Systems Structural Mechanics Section, COE Composite Structures
Transcript of Structural Mechanic Aspects of CFRP Fuselage Structures · Structural Mechanic Aspects of CFRP...
Institute of Composite Structures and Adaptive Systems
Structural Mechanic Aspects of CFRP Fuselage Structures
ESAComp User‘s Meeting 2007, April 24th – 25th, „Advances in Design and Analysis of Composite Structures“
Alexander Kling
DLR BraunschweigInstitute of Composite Structures and Adaptive Systems
Structural Mechanics Section, COE Composite Structures
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Overview
IntroductionCompetences and Working Areas in Structural Mechanics at DLRValidationExperimental MethodsNon-Destructive Testing (NDT)Virtual TestingGlobal-Local ApproachFast Tools for DesignStructural Health Monitoring (SHM)Summary and Conclusions
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Targets: Weight Reduction → Cost Reduction → Saving of Resources
Costs [%]
Weight [%]
10 20 3010
20
30
-10-20-30-40
-10
-20
-30
New Metal Technologies
Future Fibre Composite Technologies
Today‘s Fibre Composite Technologies
Today‘s Metal Technologies
Challenges and Motivation for High-Performance Lightweight Structures
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Utilization of Composites – A Steep Slope
B737-300 B747-400
B787
A300 A310-200
A320 A340-300 A340-600
A380
MD80B757 B767 MD90
B777
A400M
A350
0%
10%
20%
30%
40%
50%
1970 1975 1980 1985 1990 1995 2000 2005 2010Jahr des Erstfluges
Fase
rver
bund
ante
il am
Str
uktu
rgew
icht
Quelle: NASA, Airbus und BoeingFirst Flight
Com
posi
tes
with
resp
ect t
o st
ruct
ural
wei
ght
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Stability AnalysisStability Analysis
Damage ToleranceDamage Tolerance
Thermal AnalysisThermal Analysis
NDT/SHMNDT/SHM
ValidationValidation
ExperimentalStructural Analysis
(EXSACOM)
ExperimentalStructural Analysis
(EXSACOM)
Deformation, Stress and
Failure Analysis
Deformation, Stress and
Failure Analysis
Health MonitoringHealth Monitoring Validation and Qualification
Validation and Qualification Virtual TestingVirtual Testing
Modelling and Simulation of
whole Life Cycle
Modelling and Simulation of
whole Life CycleSimulation Based
DesignSimulation Based
Design
Working AreasC
ompe
tenc
es
Competences and Working Areas in Structural Mechanics
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Spectrum of Working Areas
Health MonitoringHealth Monitoring Validation and Qualification
Validation and Qualification Virtual TestingVirtual Testing
Modelling and Simulation of
whole Life Cycle
Modelling and Simulation of
whole Life CycleSimulation Based
DesignSimulation Based
Design
Experimental Methods
Efficient testing facilitiesQualifikation of structural conceptsStructural Health Monitoring (SHM)
Validation
Numerical Methods
Fast Design ToolsVirtual StructuresStructural Exploitation
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Validation
Validation„Solve the right equations“
Validation„Solve the right equations“
ExperimentalStructural Analysis
(Test Field,Buckling Device,
Thermex,Ultrasonic Facilities
ARAMIS, …)
ExperimentalStructural Analysis
(Test Field,Buckling Device,
Thermex,Ultrasonic Facilities
ARAMIS, …)
Stability AnalysisStability Analysis
Damage ToleranceDamage Tolerance
Thermal AnalysisThermal Analysis
NDT/SHMNDT/SHM
ValidationValidation
ExperimentalStructural Analysis
(EXSACOM)
ExperimentalStructural Analysis
(EXSACOM)
Deformation, Stress and
Failure Analysis
Deformation, Stress and
Failure Analysis
There is an industrial need of validated analysis tools
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Experimental Methods
Characterization Exp.
t= 0 ms t= 1,25 ms t= 2,5 ms t= 5 ms t= 7,5 ms t= 10 ms
Phenomenological ExperimentValidation Experiment
Experiment Nonl. FEM Analysis
Qualification Exp.
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Non-Destructive Testing (NDT)
Working Areas:
• Coupling by air
• Mobile System (MUSE)
• Detection of porosity Damages after collapse of a stiffened panel
MUSE
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Increasing Number of Material Systems
Monolithic
Sandwich
Textiles
Hybrids
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Antenna Structure Made of Perforated Sandwich
testReal sandwich material
Detailed material characterization(exp. and analysis)
Homogenized global analysis
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Virtual Testing
Shear loaded A340 panel
Set up of virtual test to:
Reduce time and cost intensive experimentsTo optimize test set-up:
“Validation” experiments„Pre-test“ analysis„First time right“
Axially loaded cylinder
FEMFull field exp.Measurement(ARAMIS)
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Global-Local Approach (Submodeling)
stiffened cfrp panel
Matlab mesh generatorGlobal model
Python script to obtain simple stress based indication of critical
areas in the stringer-skin interface
Nl. FEM (ABAQUS)
Matlab mesh generatorLocal Models with focuson the stringer-skin interface
Nl. FEMs ABAQUS +stress based failure criteria
Submodelingapproach (ABAQUS)
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Fast Tools for Design – Stability Analysis
E.g. IBUCK: Semi-analytical design toolto simulate the buckling and post-buckling behaviour ofstiffened panels
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Fast Tools for Design – Impact (1)
Impact
Debris (Take-off or Landing)
Tool-Drop
Low-velocity Impacts
• CODAC = Composite Damage Tolerance Analysis Code
• Analysis of impact damages and residual strength for composite structures
• Based on the FE-method
Fiber breakage
Matrix failure
Delamination
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Fast Tools for Design – Impact (2)
0
0.5
1
1.5
2
2.5
0 1 2 3 4 5 6t / ms
F / k
N
Experiments, 4J
no degradationwith degradation of core
with degradation of core and skin
18,5mm
15,1
withoutdegradation
with coredegradation
(upper bound)
22,4mm
with core & skindegradation
(lower bound)
37mm
Simulation
Test
• Impact simulation on composite sandwich panels
• Comparison of num. and exp. results show good results
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Structural Health Monitoring (SHM)
CFK-plate with piezoceramicactors and sensors
Objectives:
• Simplified inspection
• Continuous monitoring
Concepts:
Lamb-wave analyses
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Summary and Conclusions
Brief insight into some relevant structural mechanic aspects forCFRP fuselage structures have been given.
Validated analysis tools essential for save, efficient (cost and time) design
State of the art experimental methodsState of the art NDT/SHM methodsState of the numerical methods
Global-Local (submodeling) approach can be used as an “elevator”up and down in the “Rouchon“ pyramid
Institute of Composite Structures and Adaptive Systems
Thank you for your attention
[email protected]+49 (0) 531/295-3236
