Rear Pressure Bulkhead: Large Damage Capability Demonstration … · 2015-10-13 · PRIVATE AND...
Transcript of Rear Pressure Bulkhead: Large Damage Capability Demonstration … · 2015-10-13 · PRIVATE AND...
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Rear Pressure Bulkhead: Large Damage Capability Demonstration
Composite Transport Damage Tolerance and Maintenance Workshop, Montreal September 2015
Jean-Philippe Marouzé
Product Development Manager
Bombardier Aerostructures & Engineering Services
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CSeries RPB: Design overview
2 Composite Transport Damage Tolerance and Maintenance Workshop, Montreal September 2015
Typical skinReinforced straps
A layer of fiberglass both side for drilling protection Titanium doubler
Aluminum fuel manifold
HP Duct BMI manifold
RPB is a fiber placed tear strap design with an objective of large damage capability as perdesign principle.
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CSeries RPB: Advanced Process
3Composite Transport Damage Tolerance and Maintenance Workshop, Montreal September 2015
Automated processes brings repeatable optimized part and quality
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CSeries RPB: Tear Strap design
4Composite Transport Damage Tolerance and Maintenance Workshop, Montreal September 2015
Strap are used to demonstrate residual strength capability (orange curve)Mar-Lin curve associated to a Point-Stress approach with non-linear FEM for final analysis.
Not applied for CSeries RPB
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CSeries RPB: Tear Strap design
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Level 2:Un-configured tests
Derive Tolerance to NotchLevel 3:
Tear strap testsValidate Methodology
Level 4:Pressurized Bulkhead
Validate Bulging, Bi-axial loading and Curvature Effects
Intensive bibliography studies performed to defined preliminary and detail sizing of RPB. BA worked with NSE Composites
Test conducted with production lay-up at each stage
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CSeries RPB: Level 2 un-configured
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0 deg
There is a benefit on residual strength capability with notch of using AFP process rather than hand lay-up validated with small notches (up to 4 inches)
Final production lay-up and off-axis notch / load need to be validated by tests.
Effect of overlap and gap density on notch capability is validated by tests.
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CSeries RPB: Level 3 Tear Strap Test
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strain in perpendicular to notch direction at 39.5 kips loading
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0 0.1 0.2 0.3 0.4 0.5 0.6distance_from_crack_tip
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nonlinear FEM
full field strain
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CSeries RPB: Level 3 Tear Strap Test
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Methodology show conservatism but removing it on a RPB shall be done also with other design consideration including inherent robustness criteria and fire resistance.
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CSeries RPB: Level 4 Pressurized Bulkhead
9Composite Transport Damage Tolerance and Maintenance Workshop, Montreal September 2015
Minimum gage
Reinforcement
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CSeries RPB: Level 4 Pressurized Bulkhead – Pre-Production
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12 inch notch on the side of RPB (critical area) and in the middle
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CSeries RPB: Level 4 Pressurized Bulkhead – Pre-Production Test to failure
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Similar failure mode on un-configured plate
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Conclusion
12Composite Transport Damage Tolerance and Maintenance Workshop, Montreal September 2015
RPB is designed as a large damage capable structure demonstrating product robustness associated to a complex damage scenario for this critical part.
Large Damage Capability is also applied to other primary structure (skin/stringers) on Aft Fuselage
Methodology demonstrate conservative approach but interaction with other design criteria shall be considered (fire, robustness, bearing/by-pass).Nevertheless, improving our simulation capabilities for complex failure mode like notch is future interest:
• Inter-action between stiffening ratio/lay-up and propagation• Softening law• Progressive Failure Analysis
Objective is to maximise simulation validated by coupons tests rather larger complex one
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