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Morphing Composites
Paul Weaver Stephen Daynes
www.bris.ac.uk/composites
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Morphing Composites - Weaver
Shape Adaptation: Requirements
load carrying
shapeadaptable
light
tooheavy
tooflexible
toostiff
lightweightstructures
compliantmechanisms
conventionalmechanisms
Example: [0n/90n]T
Unsymmetric Laminates
State 2
State 1
Morphing Composites - Weaver
Prestressed Laminates
400 mm
[0/90/90/0]THexcel 913GFRP prepreg1.1% Prestrain
Morphing Composites - Weaver
Bistable Flap Design
6× GFRP prestressed bistable laminates
Rear spar
Clamp + Foam seal
100 mm0 deg
10 deg
2× [0/90/0]T GFRP skins
Daynes, S., Weaver, P. M., Potter, K. D., and Hardick, M., U.K. Patent Application for a “Device Which is Subject to Fluid Flow,” No. 0902914.1, filed 20 Feb. 2009.
D-spar
Morphing Composites - Weaver
Wind Tunnel Demonstrator
7’ × 5’ Wind TunnelSpeed = 60 m/s; Re = 2.7 × 106
0 deg
10 deg
Morphing Composites - Weaver
Wind Tunnel Test
0 deg
10 deg
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Morphing Air Scoop
• Morphing Air Scoop Design
• Finite Element Analysis
• Manufacture
• Exploitation
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Morphing Air Scoop Design• 2 stable states (open & closed/flush)
• Smooth shape (‘NACA duct’)
• Deployment time < 5s
• ±10kPa dynamic pressure with deflections < ±2mm
• -20oC to +90oC
• Waterproof
• 10 year life (5000 cycles)
Ø60mm pipe to cooling system
Volume < 360×360×100mm
Intake area > 2750mm2
Underside
NACA duct
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Morphing Air Scoop Design
Open Closed
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Finite Element Analysis
• Tri-stable behaviour
• ABAQUS FE & analytical model agree
• Principal surface strains ± 1.4%
• ±1mm max deflection due to ±10 kPa
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Manufacture
Envelope bag
Plastic mould
Tube Morphing plate
Top plate
Release film
Prepreg mould & drape
Autoclave manufacture
CFRP prepreg drape
Breather cloth
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Exploitation
• Interaction with industrial partners to find applications.
• Concept not yet patent protected.
• Potential applications:– Deployable UAV engine air intakes
– Air intakes for aircraft cooling systems
– Automotive - Ventilation- Down force generation
Morphing Composites - Weaver