Structural and Manufacturing Considerations for a Research Unmanned Aerial Vehicle

Structural and Manufacturing Considerations for a Research Unmanned Aerial Vehicle+
Design of a composite drone control autopilot radio control two stroke engine resin infusion, vacuum bagging, monocoque, flaps

1. Structural and Manufacturing
Considerations for a Research
Unmanned Aerial Vehicle
Daniel Valyou, Suresh Dhaniyala,
Pier Marzocca
Department of Mechanical and Aeronautical
Engineering, Clarkson University

2. Purpose
Develop a small Unmanned Aerial Vehicle (sUAV) to
fulfill an academic research role
<55 lb aircraft weight
Large payload capacity (weight and volume)
Low cost of construction and maintenance
Robust electrical system
Autopilot and Flight Data Recorder
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3. Goals
Reduce structural weight through use of advanced materials,
structural design, and construction methods
Composite and composite sandwich materials
Semi-monocoque structure
Vacuum molded composite subassemblies
CNC machined structural members
Emphasis on redundancy
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4. Mission Readiness
Aircraft must be adaptablee to a variety of research
Exhaust Emissions
Ability to sample unperturbed air
Low vibration transmitted to payload
Electrical storage / generation
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5. Airframe Overview
High Wing
Pusher Prop
Twin boom U-tail (split elevator)
Airfoil: Clark Y
Span: 110” (2.8 m)
Chord: 18” (0.46 m)
Engine: 7.5 hp
Gear: Tricycle
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6. Materials
Fiberglass mat (Fuselage mold)
Fiberglass cloth (fuselage / wing skins)
Carbon fiber (structural components)
CF / Rohacell foam sandwich panels (ribs)
CF / Nomex honeycomb sandwich (firewall, gear mounts)
CF roll/wrap tube (spar, tail tubes)
Rohacell foam (skin cores)
Medium Density Fiberboard / Urethane block (molds)
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7. Molds
Fuselage:
CNC machined MDF male plug; hand-laid fiberglass female mold
Wing/Tail:
CNC machinedUrethane block female molds
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8. Structure
Stressed skin fuselage with
composite hat-section frames
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Carbon fiber/nomex honeycomb
panels (firewall, gear attach
points)
Foam cored stressed skin
wing with carbon fiber /
rohacell foam ribs, carbon
fiber tube spar

9. Part Molding Methods
Autoclave
Best quality, strength/weight, thermal properties
Prohibitively expensive tooling costs
Vacuum Assisted Resin Infusion Molding (VARIM)
Dry fabric layup, even resin distribution, low void-space
More layup materials, long infusion time, uses more resin (waste)
Wet layup
Shorter curing time, fewer layup material, uses less resin
Increased risk of void space and excess resin content of finished part
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10. Control System
2.4 GHz Spread Spectrum Transmitter, redundant
receivers
Redundant r/c control through autopilot
Redundant controls (dual rudder, split elevator)
Redundant power (receiver/autopilot batteries and
generator)
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11. Aircraft must comply with FAA regulations as an sUAS
MP-2028LRC
Redundant r/f control links (2.4GHz/900MHz)
50 km range
Robust Ground Control station
GPS/inertial navigation, pitot static system, ultrasonic
altimeter
Autopilot
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12. Aircraft capable of operation as R/C or sUAS
Capable of complying with FAA sUAS regulations
Balance between optimization and manufacturing
Material selection dictated by manufacturing
CF versus Fiberglass skin materials
Foam core Frames
Redundancy key in aircraft survivability
Conclusions
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