Composite Manufacturing

1
Composite Manufacturing

• Group 15 Eglin AFB
• Brandon Bair - John Brewer - Darnell Brown - Rob
  Contes
• Sponsor Jeff Wagener - Lt Joe Czabarnek, AFRL
• Faculty Advisors Dr. Chiang Shih (ME) - Dr.
  Richard Liang (IE)

2
Introduction

• Scope
• AFRL Fuselage Specifications
• Project Specifications
• Research
• Selection
• Original Design

• Design Development
• Construction
• Testing
• Hiring
• Conclusions
• Recommendations
• Summary
• Questions

3
Scope

• The scope of this project was to redesign and
  test the fuselage of the Bullwinkle Micro Aerial
  Vehicle and hire a manufacturer to produce it.

4
AFRL Fuselage

• Length - 15.75
• Width - 2.25
• Height - 2.25
• Construction
• 2 part Design
• Male mold
• Pre-impregnated carbon fiber
• Assembled with nylon screws
• Motor Mount Sheet aluminum

5
Project Specifications

• Same size and shape
• Survive a 30o impact at 20 m/s (45mph)
• Ensure that motor heat will not affect structure
• Manufacturing
• 30 units
• 300 per unit
• 20,000 for start-up
• 1 month start-up, 1 month production

6
Research

• Materials
• Resin
• Processing
• Curing

7
Research Materials

• Glass Fiber
• Carbon Fiber
• Kevlar

8
Glass Fiber

• Pros
• Lightweight
• Inexpensive
• Cons
• Heavier than
• other composites

9
Carbon Fiber

• Pros
• Light weight
• Very strong
• Durable
• Cons
• Very expensive

materialogical.com/wordpress/?cat7
10
Kevlar

• Developed by DuPont in 1965
• Pros
• Thermal and electric insulator
• Absorbs energy
• Cons
• Breaks down in UV light
• Sublimes at 450oC

www.kevlar.com
11
Research Resin

• Polyester
• Inexpensive
• Low order crosslinking
• Epoxy
• Difficult to use
• High order crosslinking
• Vinyl Ester
• Compromise
• Easy to use

12
Research Bonding Processes

• Resin Transfer
• Contact Molding
• Vacuum Bag

13
Resin Transfer

• Process
• Material held in a closed mold
• Resin injected
• Pros
• Smooth, even sides
• Few voids
• Cons
• Complex molds
• Resin rich

http//www.rtmcomposites.com/whatrtm.htm2005
14
Contact Molding

• Also known as Hand Lay-Up Molding
• Material and resin are applied with a roller or
  brush by hand
• Pros
• Inexpensive
• Fast
• Cons
• Resin rich
• Labor
• Messy

15
Vacuum Bag Molding

• Applies vacuum to hold a part securely to a mold
• Pros
• Product is smoother
• Controlled fiber and resin ratio
• Cons
• Time consuming
• Materials

16
Possible Curing Processes

• Autoclave High temperature and pressure
• Oven High temp
• Room temperature

17
Selection

• Material Carbon Fiber
• Light weight
• Strong
• Standard in military MAV construction
• Resin Vinyl Ester
• Forgiving catalyst ratio
• Strong and tough
• Process Vacuum Infusion
• Control resin ratio
• Low voids
• Molds Female, Plaster

18
Original Design

• Solid nose
• Main structure with cap
• Four parts
• 10 Bonding strips

19
Design Development

• 4 main parts to 2 main parts
• Flat sheet
• 2 Bonding strips
• Cap
• Simpler
• Faster production
• More continuous structure and surface

20
Design Development
21
Construction Molds

• Wooden mold box
• Acrylic
• Wax
• Rapid prototyped
• male mold form
• Industrial gypsum plaster
• Wax

22
Construction Fuselage

• Wax
• Poly Vinyl Alcohol (PVA)
• Carbon Fiber
• Peel Ply
• Flow Media
• Vacuum Bag

23
Bench Test

• Run 1
• Full Power for 5 min
• No temperature change
• Run 2
• 50 for 7 min
• No temperature change

• Run 3
• 25 for 15 min
• No temperature change

24
Impact Testing

• Propelled with a pneumatic cannon
• Impacted a target ramp at 30o
• Speed measurement Calibration board and
  semi-high speed camera (120 fps)

25
Impact Results

• With motor
• Minimal damage
• Motor plate separation
• Retained structure
• With weight (3 lb total)
• Visible damage
• Motor plate separation
• Retained structure

26
Impact
27
Impact
28
Hiring

• ACMA
• Preliminary Contact
• Quote Request Package
• Detailed description
• Detailed drawings
• Prototype pictures
• Separate package
• for motor plate

29
Conclusion

• Fuselage Manufacturer TBD by AFRL
• At least 6 interested companies
• Timeline
• Production
• Motor Plate Manufacturer Milco Water Jet
• Lot Price - 190 (6.33 per unit)
• Timeline - 5 days

30
Recommendations

• Construct parts in house
• Low production numbers
• Quality control
• Variability
• Cost
• Research vacuum molding of polymers
• Quicker
• Less expensive
• Compliant parts

31
Summary

• Scope
• AFRL Fuselage Specifications
• Project Specifications
• Research
• Selection
• Original Design

• Design Development
• Construction
• Testing
• Hiring
• Conclusions
• Recommendations
• Summary
• Questions

32
Questions