Carbon Fiber Filament Winding Hal Peterson Rob Haglin
Overview Design and build a machine capable of carbon fiber filament winding Empirically test and optimize mandrel
What is filament winding? Process by which continuous reinforcing fibers are accurately positioned in a predetermined pattern to form a shape (usually cylindrical). Use machine to wrap composite around mandrel Mandrel is then removed, leaving hollow composite part Angles generally set at -45,0,+45
Why filament winding? Composite shafts have high tensile strength, low compressive strength. To overcome the weakness in compression. Gives very high strength/weight ratio Increases performance in machines or automobiles when utilized, because decrease in weight.
Applications of Filament Winding Cars Rockets Aircraft Propellers Blades Engine parts Any place where weight is an issue, or there is a desire to decrease weight to increase performance.
Winding Three types of winding Helical Circumferential Polar
The machine 2 axis movement Variable speed spindle to hold mandrel Computer controlled Various diameters and lengths of shafts Wide range of wrapping angles
The Machine
Resin Delivery 2 main forms Pre-preg (pre-coated with resin) Resin bath impregnation
Resin bath Advantages Disadvantages Cheaper Easy to store Curable at room or elevated temp. Disadvantages Inconsistent Messy
Pre-preg – our choice Advantages Disadvantages Comes coated in resin Most widely used Can be used in hand lay-up if needed Disadvantages More expensive Storage (low temperature) Cured at elevated temp
Why we chose Pre-preg Even disbursement of resin on fibers Very precise fiber/resin ratio Better control of fiber placement and angle Increases precision and repeatability with parts
Curing Room temp (can take long time) Oven (elevated temp) Only for resin bath-impregnated Oven (elevated temp) Increased pressure
Machine Design issues Design for versatility Gearing Wear of pre-preg on eyelet Machine parts filling up with resin.
General Control Scheme
User Interface Needed Information What happens Fiber Angle Tube diameter Tube length Desired speed - optional What happens Instruction set generated from parameters
What happens
Instruction Set Object Oriented Approach Visual Basic .NET Decreases programming time Use supporting programs from Galil Developers kit Advanced servo tuning ActiveX controllers - $695
Questions
References http://www.fibercote.com/pabo6.html Manufacturing processes for Engineering Materials, 5th Ed. Material Science and Engineering 6th Ed http://www.pslc.ws/macrog/mpm/composit/fiber/process/prepreg.htm Galil user documentation