Air-Frame Thermoplastic Composite Strut for Light Weight Vehicles. Tom Russell

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1 Air-Frame Thermoplastic Composite Strut for Light Weight Vehicles Presented By Tom Russell

2 Background ACT Allied Composite Technologies LLC Founded in 2007 Headquartered in Rochester Hills, MI Mission is to develop a portfolio of new and market-disruptive products based on novel combinations of technologies that offer unique, cost-effective solutions and that are protected by patents and / or trade secrets. A prime interest area is thermoplastic composite materials

3 Background - CST Composite Systems & Technology Founded in 2010 Headquartered in Massena, NY Mission is to replace conventional structural materials such as commodity metals and wood with advanced composite materials that are stronger, lighter in weight and lower cost. Air-Frame is CST s First Product

4 What is Air-Frame? Helical Braided Design Made from Thermoplastic Composite Tape Highly Productive Process Exceptional Strength to Weight Ratio

5 Initial Motivation Robot Arms Sporting Goods How about Lightweight Vehicles?

6 Plastic Strut Background Current State of the Art Thermoset resins for fiber wet-out Variety of reinforcements (mostly carbon fiber) Roadblocks Productivity (cycle time to cure resins) Piece cost due to low productivity Recyclability Issues Lead to a Thermoplastic Solution

7 TP vs. TS Strut Materials Thermoplastic Thermoset Stiffness, Impact, and/or Strength Chemical Resistance Broad Thermal Performance Durability Structural Bonding Capability Self Bonding Capability Weight Melt Recyclable Manufacturing Productivity / Piece Cost Highly Reinforced TP Composites Required For Long Term Success

8 Material for Struts Continuous Fiber-Reinforced Thermoplastic (CFRT) Tape Produced with a Continuous Oriented-Fiber Process Handles a Variety of Thermoplastic Resins and Fiber Matrixes Allows Thermoplastic Composites to be Produced with High Levels of Continuous, Oriented Reinforcements Yields Very Light, Tough, Strong and Stiff Composite Parts Ideal for Compression Molding, Thermoforming, or Lamination

9 Material Production Process Pre Tensioner Cooling Section Post Tensioner Tape Glass Fiber Thermoplastic Resin Bath Process is Developed to Eliminate Dry Fibers

10 Material Properties Typical properties of uni-tapes made from various resins and glass fiber. Reinforcing fibers such as Basalt, Kevlar, and Carbon Fiber have also been used. Resin PP PET Nylon 6 PPS Nominal Thickness (0.25 mm mm) Fiber Glass Weight % (0.25 mm mm) (0.25 mm mm) (0.25 mm mm) Density lb/in 3 (1.47 g.cc) lb/in 3 (1.89 g.cc) lb/in 3 (1.67 g.cc) lb/in 3 (1.92 g.cc) Tensile Strength 110,000 psi (759 MPa) 130,000 psi (897 MPa) 124,000 psi (124 MPa) 138,000 psi (952 MPa) Tensile Modulus 3,800,000 psi (26.0 GPa) 4,600,000 psi (32.0 GPa) 4,100,000 psi (28.3 GPa) 4,600,000 psi (32.0 GPa) Note: The above values are from lab samples; actual part and plaque properties may vary

11 (m2s 2) (kn m/kg) Comparison to Other Materials Specific Strength Specific Modulus Modify Strut Geometry to Optimize System Stiffness

12 Strut Production Overview Tape slit to proper width Put tape on a modified braiding machine Longitudinals and Helicals are applied in multiple layers Bonding is via heat and pressure applied at the machine Process is continuous Length is variable Diameter is fixed by the mandrel

13 Performance Primary interest is in compression loads that cause failure between nodes Three potential failure modes considered Compression Euler Buckling Shear Design can be Modified to Create Specific Failure Modes

14 Performance Predictions Model created to predict performance - INPUTS Unit of Measure Metric Strut Diameter 5.0 cm Strut Height 20.0 cm Angle of Helical Members 37.0 degrees ϴ Number of Longitudinal Members (24 maximum) 8 Number of Helical Starts (choose from list) 16 Width of Helical Members Thickness of Helical Members Width of Longitudinal Members Thickness of Longitudinal Members 5.0 mm 2.4 mm 5.0 mm 2.4 mm Reinforcement E Glass Resin PET Weight % of Reinforcement 60% Factor of Safety 1.5

15 Model Output Density of Composite Modulus of Members Tensile Strength of Members OUTPUTS 1.83 g/cc 33 GPa 885 MPa Area of One Helical Member Area of One Longitudinal Member 0.12 cm cm2 Radial Spacing of Longitudinal Members 1.96 cm Radial Spacing of Helical Members 1.96 cm Length of Helical Members cm Number of Rotations 1.69 Maximum Column Height between Nodes 1.48 cm Maximum Helical Length between Nodes 1.23 cm Truss Mass 0.15 kg MAXIMUM COMPRESSIVE LOADING Due to Compressive Failure Shear - (Argon, Budiansky, Fleck, ) Euler Buckling - Longitudinal Segment Output Correlates with Test Data 56,627 N 1,584 N 81,349 N

16 Performance Structure Can Maintain Loads

17 Truss During Crush Test

18 Further Development Validate Model with Bending and Torsion Loads Produce / Test Other Resins and Reinforcements Create New Geometries (square, rectangular) Joining Technology Hybrid Metal / Composite Structures

19 Potential Vehicle Applications Cross car beams Steering and suspension components Drivetrain components Energy management structures (Bumpers, IP s, Doors, Seats) Tubular vehicle structures Load floor reinforcements Possibilities only Limited by the Imagination!

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