Versions Compared

Old Version 3

changes.mady.by.user Elizabeth M Rawson

Saved on

compared with

New Version Current

changes.mady.by.user Elizabeth M Rawson

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

FiberUsesProsCons
Carbon fiberUsed for the exterior of the car
  • Lightweight
  • Conductive → does not allow radio waves to travel through it
    • Communicate with data acquisition on where they're placing the radio to make sure that you don't have carbon fiber surrounding it
FiberglassTypically used for making molds
  • Flexible
  • Cheaper than other fibers
  • Non-conductive → allows radio waves to travel through it
  • Heavy 
KevlarRequired in the canopy by regulations
  • Fireproof
  • Shatterproof
  • Difficult to cut: you need a $30 diamond dremel bit

Tow: A bundle of fiber that is identified by the number of carbon filaments they contain. Each "k" stands for a thousand fibers.

Tow

1k

3k

6k

12k




Weave: the way the fibers are bundled together

  • Fabric stability: ability for a fabric to maintain its weave angle and fiber orientation
    • The higher stability a fabric has, the lower the formability 
  • Crimp: the curvature of a fabric in a single weave
    • A very tight weave will make the crimp (curve) become more tight.
    • Plain weave crimp diagram carbon fiber sheetImage Added
WeaveAppearanceDefinitionUsesProsCons
Plain weavePlain Weave Carbon Fiber DiagramImage Modified
  • Flat sheets
  • Tubes
  • Bulkheads
    • Panels

    This is one of the most common types of weaves for carbon fiber. 

    A tow strand in plain weave passes over 1 tow and under 1 tow.

    • Flat panels (includes sandwich composites) 
      • Bulkheads
    • Tubes
    • High fabric stability
    • Poor with curved geometry/complex contours
    • Harsh crimp in the tows due to the short distance between interlaces. The harsh crimp can create stress concentrations which can weaken the part over time.

    Plain weave (spread tow)

    Spread Tow Plain Weave Carbon Fiber Diagram Checker WeaveImage Modified

    		Like your regular plainweave,
    but 
    • Flat sheets
    • Tubes
    • Bulkheads
    • Panels
    but the filaments are spread into a wider tow. 
    • Flat panels (includes sandwich composites)
      • Bulkheads
    • Tubes
    • Less harsh crimp in comparison to regular plain weave
    • Poor with curved geometry/complex contours
    • More expensive than regular plain weave
    Twill weave (2x2)2x2 Twill Weave Carbon Fiber DiagramImage ModifiedThis is one of the most common types of weaves for carbon fiber. 

    If you follow a tow strand in a twill weave it passes over a set number of tows and then under the same number of tows. Since this is 2x2 twill weave, it passes over 2 tows and under 2 tows.  There is a longer distance between tow interlaces which means fewer crimps.

    • Curved geometry
      • Typically bottom shell, canopy
    • Flexible 
    • Can conform to complex contours
    • Fewer crimps compared to plain weave thus less potential stress concentrations.
    • Less fabric stability than plain weave
    Twill weave (3x3, 4x4, etc)4x4 Twill Weave Carbon Fiber DiagramImage Modified

    Twill weave with less formability than standard 2x2 twill weave. The weave is less tight than 2x2 twill. We have historically rarely/never used this, but if you need to make a composite with many complex, tight curves then you may want to consider this.

    There is an even longer distance between tow interlaces which means fewer crimps than regular twill weave

    • Curved geometry
      • Typically bottom shell, canopy

    • More expensive than regular twill weave
    • Less fabric stability than 2x2 twill weave

    Tow: A bundle of fiber that is identified by the number of carbon filaments they contain. Each "k" stands for a thousand fibers.

    Tow1k3k6k12k


    Density

    Fabric orientation

    ...