Lernmaterialien für Composite an der Karlsruher Institut für Technologie

fiber stress distribution in an aligned fiber

• Unidirectional
• Woven
• Multiaxial
• Random

Entire shared surface between fiber and matrix

• Interlacing of warp fibers (0°) and werft (90°) fibers
• Integrity maintained by interlocking of fibers
• Used when more than one fiber direction is required

Standard:

• Cheapest
• Most common
• 65-70 °C

Engineering:

• 120-130 °C

Advanced Engineering:

• 230-240°C

Imidized Plastics:

• up to 430°C

• A-stage --> unreacted resin
• B-stage --> vitrified system below gel point
• C-stage --> completely cured resin

• Majority of fibers run in one direction
• Small amount in other direction
  • hold primary fibers in position

Bond between matrix and fiber dictates whether the fiber will improve the properties of the matrix when load is applied to the fiber

• change the surface
  • coating for more interaction
  • increase surface area
• change the matrix
  • more interaction
• do both

can make the interface region brittle 

--> faster failure

• Direct Methods
  • Single Fiber Pull-Out
  • Single Fiber Fragmentation
  • Single Fiber Compression
• Indirect Methods
  • Variable Curvature
  • Slice Compression
  • Ball Compression
• Composite Lamina Methods
  • 90° Flexual Strength
  • 90° Transverse Strength
  • 3 Point Shear

• Orientation of used fibers
• Construction methods to hold fibers together