10. Summary

Question 1

What is the fibre content for Glass fibre Sheet Moulding Compounds (SMC)?

Answer 1

20%-30%

Question 2

What is the fibre content for Twill weave carbon fibre moulded by Resin Transfer Moulding (RTM)?

Answer 2

40%-55%

Question 3

What is the fibre content for Autoclave cured unidirectional carbon fibre prepreg?

Answer 3

65%-75%

Question 4

Sketch on the same axes, the stress strain curves of: Carbon FIBRE, Nylon 6 polymer MATRIX, and the resulting COMPOSITE with Vf=0.5

Answer 4

Fibre: Linear elastic (brittle) curve

Matrix: Initially linear elastic, followed by ductile plastic deformation, large strain to failure

Composite: properties dominated by fibres, initially elastic, followed by a small ductile region with low strain to failure

Question 5

What are the material properties of industrial grade carbon fibre?

Answer 5

Elastic modulus: 240GPa

UTS: 4500MPa

Strain to failure: 1.875%

Question 6

What are the material properties of unreinforced nylon 6 polymer?

Answer 6

Elastic modulus: 4GPa

UTS: 100MPa

Strain to failure: 40-50%

Question 7

What are 2 main parameters influencing formability of biaxial NCF? describe appropriate test methods

Answer 7

In-plane shear behaviour (normalised shear force vs shear angle)
-Bias extension or picture frame shear test

Inter-ply friction
-Sled test

Question 8

What are 3 main material/process parameters for flow simulation for resin transfer moulding?

Answer 8

-Reinforcement permeability tensor (fabric permeability)
-Resin viscosity
-Applied pressure gradient

Question 9

What properties do fibre reinforced composites exhibit?

Answer 9

-High specific stiffness
-High specific strength
-Can embed sensors
-Anisotropic
-Improved fatigue resistance
-Corrosion resistance

Question 10

List the manufacture properties of Directed Carbon Fibre Preforming (DCFP)

Answer 10

Investment: £££
Cycle time: <0.5hr
Deposition: +50kg/hr
Production: <50,000ppa
Properties: 250MPa
Pros: High deposition/flexible
Cons: Lower props/consist

Question 11

List the manufacture properties of Automated Tape Layup (ATL)/ Automated Fibre Placement (AFP) preforming

Answer 11

Investment: ££££
Cycle time: 5-10hr
Deposition: 5-50kg/hr
Production: <200ppa
Properties: 2000MPa
Pros: Performance/QC
Cons: Slow / simple parts

Question 12

List the manufacture properties of 2D-3D preforming

Answer 12

Investment: £
Cycle time: 0.1-1hr
Deposition: 0.5-5kg/hr
Production: <30,000ppa
Properties: 800MPa
Pros: Simple process
Cons: Limited automation

Question 13

List the manufacture properties of 3D weaving preforming

Answer 13

Investment: £££
Cycle time: 1-5hr
Deposition: ???
Production: ???
Properties: ???
Pros: Complex parts / loads
Cons: Slow / limited part size