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Why is Carbon Fibre used in Tennis Rackets?
What’s wrong with wood or steel?
Dario Modirrousta-Galian
A brief history of Tennis
French monks in the 11th or 12th century
Wooden tennis rackets.
Introduction of Carbon Fibre.
Popularity growth.
What Properties are needed for a good tennis racket?
Low density
Strong
Stiff
Hard
DensityMATERIAL DENSITY AVERAGE
MASS OF TENNIS RACKET (grams)
CARBON FIBRE 1740 310-340
STEEL 7900 355-400
WOOD (ASH) 710 365-425
StrengthMass: 0.06kgMax Speed: 73m/sContact time: 0.03sReturn Shot: 73m/sHead Size: 0.082m2
Racket Ball
Before 0 4.38
After 8.76 -4.38
P= m × vP= 0.06 × 73P= 4.38
P= m × vP= 0.06 × -73P= -4.38
Conservation of momentum
Ball Before
Ball after F=(Δmv) ⁄t
F= 8.76/0.03
F≈300N
P=N/m2
300/0.082
=3658.54
≈ 3700Pa
Strength
Wood
Metal
Flexible
StiffnessMATERIAL YOUNG’S MODULUS (N/m2)
CARBON FIBRE 530 × 109
STEEL 200 × 109
WOOD (ASH) 4400-18100
Cost- Carbon FibreCFRP= Carbon fibre reinforced polymer
Costs per kg: £50-£75
Price of Racket:
£25.50(MAX)
Costs per kg: £5-£8
Price of Racket:
£3.40(MAX)
Cost- Ash Wood
Costs per kg: £1-£7
Price of Racket:
£2.80(MAX)
Cost- Steel
Microstructure
Strong Covalent bonds require a lot of energy/force to break. These are very directional bonds.
Macrostructure
Structure is in a cross-hatched style which makes it very tight. This makes it very useful for tennis rackets as it makes them very strong.
Carbon Fibre under an electron microscope.
So why is Carbon Fibre used instead of Ash or Steel?
Head Size: 0.039m²-0.042m²
Head Size:0.052m²-0.058m²
Head Size: 0.077m²-0.087m²
Maximum= 0.088m2