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