light as carbon

Carbonfibre

In the beginning of the sixties, Colin Chapman, chief designer of Lotus, introduced the monocoque to formula one by placing thin plates around the bars of the monocoque. This new technology increased the stiffness of the chassis.

F1 teams use carbon fibres, a pre-impregnated epoxy resin and an aluminium honeycomb layer, which is sandwiched between two layers of carbon fibre.
The chassis is usually the first part of the car to be built, due to the amount of time required. The main chassis usually comprises of about 8 parts (panels). The first stage of the manufacturing process is to build a solid (computercut) pattern, from which a mold for the panel is produced. The molds are constructed by laying a total of 10 layers of pre-impregnated (with resin) carbon fibre on top of each pattern to produce the mold. The production of the mold takes place in several stages, involving vacuum treatments, debulking and heating processes. The mold then has to be thoughroughly cleaned and prepared for use.

The next phase is the actual fabrication of a car part, made from sheets of pre-cut, pre-impregnated carbon fibre, which are carefully laid inside the molds. It is thereby vital orientate the carbon fibre sheets in pre determined directions in order to achieve the desired strength. A total of 5 layers of carbon fibre are laid, forming the outer skin of the chassis (to achieve a final, cured thickness of 1mm, a total of 3-4 layers of carbon fibre must be laid down).

It's 20 years or so since F1 constructors picked up on the idea of carbon fibre, which was previously used mainly in the aerospace industry. Now this remarkable material, which when properly treated can be three times stiffer and seven times stronger than the equivalent mass of aluminium, is employed by all the current F1 teams

Price Coming Down

The price of the basic material has been dropping steadily, though. In the mid-1990s a pound weight of carbon fibre cost over £60. Now it's more like £3 - very competitive with steel.

We're already used to seeing carbon fibre components in concept, prototype and limited-production cars. Within a few years they're likely to be much more common in mainstream vehicles, whose manufacturers like the stuff for its light weight, strength and resistant to corrosion and wear.

If carbon fibre composites are high-tech materials, the processing of them starts in a very sophisticated way and then gets more basic.

Computer finite element modelling is used to decide on the exact design required. A mould is created on the basis of those calculations. But the build-up of the laminated "sandwich" of Nomex, aluminium honeycomb sheets and carbon composite skins (looking from some angles rather like a wafer biscuit) is done by hand.