Composites reduce wheel weight

The new rims weigh less than 2 kg.
The new rims weigh less than 2 kg.

Huntsman Advanced Materials has supported University Racing Eindhoven (URE) in a project to develop a hybrid composite wheel which will feature on the university team’s electrical powertrains prototype in this year’s Formula Student motorsport competition, run by the Institution of Mechanical Engineers, London, UK.

Over the past three years, the URE team has manufactured cars with electrical powertrain systems to take part in the competition’s static and dynamic events. These include elements such as acceleration, skid pan, autocross and endurance as well as static events covering design and cost reports, business plans and fuel economy.

This year a delegation of the URE team, consisting of four Mechanical Engineering bachelor students, came up with the concept of a hybrid composite wheel, designed to help lower the weight of its latest electrical powertrain prototype and achieve a greater power-to-weight ratio.

The wheel features an aluminium core and a carbon fibre reinforced plastic (CFRP) shell for the wheel rim. The team wanted to find an epoxy infusion system that would support their aim to achieve both cost and time savings in producing the composite shell for the rims using simple manufacturing methods.

An epoxy based resin infusion system from Huntsman Advanced Materials was selected.

The moulds for the wheel rims were milled and polished to create a smooth surface. They were then cleaned and a release agent applied. Dry carbon fibre plies were then draped into the moulds and peel ply, flow mesh, release film, breather and tubes for the epoxy resin flow were applied. The last step involved vacuum bagging the moulds in preparation for the vacuum assisted resin transfer moulding (VARTM) process.

In previous years the URE team used wheel rims weighing 4 kg each. The new rims weigh less than 2 kg, reducing the overall weight of the 230 kg car by 4%.

The CFRP rims will first be used on the electrical powertrain prototype when the URE team competes in Formula Student UK on 13-15 July.