Formula Student 2015 testing at Silverstone

Materials World magazine
3 Sep 2015

James Perkins witnessed static testing day at Formula Student 2015, at Silverstone, and talked to the students about their materials choices.

Maraging steel with carbon fibre

A goal for the University of Bath at the start of Formula Student 2015 was to be best of the British teams, but by wining the endurance event and achieving fourth place overall, Team Bath Racing (TBR) exceeded expectations.

One of the innovations that helped push the team towards such a strong result was the use of 3D-printed maraging steel for both the centre of the newly designed wheels and for the suspension uprights.

The team achieved a 60% weight saving on each wheel (1.1kg) compared to the previous year.

Mechanical engineering student Martin MacDonald explained TBR's choice of material for the wheels, 'When you look at printing in general, you mostly look to titanium, but if you look at the specific properties of this steel compared to titanium, it is really quite good – it has a UTS (ultimate tensile strength) of about 1,900MPa, yield of about 1,750MPa, and the fatigue properties are better than than what you see in titanium as well.'

The steel is needed to reinforce the carbon fibre exterior. The two parts are joined together by five bolts, which also attach the wheel to the rest of the vehicle. 'If you use carbon fibre you need some kind of reinforcement due to the stress concentration you get from the bolts', explained MacDonald.

By 3D printing the suspension uprights through the same process and material, the team saved 20% weight, compared to the previous year. 

Bath's use of 3D printing impressed IMechE President, Richard Folkson, himself a former Formula Student Head Judge.

'I had never seen anything like that in production – it is really impressive stuff and showing Ross Brawn (former Mercedes F1 Team Principal) around, he is seriously impressed by what he has seen the students doing.' 

TBR Project Manager, Tom Peirson-Smith, said, 'We are incredibly proud of what we managed to achieve [at Silverstone]. To prove we had the pace to run with the best teams in the world, despite being a rookie team, was really satisfying. To also win the main event on Sunday (the 22km Endurance) was something I never could have imagined doing before the event. We have now equalled Bath's highest result at any event, with 4th overall out of 100 teams. Our motivation is now very high going into [Formula Student at] Austria and Spain, where we hope to go one better.' 

Watch this space, because TBR's 2016 car won every category it entered in Class 2 development category this year.

University of Bath mechanical engineering student Martin MacDonald holds aloft the 2015 wheel that he designed for the Team Bath Racing Formula Student 2015 car (left) and the previous year's wheel (right).

The 3D-printed core of the Team Bath Racing wheel, made with maraging steel in a laser melting process in 48 hours.

Tilt testing underway at Formula Student 2015.

The Ecole Central Lyon team driver practices some agility work at Silverstone on Formula Student 2015 static testing day.