Development partnership produces prototype car

A Huntsman Advanced Materials product story

Edited by the Engineeringtalk editorial team May 25, 2007

The Pescarolo team has worked closely with Huntsman and drawing on their combined expertise in composite materials.

Less than six months after announcing their development partnership, the Le Mans racing team, Pescarolo Sport, and Huntsman Advanced Materials have successfully trialled a new prototype car, the Pescarolo 01.

The Pescarolo 01 prototype has been constructed to exactly the same scale as the finished vehicle and must be able to perform in strength and crash tests to a comparative standard.

In order to achieve this, the Pescarolo team has worked closely with Huntsman and drawing on their combined expertise in composite materials.

The Pescarolo and Huntsman technicians chose Huntsman's RenShape BM 5055 epoxy tooling board to build the carbon fibre moulds for the car's chassis, all the bodywork and all the interior components for the Pescarolo 01.

All the models for the chassis and bodywork components were CNC milled out of BM 5055 boards.

Several layers of carbon fibre were then impregnated with Huntsman's RenGel SW18 / Ren HY 2404/HY 5159 epoxy resin system and laid on top of the models, making sure the resulting composite structures were voidless.

An autoclave cure was then undertaken to provide the extra strength and resistance the models required in order to withstand the tough FIA strength and crash tests.

The cure temperature ranged from 60C to 80C over a 14-hour period to ensure the composite parts were tough and strong enough for their purpose.

The chassis and bodywork composite parts were then bonded together using Araldite 2014 two-component epoxy adhesive and Araldite 204 one-component foaming adhesive to fill any small gaps between the component parts.

"The physical properties of the BM 5055 tooling board and the RenGel SW15 epoxy resin system proved particularly suitable for this demanding application" according to Michel Elkoubi, who is overseeing the Le Mans development project at Psecarolo.

"The high temperature resistance and durability are key requirements for us".

"Also, BM 5055 is easy to machine with a good surface finish after milling".

"This enabled us to significantly reduce any additional polishing and finishing, so speeding up the entire manufacturing process by about 20%" On completion of this first prototype model, the Pescarolo 01 was then submitted for the mandatory FIA strength tests in Italy, including a crash test in which the model is run into a wall at 50km/h.

Without passing these tests, the Pescarolo 01 would not be allowed to compete at Le Mans IV and it would be back to the drawing board for the team.

For the first test, the rear of the model was fixed onto an aluminium plate.

This assembly was then placed on a frame surrounded by jacks to support different parts of the model.

The model was then subjected to a series of strength and pressure tests with anything from six to 14 tons of pressure being placed on different parts of the model shell.

The rest of the model's component parts, including the fuel tank were then subjected to the same stress tests as well.

The results were monitored by computer and checked by an FIA technician, who cleared all the Pescarolo 01's component parts.

The road crash test was undertaken on a special track at the local university in Milan, which comprised a 50m stretch of track with a crash test wall at the end.

The Pescarolo 01 model was mounted on a trolley and then propelled towards the wall at 50km/hour.

To pass this test, there must be no cracking on the model shell after the test as the crumple zone on the front chassis must safely absorb all the impact.

To make the test more realistic a 75kg model is put in the cockpit to represent realistic on-board weight and the fuel tank is filled with water to make sure it has not ruptured in the crash.

During the Pescarolo 01 test, the front crumple zone of the model disintegrated into large pieces of carbon fibre on impact, as expected, but the shell remained intact and the deceleration rates were also within guidelines.

Though critical, the prototype used for these FIA tests is just the first in a series of six models that will be built before the actual Pescarolo Le Mans car hits the track.

"The next phase of testing will be with a fully functional prototype in about mid-April" said Michel Elkoubi.

"That will be the stage when standards are being set and we will, for the first time, start to see what the competition at Le Mans 2007 is likely to be".