Not Composite yet – article by Dan Fleetcroft in **F1 – Monitor
Carbon fibre reinforced polymer (CFRP) composites first found their way into Formula One during the mid-1970s; however their full potential was not universally recognised until 1981 when John Barnard pioneered the carbon fibre monocoque with the McLaren MP4/1. After John Watson’s crash at Monza that season silenced sceptics’ concerns over structural integrity during impact, all Formula One teams followed suit, developing their own composite monocoques. The carbon fibre revolution had begun.
The superior specific strength and stiffness of CFRP to that of metals, as well as its formability, have made it the primary choice for highly loaded and aerodynamically optimised components of the modern Formula One racecar. More and more parts have evolved from metallic to composite construction as the teams’ engineers fight to reduce weight. More than three-quarters of a contemporary Formula One car’s volume is now made from CFRP, while it accounts for less than a third of its mass. So as this material offers such performance benefits, why aren’t even more components constructed from carbon composite?
Outside of Formula One, the greatest obstacle would be cost (design, materials and production), but in the highly competitive world of motor racing this is unlikely to be prohibitive. The technical regulations restrict the use of materials for certain components, forbidding the application of composites in some areas, but one of the major limiting factors is structural integrity at elevated temperatures above 400 C.
Carbon fibres themselves have very high temperature resistance (carbon sublimes at above 3000 C); however it is the polymer matrix that limits the ultimate operating temperature of the composite. The predominant matrices are thermosetting polymers, examples being epoxies and polyesters, with Formula One composites being dominated by the former.
Epoxy systems exhibit maximum glass transition temperatures (Tg) of around 180 C above which the matrix softens, taking on a rubber-like state, greatly reducing the load-carrying capability of the composite. There are alternative polymers, including bismaleimide (BMI) and cyanate ester, which can achieve transition temperatures of up to 380 C.
(Read the full article at F1-Monitor here http://www.highpowermedia.com/F1-Monitor/3648/not-composite-yet)« Back to Blog & News Entries