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Similar to the
monocoque in Formula 1, the robust cell in passenger cars represents the
heart of passive safety. It too should be affected as little as possible in
the case of serious accidents. “It is crucial that the doors can still be
opened easily after an accident,” said Dr. Hartmuth Wolff from the Allianz
Centre for Technology (AZT). “This stability is achieved with the selective
use of high-strength steel in areas that require high rigidity: for example,
in the pillars.” However, rigidity alone is not enough in the area of the
passenger cell. “For ideal occupant safety, the deformation behaviour, the
rigidity of the cell and the function of the restraint systems and the seats
must be coordinated precisely with each other,” said Wolff.
In the Formula 1, the monocoque has become the most important component in
the drivers’ overall safety package since McLaren first sent cars with a
carbon fibre safety cell onto the starting grid in 1984.
In spite of the high standard achieved, however, Formula 1’s governing body,
the Fédération Internationale de l’Automobile (FIA), never ceases in its
efforts to improve safety in the sport even more. The crash tests which have
been stipulated by the FIA since 1985 guarantee the load capacity of the
monocoque and the crash structure, and they have become more and more
stringent over the years.
Since 1997, it has been obligatory for the rear structure as well as the
side crash structures and the roll-over bar to pass a crash test before
every season. Here, again, the FIA is not satisfied with the standards
already achieved and raised the level of the requirements a little higher
before the 2006 season began by increasing the impact speed for the dynamic
crash test of the rear area from 12 to 15 metres per second. That
corresponds to an increase of 56 per cent in the impact energy on the rear
crash structure, showing how much importance the FIA attaches to crash
safety as reliable life insurance for the drivers.
The monocoques are made from carbon fibre, a composite material that is
twice as strong as steel, but five times lighter. It consists of up to 12
layers of carbon fibre mats, in which each of the individual threads is five
times thinner than a human hair. A honeycomb-shaped aluminium layer is
inserted between these mats, which increases the rigidity of the monocoque
even more. The whole shell is then heated under pressure in the autoclave, a
giant oven. After two and a half hours, the shell is hardened, but still the
baking procedure is repeated twice more.
As a result, the monocoques are strong enough to protect the drivers even in
the most serious of accidents, like the one involving Giancarlo Fisichella
at Silverstone in 1997. The evaluation of the black box showed that his
Jordan slowed from 227km/h to zero in just 0.72 seconds, which corresponds
mathematically to a fall from a height of 200 metres. Even so, the Italian
only suffered a minor injury to his knee – thanks in part to the monocoque.
Allianz Safety Check: Albert Park Circuit - by WilliamsF1 Team driver Mark
Webber:
“On a road course such as Albert Park, we are inevitably relatively close to
the walls. That can be dangerous both for us drivers and for the spectators.
In recent years, the organisers have worked extremely hard to improve safety
for the spectators – and they’ve succeeded. But they didn’t forget the
drivers, either. There are run-off zones at key points on the circuit. It
wasn’t easy to integrate them, but the people in charge have found an
excellent solution.” |