Monocoque
A monocoque [mɔnɔkɔk] (from the Greek mónos alone, single and French coque for the shell of a nut or other fruit) is a one-piece , partly hollow body built from flat elements (sheet metal, sandwich panels) as a chassis or general frame of a vehicle.
In contrast to a traditional construction made of rods or tubes , the large shell of the monocoque resists attacking force, which enables a lot of rigidity with little mass . However, some monocoques are complex to manufacture.
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Planes
Aircraft fuselages were originally made as a framework made of wood or steel profiles and covered with cloth . With monocoques, the half-timbering was eliminated in the early 20th century, the outer skin was glued together from several layers of canvas and crossed veneer strips.
The Luft-Fahrzeug-Gesellschaft Roland developed the patented wrapped fuselage , the process of which was later licensed to the Pfalz Flugzeugwerke for the construction of combat aircraft. The fuselage was made in two halves by placing two layers of plywood strips with a middle layer of textile over a mold. At that time, however, the glue wasn't very moisture-resistant.
Similar monocoques did not appear in other vehicles until decades later, where the term is interpreted less narrowly. In aircraft construction, the semi-monocoque ( half -monocoque) prevailed, which can be built in half-shell construction and is provided with thin frames and stringers .
Automobiles
When automobile were first leadframe used and later in motorsport and bus construction space frame introduced. In the case of mass-produced vehicles, monocoques became established in the 1930s. The more common name for this type of construction is "self-supporting body". They are usually made from deep-drawn, spot-welded sheet steel parts. In 1962, the Lotus team opened the era of monocoque in Formula 1 with the Lotus 25. Instead of the lattice frame, aluminum sheet was joined with rivets to form a tub with hollow walls on the sides and framed at the front and rear. The upper non-load-bearing panel was removable. The following year, 1963, Jim Clark became world champion with the Lotus 25. Many sports cars with monocoque still have a separate body , since streamlined, rounded shapes can only be made from the plastic sandwich panels used there with unreasonable effort.
The first automobile with a monocoque (self-supporting body) made of fiber-plastic composite was the Berkeley Sports B60 sports car in 1956 . The Lotus Elite became better known in 1957 . At that time, fiberglass was used. The Lotus Elite achieved good placings at the 24 Hours of Le Mans for several years . The concept not only showed its efficiency, but also the dependency of durability on better materials and material-appropriate constructions.
In racing cars, such as in Formula 1 , the monocoque is also the body and, together with the engine and the vehicle transmission, forms the chassis.
This design was quickly developed and became common. The monocoques were largely closed at the top. Executing the shell in sandwich construction , with fillings up to honeycombs made of aramids , increased the area moment of inertia .
The first monocoque carbon fiber - composite was 1981, the McLaren MP4-1 of McLaren Racing . Such monocoque consist of impregnated with resin or tissue located with a high fiber volume fraction ( prepreg ), which at high temperature and high pressure in a autoclave cures.
The three designers who developed this construction method the fastest were John Barnard from McLaren, Colin Chapman from Lotus and Gustav Brunner from the ATS Racing Team , who was the first to develop an uncovered monocoque from this material.
Monocoques made of synthetic resin reinforced with carbon fibers were far superior to their aluminum predecessors in all stiffness values while being lighter. However, design and manufacture made completely new and expensive demands on the racing teams. The first chassis were still manufactured by the aviation industry, and it was only after a few years that all racing teams were able to manufacture the monocoques themselves.
For safety reasons, this design also caught on in the subordinate formula series such as Formula 3 , Formula 3000 and the IndyCar and Champ-Car series, which are comparable in the USA . This design has also found its way into the sports car sector.
The first production car with a CFRP monocoque is the Alfa Romeo 4C, which was first offered in 2013 . The BMW i3, sold in Germany, followed in the same year .
motorcycles
When motorcycle there monocoque almost as long as the automobile. The frame of the Megola from 1920 was just as unconventional and consisted of self-supporting, curved and riveted steel sheets.
Today, sheet metal and cast parts made of aluminum are combined into a single large part, in which, in addition to the intake air duct including air filter, the tank is also integrated. Yamaha TR 1 with monocoque as airbox , Kawasaki ZX-12R and the Ducati 1199 Panigale use this design.
Cycles
According to the Union Cycliste Internationale, a bicycle consists of several tubes, which is why it no longer allows monocoques in cycling, only diamond frames . Many hourly world records were canceled long after they were set because of novel, inadmissible bicycle technology. State of the art technology was achieved when Chris Boardman won the 1992 Olympics on the Lotus 108 monocoque bicycle .
Velomobile
Today's velomobiles are also increasingly being manufactured in monocoque construction, because the weight reduction, which is particularly important for the heavier velomobiles due to their construction, can be achieved more easily.
Web links
Individual evidence
- ^ Engineering Division McCook Field (ed.): Structural Analysis & Design of Airplanes . United States Army Air Service , 1920, p. 228 also ( online [accessed January 15, 2013]).
- ↑ Information taken from the English Wikipedia on July 15, 2017; referenced there as: "FAA, 2001, p.1.2"
- ^ Mark Whitelock: 1½-liter Grand Prix Racing 1961–1965 . Veloce Publishing, p. 269 ( online [accessed January 15, 2013]).
- ↑ Michael Trzesniowski: racing car technology . 2nd Edition. Vieweg + Teubner , 2010, ISBN 978-3-8348-0857-8 , pp. 777 ( online [accessed January 15, 2013]).
- ↑ cockerell.de: From PAX and MEGO to MEGOLA , accessed July 19, 2013
- ^ Adrian Turpin: On your SuperBike . The Independent . August 5, 1994. Retrieved January 15, 2012.