Why do F1 cars have an aerodynamic shape

Background: How is a Formula 1 car constructed?

(Motorsport-Total.com) - In a few weeks the time has come: The long winter break is drawing to a close and the teams have been looking forward to the season opener in Bahrain for some time. The racing teams have by no means been idle since the last race of the past racing year, as a number of new vehicles had to be designed and built during the long Grand Prix break.

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Countless carbon fiber honeycombs - brought into shape - result in a Formula 1 vehicle

As much as the Formula 1 rules may change from year to year, the challenge for the engineers and technicians has always remained the same: Before each new season, it is important to make the best possible use of the team's resources, in order to have a quick and safe one in the spring Race car released on the test track. Read here what is important in this work process ... # w1 #

The monocoque

The monocoque is the core of every Formula 1 car. It is the pilot's workplace and survival cell in one. The engine is flanged at the rear, the vehicle nose at the front. The shape of the monocoque results from a number of factors such as the length of the wheelbase, the size of the fuel tank, the physique of the pilots and aerodynamic requirements.

When designing the monocoque, the surface shape is defined first. Various calculations are then carried out to guarantee that the safety cell meets the rigidity and strength requirements calculated by the engineers. These result on the one hand from the dynamic driving loads and on the other hand from the safety regulations of the FIA.

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Formula 1 cockpits are designed to offer the driver a lot of protectionZoom

These requirements have been continuously increased in recent years, which has significantly improved passive safety for the pilots. The most important tests are the frontal crash (with nose) at a speed of 15 m / s, the side crash at 10 m / s and the static load test of the roll bar, which has to withstand a pressure of around 12 tons. A total of five dynamic and ten static tests are carried out on the entire vehicle.

The monocoque consists of a composite of carbon fiber and aluminum honeycomb. This combination results in a very high level of rigidity and strength combined with low weight. The composite engineers define how many layers of carbon fiber are required at which point in order to meet the diverse requirements.

You can also choose between different types of carbon fiber - depending on whether forces act in one or more directions. Up to 60 layers of carbon can be processed on top of each other in areas with particularly high loads. In total, a monocoque consists of around 1,500 individual pieces of carbon fiber.

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Care is the top priority: the teams take their time to zoom when setting up the car

It is made from two half-shells into which additional reinforcements are glued. After several baking processes in the autoclave, the half-shells are glued together. The final step involves assembling numerous fastening components.

Due to their extremely high strength, monocoques offer pilots maximum protection even in very serious accidents. Because the fuel tank is also housed in it, dramatic fire accidents are a thing of the past. The safety cell can almost always be repaired after an accident.

The Sauber team in Hinwil produces an average of four to five monocoques per year, which are used for racing and test use as well as for the test bench trials. Each individual safety cell has to be homologated by the FIA, whereby only the first copy has to pass all tests.

The driver's seat

The current Formula 1 cars achieve lateral accelerations of over 4 g when cornering, and when braking it can even be over 5 g. During a race, these forces act repeatedly on the drivers over a period of one and a half to two hours. A perfect sitting position is therefore an absolute must. The smallest pressure points lead to pain or muscle cramps. That is why every pilot uses his own seat, which is precisely adapted to his body mass.

When manufacturing a new seat, you use a basic seat shell made of carbon fiber, which is lined with a plastic bag. This contains either a two-component foam or styrofoam balls that are vacuumized. The driver sits down and waits until this mass slowly adapts to his body. At the same time, small changes are made over and over again.

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The position of the steering wheel and pedals is tailored to the respective driver

The position of the steering wheel and the pedals are also adjusted. When everything fits perfectly, the seat foam or the styrofoam balls can be hardened. Such a seat rehearsal takes between half a day and a full day for the pilot. The seat created in this way is a transitional version that is used for the first test drives and serves as a prototype for the permanent seat.

To produce it, the inside surface of the temporary seat is electronically scanned. The engineers use this to create a mathematical surface, on the basis of which the shape is milled into a so-called tooling block. The definitive seat is then created on this by placing individual carbon fiber mats, which is then baked in the autoclave.

The final step is to finish the seat. This includes, among other things, the milling of the openings for the safety and rescue straps and the application of upholstery about a millimeter thick. The weight of a finished seat is around three kilograms.

The steering wheel

The steering wheel of a Formula 1 car is the control center for the pilot. It steers, couples, shifts and can influence numerous electronic functions with several buttons. In 2009, for example, the KER system was activated there at the push of a button, and this season the driver can make use of a range of aids such as pit radio, drinking equipment or speed limiter.

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A modern Formula 1 steering wheel is bursting with setting optionsZoom

In the first step of the steering wheel design process, the engineers define the functions that are to be varied using buttons or rotary switches. A first layout is then determined before a provisional version of the steering wheel is produced using rapid prototyping. The driver now assesses whether all buttons are optimally positioned. If not, he brings in his change requests.

Now the production of the definitive steering wheel begins. The basis is the so-called frame, which is made of carbon fiber. The holes for the switches and buttons are drilled into this frame, then the foam for the handle is applied, which is then wrapped again with carbon fiber. In the finish, different variants are used as a cover.

Depending on the pilot's preference, the handle can be covered with leather or designed with a silicone compound that is adapted to the shape of the hand. Now the buttons and switches are mounted and wired to the circuit board before the display is also connected. Since 2008, both the circuit board and the display have been part of the standard electronics and are made available as standard parts by the FIA.

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The driver can only get in or out when the steering wheel is removed

After completing all the electronic work, the specialists assemble the mechanical parts on the back, such as the shift and clutch paddles and the quick release. As is well known, pilots remove the steering wheel to get in and out and put it back on afterwards. The quick release is also required to complete an FIA test, which requires the pilot to leave the cockpit within five seconds.

Before the steering wheel is used, like all other components, it is first tested on the test bench. Only when these attempts have been successfully completed are the buttons and switches glued to the back of the frame. The high-tech component, which weighs around one kilogram, is now ready for use in the racing car.

Keyword: carbon fiber

With the exception of the engine, gearbox inners and wheel carriers, a Formula 1 car is made almost entirely of carbon fiber. High rigidity and strength paired with very low weight are the outstanding properties of carbon. It has a similar stiffness to steel, but is around five times lighter.

On the negative side are the complex manufacturing process and the high material price. A square meter of impregnated carbon fiber mat costs between 50 and 200 euros. Carbon fibers are 5 to 8 micrometers in diameter. Usually between 1,000 and around 20,000 fibers are combined into bundles that are woven into textile structures.

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The carbon fiber components are "baked" in such an autoclave Zoom

About 20 different types of carbon fiber fabrics are used in Formula 1. These differ in their structure and the type of resin with which they are impregnated. If forces only act from one direction, unidirectional layers are used; if they act from different directions, bidirectional fabrics are used.

Specialized composite engineers define which fabric with which resin and in how many layers is required to achieve the desired properties. The manufacturing process for a carbon fiber part ultimately involves several steps. First, the component is designed on the computer using CAD (Computer Aided Design; editor's note). These data are then processed and serve as the basis for computer-controlled production (CAM, Computer Aided Manufacturing; editor's note).

The corresponding shape is milled into a tooling block on a five-axis milling machine, which serves as a positive shape. According to the plans of the composite engineers, the laminators place the precisely cut pieces of carbon fiber on this tooling block - one after the other. After completing this work, the whole thing is packed in a plastic bag, vacuumized and then baked in an autoclave for ten to 20 hours at a temperature of around 50 degrees Celsius.

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Each front wing is a small work of art and consists of many layers of carbon fiber

The resulting negative form is then fine-tuned and ready for the production of the actual carbon fiber component. In the negative mold, the laminators place the previously cut pieces of carbon fiber on top of and next to each other. Depending on the component, this can be up to several hundred pieces.

When everything is ready, the form with the inserted carbon fiber is also packed in a plastic bag, vacuumized and baked at a temperature of around 150 degrees Celsius for five to six hours. After the baking process has been completed, the individual parts are processed further and then assembled into complete components. A front wing, for example, consists of around 20 individual carbon fiber parts. For components that have to be particularly tough, Kevlar or Zylon are used in addition to carbon fiber.