How to Reduce Car Pedal Weight by 47% with FEA
As everybody knows, in motorsport is necessary to optimize every component of the car, not just the core parts as the engine, the aerodynamics or the tires. One of the most important parameters to improve is the weight. Although in every category there is a minimum weight for the cars, it is very important to optimize the weight of the different components in order to distribute it over the car on the best way to improve the vehicle dynamics.
This way of working is shown in its most extreme form in Formula One, where the engineers develop the most breakthrough ideas to reduce the weight of the cars. For example, they started to manufacture components with carbon fiber to reduce the weight or even drivers have to follow strict diets to be as slim as possible.
Following this idea, engineers started to lighten up the different components, firstly using new materials with the same properties of resistance and hardness but less density, such as titanium or magnesium. When they couldn’t improve the weight in this way, they started changing the design of the components, trying to use as little volume as possible.
This method affects every component of the car, from the suspension arm to the support plate of the engine. It is even used on the steering wheel or the accelerator and brake pedal.
In this article, we are going to analyze how to reduce the weight of the brake pedal of a motorsport car changing its design. As most people know, there are different types of pedal systems, depending on position, distribution, and way of working. The most common systems are the pedal over the soil and hanging pedal.
In a common car, the most used is the hanging pedal, but in motorsport, the pedal over the soil is preferred. In minor categories, both throttle and brake work by wire, but in Formula 1 and other main categories, it is common to see brake by wire and electronic accelerator with sensors to control the engine.
Three Design Changes of Motorsport Car Pedal
To design our pedal, we will consider a system over the soil. For this, we should include the pedal and the base of it in our simulation to control its rotation. We can see the basic design on the next figure:
We are considering that the pedal is made of aluminum. Taking this into account, the weight of this pedal is 337 g.
To develop the simulations of the pedal, we should study the constraints and loads over it. The main constraints are the different set of parts (to keep them joined) and to block the movement of the assembly. We also can include a restriction of rotation, simulating that we have a spring to control the pedal.
As a load, we should consider the force that the driver can apply on the pedal. To analyze the resistance of the design, we have to consider the maximum force that, for example for F1, is about 110 kg.
With all these parameters, we can run the FEA simulation and see that this design has no problem to support the stress to which it is subjected. In any case, the only part that is suffering a bit is the join between both sides of the pedal, but this stress is not a problem.
Now that we have the basic design, we will try to reduce its weight by removing as much volume as we can. To develop this task, we should follow a matrix design, trying to keep enough material to support the loads.
Following this criteria, we create a new design and we simulate it to see if we have weakened too much our pedal or if it is strong enough.
Considering that we have the same scale to show the results, we can see that our component now is suffering more than before. We can also see that we have an area at the top of the side plate where the stress is bigger than it can accept, so we should re-design it to ensure that its performance will be as good as it should.
With this final design, we can see that our pedal supports the enormous force that the driver applies over it and it is as light as possible. This design has a final weight of 178 g, which is 159 g less than the first design. This represents a weight reduction of a 47%.
The obtained reduction maybe seems to be insignificant but, if we consider that we reduce the weight of both pedals and, even more, we use this methodology to lighten up other components, we can achieve reductions of 5-6 kg which can be very useful in a F1 competition where the difference between victory and defeat can be in milliseconds.
Interested in learning more about FEA, CFD, and Thermodynamics applied in F1 car design? Join this free webinar: APPLICATION OF CFD IN FORMULA STUDENT AND FORMULA SAE.