Lightweight Design of a World Champion

You can see here the rear Bell Crank of a Formula SAE car. It's made of aluminium (7075-T6) and the design is topology optimized. It weights only 45 g.

Topology Optimization allows the designer to create superlightweight components that are also very strong.

The component is part of the Suspension System of the racecar F0711-7 made by the team Rennteam Uni Stuttgart:

This masterpiece of hi-tech engineering was made by 40 students of the University of Stuttgart in 2012. The car won 3 international competitions, reaching 1st place on the World Ranking.

Suspension uprights, brake pedal, differential carriers... many components of the car were topology optimized, making each of them as light and strong as possible. The result: 180 kg.

Topology Optimization is a very useful tool that allows engineers to create superlightweight designs - like this car. I'm sure you are going to hear a lot more about this cutting edge technology in the future!

- Dad, why do they put holes right there?

- Because they want to make the structure lighter and spare some material.

Dad was right. But he didn't have a clue what his son was about to discover some years later.

His son graduated as a Mechanical Engineer and became a specialist in Structural Optimization. He was able to create superlightweight designs. And they were strong. Very strong...

He started his own company - Aligerator - and began doing things like this:

Costumer: Can you improve this design for us?
Aligerator: What do you really want? A cool design? Or something light and strong?
Costumer: Both.
Aligerator: OK. Let's see what we can do.

The problem was the following: We want to find the lightest component that can withstand 5000 N. The component is made of steel (S235) and the maximum dimensions are shown here:

If you ask an experienced Mechanical Engineer, he would say: Make some holes!

However, in Aligerator we don't believe in experience. We always want to find the best solution. So what we did is a Topology Optimization!

Taking into account the solution of the Topology Optimization, we designed a new component:

Which design is better: the design with holes, or the optimized one?

Let's compare both. Let's do a Finite Element Analysis and decide which one is better. In the following pictures you can see the stress values (von Mises) of both designs:

Both options are within safe values of stress. The design with holes is 20% lighter than the original. Not bad. However, the design made by Aligerator is 40% lighter. AMAZING!

NOTE FOR ENGINEERS

Steel S235 has a yield strenght of 235 MPa (for 5 mm thickness). Using a Factor of Safety of 1.5, maximum von Mises stress should be below 155 MPa. Both cases are below that level (with holes: 110 MPa, optimized: 130 MPa). Maximum displacements are around 0.4 mm in both cases.

A Topology Optimization maximizes the stiffness of a component applying a volume constraint (for example, you can maximize the stiffness of the component reducing 40% in volume). Translation: you get a very lightweight solution which is also very strong.

You can also see that the stress distribution in the model optimized is much better than in the model with holes. Why? Because most of the component is under stress, leaving no area unstressed. This means material being used only where it's going to be necessary (under stress). Intelligent use of material!

Welcome to Aligerator!

Aligerator

We are going to change the world.

Let´s go lightweight!