Optimizing Jet Engine Bracket

Motivation

I have a profile on GrabCAD where I sometimes upload a few 3D designs. It is also a convenient and excellent place to grab some cad files you can use in your designs, or maybe even get inspired by the big talent mass present on the site.

Sometimes they make competetions and in 2013 they teamed up with american company General Electric to approach the crowd, and try if they could come up with an optimized design of an existing Jet Engine Bracket used in modern jet planes.

The concept was to replace conventional CNC manufacturing techniques, with new methods of 3D print. The material should be in a strong and light weight Titanium-Aluminium alloy and if designed correctly, it could have the potential to replace all jet engine brackets saving a lot of weight and money. While the overall goal was to minimize material and weight of the bracket, it should be ensured material strength could be equivalent to the existing design.

Results

Using some 3D CAD and simulation Techniques, it was possible in relatively short time to optimize the original design into a new improved design. Result was 80% mass reduction, while maintaining strength.

Methods Used

Simulation Mechanical Strength using FEA

Very often a 3D CAD file is used for manufacturing, and it can also be simulated for various physical conditions. One method is Finite Element, where the part is divided into multiple small pieces. Each piece is combined, and strength is calculated on the overall structure. This would take forever for a human to do, but the computer is an excellent book-keeper and calculates multi-millions of elements with ease. Making it a very strong tool to simulate components before they are manufactured - if used correctly (as with all technology).

Today there are many tools available and very often integrated into the 3D CAD packages.

Topology Optimizations

As it happened to be, I just finished an advanced course in Finite Element Analysis at my university. To achieve a better understanding of the methods, we programmed our own algorithms and compared them with state of the art analysis tools in software package called Ansys.

One of the more exciting topics we did, was programming our own Topology Optimizations algorithms. Topology Optimization is a mathematical way to make the computer iterate simulations of the component. During each step, the computer removes redundant or less important material. With this method, it should be possible to make the computer suggest an optimal design in a very short time.

It might not be the perfect design, but it can be a really good suggestion (or inspiration) achieved in a short period of time.

Topology Optimization is a great tool to have and I also used it to redesign a robotic gripper in another similar competetion

My Final contribution

Using the described methods, I did a few iterations, and decided to upload my design the competetion. Working only ~1-2 days on this design, it was possible to achieve 80% mass reduction of the component, while maintaining structural integrity. At least in theory.

Competetion Results

I really enjoyed being part of it - and it truly was a great inspiration for me, to see the 10 winning designs. The winner only used 16% of the original mass, and the rest used ~15-20% of original mass, and GE actually printed and tested these designs for strength. All but 1 were strong enough !

Imagine combining 3D CAD with advanced simulations and optimizations. Use new manufacturing methods, such as 3D printing to achieve new type of designs that was too expensive before, or maybe even impossible. Combine it with the wisdom of the crowd - people actually shared their designs and helped each other.

Check out all of the rules and results here

Simulating Mechanical Layers

Because of the open source aspect to this competition and freely shared designs, I was also contacted by Nils Keller, at the time a Ph.D. student at university of Bremen. They were researching additive layers using laser printing in metal. We agreed they could use my design suggestion for research and I was acknowledged in their paper: “Thermo-Mechanical Simulation of Additive Layer Manufacturing of Titanium Aerospace Structures”

They used my design for a case in their specially developed software, which later became a company called additive works. My piece is used as a showcase

3D Printed Bracket

For showcasing, they also did make a 3D print