Why Marry 3D Printing with Topology Optimization?

Topology optimization is an additive design approach to produce models to fit the operation conditions. Image courtesy of solidThinking.

3D printing gives engineers the freedom to design products that cannot be manufactured any other way.

The process of adding material, as opposed to subtracting material, allows for more intricate shapes. This has given engineers an unprecedented chance to design lighter, more organic looking products.

Historically, the way we make objects has influenced the way we design them. “When we use a traditional CAD to design a part, the CAD is based on Boolean operations or subtractive design,” said Jaideep Bangal, senior application engineer at solidThinking.

However, software tools such as solidThinking Inspire produce designs the same way 3D printing does: additively. Using topology optimization, Inspire uses a mathematical approach to optimize the layout of material based on a given design space and operational conditions (boundary conditions and loads).

“[Inspire is] based on human bone growth algorithms,” said Bangal. “In nature, the bone will react to different forces when applied. It will be a very organic looking design, and that is what you get with topology optimization — the most efficient shape mathematically.”

“On the [production] side, 3D printing offers structural freedom,” said Bangal. “You can design the most efficient and functional part and still 3D print it. You don’t have to worry about how you will manufacture the part in the traditional way.”

Topology Optimization Is Fast

It would be difficult to design this bracket in CAD. Image courtesy of solidThinking.

Since 3D printing offers shape flexibility, compared to traditional manufacturing, engineers can add more value to their designs. These performance enhancements can come in the form of lighter, stronger parts and cheaper customization.

However, engineers can spend a considerable amount of time designing those enhancements.

Fortunately, Inspire can perform fast topology optimizations to determine multiple design iterations optimized for various criteria.

“Topology optimization comes up with something very organic based on how nature would react to the forces. The design process changes from days to hours in Inspire based on the calculations running in the background. You can then take these designs back to 3D printing,” said Bangal.

For example, Bangal described a bracket designed by one of his customers. He then said, “Can I come up with this design in CAD? Maybe in two to three weeks. Can I design it structurally? Maybe, but I will have to go back and forth between CAD and simulation. This is a very traditional way to design.”

Some performance enhancements Inspire can optimize for include:

Maximize thickness only where it is needed
Minimize mass
Optimize natural frequencies

No Supply Chain? With 3D Printing, No Problem.

3D Printing offers cool designs with structural freedom made without retooling your manufacturing process. Image courtesy of solidThinking.

3D printing offers another benefit to design engineers: no supply chain. Just as engineers no longer have to worry about how to build the design, they also don’t have to worry about how to source it. All they need is a printer and a CAD file.

For instance, engineers can scan the part they wish to redesign, optimize it in Inspire and 3D print on-demand.

“You can print it right there. You don’t have to worry about the supply chain, and no retooling is required,” said Bangal. “I can come up with a design that can be manufactured right away.”

Instead of building all of the tooling needed to make a single highly customized part, you can instead send it to the 3D printer and build the whole part right away. Within a day, you can have your finished complete part. Conversely, making a single highly customized part will take much longer with conventional manufacturing practices.

However, it is worth noting that on a longer timeline mass production of identical parts tends to be cheaper and faster than mass producing parts using 3D printing.

None the less, Bangal offered another way 3D printing can save money. “Inspire-driven design unlocks the potential of additive manufacturing,” he said. He went on to explain that various solidThinking users were able to reduce the weight of their products from 25 to 75 percent when using 3D printing as their method of production.

Can Inspire Optimize Your Part for Other Manufacturing Options?

Part is optimized for manufacturing processes other than 3D printing. Image courtesy of Altair.

In addition to optimizing the part for performance, Inspire can also optimize a part for a given manufacturing process.

For instance, shape controls are used to have Inspire create parts that are cast-able. As a result, your part can be optimized for weight and manufacturability via traditional means.

“We can then use Inspire to create something that is manufacturable or 3D printable. Most of the time you will see weight saving as Inspire adds the material where it is absolutely needed,” said Bangal.

In other words, Inspire’s topology optimization is used to come up with a concept shape. This concept shape can be optimized with controls to ensure the part can be fabricated by various manufacturing procedures.

However, as this is only a concept shape, engineers will typically still need to fix up the part to be manufacturable. This can be done by importing the shape into CAD for the final touches. Engineers should note that this procedure may be needed if printing the part or using traditional manufacturing.

However, Bangal noted that there is a current trend with these shape controls. He said, “Today we are going backwards. We are making very organic designs without these controls that are just 3D printable.”

How Do I Design My Part in Inspire?

Part is much lighter thanks to Inspire. Image courtesy of solidThinking.

Engineers typically have two starting points for a topology optimization, the first is to design from scratch, the second is to optimize an existing design.

In both cases, you will need your operating conditions and a packaging space to get Inspire to work.

If you are using your existing design, constraints and design criteria, then Inspire will highlight all the fillets and holes in your geometry. The purpose of this is to help the engineer expand the packaging space to allow for more freedom during the optimization.

Next, you tell Inspire how a part is anchored by adding bolts, pins and surface connections. You then define what the part is to be made from using a material database or by using custom material parameters. Once the loads are input into program, the optimization can start.

Inspire will add material until the shape will satisfy the operating conditions. Therefore, depending on the properties of the material, loads, design space and performance criteria, more or less material will need to be added to avoid certain failure conditions or save more weight.

Inspire can then be used to validate the part based on the loading conditions. However, engineers will likely need to export the part to CAD for further design changes. Once this process is done, a finalized part can be sent to the 3D printer and/or prototyping team.

“Inspire displays material where it is absolutely needed based on the given operating conditions,” said Bangal. And thanks to 3D printing, the engineer can use Inspire to its fullest to design a complex component that is highly specialized.

To learn more about Inspire and 3D printing, follow this link.

solidThinking has sponsored this post. They have no editorial input. All opinions are mine. —Shawn Wasserman