The additive technology link with digital twins

Recently, I had a conversation with Jeff Blanford, a Solution Architect at Morf3D, to discuss the latest developments with additive technology in the aerospace industry and on supply chains. This conversation shifted to looking at additive technology as more of a digital enabling technology, not just a different way to build parts. Here are highlights from the conversation.

Metal materials
The additive industry is seeing a tipping point, whether it’s because of need, cost, or supply chain issues, vendors are seeing more demand for additive metal parts.

Part of the reason is a general maturity of materials. Aerospace and defense customers are aware of the testing additive vendors are using to qualify materials. “We know with confidence what’s coming off the machine and whether it will deliver the material requirements that needs to be delivered,” notes Blanford.

Many materials are a result of the additive process and vendors tend to know what’s coming off the printer. The design processes also affect the final outcome. Customers and vendors are reaching a point where both have confidence in the solutions.

Digitization
Look at additive as part of the digital twin, digital thread approach. In additive, this approach is even more demanding and more relevant with additive than traditional CNC G-code kind of type manufacturing, for example.

“Everything is software driven with additive,” says Blanford. “You develop a specific program through software to develop hardware–you’re going from bits to atoms quite directly. This “digital twin” of that model gives you “what you see is what you’re going to get” information. A CAD model may look great, but it’s in the 3D printing that you find the “holes” in the design. And then you go into the digital twin, the CAD model of that part, and see the issue.”

This idea of a digital thread probably applies to additive more than any other manufacturing technology up to this point. So how do you make sure that you have a quality digital twin all the way through that digital thread? One of the biggest challenges in the industry today is that a lot of software providers in this space have come up with many amazing tools. Tools that can do things like generate lattices and topology optimization. And the build processor interprets that CAD model and turns it into code that the printer can read.

Then there are simulation tools that let you simulate the actual metal part building up in real time, so you can actually see how it’s building layer by layer and adjust your support strategy, or compensate for distortions. These are all really valuable tools, but they all live in “silos.”

Thus, engineers must do some of the work in one tool, then export and import into another tool, and so on. Then they print the part and inspect it. If they find an issue, which is not uncommon, they need to go back and fix it.

But the challenge was doing all that work in different places; it’s hard to track what you did where. Not to mention the fact that now you have N number of different tools to maintain, or train on and update, as well as working with different engineers on the design.

Thus, many in the industry are trying to connect that digital thread in a way that is concise and traceable. Especially, as additive in the metal world continues to push into more defense and commercial contracts. That traceability, to be able to look at a serial number on a part and have complete lineage all the way through, from the CAD model, to simulation models, to the manufacturing models, which printer it was printed on, what version of the software was used, having all of that maintained and tracked across a connected digital thread is really what’s required.

“The digitization of the engineering process, I would say is as important, if not more important for additive than it is for any conventional methodology of manufacturing,” adds Blanford.

Value
The broad strokes of the value proposition of additive are twofold. First, additive breaks the relationship between cost and complexity. For example, consider printing a part with a lattice structure component to it. As far as the actual additive process is concerned, whether you’re printing that complex lattice structure or a solid block of material, the costs essentially are the same; it comes down to run time and powder consumed.

This example would not be the case for CNC machining a complex part. And the degree of complexity and blends and curved surfaces to the part, the greater the increase in time needed to machine it, which can sometimes be an exponential increase. So, additive breaks the relationship between cost and complexity.

Second, additive breaks the relationship between cost and time, effort, money, and lot size. Especially for anything that’s casted or molded. Anything that requires a lot of tooling means most of the design work will involve simulation and digital programs because testing opportunities are limited. Casting the complex part is where a lot of the up-front money goes.

Additive eliminates that fixed cost, and replaces it with a variable cost. “You can throw something on a printer, see how it prints and get feedback, go in and change your model, and then print it again,” says Blanford.

Combine that capability with advanced simulation tools, such as non nonlinear structural analysis, computational fluid dynamics, and so on. “With the ability to quickly print a physical version of that digital simulation, you gain higher levels of correlation and can have much better confidence that the answers coming on the computer screen match the answers you get in real life,” says Blanford.

In this arena, additive plays really well with simulation. Simulation and additive are symbiotic because one can reinforce the other and allow an engineer to come up with designs they wouldn’t have the ability to so otherwise.

Selecting the right additive project
One of the biggest challenges and biggest opportunities when working with customers is to find design candidates that give deliver the greatest value and make the most sense to do additively. Digitization can give you that leverage.

“I like to refer to additive as an enabler,” says Blanford. It’s a technology, but it’s really an enabler. It’s up to the engineer to use design tools, and to use this digital thread to take advantage of what additive can enable.”

Design tips
“Many users want to jump right in and work with additive,” says Blanford. “But there’s a bit of a drawback to this approach. They often begin with designs developed for conventional manufacturing methods, such as casting, forging, and milling. They want a quote and they want to know what the print might look like. More times than not, the economics and the value proposition are going to be an instant loser. And the user will say that using additive is way too expensive. The issue is that you didn’t design that parat for an additive process, so yes, trying to replicate a machined or injection molded part using additive will generally cost too much to make.

“Focus on what you’re trying to achieve, and then go out and talk to the experts and the folks who know what these machines and technology can do and what it can’t do. And then go from there.

“And that is where the ‘rubber meets the road’ in terms of value. If we’re able to work with a customer who is trying to get into this technology and walk them through why a part needs to be designed in a certain way, or where it makes the most sense, that’s where we can actually push through and get that value proposition across the line.

“And the other piece of device I would give is to be open-minded in terms of what capabilities and what technologies you need to deal with. Because often if you go into a problem with a predefined idea, you might not be right. So, look at what your actual problem is that you’re trying to solve, and then try to pick the technology that makes the most sense for that problem.”

A tip is to start with a demonstration project. Don’t dive right into something that’s already being manufactured conventionally and expect that to just work for additive.

“I think a lot of people think that they can take any design and throw it in and hit a button and it’s going to work,” says Blanford. “It won’t, and even if it did you’re not really getting any benefit out of that.”

The best way to achieve value out of additive is to create designs that can only be made through additive to drive value. So, start with the demonstration project.

“You have your original design, all the costs and the benefits and the performance lined up, and then go and see what a demonstration part will tell you. Sometimes it’s not even at a part level. Sometimes it’s that system level. Where you’re looking at not only an individual component, but actually looking at the surrounding component and saying, ‘How can we combine these into one single piece and eliminate all the assembly costs? That’s a huge value driver for additive. And as the machines get bigger and bigger, that opportunity also scales with that size increase in machine. So go build a demonstrator, and go prove it to yourself, and prove it to your stakeholders that additive can be done. And go into that with an open mind. And again, sometimes it might not work and understand that failure is part of the equation. And sometimes you’re going to have to go through some failures to get to the successes, and that’s best achieved in a demonstration kind of prototype opportunity, as opposed to just expecting it to work right off of that.”

Service Bureau tips
Service providers offer different capabilities. It’s challenging for an engineer who’s trying to figure out how to get a project done to know where to go and who to talk to.

“Many additive solutions providers in our space, their main value proposition is printing. Whether that printed part will function as needed is a concern for the solutions provider as they are printing what was designed. Some providers don’t go into that level of detail. It’s important to find a provider that will work with you to come up with a cohesive solution. It takes a high level of collaboration, not only with customers, but also with suppliers to develop solutions that are actually going to drive value. Because at the end of the day, if it’s not better, or faster, or cheaper, then it’s a cool science project up until that point.”

It’s challenging to do everything yourself. But where the industry is today, it’s going to take collaboration between materials providers, software providers, the printer OEMs to really come together with the customers to come up with the right solutions. Look for partners who have that kind of mindset.