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Dassault Systemes Highlights the Role of Simulation in 3D Printing

Dassault Systèmes kicked off its Science in the Age of Experience conference in Chicago last week with an Additive Manufacturing Symposium. The Science in the Age of Experience conference distinguishes itself from the company’s Design in the Age of Experience conference by focusing on the SIMULIA, GEOVIA and BIOVIA simulation brands; as opposed to Dassault’s CATIA and SOLIDWORKS brands. What does simulation have to do with 3D printing? Plenty, as it turns out, and plenty more is possible by simulating various additive manufacturing (AM) processes, machines and materials.

Penn State's Timothy Simpson shows an example of distortion during his presentation at Dassault Systemes' Additive Manufacturing Symposium.

Penn State’s Timothy Simpson shows an example of distortion during his presentation at Dassault Systemes’ Additive Manufacturing Symposium.

The Hole Story

“Why are holes circular?” asked Timothy Simpson, professor of mechanical and industrial engineering at Penn State University and co-director of the Penn State Center for Innovative Materials Processing through Direct Digital Deposition (CIMP-3D). “Is this the most efficient use of material? Is this the way Nature intended? No, it’s because this is how we’re used to making them. We’ve been making them for hundreds of years. It’s cheapest, fastest, quickest to drill a circular hole. Holes don’t have to be circular anymore. You can print all sorts of geometries now.”

That simple realization can cause a ripple effect in design thinking. 3D printing technologies make it possible to rethink standard shapes, combine different materials, apply materials in different densities in the same part, and combine multiple parts into one.

“You can change alloys on the fly,” Simpson said. “You can get corrosion resistance here, fatigue properties there, better hardness there … all in a single component.”

However, it’s not that simple when it comes to integrating those possibilities into product design and development. “How do you design that single component in your CAD system that has multiple materials? How are you going to analyze that in your finite element analysis (FEA). Even worse, now that we can print it, how are you going to certify that you have the right microstructure in the right place?” Simpson asked. “This is what’s causing both the excitement and companies to sort of freak out a little bit about where we’re going with additive.”

Challenges of Simulating Additive Manufacturing

And we’ve got a long way to go when it comes to efficiently combining design and simulation with additive and traditional manufacturing. Sometimes holes are circular in parts because they need to be bolted onto existing assemblies. Right now it’s difficult to take into account all the possibilities of 3D printing and combine them with traditional manufacturing requirements while optimizing them for specific AM processes and machines. Simpson gave one example of his students “not knowing what they can’t do” and cobbling together four or five different software packages to design an optimized part, only to spend 30 of the 54 hours of build time—and $1500 of the $2000 in materials costs—on supports, not the actual part.

“A lot of our tools, our simulation models, the design workflow that we have, is now the bottleneck in our system,” Simpson said.

Subsequent presenters shared their work on removing those bottlenecks. Jack Beuth, professor of mechanical engineering at Carnegie Mellon, director of the university’s NextManufacturing Center shared his work on developing process maps. Process mapping is a means of understanding the capabilities and variabilities in AM machines via experiments and simulations to control process outcomes and qualify parts.

“You can also design the [AM] process itself,” he said. “Most people don’t fully appreciate how much freedom there is in designing the process. It’s very possible to manipulate the process variables significantly on existing machines.”

Beuth is working on process mapping software that someone could use to design the process variables as they’re designing the part. Learn more in this video:

Process Simulation

Jacob Rome, a structural analyst at The Aerospace Corporation, focused his presentation on simulating the process of developing and qualifying AM parts for space applications.

“In the aerospace industry, there is a lot of emphasis on making things properly that work the first time,” he said. In AM, variables such as the orientation of the part, the moisture content of the metal powder being used, where supports are placed, and laser print speeds, power and patterns, just to name a few, can affect the quality of the parts.

“Tools are available now and becoming more available to simulate AM processes,” Rome added. “In the future, software will be capable of pre-correcting distortions, predicting microstructures and optimizing build parameters.”

But Rome was quick to point out AM is not magic. The old design constraints have been replaced by new ones. “You can’t make anything you want with any properties you want.”

The trick is knowing what is possible during the design stage and what your virtual changes will mean to the physical part. A lot of those variables depend on the material being used.

Material Matters

As Lyle Levine from the Materials Measurement Lab at National Institute of Standards Technology (NIST) put it: “Frankly, if people had asked me many years ago, ‘What is the worst possible way to build a material?’ I probably would have said ‘by welding millions and millions of little bits of metal together.’”

Levine’s job today is all about making that metal AM process work better. Specifically, he’s trying to help “build the tools that will allow engineers to design a specific part for a specific engineering application with a specific additive manufacturing machine.” As part of that mission NIST has founded AM Bench, an AM benchmark test series of highly controlled builds and detailed measurements that they plan to make available publicly so people can validate their simulations.

Integrating 3D printing, whether metal or polymers, into a production environment, takes longer than many companies expect. Mike Vasquez, a consultant from 3Degrees, said it can take six months, if everything goes well, just to begin part production. Companies that go into AM for production need to understand the challenges involved.

From Dassault Systèmes’ perspective, the solution to many of these challenges can be realized via collaboration on a single platform. At the conference, the company shared its vision for combining design, simulation and optimization for additive manufacturing via the 3DEXPERIENCE platform.

“Two to three years ago, there was a lot of hype for AM. When hype met reality, we got pulled in,” said Subham Sett, director of Additive Manufacturing & Materials at SIMULIA. “Things were failing, distorting. When we looked at it, we looked at it not just from the simulation side. The simulation side alone doesn’t help AM. It’s an ecosystem from design to simulating manufacturing to production.”

Sumanth Kumar, VP of SIMULIA Growth at Dassault Systèmes, said the journey for simulating AM is just beginning, and it’s already revealing some unexpected benefits.

“One side effect of the transformation in AM is that the designer or the engineer is getting very familiar with the value of simulation,” he said. “The analyst is now understanding how to design parts. So the silos we’ve had are changing. Customers such as  Airbus have made monumental changes in their organization. The boundaries between various roles are changing. It’s a fantastic side effect I’m seeing from all this transformation.”

In the followup to this article, we’ll expand beyond AM to look at Dassault’s vision for advancing simulation that it shared during the Science in the Age of Experience 2017 conference. Additive manufacturing is just one disruption companies need to respond to as we enter into what the company calls the Age of Experience.

About Jamie J. Gooch

Jamie Gooch is the editorial director of Digital Engineering. Contact him at de-editors@digitaleng.news.