Simulation Key to Additive Manufacturing Analysis at MTC

MTC researchers created this seat bracket via electron beam melting. (image: MTC)

When 3D printing first hit the consumer market, it was considered a novelty and a gimmick. However, the professional market has leveraged the technology, incorporated other materials and systems, and created the burgeoning field of additive manufacturing (AM) that is revolutionizing the industry. Borja Lazaro Toralles and the Manufacturing Technology Centre (MTC) in the UK have recognized additive manufacturing as a field that is going to play a vital role in the future across multiple industries.

The MTC app enables the user to make design adjustments and test changes in the simulation, but without showing the underlying multiphysics model. (image: MTC)

MTC created the National Centre for Additive Manufacturing (NCAM) in 2015. The purpose of the center was to develop production-ready AM processes, overcoming the barriers to wide-scale adoption and working on legislative and standardization issues in the emerging field.

While the consumer-end of 3D printing has focused on plastic applications, AM has incorporated advanced metal forming techniques. With more advanced material usage, more technical processes have had to be developed to manage those materials. NCAM has approached these challenges with three specific engineering teams.

First, there are Component Technologists that produce items. These members perform the additive manufacturing, including laser engineered net shaping, laser welding and surface finishing. Then, there is the Advanced Systems team who make all the technologies work together as well as create the equipment that carry out these techniques, including robotics, advanced tooling and an electronics lab. The third team is the Digital Engineering area.

“We are the people who manage the data, the information,” said Toralles, the physics modeling team leader at MTC. “That goes from concepts like Industry 4.0, Big Data and Informatics down to physics modeling, where we examine the exact physical phenomenon that is happening. And we help the engineers understand why the process is not going as expected, why after printing it distorts, why the material is cracking or not behaving as it should be. We do this from a very low, fundamental physics level all the way up to full factory level for production, managing the whole flow of the manufacturing process and optimizing it for best use of the resources.”

Simulating distortion

New AM processes are constantly being developed as the field grows to meet continually advancing industry needs. Toralles has experienced different processes being used for different applications. Laser processes like laser powder bed fusion are used to address component surface design requirements like wear resistance or repelling organic growth. Processes like net shaping form consistently structured components from metallic powders in a reservoir using high pressures in a vacuum. There are also speed-versus-quality requirements that drive which technique is used.

AM also brings about unique challenges. Toralles and his team have experienced this firsthand from the modeling perspective. Designing a component layer by layer on a micron level can require unreasonable amounts of time. Also, performing a finite element analysis (FEA) on that component may take even longer. His team uses COMSOL Multiphysics simulation tool to analyze the design of a 3D-printed component.

The software shows how much a part will distort during production and whether it will continue to meet the design tolerances allowed. Another COMSOL ability is lumped modeling, which simplifies components to be rendered in a more timely manner.

“What industry wants is a concept or tool that has already been proven and demonstrated on a large scale that they know they can buy and implement directly in the production line,” Toralles said. “We then try to upscale the laboratory research to a production-scale magnitude, but also try to validate to make sure it operates properly.”

Bridging the ‘valley of death'

The COMSOL simulation results show displacement in the impeller to predict the final part shape. (image: MTC)

The MTC was founded in 2010 as an independent research and technology organization from a UK government initiative called the Catapult Programme. The purpose of Catapult centers is “to transform the UK’s capability for innovation in specific areas and help drive future economic growth.” The MTC is just one of seven centers of the initiative, but one that has a unique mission for the country’s manufacturing industry.

“We are part of the centers that conform the High Value Manufacturing Catapult,” said Toralles. “Instead of going for high volume and cheap prices, we stand for higher quality and high value. MTC tries to bridge this gap for academia and industry.”

Bridging that gap, the “valley of death” as they refer to it, is key to the MTC’s growth and success. When the organization started, it had just over a dozen industry partners and under 50 employees. Now, they have more than 500 employees and about 100 industry partners that include well-known manufacturers like Rolls-Royce, Airbus and GE Power. The organization also has key relationships with four major UK universities: Loughborough University, University of Birmingham, University of Nottingham and TWI.

“We engage with them directly on one-to-one with a particular customer. Sometimes, we go into a consortium where we have a big end user, an OEM, accompanied with some of their supply chain. We make them all work together. Because it is not enough just to get the big companies advancing their technologies if you don’t drive the entire supply chain,” Toralles explained.