Johns Hopkins, Carnegie Mellon to co-lead new NASA institute

Johns Hopkins engineers are partnering with those at Carnegie Mellon University to ensure that additively manufactured metal parts used by NASA in everything from rocket engines to eventual human outposts on other planets are durable, safe, and capable of withstanding the stress of the space agency's most ambitious exploration missions.

The JHU-CMU team is spearheading one of NASA's two new Space Technology Research Institutes, or STRIs, which bring together university-led teams to develop technology. While the JHU-CMU-led institute will work to enable rapid certification of metal parts created using advanced manufacturing techniques, another headquartered at the University of Texas at Austin will focus on quantum sensing technology in support of climate research. Each institute will receive up to $15 million over five years.

"I don't think it is overstating to say that the results of our STRI will mark a paradigm shift in the way these materials are produced, qualified, and certified as being equal to the jobs they will be asked to do on critical space missions," said Somnath Ghosh, a professor of civil and systems engineering at the Whiting School of Engineering, who is the STRI co-primary investigator. Tony Rollett, professor of metallurgical engineering and materials science at Carnegie Mellon, is the institute's primary investigator. Ghosh and Rollett are co-directors of this institute.

Additively manufactured metal parts are made from powdered metals, which are melted in specific ways and shaped into useful parts, such as spacecraft components. The internal structure of this type of part is much different than that produced by other methods. It is difficult to predict with high accuracy how these materials will behave in real—often very stressed and high-stakes—environments.

"Practically speaking, it is obviously impossible for NASA to test every part in advance in every scenario, so that is where our 'digital twin' approach will prove invaluable," explained Ghosh, an expert in integrated computational mechanics and materials modeling and director of Johns Hopkins Computational Mechanics Research Laboratory and the Center for Integrated Structure-Materials Modeling and Simulations.

"Digital twins" are computer models that will allow the team to understand the parts' capabilities and limitations, such as how much stress they can endure before breaking. Such models enable optimization of process-structure-property relationships that are key for certifying the parts for use in the real world.

"Experimentally validated digital twins allow us to test a variety of metals and additive manufacturing materials in a computer, without necessarily going into a lab," Ghosh explains. "The simulations test the materials in a mere fraction of the time and expense it would take to test on the actual materials. And this way, we find out if the material will provide the performance we need and the lifespan we are looking for."

In addition to creating digital twins for additively manufactured parts made from spaceflight materials that are currently used for 3D printing, the research team will also use the approach for evaluating and modeling new materials. According to Ghosh, the digital model scenarios will employ physics, mechanics, and machine learning (AI), resulting in what he deems "an enriched model that can provide you with the big-picture view of what is going on."

Ghosh predicts that the result will be a gamechanger not only for NASA, but also for aircraft companies who need to test materials in a variety of high-stakes scenarios.

The Johns Hopkins team includes Jamie Guest, professor and head of civil and systems engineering; Jaafar El-Awady, professor of mechanical engineering; David Elbert, research scientist in the Hopkins Extreme Materials Institute; Maggie Eminizer, associate research scientist in physics and astronomy at the Krieger School of Arts and Sciences; and at Johns Hopkins University Applied Physics Laboratory, Li Ma, senior staff engineer; Michael Presley, additive manufacturing engineer; Steven Storck, senior staff scientist; and Morgana Trexler, program manager, science of extreme and multifunctional materials.

Also partnering with JHU and CMU on the project are researchers at Vanderbilt University, University of Texas at San Antonio, University of Virginia, Case Western Reserve University, Southwest Research Institute, and Pratt & Whitney.