“Collectively, this provides not only a very strong demonstration, but actual usage in a commercial application,” says Vaidya. “Any future work will build off of this.”

UTK and ORNL are now collaborating with several organizations on materials, design, manufacturing and installation of the panel systems, which they anticipated beginning at the end of September. Partners include IACMI – The Composites Institute’s Scale-Up Research Facility, DB Technologies, Compsys Inc. and Olin. While certain composite materials will be used for the demonstrator panel system, Vaidya says the design allows for flexibility.

“Ultimately, we are looking for low-cost, high-performance solutions. Economics will be the driver,” he says. “Building construction is continuously innovating, and our approach uses advanced materials in a cost-effective way.”

From left, undergraduate researcher John Klepzig and graduate student Vinit Chaudhary work with Alexia Rice, a staff member at UTK, on a composite panel.

Photo Credit: University of Tennessee, Knoxville

Cracking a Critical Curing Problem

Project: Process Modeling of Composite Microcracking

School: UMass Lowell

Location: Lowell, Mass.

Principal Investigator: Marianna Maiaru

Marianna Maiaru began modeling aerospace thermoset composites as a graduate student at Turin Polytechnic Institute in Italy. Working in collaboration with the University of Michigan, she developed computationally efficient multiscale approaches for progressive failure analysis of fiber-reinforced polymer composite structures. Since then, her work with industry and government agencies has further illuminated major technological challenges in composite manufacturing.

Earlier this year, Maiaru received the CAREER Award, an early-career development award from the National Science Foundation that included more than $568,000 in funding. She will use the five-year grant to perform computational modeling to predict damage and to validate her process modeling techniques and predict curing-induced microcracking.

“Extensive microcracking can compromise the strength of the thermoset and contribute to the structure’s subsequent failure,” says Maiaru, an associate professor in mechanical engineering at the University of Massachusetts Lowell. “The failure is very difficult to predict, so when manufacturers take the component out of the oven and see it’s fractured, they typically have to dispose of the part.”

Maiaru’s team will first seek to understand why microcracking occurs during curing, then develop software to predict the microcracking process. “We will subsequently optimize the cure cycle to prevent microcracking,” she says.

One key to predicting microcracking is understanding material behavior during curing. Maiaru will test various thermoset materials used throughout industry, including resins that are more prone to microcracking.

“One of my hypotheses is that resin brittleness influences microcracking,” she says. “Depending on processing conditions, if the resin is a little more brittle in some parts of the cure cycle, then it’s more prone to crack.”