Embedded sensors, edge computing, machine learning and high-fidelity simulations are part of the toolkit for Paul Ziehl and the research team he works with at USC’s McNAIR Center for Aerospace Engineering and Research.
The team’s current focus is on detecting structural defects that occur during aerospace manufacturing processes to speed production and reduce costs associated with manufacturing, or in-flight decision making after bird strikes and similar events. Ziehl, a mechanical engineering professor in the Molinaroli College of Engineering and Computing, partners in the research with fellow engineering faculty members Sourav Banerjee, Andrew Gross, Wout De Backer, Darun Barazanchy and Ramtin Zand, as well as Joshua Widawsky, a graduate of the college’s first cohort in aerospace engineering.
Most of the team’s current projects are focused on advanced manufacturing for the aerospace industry, which is poised to begin using thermoplastic composites in place of traditional thermosets, particularly in the realm of commercial air taxi production. The team’s research is aimed at better understanding and improving advanced manufacturing processes so that the lightweight, impact-resistant thermoplastic composites can be applied to commercial aircraft production.
“Most of our work has to do with advanced manufacturing, producing complex components with aerospace quality, which is a very high level in comparison to other industries,” says Ziehl, who joined the Molinaroli College of Engineering faculty in 2004 and has been part of the college’s McNAIR Center for Aerospace Engineering and Research since 2013.
“Once thermoplastic composites are widely certified for aerospace applications, I don’t see much holding them back.”
“Strength to weight is everything in aerospace applications, and everybody wants the components manufactured at automotive production rates but with much higher quality standards. That’s where the research at McNAIR comes in.”
The team has attracted several contracts in recent years to study the physical condition of structures either during or after the manufacturing process. That’s where minimally intrusive sensors, machine learning and physics-based simulations come into play. Ziehl and the team partner extensively with Columbia, S.C.-based Integer Technologies LLC. Integer helps the McNAIR Center to move from laboratory scale innovations to industrial solutions through transition of relevant technologies.
The team is also partnering with Maher Advanced Composites in Greenville, S.C., to understand and improve a proprietary manufacturing process and to speed production for aerial drones that might accompany manned aircraft.
“Our team will work on minimally intrusive sensing during the manufacturing process, to understand the root cause for defects that may occur during the process,” Ziehl says. “We will leverage machine learning and set up a small assembly line at the McNAIR Center for the development of a highly skilled workforce. In parallel, we will conduct physics-based simulations at McNAIR to rapidly learn from and improve the manufacturing process itself.”
This type of analysis is crucial to advancing the use of thermoplastics and other advanced composites in aerospace manufacturing, which will enable accelerated aircraft production, Ziehl says. Unlike traditional aluminum alloys and thermoset composites now in use, thermoplastics can be fusion or co-fusion welded instead of fastened with rivets and bolts, and this capability, combined with high strength-to-weight ratio, might reduce structural weight by 20 percent.
Because they can be reformed, thermoplastics might be advantageous for space construction and modification since the material can be reshaped and reused, he says.
“Once thermoplastic composites are widely certified for aerospace applications, I don’t see much holding them back,” Ziehl says. “They provide a path to lower-cost and more rapid manufacturing — there are many advantages to thermoplastics.”