The Li Lab Spring 2020 Undergraduate Researchers
Connor
Rising 4th Year UVA Mechanical & Aerospace Engineering Student | LinkedIn
After a year of full time involvement in our Department of Energy carbon fiber research project I had amassed enough projects that I could use some extra hands to get them all done. Many of these projects would make great learning opportunities for an undergraduate mechanical engineering student, and when I pitched the idea of hiring one to my professor he responded, “Why not two?” So, that’s just what I did. After interviewing several candidates I chose two stellar soon-to-be engineers: Connor, a third year mechanical engineering student, and Huy, a fourth year aerospace engineering student.
My Mission
During the summer before my junior year at Clemson, I took a research assistantship at the Clemson University International Center for Automotive Research. It was a great practical experience; I designed custom wheelpan load cells for their vehicle dynamics “shaker” rig and experienced automotive simulation software. However, I felt like I was missing the true research experience because I didn’t work with any of the graduate students and I wasn’t connected to active research in pursuit of publication. I wanted to rectify this for my undergraduate research assistants, so I made it my mission to involve them as broadly as possible with our lab’s research and to tailor their work to their interests and what they wanted to get out of the experience. I wanted to achieve three things as a mentor to our undergraduate research assistants: 1) expose them to graduate research work, 2) offer feedback on their designs based on my professional experience, and 3) give them hands on fabrication experience making the things that they designed.
Adjusting To COVID-19
The COVID-19 pandemic put a damper on my goal of giving my undergraduate researchers the experience of fabricating the things they designed, but we were able to maintain progress nonetheless. Using communication tools that have recently achieved near-ubiquity, such as Slack and Zoom, we were able to stay in touch and collaborate regularly. We were able to make use of Solidworks by keeping our files on a university-managed network attached storage drive, and we also modeled systems in Autodesk Fusion360, which offers free licenses and cloud file storage for students. Using Airtable to track our projects, tasks, and worked hours was hugely helpful in keeping us organized. Connor and Huy were flexible and adjusted quickly to the new normal, which I greatly appreciated.
Projects
Over the course of the semester, Huy and Connor were involved in a handful of projects. I’ve highlighted their major accomplishments here.
High-Speed Godet Module For Li Lab Melt Spinning System
Huy’s major project of the semester was the development of a high-speed godet module for our melt spinning system. The goal was to design and build a high speed-capable godet that could also be used as a takeup winder and could be controlled via LabView. Such a design would enable better control of our fiber takeup rate as well as greatly expand our takeup rate envelope. This capability is critical for investigating microstructure development in the precursor fibers that we spin and may have a crucial impact on the subsequent carbon fibers. Furthermore, this modular package would allow for the installation of multiple godets, which would enable post-extrusion drawing of the fiber to further affect fiber microstructural properties.
Top: Huy’s godet module design featuring a 6” aluminum godet that can spin up to 8300 RPM. Bottom: Huy determined the first harmonic of the system using finite element analysis, which guided component sizing to ensure the safety of the module at full speed.
Huy and I developed a list of constraints and criteria based on the system we have in the lab and a functional performance envelope that would enable novel research. Then, he took the project in full stride. He modeled the performance of the system to validate component sizing and then generated a CAD model in Solidworks to embody the design. He developed a finite element model in NX Nastran and meshed with Hypermesh to find the first mode of the system to further validate that the design could hold up to velocities and loads that would occur at the top end of our performance envelope. Femap was used to generate pre- and post-process visualization. As the semester came to a close, Huy worked on the finishing details of the assembly to account for ease of use and user safety. In all, I am excited to bring his design to life very soon so that it can be put to use and advance our understanding of precursor fiber microstructure effects on carbon fibers.
IN-Microwave Submerged Fiber Sample Tensioning Apparatus
Connor’s major project of the semester was the development of an apparatus that would allow our lab mates to experiment with the microwave irradiation of carbon fiber precursor fibers. This work is crucial to accelerating the oxidation phase of carbon fiber precursor conversion, and the lab has submitted a patent on the technique. Much more work is to be done, and a method of immersing the fibers in a solution with a controllable and quantifiable amount of tension while being irradiated was needed.
Left: The final design of the in-microwave submerged sample tensioning apparatus is composed of teflon plates, rods, screws, and sleeves as well as glass rods to make the design chemical and microwave resistant while minimizing tension losses due to drag. Right: The apparatus with fibers attached and weighted, submerged in a heated bath at 95C.
Connor worked with post-doctoral researcher, Zan Gao, to determine the constraints and criteria of the anticipated design and to gain an understanding of how it would be used. He sketched concepts for the apparatus and then CAD modeled it in Autodesk Fusion360. We worked through material options for suitability to the target operating environment, then made engineering prints to communicate the design for an external machinist to complete (the student machine shop was closed by this point due to COVID-19). The design was fabricated at the end of the semester and garnered rave reviews from the end users. In fact, a second version was requested because the first worked so well!
other Activities
Fortunately, Huy and Connor got some hands-on experience before on-Grounds activities were halted. Connor used the CNC machine available to students in Lacy Hall to fabricate a brass adapter for our spin line’s aspirator gun, and Huy fabricated a contained sample tensioning system for applying tension to fiber samples while immersed in 98% sulfuric acid at 150C. Connor also completed his in-microwave fiber tensioning apparatus with enough time to create a concept model of a rearranged spin line that includes a melt metering pump and raised spinneret position to enable more space for fiber cooling preceding takeup.
great job, Guys
Huy and Connor were exemplary undergraduate research assistants, and they exceeded my expectations at every turn. They were flexible and adaptable in the face of the largest health crisis that this country has faced in over 100 years, and I think we made great progress on this project’s goals as well as a good learning experience out of it. Huy has gone on to begin his own PhD program at the University of Illinois at Urbana-Champaign, and Connor has entered his fourth year at UVA in which he’ll be focusing on the development of the school’s first Formula SAE car. I wish you both the best in your future pursuits, and hope you enjoyed our semester working together as much as I did!