Jacknetson Naw has spent the last two years learning how to scan structures.
Naw, a civil and environmental engineering senior, has conducted undergraduate research under CEE Associate Professor Hannah Blum, who leads the Steel Systems Innovation Research Lab. She’s testing and comparing a variety of measurement methods—ranging from old-fashioned hand tools like calipers to modern 3D scanners and even iPads—to determine whether lower-cost alternatives are up to the task.
Using those methods, Naw and former graduate student Richa Rahkee (MSCEE ‘25) have been working on a project to scan a steel deck, which is a sheet of corrugated metal that is often used in roofing or similar structures. Part of the project includes creating point cloud models using the high-tech Artec Leo, which is a handheld scanner capable of taking 3D scans of objects or parts of a structure up close. Point cloud models are 3D representations of an object or structure that are made of almost countless, precisely arranged individual points.
“Once you’ve made the model, you can do other things with it,” Naw says. “For example, with a steel deck, we exported cross sections at varying locations along the deck span —one in the middle and between the middle and each end—and imported them into AutoCAD. After doing that, we can measure them to look for as-fabricated geometry and imperfections and conduct further structural analysis.”
Naw’s work is a crucial part of a group effort in Blum’s lab to create a workflow that incorporates steps from scanning to creating models. “We can use this tool to measure ‘as-built’ conditions, which can influence a structure’s strength,” Blum says. “Jenet has been helping a lot with the scanning, and the team has gotten together to figure out a workflow for the process, and coding for importing the point clouds to help automate the process. This is going to give us very precise results, especially for research purposes.”
As another part of the project, Naw has assessed how well an iPad Pro might work as a low-cost alternative for structural scanning. While tools like the Artec Leo can capture incredibly precise scanning data, at tens of thousands of dollars apiece, they’re very expensive compared to an iPad.
Scanning a steel deck isn’t as simple as just pointing the scanner at it. Because the metal is reflective and the surface is mostly uniform, Naw says, it needs to be painted with a matte finish. Then, she adds markers or characters with sharp edges that she can use to align scans from different orientations during post-processing.
After setting up an iPad to scan the steel deck and then analyzing the results, Naw found the iPad ultimately wasn’t up to the task. The scans had rounded edges where there should have been sharp corners—which, she says, is a pretty significant error—and struggled to accurately capture features like embossments.
Blum presented Naw and Rakhee’s iPad vs. Artec Leo vs. hand tools scanning analysis at the 2025 International Colloquium on Stability and Ductility of Steel Structures in Barcelona, Spain. “The room was packed,” Blum says. “People were really intrigued because, of course, you’d want options using the less expensive method, but the technology isn’t there yet.”
Naw and Rakhee also scanned the Camp Randall Memorial Arch and the Agricultural Bulletin Building, both on the UW-Madison campus. For scanning those structures, they used the Artec Ray, a larger scanner than the handheld Leo—and Blum says the scanning was practice for a larger ongoing project to monitor historic structures she’s conducting with colleague Jesse Hampton.
As she finishes her senior year, Naw, a first-generation college student from Myanmar, says she’s learned a lot from being in Blum’s lab and is considering pursuing a master’s degree in structural engineering.
“I’m really happy that I’ve had the opportunity to work in a research lab,” she says. “It’s been a great experience, and not just with my projects, but seeing all of the experimental work going on here has been really cool. Coming in I wasn’t really sure what I wanted to do because civil engineers can go into so many areas, but Hannah’s lab has really helped me find what I want to do for the future.”
Blum is the Alain H. Peyrot Associate Professor of Structural Engineering.