Dr. Ben Schafer, Willard and Lillian Hackerman Professor of Civil and Systems Engineering at Johns Hopkins University, has spent over two decades advancing the structural capabilities of cold-formed steel (CFS).
In a recent episode of DesignSafe Radio, Schafer spoke with Dan Zehner of the U.S. National Science Foundation’s Natural Hazards Engineering Research Infrastructure program about the evolution of CFS research — from its early development to the groundbreaking 10-story CFS building now undergoing seismic testing at University of California San Diego’s LHPOST6 shake table.
Understanding Cold-Formed Steel
CFS differs from hot-rolled steel in both material thickness and fabrication method. Thin sheet steel is shaped at room temperature into structural components, allowing for high strength-to-weight ratios and adaptable performance.
“Cold-formed steel is really a material efficiency idea from the start,” Schafer said. “Can I use the absolute minimum material? That’s a big sustainability goal.”
Because CFS is manufactured from sheet and coil — often using recycled steel via electric arc furnaces — it also contributes to circular economy goals in construction.
The Case for Seismic Resilience
CFS is increasingly used not only in non-structural steel framing but also in full load-bearing systems. Schafer’s work has focused on maximizing the seismic resilience of CFS buildings, leveraging the unique properties of thin-gauge steel to control deformation and dissipate energy during earthquakes.
“You have to up your engineering game,” Schafer said. “If you choose to build your whole structure out of 2 mm thick sheet steel, local buckling is going to happen. You have to decide how to deal with that — and still get the performance you want.”
This challenge inspired the current NHERI-supported CFS10 project, a full-scale, 10-story CFS building that pushes beyond current code limits.
Researchers at UC San Diego simulated a 6.9 earthquake to see if this 10-story building would hold its integrity.
CFS10: A Series of Landmark Shake Table Tests
Constructed on the newly upgraded six-degree-of-freedom shake table at UC San Diego, the CFS10 structure combines modular and panelized construction methods. It’s the tallest CFS framed building ever tested under seismic conditions.
“We detailed and assembled a 10-story cold-formed steel building — beyond code height limits — to show how far we can go with lightweight structural systems,” Schafer said.
The test building includes both structural and non-structural systems, from staircases and gas lines to sprinkler systems and wall finishes. Sensors throughout the structure are monitoring thousands of data points to evaluate performance under realistic earthquake motions.
Systems Behavior and Broader Lessons
Past full-building tests revealed that CFS systems perform better than traditional engineering models predict, thanks in part to the interaction between structural and non-structural elements.
“The secret sauce is understanding the load sharing between the designated structural system and all the rest of the building,” Schafer said.
That insight is informing not only seismic design but also code development, industry best practices and educational efforts across the U.S.
What’s Next? Fire Tests and More
Schafer and his team are preparing for upcoming fire tests, subsystem evaluations and data analysis as the CFS10 testing progresses. He encourages those interested in the research to follow developments on the website, CFS-NHERI: 10-Story Building Capstone Test Program
These tests mark a defining moment in the advancement of resilient, lightweight and sustainable buildings, offering a glimpse into the future of structural engineering.
