ERI: Seismic Performance of Buckled Cold-Formed Steel Panels Repaired with Fiber-Reinforced Polymers

Lightweight cold-formed steel shear panels are widely used for the construction of nonresidential buildings across the United States due to their high strength-to-weight ratio and ease of assembly. However, these structural components are vulnerable to buckling during seismic events, which can lead to significant damage or collapse. While restoring the post-earthquake structural integrity of affected buildings is critical for community resilience; however, repairing buckled elements, particularly those with globally deformed cross-sections, remains a significant challenge.

This grant for Engineering Research Initiation (ERI) will support research that explores a novel repair technique that combines thermal straightening and reinforcement with basalt fiber-reinforced polymers to restore the strength and stability of buckled cold-formed steel members. By addressing a critical gap in current repair methodologies, this work has the potential to improve post-earthquake recovery efforts, reduce economic losses, and enhance the sustainability of steel structures.

The findings from this study will support the development of durable retrofitting strategies, ultimately advancing national welfare in disaster resilience and infrastructure sustainability. This award will contribute to NSF's statutory role in the National Earthquake Hazards Reduction Program (NEHRP).

This project will develop a science-based analytical model to predict the cyclic performance of repaired cold-formed steel lipped channels under seismic loading. A key focus will be to model the bond-slip behavior at the interface between fibers and steel, which governs the effectiveness of repairs. The research will integrate full-scale experimental testing and numerical simulations to characterize the impact of thermal processes on surface bonding and develop a nonlinear hysteretic bond-slip model.

The validated model will be used to generate seismic fragility functions for repaired structures, enabling the assessment of their resilience against multiple seismic events. The outcomes of this study will contribute to the broader field of earthquake engineering by providing a systematic approach to evaluate and enhance the performance of retrofitted cold-formed steel shear walls.

Additionally, the research will yield practical insights for engineers and manufacturers, facilitating the adoption of more resilient and sustainable repair techniques for steel structures. Project data will be archived in the NHERI Data Depot (https://www.DesignSafe-ci.org).

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.