Impact of detailing on the lateral performance of cold-formed steel framed walls

The main objective of this study is to investigate the impact of structural and non-structural detailing that is not directly accounted for in conventional lateral strength and ductility design of wall-lines constructed of cold-formed steel (CFS) framed steel sheet shear walls. A key structural detail that commonly occurs in wall-lines, but not in shear wall testing, is the presence of a heavy ledger track attached along the top of the wall, as this facilitates connection of the floor system with the wall. A key non-structural detail, which will impact the wall-line’s lateral performance, is the presence and type of finish system (e.g., gypsum board). Herein, a numerical study employing OpenSees is validated and exercised on wall-line models with or without ledger tracks as well as with or without finish. Modeling results predict the degree by which both strength and ductility of wall-lines increase due to the presence of a ledger track and/or finish system. The strength increase can be attributed to the engagement of ledger track-to-stud connection moment resistance and additional direct shear resistance provided by an applied finish layer. The developed OpenSees model is able to capture the impact of detailing and can be incorporated into building-level simulations.

Proceedings of the 12th National Conference on Earthquake Engineering, Earthquake Engineering Research Institute, Salt Lake City, UT.