Experimental hysteretic response of cold-formed steel fastened connections sheathed with fiber-cement boards with varied edge distance

Continued development of cold-formed steel (CFS) systems in earthquake-prone areas necessitates study of innovative structural systems and materials. Since cement-based sheathing boards can increase strength and energy dissipation properties – desirable in high seismic zones – fiber-cement boards (FCBs) in particular have become ubiquitous in North American light-framed construction in recent years. This study investigates the effect of three variables, edge distance, stud thickness and fastener type, on the hysteretic performance of 108 CFS-fastener-FCB sheathed specimens. In addition, the impact of over-driven fasteners on cyclic response of the 108 specimens is assessed, and failure modes and tilting of the fasteners are discussed. The tested specimens are designed to simulate a slice of a shear wall. Two studs, one at the top and the other at the bottom, are doubly-sheathed with FCBs, connected via eight fasteners. The specimens are tested cyclically using the FEMA 461 loading protocol, providing extensive experimental data for these connections. Population-level results are analyzed to determine relationships between experimental variables and failure modes. The results of this project will inform national design specifications and establish a comprehensive database of cyclic behavior of CFS-screw-FCB sheathed connections to facilitate the design of the cold formed steel shear walls and diaphragms sheathed with fiber-cement boards.

Scroll to Top