Cold-formed steel sheathing connections at elevated temperature

The objective of this paper is to provide experimental results related to the elevated temperature performance of connections between cold-formed steel members and sheathing. Cold-formed steel building structures rely on sheathing for their mechanical benefits including bracing against member twist, global flexural and flexuraltorsional buckling, and cross-section distortional buckling, as well as to supply lateral strength and energy dissipation in shear walls and diaphragms. Sheathing is also relied upon for non-structural benefits, including: fire, acoustic, and thermal performance. Predicting the degradation of the connection performance between coldformed steel members and sheathing at elevated temperature is critical for any attempt to predict the structural performance of cold-formed steel buildings under fire demands. Steady-state connection tests were conducted under in-plane shear and pull-through at temperatures up to 400 C for cold-formed steel members attached to gypsum board and oriented strand board. By combining the conducted tests with others in the literature retention factors for initial stiffness and ultimate strength of the connections are proposed.