Experiments on cold-formed steel sheathed studs at elevated temperatures

摘要

This paper aims to assess the stability of cold-formed steel studs at elevated temperatures through experimental methods. Short and intermediate-length studs braced with gypsum, fire-rated gypsum, and oriented strand board were subjected to compressive axial load and temperatures ranging from 20°C to 600°C. Compressive axial load was applied to the studs until failure occurred. Results show that the load-carrying capacity of the structural members lowers with increasing temperature, as the mechanical properties of cold-formed steel reduce, and the bracing provided by the sheathing degrades. Local and distortional buckling failures are observed in the cold-formed steel member. The stabilizing effect and increase of load-carrying capacity attributed to sheathing is eventually lost, and the behavior of the sheathed studs becomes similar to the behavior of unsheathed members. Direct Strength Method equations provided in AISI-S100-12 are used to predict the load-carrying capacity of the studs, then compared to experimental results to explore the feasibility of current design methods for performance-based fire design applications.