Behavior of Cold-Formed Steel Beam-to-Column Clip-Angle Connection at Fire

This study examines the behavior of cold-formed steel (CFS) beam-to-column bolted clip-angle connections under ambient and fire conditions. A total of 26 experimental tests were conducted, varying the width and depth of the clip angles. A specialized test setup with a custom-built furnace was developed to evaluate the beam-to-column connection under fire conditions. The digital image correlation (DIC) technique was also employed for deformation measurement and validated under ambient and fire conditions. Fire tests were conducted using the transient state method, in which 50% of the ultimate load determined from ambient temperature tests was applied, while the connection was subjected to an ISO 834 temperature profile to assess its performance under fire conditions. The primary failure modes observed at ambient temperature were local buckling and tearing, and connections were classified based on the flat width-to-depth ratio of the clip angle. In contrast, all specimens tested at fires failed primarily due to local buckling. The critical temperature and corresponding time (critical time) of the connection were assessed, as these parameters are essential for understanding its structural performance and fire resistance at fires.