Cyclic axial behaviour of built-up cold-formed steel columns

Overview

This technical talk will provide insight into the cyclic behaviour of cold-formed steel framing structures and the benefits they can offer when used in earthquake-prone regions. This experimental study was supported by SECED Fund 2023.

Cold-formed steel (CFS) framing structures provide benefits such as a high strength-to-weight ratio, usage of recyclable steel, and rapid construction. Their lightweight construction is advantageous in earthquake-prone regions. 

Built-up cold-formed steel columns are key elements of the shear walls of CFS framing. In CFS strap-braced shear walls, the braces carry the lateral load to the columns, which then transfer the loads to the foundation through hold-down devices and anchor rods. Understanding the cyclic axial behaviour of CFS built-up columns is, therefore, essential for the capacity-based design of CFS strap-braced shear walls.

In this study, six specimens of built-up CFS columns were tested with an axial cyclic protocol at the Heavy and Light Structures Lab at the University of Bristol. The first set of three specimens consisted of two back-to-back C sections joined together, while the other three were made of U sections using self-drilling fasteners.

Additionally, two specimens were created by combining two Sigma sections with bolts. These specimens were then subjected to cyclic and monotonic loading tests at Imperial College London's lab.

Programme