Author:

Keywords:

Cold-formed steel, Built-up members, FEA, Parametric study, Non-linear buckling analysis

Abstract:

The standard cold-formed steel profiles are easily paired to form built-up members, when higher loads are to be taken. The resulting members are more stable and of higher strength; besides, the production method remains unchanged. Previous investigations, performed by the authors, revealed the response and failure pattern of one type of built-up member. Full-scale tests were performed on double-Z members, both in compression and weak-axis bending, in order to study how the flexible interconnection between the Z-profiles influences the member response. A finite element model was validated based on the experiments. This numerical model is used to optimise the geometry of the investigated members, so that higher ultimate strength-to-weight ratios can be achieved. The objective is to deliver highly stable member geometry and to exclude effects that can deteriorate the axial buckling capacity. The member type can then be employed to take up the increasing loads and spans in ambitious structural applications of light-steel framing.