Design of locally buckling cold-formed steel built-up columns formed by unlipped channel sections

This study proposes a design procedure for the local buckling strength prediction of cold-formed steel (CFS) built-up I and box section columns based on Effective Width Method (EWM) Direct Strength (DSM). For this, ultimate sections made two plain unlipped channels is obtained using finite element (FE) analysis. First, some compression tests are performed to validate FE models. Then, detailed parametric validated models conducted with wide range slenderness (1??l?3) where ?l square root ratio yield stress cross-section. The results show that equal sum its section’ strength, whereas sections, can be 20%–25% higher as nesting will alter characteristics. EWM (with k factor approach) authors’ DSM predict strengths well but conservative sections. issue resolved in this paper by proposing simple cross-sectional model constrained deformations section. When proposed were used procedures, predicted matched those present numerical study. In addition, provided more accurate predictions than existing presented literature columns.