Numerical Design Calculation According to EN 1993-1-14 of Innovative Thin-Walled Columns with Sectional Transverse Strengthening

This paper presents a numerical analysis of cold-formed thin-walled columns reinforced with sectional transverse stiffeners (STSs) based on the recent part of EC3 concerning the finite element analysis. Columns that are 1 m tall with various arrangements of STSs were modeled in the AxisVM environment. Numerical design calculations were completed using an analysis requiring a subsequent design check. This included a geometrically nonlinear analysis considering imperfections (GNIA) along with linear analysis (LBA) to assess the columns' susceptibility to second-order effects. Reinforcing columns with STSs did not show a significant effect on the local buckling behavior of the elements. However, the results indicated that increasing the number of STSs positively influenced the columns' resistance. This modification reduced the magnitudes of distortional, global flexural, and torsional buckling. Additionally, adding more than three STSs increased the critical loads related to distortional, flexural, and torsional buckling by 58-90%, 52-119%, and 19-154%, respectively. For the GNIA, two combinations of imperfections were analyzed: global flexural imperfection paired with either local or distortional imperfection. LBA was used to apply the imperfect geometry of the columns with the appropriate magnitudes of imperfections. The results between LBA and GNIA for the single-branched columns varied by 8-24%, while for the double-branched columns, the differences were less than 3%.