Cold-formed ferritic stainless steel perforated tubular stub columns: Behaviour and design

This paper reports the numerical axial behaviour of cold-formed ferritic stainless steel (CFFSS) stub columns with two circular perforations on opposite faces located centrally along the width and height of the column specimens. Numerical models are established using the finite element (FE) package ABAQUS and validated by using the test results of cold-formed carbon steel stub columns with perforations and CFFSS shallow stub columns reported in the literature. The modelling of the material properties and geometric imperfections has carefully been considered in the developed FE models and validated rigorously against the available test results. The validated FE models are adopted to perform a comprehensive parametric analysis by varying the cross-sectional geometries and the diameter-to-width ratio of the circular perforation. The parametric results are used to examine the accuracy of the current direct strength method (DSM) and the DSM proposed by other researchers in the literature on CFFSS tubular stub columns. The comparison of the strengths indicates the need for proposing specified design rules for the compression capacity of the perforated CFFSS stub columns. Accordingly, new design recommendations are proposed for DSM for accurate compression strength predictions for CFFSS tubular stub columns which are verified through reliability analysis. •A finite element model for CFFSS short columns under axial loading is presented.•Using ABAQUS, 3D finite element CFFSSs with perforations are developed and validated.•The accuracy of current and modified DSMs is checked for CFFSS stub columns.•The proposed DSM is shown to predict well the strengths of CFFSS short columns.