Marchant - Rankine’s - Murzewski approach for modelling of the buckling resistance of welded I-section columns

This paper discusses different aspects of analytical and numerical modelling of the buckling resistance of welded I-section columns subjected to axial compression. The section considered is of class 1 that implies no local buckling affecting the column performance. The proposed analytical formulation of the buckling resistance is based on the so-called Marchant-Rankine's-Murzewski approach (M-R-M approach). The model proposed is of a 2D type and is a simplification of the 3D one that has recently been presented by the authors. The parameters of equivalent stress-strain model of the postwelding steel are calibrated in two stages of the best fit approximation procedure and with use of numerical results of the finite element simulation of the buckling resistance. In the first stage, the postyielding inelastic tangent stiffness parameter ξ E,eff is evaluated with fixed value of the first yield parameter ψ eff = ψ com . A target of the second stage is to assign the best fit value of the first yield parameter ψ eff and the imperfection factor n that allows for accounting the effect of geometric imperfections.