Buckling capacity of welded stainless steel flanges by finite element analysis

This paper presents the development of a finite element analysis method to predict the buckling capacity of welded stainless steel unstiffened plates. Material and geometric nonlinearities, geometric imperfections, and residual stresses are included in the development. The resulting method is validated with experimental results on specimens of cruciform shape and is used to measure the sensitivity of the compressive capacity of plates, whose boundary conditions simulate the flanges of stainless steel plate girders, to local geometric imperfection, length-to-width ratio, and slenderness. When the slenderness parameter of a flange is greater than 1.0, as the mode value of the imperfection increases, the compressive capacity increases, and when the slenderness parameter is less than 0.5 the mode value has negligible effect on the compressive capacity. When a flange length, a, is less than twice its width, b, the value of a/b has a much greater impact on the ultimate load capacity of the flange than when it is greater than twice its width. The parametric study results are compared to American, European, and Japanese design specifications for unstiffened steel cross-sectional elements. For a given value of slenderness, the AISC nominal design buckling resistance is close to the average of the ultimate loads obtained from the parametric study and the Eurocode and JSSHB specifications are generally conservative.