Inelastic Moment Resistances of Welded Steel Beams with Initial Shape Imperfections

Abstract Numerical procedures based on geometric and material nonlinearities are proposed in the present study to evaluate the inelastic responses of welded steel beams with the initial shape imperfections of welds, braces and out-of-straightness. The convergent deformations/moments of the present solutions are excellently validated against experimental results. Thirty-seven steel beams with different sectional classes are then proposed to quantify the effects of initial shape imperfections of welds, braces, and out-of-straightness on the system deformations and moment resistances. It is observed from the present study that the moment resistances strongly depend on the residual stresses, bracing heights, and out-of-straightness shapes for the beams with compact and non-compact sections, but they are insensitive for the beams with slender sections. The effects of weld shapes on the moment resistances are found to be small. Through an evaluation of the moment resistances of typical design specifications, design considerations are proposed for the steel beams subjected to the initial imperfection shapes.