This paper studies the contribution of initial geometric configuration to the limit load defined by a second-order plastic-zone inelastic analysis applied to steel plane frames. This initial configuration must include geometric imperfections (out-of-straightness and out-of-plumb) that are required for qualifying the inelastic analysis as advanced one. The necessary steps to apply this analysis are shown, including formulation, requirements and the studied examples. Lastly, a step-by-step procedure and a conclusion are given, providing the critical initial configuration by which the engineer will define the limit load for more complex structural problems.
steel frames; advanced analysis; plastic-zone method; initial configuration; geometric imperfections