| The aim of this thesis is to present a practical advanced analysis method for steel frame design, based on a simplified second-order elastic analysis of the structure with an equivalent geometric imperfection. The second order effects are calculated using the orthogonality properties of the buckling modes. The geometric imperfection is obtained from the buckling mode by a suitable scaling procedure using a generalization of Dutheil's method.; In this method we add to the resulting primary stresses of the structural analysis, the secondary associated with all the factors not considered in the analysis: Geometric imperfections, residual stresses, etc. So we can eliminate from our design method "amplifying" coefficients that give place to slightly transparent formulations.; To fulfill these objectives, in first place a methodology to obtain the equivalent geometric imperfection is proposed, this includes all the factors not incorporated in the analysis. This imperfection can be applied to any kind of structures being a generalization of the Eurocode 3 proposal. |
