Global Sensitivity Analysis in Stability Problems of Steel Frame Structures

Slender steel frame structures are characterised by a number of imperfections which may reduce their load carrying capacity drastically. This article studies the effects of these imperfections on the load carrying capacity of a single storey steel plane frame using global sensitivity analysis and geometrically nonlinear (second-order) elastic finite element analysis. Imperfections are considered as random variables. Statistical load carrying capacities needed for the evaluation of sensitivity analysis are processed using classical statistical methods upon the emulation of Latin Hyper­cube Sampling simulation methods. The main interaction effects of random imperfections on the load carrying capac­ity are identified using global sensitivity analysis. It is illustrated that the effects of imperfections on the load carrying capacity varies dramatically depending on the height of the columns and the boundary conditions of the end conditions of the columns.