BEHAVIOR AND ULTIMATE LOAD ESTIMATES FOR THIN-WALLED TRUSSED PLANE FRAMES

The elastic non-linear buckling behaviour and collapse of trussed plane frames having cold-formed steel members are analysed via FEM models. Local buckling interaction at a section level between the thin walls of a member is taken into account through the effective width approach. Interaction between this local and Euler buckling mode is also considered in the analysis. The solution of the resulting non-linear equations is sought by a hybrid numerical scheme that makes use of both incremental-iterative plus secant methods. Large-span thin-walled trusses are analysed and the resulting nonlinear behaviour and associated ultimate loads are critically examined in the light of conventional elastic calculations and predictions from existing design codes. Correlations with experimental results for pin-ended columns with slender cross-sections are also presented to back up the results found for trussed plane frames.