Stability analysis of a steel roof truss

A steel structure of a storage building is analyzed. The main structure of the building consists of several plane frames of 20 in span, spaced every 5 in. The light roof lattice girders are supported by H-shaped columns. ne purlins are made of cold formed channel sections with pinned connections to the upper chord of the trusses. The main risk of collapse of this structure is out of plane buckling of the upper compressed chord of the lattice girder. Non-linear buckling analysis using ROBOT software was conducted for several models of the structure. The results of the analysis show that the EC3 recommendations for design should be complemented in terms of required stiffness of the bracing system. Possible simplified model for analysis as well as guidelines for designers have been pointed out.