Analysis of the influence of rigid secondary stress on flat steel roof truss joints

steel roof trusses;  node rigidity;  secondary stress;  Sub-internal force

Using finite element analysis software, the secondary stress generated by the rigidity of typical flat steel roof truss joints under two spans was analyzed and calculated. The planar articulated model, planar rigid joint model I and planar rigid joint model II were used for typical flat steel roof trusses, and the magnitude, distribution law and main factors affecting the secondary internal force of steel roof trusses under ordinary load were analyzed, and the influence of secondary stress on the calculation method of steel roof truss was preliminarily discussed. The results show that the secondary internal force of the steel roof truss members increases with the increase of the linear stiffness of the members, and the influence of secondary stress increases with the increase of the span of the roof truss, and the influence of secondary stress cannot be ignored. This conclusion can provide a reference for the design of steel roof truss considering secondary stress.