Design of a Special-Shaped Steel Structure and Analysis of Ultimate Bearing Capacity of Its Intersecting Joints

Currently, spatial intersecting nodes are widely used in complex steel structure projects with large spans and irregular shapes, but existing codes lack clear guidance on their detailed design and analysis, which restricts the promotion and application of such nodes. This article is based on an actual engineering project of a spatial irregular steel structure, carrying out research on the overall structural stability and the ultimate bearing capacity of key intersecting nodes, in order to provide a basis for engineering design. Using Rhino 8 Grasshopper to achieve structural parametric form-finding and component layout, completing the overall structural stability analysis based on Midas Gen, and conducting member section verification through the direct analysis method; combining Midas Gen with FEA NX for collaborative modeling, performing detailed nonlinear finite element analysis on the most critically stressed intersecting nodes. The results indicate that under wind load-controlled conditions, the structural linear buckling, geometric non-linearity, and combined geometric-material non-linearity stability safety factors are 40, 15.5, and 5, respectively, all of which meet the overall stability design requirements. Using 2% of the main diameter as the limit deformation value, the ultimate bearing capacity of this intersecting node is approximately 2.4 times the design load, and the intersecting line area is prone to local yielding due to stress concentration. The refined design and analysis method of multi-software collaboration adopted in this paper can provide a reference for the engineering design of similar irregular steel structures and intersecting nodes.