Steel structures, as a type of high-order statically determinate structural system for indoor space truss construction, are favored due to their excellent compressive characteristics (theoretically, members only bear load effects), high bending stiffness, good seismic resistance, strong load-bearing capacity, minimal impact from uneven foundation settlement at supports, and strong adaptability. The increasing perfection of the theoretical calculations for grid fabrication and the rapid development of electronic information technology contribute to this.

Enabling the analysis and design of extremely complex three-dimensional structures, truss structures are widely used in the industrial production and industrial construction industries. If the rigid structure of a truss manufacturing factory is not scientifically designed in terms of its supporting structure, support forms, and initial conditions, it can harm the safety factor and rationality of the truss structure.

The support nodes of the truss structure should be capable of reliably transferring the bearing axis forces, thus requiring sufficient strength and bending stiffness. Under the action of longitudinal loads, the support nodes are generally under stress, but in some oblique-angled spherical trusses, certain support nodes may possibly serve as tensile force resistors, and sometimes may also need to bear horizontal forces. The design should integrate the structural features of the support nodes with their load-bearing characteristics. At the same time, the structure of the support nodes should as much as possible conform to the calculation assumptions and fully reflect the design intent.

Due to the truss structure being a high-order hyperstatic structural member management system, the constraint equations at the support nodes significantly affect the node displacement of spherical trusses and the internal work of members; differences in constraint equations between structure and design will immediately cause changes in the internal work of members and the support axial forces. Therefore, sufficient attention should be given to the design of the truss structure's support nodes.

The design of a grid structure's safety and economic development primarily depends on the selected support structure, the type of support, and whether the initial conditions are effective. Therefore, in actual design, it is advisable to avoid analyzing and designing the upper grid structure independently from the lower support system. Particularly when the offset of the spherical grid support relative to the lower structure is difficult to simulate using the flexibility constraint method, the grid factory should conduct a comprehensive model and calculation analysis of the support structure and the upper spherical grid together to ensure the calculated results are more realistic.