Points for Attention in Deepening the Support Nodes of Grid Structure

As a high-order statically indeterminate space structure, the grid structure has good mechanical performance (theoretically, the members are only affected by axial force), large rigidity, good integrity and seismic performance, strong bearing capacity, and support The uneven settlement of the seat has little impact and strong adaptability. The increasing perfection of calculation theory and the rapid development of computer technology make it possible to analyze and design any extremely complex three-dimensional structure. Therefore, the grid structure is widely used in industrial and civil buildings. In the field. However, unreasonable design of the supporting structure, support type and boundary conditions of the grid structure will have an important impact on the safety and economy of the grid structure.

The support node of the grid structure should be able to ensure the safe and reliable transmission of supporting reaction forces, so it must have sufficient strength and rigidity. Under the action of vertical load, the supporting nodes are generally under compression, but in some diagonally placed grids, local supporting nodes may bear the action of tensile force, and sometimes they may also bear the action of horizontal force. The support should be designed. The structure of the seat node adapts to their force characteristics. At the same time, the structure of the bearing nodes should also conform to the calculation assumptions as far as possible and fully reflect the design intent. Since the grid structure is a high-order statically indeterminate member system, the constraint conditions of the support nodes have a greater impact on the node displacement of the grid and the internal forces of the members; the difference between the constraint conditions in the structure and design will directly lead to the internal forces of the members The change of the reaction force with the support sometimes causes the internal force of the rod to change sign. Therefore, sufficient attention should be paid to the design of the support node of the grid structure.

Whether the grid structure design is safe and economical, the most critical factor is whether the selected supporting structure, support type and boundary conditions are reasonable. Therefore, in the specific design, we try to avoid separate analysis of the upper grid structure and the lower supporting system. , Design, especially when the displacement of the grid support relative to the lower structure is difficult to simulate by the elastic restraint method, the supporting structure and the upper grid should be modeled and calculated together to make the calculated results more Realistic.