Design, fabrication and inspection of support for grid structure

Design, fabrication and inspection of support for grid structure

Grid structures are generally supported on lower supporting structures such as column tops or ring beams, and support nodes refer to the grid nodes located on the supporting structure. It not only needs to connect the members intersecting at the support of the grid, but also supports the entire grid and transfers the load acting on the grid to the lower supporting structure. Therefore, the support node is the link between the grid structure and the lower supporting structure, and is also an important part of the entire structure. A reasonable support node must have clear stress, simple force transmission, safety and reliability, and should also achieve simple and reasonable structure, simple and convenient production, and good economic efficiency.

1、 Design of Support for Grid Structure

The support nodes of the grid structure should be able to ensure the safe and reliable transmission of support reactions, so they must have sufficient strength and stiffness. Under vertical loads, support nodes are generally compressed, but in some inclined grid structures, local support nodes may withstand tensile forces and sometimes horizontal forces. When designing, the structure of support nodes should adapt to their stress characteristics. At the same time, the construction of support nodes should also try to conform to the calculation assumptions and fully reflect the design intent. Due to the fact that the grid structure is a highly statically indeterminate member system, the constraint conditions of the support nodes have a significant impact on the node displacement and member internal forces of the grid; The difference in constraint conditions between construction and design will directly lead to changes in the internal force of the member and the reaction force of the support, and sometimes even cause the internal force of the member to change. Therefore, sufficient attention should be paid to the design of support nodes in grid structures.

The safety and economy of the design of a grid structure depend primarily on the rationality of the selected support structure, support type, and boundary conditions. Therefore, in the specific design, we try to avoid analyzing and designing the upper grid structure and lower support system separately, especially when the displacement of the grid support relative to the lower structure is difficult to simulate through elastic constraint methods, The supporting structure should be integrated with the upper grid structure for overall modeling, calculation and analysis to make the calculated results more realistic.