During the construction of the grid structure, the loading method of the ceiling load should conform to the calculation model of the grid structure and the handling method of the ceiling load in the design. That is, it must be based on the principle that the rod does not generate shear and bending moment, but only generates axial force.
According to this principle, the ceiling load should first act on the nodes of the grid. Then through the node, the rod can only generate axial force, and can not directly act on the rod to generate shear and bending moment.
Of course, in actual engineering, the rods are also subject to shear and bending moments. Construction loads such as the dead weight of the rods and the construction personnel walking on the chords all cause the rods to produce certain shear and bending moments.
However, it must not be considered based on this that it is fine to apply ceiling loads and equipment loads to the chords; if the lateral loads such as equipment and ceilings acting on the chords are too large. Under the action of shear and bending moment, the rods are damaged. The internal forces of the grid will be redistributed and may exceed the design control value. It is very dangerous to cause the grid to lose stability. Therefore, the designer should indicate in the drawings regardless of the size of the load. Must be added to the grid node. As for whether or not the load can be added to the member, or how much load can be added, it must be determined by calculation.