According to different shapes, the space frame can be divided into two-layer plate-type space frame, single-layer and double-layer shell-type space frame. The plate type space frame and the double-shell type space frame are divided into upper chord, lower chord and web, which are mainly subjected to tension and pressure; the single-layer shell type space frame is subjected to tension and pressure, and is also subjected to tension and pressure. Bending moment and shear force. At present, most of China's space frame adopts a plate type grid space frame.
The plate type space frame structure is mainly divided into three types according to the composition form: the first type is composed of a plane truss system, which has a two-way orthogonal positive space frem, a two-way orthogonal oblique space frame, and a two-way oblique space frame. And three-way space frame four forms; the second category consists of four pyramid elements.
The structure of the space frame structure is composed of a four-cornered cone space frame, a positive-draining quadrangular pyramid space frame, an oblique quadrangular pyramid space frame, a checker-shaped quadrangular pyramid grid and a star-shaped quadrilateral cone space frame; the third category consists of triangles. The cone unit is composed of a triangular cone mesh frame, an evacuated triangular cone mesh space frame and a honeycomb triangular pyramid mesh frame. The shell-type space frame structure is mainly divided into a cylindrical shell type space frame, a spherical shell type space frame and a hyperbolic parabolic shell type space frame according to the shell surface form. The space structure is divided into a steel grid, a reinforced concrete grid and a combined grid of steel and reinforced concrete according to the using of the materials.
The bar section of the space frame structure should be determined according to the calculation of strength and stability.In order to reduce the calculated length of the compression bar and increase its stability, measures such as adding sub-bar and support bar can be adopted.There are three types of steel plate type space frame and double shell type space frame joints, which are cross plate joint, welded hollow ball joint and bolt ball joint.The cross plate joint is suitable for the space frame structure of shaped steel bars.The hollow ball joint and bolt ball joint are suitable for the space frame structure of steel pipe rod.The joints of the single-layer shell type space frame structure should be able to bear the bending internal force. In general, the steel consumption of the joints accounts for 15 ~ 20% of the steel consumption of the whole steel space frame.