Several kinds of grid structure and performance characteristics

The grid steel structure can be divided into double layer plate structure, single layer and double shell structure.

Plate type and double shell type network frame is divided into upper string, lower string and belly rod, the first to accept tension and pressure. The nodes of single-layer shell grid are assumed to be rigidly connected, which should be calculated by finite element method of rigidly connected rod system. Double shell type grid can be calculated by the finite element method of hinged rod system. The pseudo-shell method can also be used to simplify the calculation of single and double shell grid.

The rods of single-layer shell grid accept not only tension and pressure, but also bending moment and shear force. Now most of the grid structures in Our country choose plate grid structure. Grid structure is a kind of spatial grid structure. The so-called "space structure" is compared with the "plane structure", it has the characteristics of three-dimensional action. Since the emergence of space structure, with its efficient stress function, novel and beautiful way and fast and convenient construction has been welcomed by people. Space structure can also be regarded as the expansion and deepening of plane structure. The grid structure is a space bar system structure, which mainly accepts the axial force and has a relatively small cross section scale.

Grid structure has become one of the new structures widely used in the modern world. In China, the research and selection began in the 1960s. In recent years, due to the rapid development of electronic accounting technology, the accounting problem of high-order statically indeterminate structure of the grid structure has been dealt with, which promotes the development of the grid structure both in terms of type and practical engineering use.

Network frame in the demand of large span, large space stadium, exhibition center, civilization equipment, transportation hub and even industrial plants, all see traces of space structure. The advantages of grid structure are small amount of steel, good overall, convenient production device, can be used for messy plane. Suitable for various span structures, especially for messy plane shape. These spatial intersection of the rod and support each other, the force rod and support system organically combined, so the material economy.

The grid is mainly used for large and medium span public construction, such as gymnasium, hangar, salon, exhibition hall and waiting hall, etc., and small and medium-sized industrial plants have also begun to promote the use. The larger the span, the more obvious the superiority and economic effect of this structure. The plate type grid structure can be divided into three types according to the composing mode: the first type is composed of plane truss system, including bidirectional orthogonal forward grid frame, bidirectional orthogonal oblique grid frame, bidirectional oblique oblique grid frame and tridirectional grid frame; The second type is composed of four pyramidal units, there are five types of four pyramidal network frame, four pyramidal network frame, diagonal network frame, checkerboard pyramid network frame and star pyramid network frame; The third type is composed of triangular pyramidal units, including triangular pyramid network frame, leisure triangular pyramid network frame and honeycomb triangular pyramid network frame. According to the mode of shell surface, shell frame structure can be divided into cylindrical shell frame, spherical shell frame and hyperbolic paraboloid shell frame. According to the data used, the grid structure is divided into steel grids, reinforced concrete grids and the combination of steel and reinforced concrete grids, which are used more by steel grids.

According to different shapes, the grid structure can be divided into double plate grid structure, single layer and double shell grid structure. Plate type grid frame and double shell type grid frame is divided into upper chord rod, lower chord rod and belly rod, the first to accept tension and pressure; The rods of single-layer shell grid accept not only tension and pressure, but also bending moment and shear force. Now most of the grid structures in Our country choose plate grid structure.

According to practical use: steel structure by a plurality of rods in accordance with a certain grid way through the node connected space structure. It has the advantages of space force, light weight, large stiffness and good seismic function. It can be used as the roof of stadium, cinema, exhibition hall, waiting hall, stadium stand awning, airplane hangar, bidirectional large column net frame structure and workshop.

The network frame has the characteristics of light weight, high strength, good rigidity and strong deformation ability. Now the demand for the network frame is also increasing. The roof of the structure is composed of cold-formed thin-wall steel members, and the steel bones are made of super anticorrosive and high-strength cold rolled galvanized sheet, which can prevent the corrosion of steel plates in the construction and use process and increase the service life of light steel members. Structure life can reach 100 years.