Truss B5 welding assembly technology

Lattice structure is a system of rods connected at nodes in such a way that they experience mainly tension or compression; lattice structures include span structures, trusses, masts, reinforcement meshes and frames. Such steel coverings are part of overpasses, passages, enclosing structures that protect the structure from atmospheric influences. The design of such structures is of crucial importance, since they make up 30-40% of the total construction cost of the facility. The choice of structure significantly affects the space-planning solution of the entire structure: column pitch, arrangement of overhead light, roof, axis of suspended ceilings, the possibility of installing suspended equipment, etc.

The diploma project proposes for consideration a lattice through structure B5, consisting of individual rectilinear rods connected to each other at nodes. The structure works in bending from an external vertical load, usually applied at the nodes. Due to this, axial tensile and compressive forces arise in the structural elements, which ensures the most complete use of the bearing capacity and material than in bending elements (beams). The feasibility of this design increases with an increase in the span and a decrease in the estimated load on it.

The span structure is assembled (enlarged) at the installation site from two truss frames, connected to each other by three braced diagonals position 8 and position 9 and ties along the upper chord position 3 and position 6.

The geometric scheme of the B5 span structure is determined by the outline of the chords and the type of lattice of the frame-trusses. According to the outline, the B5 flight structure has parallel chords. The ease of manufacture determined the possibilities of their wide application. Due to high technical and economic indicators, such a design is successfully used for spans of 18-120 m and has a relatively small construction height compared to trusses of other outlines.

The stability of the structure under any load is achieved by the device of the lattice, forming a system of triangles. In this design, a diagonal lattice is used, its feature is the ability to regulate the sign of the force. The rational angle of inclination of the diagonal lattice to the lower chord is 35-450. The descending diagonals are stretched, and the short posts are in compression.

Position 1 is the upper chord of the frame-truss, position 2 is the lower chord of the frame-truss. The posts and diagonals position 4 and position 5 are combined into nodes using gussets position 12, position 17, position 19, position 21, position 20, position 18, position 14, position 15 and position 16. The span structure is assembled and enlarged at the installation site from two trusses connected to each other by three connecting frames position 8 and position 9 black. bolted connection position 7 and ties along the upper chord position 6 (graphic sheet No. 1).

The frame in this design is a three-dimensional spatial structure intended for connecting individual frame-truss planes into a single structure - a span structure. The frame is made of bent sheet metal in the form of a channel position 8 and position 9. The main requirement for the frame is the rigidity of the structure. Therefore, the beam blanks included in the welded frame are connected to each other rigidly. The frame is delivered to the assembly site separately as an assembly element, table 1.