The steel ball is too small for the installation of the space frame structure, which is easy to cause the rods to collide and hinder the installation work. On the contrary, in the construction drawings of large-scale space frames and special-shaped space frames, bolt balls with a diameter greater than 300 often appear, that is, the steel balls are too large. Due to the influence of various factors such as market, processing, and on-site installation, the installation work is ultimately hindered. To solve the problem that the steel ball is too small, it is easy to cause the rod to collide, and the following methods can be used.
When the conditions are convenient, the big ball can be replaced and the corresponding rod can be modified. Otherwise, part of the cone head and the rod of one of the touching rods will be burned off, and then a steel plate with a thickness of 2-4mm thicker than the pipe wall will be imitated and welded. The open edge of the cone head and the rod and the steel plate to be repaired should be beveled (with a hand-held grinding wheel). The above processing method should follow the following principles, that is, to check the force status of each rod in the electronic calculation.
(1) When the stress is similar, it is easy to deal with the pressure rod. Because the compression rod is affected by the initial bending and Euler critical force, the bearing capacity of the central section of the rod is reduced more, and the section of the rod is vibrant.
(2) Take the one with the more minor stress among the two rods for treatment.
(3) For rods with similar stress, take the larger section to reduce the percentage of section weakening.
(4) For the rods with relatively large stress, it is advisable to cut off a part of them and then perform repair welding, the purpose is also to reduce the percentage of the weakened section. In order to prevent the members from colliding, large-scale detailed drawings are drawn for the nodes in question for inspection. The fundamental method is to carry out computer aided design for the processing details of the space frame. To solve the problem that the steel ball is too large, due to the influence of various factors such as market, processing, and on-site installation, the construction of the easy-to-guide =space frame can be carried out according to the following methods.
In order to solve the problem that the bolt ball is too large, in the construction drawing of the space frame, the bolt ball with a diameter larger than 300 is changed to a 300 bolt ball. When making and processing, the angle and diameter of the bolt on the original ball are changed to a 300 bolt ball. Machining, then check for interference and deal with it. Usually, the method of welding sleeves on the connecting plate is used. The processing method should follow the following principles.
(1) The connecting plate is made of a 45# steel plate with a diameter of more than 20mm, and the cross-sectional area of the connection between the steel plate and the ball should be greater than 0.6 times the sum of the cross-sectional areas of the two connecting rods.
(2) The nut is made of a solid 45# steel bar 10mm larger than the sleeve, and the thread processing process is the same as that of the bolt ball.
(3) The welding seam is welded with an E5XXX type electrode, and measures should be taken to prevent welding deformation during welding. (4) The mechanical test shall be carried out on the nodes with greater stress.