How to prevent the deformation of building steel structure

In the construction of building steel structure, welding deformation directly affects the installation and use of building steel structure and building steel structure. And because the additional bending moment and secondary stress generated during the loading process indirectly affect the performance of the building steel structure project, the control of welding deformation is very important. Here to tell you how to control the deformation of the building steel structure.

According to the causes and influencing factors of welding deformation, the following methods can be used to control the deformation of building steel structure:

1. Reduce the cross-sectional area of the weld: Under the premise of obtaining a good weld and not exceeding the standard defects, the size of the groove (angle and gap) should be as small as possible.

2. For steels with yield strength below 345MPa and weak hardenability, it is recommended to adopt small heat input, and try not to preheat or appropriately reduce the preheating and interlayer temperature: the gas is preferentially shielded by welding methods with less heat input such as CO2.

3, thick plate welding as far as possible with multi-layer welding instead of single-layer welding.

4. In the case of meeting the design requirements of building steel structure, it is suggested that the welding method of longitudinal reinforcement and transverse reinforcement can be used.

5. Double-sided symmetrical groove should be adopted for double-sided welding operation, and the welding sequence of symmetrical components and axis should be adopted for multi-layer welding.

6. When the thickness of T-joint is large, the slotted butt weld is adopted.

7. The anti-deformation method before welding is adopted to control the corner deformation after welding.

8. Rigid fixture shall be used to control the post-welding deformation of building steel structure.

9. For the deformation of long parts, it is mainly to improve the flatness of the plate and the assembly accuracy of the parts, so that the groove angle and gap are accurate, the arc pointing or centering is accurate, and the angle and longitudinal deformation of the welded wing and the web are deformed. The value is consistent along the length of the member.

10. In the design of building steel structure, the number and size of welds should be minimized; welds should be arranged reasonably. In addition to avoiding over-tightening of the weld, the position of the weld shall be as close as possible to the neutral axis of the member, and the arrangement of the weld shall be consistent with the neutral axis of the member.

11. The assembly welding of multi-weld components or the installation of building steel structures shall adopt a reasonable welding sequence.