10 measures to control welding deformation of steel structure
The welding deformation directly affects the installation and function of steel members and steel structures, and because of the additional bending moment, secondary stress and so on, which indirectly affect the service performance of steel structure engineering, so the control of welding deformation is very important.
According to the causes and influencing factors of welding deformation shared by the previous editor, the following misapplication of deformation can be controlled:
- Reduce the cross-sectional area of the weld: on the premise that the weld is intact and without excessive defects, the size of the groove (Angle and gap) should be smaller as far as possible.
- For the steel whose yield strength is below 345MPa and whose hardness is not strong, small heat input is adopted.
- As far as possible, muti-layer welding should be used instead of single-layer welding for thick plate welding.
- Under the condition of meeting the design requirements, the longitudinal stiffening plate and the transverse stiffening rib can be welded by the intermittent welding method.
- When both sides can be welded, double-sided symmetrical grooves should be used, and the welding sequence should be symmetrical with the member and axis in the multi-layer welding.
- When the thickness of T-shaped joint plate is large, the butt-welding seam with sloped Angle is adopted.
- Adopt the method of reverse deformation before welding to control the Angle deformation after welding.
- Adopt rigid fixture fixing method to control the deformation after welding. The reserved length method of member is used to compensate the longitudinal shrinkage deformation of welding seam. For the long component distortion, mainly by improving the flatness of the plate and component assembly precision, make groove Angle and gap accurate, arc pointing or alignment accurate, in order to make the weld Angle deformation and the longitudinal deformation value of the wing plate and web along the length of the component consistent.
- The number and size of welds should be reduced as far as possible in design; Reasonable weld layout, in addition to avoid weld density, but also should make the weld position as close as possible to the component of the neutral axis, and the weld layout and component of the neutral axis relative weight.
- Reasonable welding sequence should be adopted when assembling components with numerous welds or installing steel structures.