What are the requirements for the processing of steel H-beam?
When the steel structure processing arc curved bar is bent, the upper and lower flanges produce out of plane stress. For an arc, its value is inversely proportional to the radius of curvature. When there is no stiffener, the beam web bears the tension or pressure generated by it. After the stiffening rib is set, it is shared by the stiffening rib and the beam web. In addition to the original stress, the flange should also consider its out of plane stress, which is calculated as a three side support plate.
In addition, it should be noted that the stiffness of the flange close to the web of the H-beam is relatively large, so the stress distribution outside the flange plane is the law that the closer the flange is to the web, the greater the value. The stress distribution along the flange plane is also the same.
As the flange plates of the steel H-beam are connected through the welding joints, the welded beam composed of multi-layer plates will produce large welding stress and welding deformation during the welding process, and the stress is uneven. In particular, the mutation of internal force line at the variable section of flange leads to stress concentration, which makes the beam in an unfavorable working state. Therefore, it is recommended to use one layer flange plate. When the load is large and the single-layer flange plate of H-beam cannot meet the requirements of strength or weldability, double-layer flange plate can be used.
When the outer flange plate is not set in length, the value of the extension length at the theoretical cutoff point is determined according to the test results. In the double-layer flange plate beam of welded steel H-beam, the measured stress in the flange plate is different from the theoretical calculated value within a certain length range from the end of the flange plate. At the end, the difference is the largest, and gradually narrows inward until the distance from the end is basically the same. The size of the end is related to the presence or absence of end weld and the ratio of weld thickness to flange plate thickness.