High-strength cold-formed structural steel defect

High-strength cold-formed structural steel defect

Roll forming process is a very complex process, if the design is unreasonable, in the debugging process will appear wavy edges, pocket wave longitudinal bending, folds the corners, cracks and distortions deformation defects, which are often in debugging the production process can be found, and if it is found to be a good solution to these problems, otherwise the existence of the defect deformation will further undermine the structure of high-strength steel sheet of the roll forming process.

(1) High-strength cold-formed structural steel main defects Bending Crack, which is composed of high-strength structural steel material characteristics of the decision itself.

(2) The bag-wave generation is mainly due to high-strength structural steel to produce uneven stress transversely stretched during bending, strain, and the sheet thickness direction strain is relatively small, according to material deformation of the Poisson relationship inevitably deformation are concentrated in parts of the longitudinal contraction deformation. And this role will be repeated elastic deformation is formed to produce high-strength structural steel surface cracks.

(3) Edge waves generated mainly two effects combined: the front of the bag with the same first-wave mechanism of action; the second is part of the first edge of the material in the external force is stretched shear length, then compressed again cut the plastic deformation caused by edge waves.

(4) To cause the buckling many reasons, one of the very important role because of the cross section of the edge is subjected to tension during the bending side, trying to lengthen the entire cross-section longitudinally, but insufficient to elongate tension the rigidity of the entire cross-section, resulting in rolling’s front-end bent upward or downward of the phenomenon, than the thin slab are more prone to buckling. At present, because the equipments have alignment means to make the correction, so do not pay attention to a lot of people.