Stability Behavior Research On Channels With Complex Edge Stiffeners And Web Holes Under Axial Compression

With the use of new section shapes and high strength steel plates with thinner thickness, some new stability problems are brought simultaneously. Such as, the compression load carrying capacity of members with different section shapes under interaction of local, distortional and overall buckling conditions. As well, with the style more and more complex, the distortional buckling will play a significant role in ultimate load-carrying capacity. At present, the research method of cold-formed channel bearing capacity under axial compression has been comparatively ripe, but the research of components with holes are still in research phase, especially for channels with complex edge stiffeners and web holes.In response to the research status, taking the axial bearing capacity of thin-walled steel members with web holes and different section shapes as the research object, a total of 10 simply supported compression members with two types of complicated sections including channels with complex edge stiffeners and web holes, channels with complex edge stiffeners and I type web stiffeners and web holes were tested. The ultimate load-carrying capacity, buckling modes and deformation behavior of cold-formed steel members with complicated cross sections in this paper were studied. The results indicate that the axial compression loading efficiency of ?-section specimens with web holes can increase about 30% to 50% compared with channels with complex edge stiffeners and web holes under the same conditions. Compared with the specimens without holes, the failure modes do not change, but the failure positions are near holes.Tests were simulated by finite element analysis (FEA). The analysis results agree well with experimental data. Based on it, the carrying efficiency and Von Mises stress distribution of channel columns with web holes were compared with those without holes by FEA. It is shown that the carrying efficiency of ?-section models with holes decrease by 25.57% compared with the same section models without holes while channel section models with complex edge stiffeners and holes decrease by 6.15% average. Because of perforations on the web, the positions of the stress concentration and the max stress change from the webs near the mid-height of models to the locations adjacent to holes.The flange width, the thickness of plate and the length of components are changed. The variable parameter models with holes were simulated. The FEA results indicate that the degree of damage is more serious with bigger flange width. The thickness of plate will influence deformation amplitude of holes. The variation of length can influence slenderness ratio and buckling waves, change the buckling modes of models. DSM method of specimens with web holes and specific section is researched. A total of 18 Cl-section channels with complex edge stiffeners and web holes are calculated. The DSM method results agree well with FEA results, so the range of the method is expanded.