Test Research On Local Stability Of Web Of Cellular Beams Under Bending Shear Stress

Cellular beam is a kind of the steel structure formed by dislocation welding after cutting along the broken line of H.steel or I.steel web. Cellular beam possesses high flexural capacity and reduces the story by crossing the pipe through the hole. It is well mechanical, esthetical and economical. In recent decades, cellular beams are widely used in industrial plant and high-rise buildings in USA, Japan and some European countries.The simplified calculation method of cellular beams was brought into the corresponding procedures. There is no design specification for cellular beams in our country for now, in order to meet the increasing need of engineering and to provide reference for relevant standard. We should make extensive and in-depth study on cellular beams. Local stability of web of the cellular component is an important factor affecting the bearing capacity. With the increasing improvement and development of production level, production conditions and the application of high strength steel, the cellular component not only toward more light and more thin, but also more prone to instability. Analyzing on the factors affecting the local stability of web of cellular component is necessary.The local stability of web of cellular beams under bending shear was studied through the combined method of test and finite element analysis. The main influencing factors were studied as follows:the requirements of regulation of cellular beams were based on the analysis of theory and the relevant foreign standards and the calculation provisions of local stability of beam in related design method, determining the direction of research.The local stability test of 3 cellular beams which are respectively two groove (hexagon, round) and two opening rate (60%,70%).Experimental study on the law of the influence of groove, opening ratio and web depth thickness ratio on the local stability of web of cellular beams. And compare of different pass, the buckling load of different hole rate, ultimate load and failure mode. The experimental study of local stability of web of cellular beam as the basis, contrasting the buckling load using the finite element software ANSYS and the buckling load getting from the calculated formula, found good fitting. And then contrasting test and finite element calculation of deformation and load-displacement curve results, obtained good fitting validity of finite element model is established in the right way.On the basis of experiment, the large numbers of parameters of cellular beams were under finite element analysis. The failure mode, ultimate bearing load and elastic buckling load of cellular beams were studied and analyzed under different groove, different web depth thickness ratio, different shear span ratio and opening ratio.Analysis the influence of each parameter for elastic buckling load and ultimate load.Through the relationship between parameters and elastic buckling load. Finally using the nonlinear regression analysis of mathematical software SPSS fitting formula of elastic buckling load of cellular beams.to provide a reference for practical design. Derived limit formula of high thickness ratio of castellated beams through theoretical analysis.The research results above not only providing a theoretical basis for the design of local stability of cellular beams, but also providing a reference for engineering application.