Finite Element Analysis on Flexural and Lateral Torsional Buckling Behavior of Steel I-Beam with Web Opening

Abstract

A steel I-beam with different types of web openings makes in different structures, where in the different technical utilities such as ventilation ducts, electric cables; water carrying pipes and others can be incorporated. But the provision of web openings in I-steel beams introduces typical failure mode. Among that flexure and lateral torsional buckling are a typical failure that occurs in steel I-beam. The main objective of this research was to investigate the behavior of flexure and lateral torsional buckling of steel I-beam with web opening and its ultimate load carrying capacity and buckling moment resistance using nonlinear finite element analysis, Both geometric and material nonlinearities are included in the finite element model The research focused on the effect of shape of opening, total depth to opening depth (D/Do) ratio and spacing to opening depth (S/Do) ratio on the flexural and lateral torsional behavior of steel castellated beam with web opening. Total 62 samples of steel I beam with web opening studied using non-linear finite element analysis with ABAQUS Software package under concentrated load at mid-span of the beam. The FE models are validated with existing experimental data from literature for flexural behavior and numerical calculation by using EBCS-3 code for lateral torsional buckling to examine the accuracy of the simulations. Values from FE model agree with the test and numerical calculation results. In conclusion, the analysis result showed that, Shape of opening has a significant effect on the ultimate load capacity and buckling moment resistance value. Ultimate load-carrying capacity of Castellated beam with diamond, circular, hexagon opening become bigger 28.5%, 22%,7.8% compared with the beam without web opening (original beam), but reduct 26.82 % compared square opening with original beam, and also Buckling moments resistance value with diamond, circular, hexagon opening become bigger 17.6%,14.2%,8.2% compared with the beam without web opening (original beam), but reduct 16.3% compared square opening with original beam. D/DO and S/DO has a significant effect on flexural behavior and D/Do ratio has slightly effect on the buckling moment resistance value, but S/Do ratio has a significant effect on buckling moment resistance value. Beam with depth of opening 0.7 times its overall depth with S/Do=1.4 is the optimize section which has high ultimate load carrying capacity for circular, hexagon and square opening and also beam with depth of opening 0.78 times its overall depth with S/Do=1.4 is the optimize section which has high ultimate load carrying capacity for diamond opening