Senior Structural Steel Supporting The Hysteretic Behavior Analysis And Seismic Design Of Countermeasures

Steel structures are playing more and more important role in modern structure. As themain member to reduce displacements produced from lateral loading and dissipate energy,steel braces have a non-fungible position. But a sound knowledge of the collapse mechanismof stpel braces under seismic loading is still lacking, so that local damage and, even collapseof steel structures under earthquake still takes place. As a result, the analyses of response andof collapse mechanism of steel braces under seismic loading are not only significant intheoretical aspect, but also important in practice.Because of the requirement of a precise mathematical model as well as material modelon the study of the behavior of steel structures under seismic loading (cyclic loading), thispaper adopts the nonlinear large-deformation degenerate shell element, together with a newmixed hardening rule, which linearly combines isotropic and kinematic hardening, tocalculate the hysteritic behavior of steel braces. At the same time, the damage accumulationand residual stress are introduced into the program. The approach adopted in this study isthought to be a banner one.After the derivation of nonlinear finite element procedure, the developing anddebugging of the program, validity of program is tested based on trial data from literaturesall over the world. Then a systematic analysis has been carried out on the behavior ofbox-section steel braces under tension-compression cyclic loading. In terms of thecalculation results, the influence of residual stress, boundary condition and size are analyzed.The stiffness, bearing capacity, the residual deformation and ability of energy dissipationunder cyclic loading are also analyzed, and the relationship between structural strength andthe slendemess Of braCe is given. The limiting widthedcknss ratio of the fiang ofbox-section braces under seismic Ioading is derived, which is b/t S 19N. Finally,the same research Procedure is used to anaiyZ the hySteric behavior of I-section braces. Thelimiting widthtO-thickness ratio of the fiange of I-section braces Under seismic loading isderived, which is b,/t S 7N. These vaiues are well fit the Code fOr Seismic Designof Building.In conclusion, the theoretical analySis Presented in this paPer may well fit the realisticbehavior of steel StrUCtUrs Under seismic lOading, the Stody is rathr thOUgh and syStemedqand the concIusions can be usefu fOr revising stee1 strUCtUrs desbo code.