| Eccentrically braced steel frame is an ideal lateral resisting system with reasonablemechanical performance, this type of structure has a good adaptability in high-intensityseismic regions. The Q345steel is used to the links and braces of the high strength steelcombination eccentrically braced steel frame in order to achieve a good performance instiffness and energy dissipation. Other parts of the frame, such as the columns andbeams are adopted by Q460steel or Q690steel, this is because that it could effectivelyreduce the section. Studies on high strength steel combination eccentrically bracedframe are at the begging, this is particularly true for the seismic performance of thissystem.In this paper, the finite element software Abaqus6.12is adopted to developnonlinear finite element model, in which all parts of the eccentrically braced steel frameare treated as beam elements except for the links with large deformation and yielded(treated as solid element). In the analysis process, the effects of material nonlinearityand P-Δ are taken into account; meanwhile, multi seismic waves are inputted in the timehistory analysis in order to test the seismic performance of the eccentrically braced steelframe. In specific:First, different length of links and different strength of steel for D-typeeccentrically braced steel frame were designed. At the same time, single frameeccentrically braced steel frame finite element model is established. According to thecomparation with the experiment, the model is proved to be appropriate.Moreover, the dynamic response and seismic capacity of the high strength steelcombination D-type eccentrically braced steel frame are analyzed under the earthquakeactions. It is shown that the links can dissipate seismic energy through bending followed by inelastic deformation, and the other parts can be protected in the condition of elasticstate under severe earthquake.Thirdly, taken the combination of Q345steel and Q460steel as a case, andexamined the effects of the length of links to the seismic performance of the structure inthe way of changing the length of links. Conclusion can be made that whether the linkstoo long or too short, it is bad for the seismic performance of the D-type eccentricallybraced steel frame.Lastly,seismic performance and economical efficiency of3kinds of differentstrength of steel D-type eccentrically braced frame are compared.It proves that:All kinds of different strength of steel D-type eccentrically braced steel framecan wellfulfil the requirements for seismic resistance.Compared with Q345one,high strength steel D-type eccentrically braced frame can save the use of steel,reducing the construction cost which can improve the economic benefit. |
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