Study On The Influence Coefficient And Displacement Amplification Factor Of Y-Typed Eccentrically Braced Combined With High Strength Steel Structure

The Y-typed eccentrically braced combined with high-strength steel structure is a new type structure.Ordinary steel（f_y≤345MPa）is used in the link to ensure the structure has good plastic deformation ability under earthquake action,and high-strength steel（f_y≥460 MPa）is used in the frame beam and column to reduce the cross-sectional dimension of the component while ensuring the elastic stress state of the non-energy consuming component.The new structure has good ductility and energy-consuming capacity.R,the structural influence coefficient is a crucial part of the performance-based seismic design method.The seismic design of structure is more reasonable and more economical if a reasonable value of R is used.It is obviously not reasonable to hide the concept of the structural influence coefficient and adopt a fixed value for all structural systems in the 2016 edition of China’s code for seismic design of buildings（GB50011-2010）.It is important to study the structural influence coefficient and displacement amplification factor of the Y-typed eccentrically braced combined with high-strength steel structure,it can not only improve the structural performance design method,but also provide reference for the future design value of the structure,and promote the application of the structure in seismic fortification zone,and it presents excellent seismic performance.The prototype structures of 12 Y-typed eccentrically braced combined with high-strength steel frames are designed with different stories（4-story,8-story,12-story,16-story）and different link lengths（0.7m,0.9m,1.1m）based on the performance-based seismic design ethod（PBSD）,and the component cross-sectional dimensions are finally determined.The finite element analysis model of each prototype structure is established by finite element analysis software SAP2000.The static elastic-plastic analysis（Pushover analysis）of 12 Y-typed eccentrically braced combined with high-strength steel frames is carried out.The performance curve is obtained.The structural influence coefficient R and displacement amplification coefficient C_d of each structure are calculated repeatedly by the capability spectrum method,ductility reduction factor R_μ and structural super-reduction factor R_Ω are calculated also,and the influence of structural story number N and the length of link e on each performance coefficient is analyzed.Incremental dynamic analysis（IDA）is carried out on the finite element model of each Y-typed eccentrically braced combined with high-strength steel frames,and the data obtained by IDA analysis was fitted to reach the IDA performance curve of the structure.The R,C_d,R_μand R_Ω of each prototype structure were calculated by the capability spectrum method,and compared with the results of the Pushover analysis.The influence of the number of structural story N and the length of link e performance coefficient is analyzed.The recommended values of R,C_d and R_Ω of Y-typed eccentrically braced combined with high-strength steel frame are linear correlation with the ductility coefficient μs and the fundamental period T₁ of the structure,based on the performance coefficient of each structure obtained by Pushover and IDA results,which can provide a reference for the performance design of the new structural systems.