RESEARCH ON ASEISMIC PERFORMANCE AND LIMIT VALUE OF PLATE WIDTH-THICKNESS RATIO OF STEEL SPECIALLY SHAPED COLUMNS WITH CRUCIFORM SECTION

Referencing to the load conditions of steel frame column members in meizoseismal area and aiming at engineering application of profiled bar combination under active international code,this paper designed a total of 36 calculation models of steel specially shaped columns with cruciform section of different flange width-thickness ratio and web depth-thickness ratio under different axial compression ratio,which were equal-stress and 1∶ 2 scale. These models were analyzed by the numbers under low cyclic loading and constant axial compression considering their initial imperfection and material nonlinearity. The paper simulated the entire process of their forcing,deformation and destruction,studied their seismic performance such as bearing capacity,rotational performance,hysteretic behavior, energy dissipation capacity,destruction mode and so on,also analyzed the influencing rule of flange width-thickness ratio,web depth-thickness ratio and axial compression ratio on the seismic performance,and evaluated the holistic seismic behavior of these models. Finally,based on the requirements of seismatic bearing capacity and holistic seismic performance,the paper proposed the limit values of flange width-thickness ratio and web depth-thickness ratio under different axial compression ratio for application of steel specially shaped columns with cruciform section in meizoseismal area,and provided theoretical foundation for practical engineering applications and the compilations of Technical Specification for Steel Structures with Specially Shaped Columns.