| Box-section beam-column is used more and more widely because of its goodload-carrying capacity. The Chinese Code for Design of Steel Structures(GB50017-2003) has not proposed a detailed method in the design of box-sectionbeam-column considering plate local buckling. For a multi-storey steel frame, thedesign can save a great amount of consumed steel if local buckling of plates formingbox section is permitted. But the present specification did not propose thecorresponding design method.A 4 nodes and 24 DOFs shell element provided by ANSYS software package isemployed to investigate the influence of component plates' local buckling on theultimate load-carrying behavior of box-section beam-column. The influence of largedisplacement and elastic-plastic material, residual stress and initial imperfection arealso incorporated into the analysis.A detailed parameter study on the box-section beam-column subject to the axialcompressive force, pure bending and both the axial compression and end moments iscarried out to review the effect of component plates' width to thickness ratio (D/t),section aspect ratio (B/D) and member's slenderness ratio. Based on numbers ofnumerical results, design formulas that are expressed directly as the function of widthto thickness ratio (D/t), section aspect ratio (B/D) and member's slenderness ratio (λ)are proposed.The nonlinear effective moment factor is researched, and a comparison of theelastic effective moment factor with the results from current Chinese steel structuredesign code is made , respectively.The ultimate load-carrying capacity of steel frame is researched, and the effect ofcomponent plates' local buckling on the frame's load-carrying capacity and failuremode is reviewed.The hysteretic behavior of box-section beam-column subject to cyclic axial loadand a combination of the constant axial compressive force and cyclic moment isresearched. The influence of component plates' width to thickness ratio (D/t), sectionaspect ratio (B/D), member's slenderness ratio (λ) and the amount of axialcompressive force is studied detailedly. Based on the evaluation of members'hysteretic behavior, some design suggestions are presented.The effective length factor method, second order elastic analysis method andsecond order elastic-plastic analysis method are used in the design of six typicalframes individually. Based on the comparison of calculation results, an evaluation ismade to the precision of the above methods.
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