Study On The Eccentric Compression Capacity Of Variable Cross-section Box Compression

In recent years, the structural forms of the steel member are gradually tend todiversify with the increase of steel production. The box-section member has betterbending stiffness and torsional rigidity in the both two principal axes and the wedgemember has a cross-section changes and internal force change to suit the advantages arewidely used in various building. At the same time, the useness of the variablecross-section box member is also quietly rising in the construction field.In this paper, considering the elastic-plastic, large deflection, using ANSYSprogram to established the variable cross-section box biaxial eccentric compressionfinite element model. In order to simulate the real stress condition, considering residualstress and initial geometric imperfections. Then by changing the ratio of height to widthratio of section, wedge, member slenderness ratio, web width-to-thickness ratio andload eccentricity on the component parameters, to investigate those effect of theultimate stability capacity.Combination of “Code for Design of Steel Structures”(GB50017-2003) and“Portal Frame Light Steel Structure Housing a Technical Specification”(CECS102:2002), presenting variable cross-section box members subjected to eccentriccompression bearing capacity calculation formula. Then the proposed formula isamended according to the influence of each parameter on calculation results. Finally,the calculation accuracy of the correction formula is verified through the section ratioof height to width, wedge ratio, slenderness ratio, the web member width-to-thicknessratio and other parameters change in total of330components’ results of finite elementcalculation, to demonstrate its applicability.