Experiment And Theory Study Of Bearing Capacity Of Steel Plate Shear Walls On Compound Load Action

Steel plate shear walls is transiting from research to application for excellentseismic capability, some engineering projects adopted SPSWs is constructing orcompleted, though there is no corresponding national standards to be followed and noresearch achievements of bearing capacity on the compound actions.The method of pseudo-static experiments and theoretical analysis is taken, bearingcapacity of stiffened and no-stiffened thin SPSWs on the compound load action havebeen discussed, theory for the engineering application is provided. Main contents andthe results are as follows.The pseudo-static experiments have been done on15stiffened and no-stiffenedthin SPSWs with moment frame. The analysis includes the damage mode, limit driftratios, skeleton curves, hysteretic curves and the bearing capacity etc. Test results showthat stronger and better ductility frame is the condition of tension-field developed fully.SPSWs with stiffener or enhancing frame has higher elastic strength and rigidity,member has excellent ductility, damping coefficient of seismic code is suitable to thinsteel plate shear wall.Regarding height to thickness ratio, axial compression ratio, overall and localheight to width ratio as affecting factors, specimens is designed using four factors ofthree levels orthogonal table, SPSWs on shearing, compression-shearing andbending-shearing action is analysis with finite element methods. On the condition ofstronger frame, it is suggested that ultimate shear strength is taken the stress wheninter-story drift ratio is about1/500, the shear strength and stiffness is mainly relatedwith ratio of height to thickness, the trend is declined nonlinearly with ratio of height tothickness increased, calculation method is presented. Axial load reduced about10%shear strength; moment reduced about40%shear strength. The axial compressive stressafforded by inner-plate transits to frame with the forming process of tension field, the burden of column increased. Overturning moment is mainly bearing by out-frame. Forstrong-frame and weak inner-plate members with high height to width, when lateraldisplacement is increased, the lateral deformation may turn from bending tobending-shear modes, leading to the redistribution of internal force, which haveinfluence on shearing force redistribution in frame-shear wall structures.Two groups of different width series specimens with3,6,9floors is designed,inverted triangular lateral load is applied, the results is compared from the finite elementmethods and USM model. It shows that USM based on post-buckling shear strengthformula is harmonious with shear mechanism, can relatively accurately simulatedbehavior before yield, specific method is provided.Using the method of comparison between theory and finite element results, rib toplate stiffness ratio is studied. Based on no significant changes of performance inelastic-plastic stage, it is suggested that the threshold values of rib to plate stiffness ratioof SPSWs is not less than30⁴0, upper values is suitable to higher ratio of height tothickness. The value should be increased in the condition of compound-load action.Regarding height to thickness, height to width ratio, axial compression ratio, rib toplate area ratio as influence factors, stiffen-specimens is designed using four factors ofthree levels orthogonal table, SPSWs on compression-bending-shearing actions isanalysis with finite element method. It is feasible to limit drift ratio to1/400for thehigh-rise buildings, multistory buildings should be controlled strictly. When frame isstronger, shear bearing capacity of stiffened SPSWs reduced10%on the axial loadaction, and reduced42%on the compound load actions. The local internal force ofcomponents can be approximately calculated taken distribution loads from inner-platetension field as0.5t tor (t_u-t_cr)t tin the ultimate shear state approximately.Overturning moment is mainly bearing by out-frame, improvement and evaluation ofthe overturn-resistant ability need deeply study when using in tube structures.*sponsored by Lai-wu iron and steel corporation...