Research On Mechanical Performance Of Low Yield Point Steel Shear Walls

In recent years, the mechanical performance of steel plate shear wall is studied bymany domestic and foreign scholars. But most of the infill plates adopt the ordinarysteel; little research of low yield point steel plate shear wall whose infill plate is made oflow yield point steel has been carried. Based on theoretical analysis of the mechanicalproperties, the low yield point steel plate shear wall is simulated by ANSYS toinvestigate the elastic and elastic-plastic buckling behavior of infill plate and the lateralstiffness, shear bearing capacity and hysteretic behavior of the steel shear wall. Inaddition, effect of infill plate on the stability of the frame column is studied in this paper.The above research of low yield point steel plate shear wall could provide the theoryand design criteria in the practical application. Research contents and correspondingresults in this study are listed as follows:First the shear buckling stress analysis of the low yield point steel plate shear wallhas been carried. The obtained results show that buckling stress calculation method inthe current technical specification for high rise steel structure (JGJ99-98) cannot bedirectly applicable in the low yield point steel plate shear wall. The suggestions ofcalculation method of its shear buckling stress are therefore proposed.Under the same horizontal load, the thickness and buckling stress of infill plate oflow yield point steel plate shear wall would be greater than ordinary steel plate shearwall when the identical frame are used. The infill plate depends more on pure shearresistance to lateral before buckling in low yield steel plate shear wall. As lateralstiffness of infill plate before buckling is about28.2%greater than which after buckling.Therefore, more initial lateral stiffness could be obtained when low yield point steel plate shear wall are applied in practical projects, which is beneficial to the lateralresistance of the whole structure.The lateral resistance performance of low yield point steel plate shear wall couldbe obtained by a superposition of frame and infill plate. Special attention to analysis oflateral resistance performance in frame should be paid: No matter infill plate depends onpure shear resistance to lateral force before buckling or tension strip after buckling, bothwill generate an axis pressure in the right column that should not be negligible, whichwill result in the reduction in total plastic-hinge moment and ultimate shear capacity,while the lateral stiffness of frame will not be affected.The infill plate can generate additional bending moment and the additional axialforce in the frame column after buckling, which will affect the stability of the frame.The obtained results show that low yield point steel plate shear wall can greatly reducethe additional bending moment on the frame column compared to ordinary steel plateshear wall, thereby reducing the level of demolition of the frame column to ensure thestructural integrity security.The hysteresis loop of low yield point steel shear wall under the cycle load is fullerthan ordinary steel shear wall, and the ultimate bearing capacity is lower than the latter,while the ductility and energy dissipation performance is better than ordinary steel shearwall. The fullness of hysteresis loop and energy dissipation performance is not affectedby plate aspect ratio, but with the certain height, the ultimate bearing capacity and thewidth of plate are in direct proportion. The ductility of thin steel shear wall has nothingto do with the aspect ratio, while the ductility of thick steel shear wall increase with thedecreasing in the aspect ratio.The infill plate could greatly decrease the beam response from ground motion,while which would increase the column response. Therefore, the stiffness requirementsof the steel frame column are the premise to ensure that steel frame-steel plate shearwall plays fully a role. The SF-LYPSPW whose infill plate is made of low yield pointsteel could decrease greatly the additional force to edge frame and the column stiffnessrequirements. Under rare earthquake, with respect to the frame and SF-SPSW structure,SF-LYPSPW could better protect the outer frame, thereby reducing the outer framedamage level and ensuring the security of the whole structure.