Investigation Of Mechanical Behavior And Design Approach Of Steel Plate Shear Walls With Sliding Lateral Constraints

Steel plate shear walls(SPSWs)are a sort of lateral-force resisting members with good seismic performance,and an increasing number of multi-story or high-rise buildings employ them as main lateral bracing members in recent years.However,the development of SPSWs is blocked due to the premature buckling of infilled plates,and the vulnerable or difficultly processed restrained members in traditional SPSWs.Therefore,two kind of SPSWs with sliding constraints,which were restrained by X-shaped constraints(XSPSWs)and wave-plate constraints(WSPSWs),respectively,were proposed to efficiently improve the lateral-force resisting behavior and energy dissipation property of shear walls under severe earthquakes,and to protect the sliding constraints from taking part in resisting lateral-force.Therefore,the seismic rehabilitation of structures only needed to replace infilled plates,and the sliding constraints could be reused.Theoretical analyses and experimental investigations have been conducted to study the mechanical mechanism,seismic property and design method of the two SPSWs with sliding constraints;a simplified method was also established for the system analyses of SPSW structures.The main works finished in this thesis are listed as follows:1.Introduction of the two steel plate shear walls with sliding constraints.To solve the problem of the premature buckling in unstiffened SPSWs,the vulnerable stiffeners in stiffened SPSWs and the processing difficulty in buckling-restrained SPSWs,two SPSWs with sliding constraints were proposed based on the stability theory of plates and the constructing feature and mechanical property investigation of traditional SPSWs.The proposed SPSWs not only could efficiently improve the seismic performance of shear walls and prevent the sliding constraints from taking part in resising lateral-force,but also could realize the industrial producing and fabricated construction of SPSWs.2.Experimental research of the two steel plate shear walls with sliding constraints.A series of quasi-static experiments was conducted for unstiffened SPSWs,XSPSWs and WSPSWs.Based on the experimental phenomena and data,the feasibility of the SPSWs with sliding constraints was verified.The experimental data could also provide technical supporting for the validation of the fine numerical simulating method and the simplified structural analysis method of SPSWs.3.Numerical seismic analyses of the two steel plate shear walls with sliding constraints.A fine numerical simulating method for unstiffened SPSWs and SPSWs with sliding constraints,which could take the nonlinear hardening properties of steel,initial geometric imperfections,and the interactions between each components into consideration,was established and validated based on the experimental data.It was systematic investigated that the mechanical mechanism and the influence of the slender ratio of infilled plates(λ)and sub-plates(λsub),and the length-to-width ratio of sub-plates on the seismic performance of XSPSWs and WSPSWs.4.Design method and simplified analysis model of the two steel plate shear walls with sliding constraints.By combing the peak load strengthening effect of sliding constraints and the load-carrying capacity theory of unstiffened SPSWs,it was proposed that the shear bearing capacity calculation method of the SPSWs with sliding constraints.Based on the geometric and physical boundary conditions of the two kind of sub-plates,their elastic buckling properties were analyzed via energy methods.Based on the buckling analysis results,the maximum λsub of XSPSWs and WSPSWs were limited to avoid that the buckling of sub-plates was prior to the yielding of infilled plates in shear.In order to provide sufficient restraints to sub-plate boundaries,a dimensionless parameter,named as stiffness ratio,was introduced to establish the relation between the stiffness of constraints and the cylinder stiffness of infilled plates.The minimum bending and torsion stiffness requirements for the sliding constraints were provided via eigenvalue analyses.Based on the interaction behaviors between constraints and infilled plates,it was developed that a simplified out-of-plane pushing force model and corresponding load-carrying capacity checking method for the sliding constraints.According to the anchoring feature of strips in infilled plates,the strips were classified into 3 types.And then,a tensional-compressional strip model was developed,which could consider the interaction between infilled plates and their boundary members and further simplify the modeling process of SPSWs.The determining method of model parameters was also proposed on the basis of the elastic stability theory.A simplified structural analysis method,which could overcome the modeling complexity and time-consuming problem in the structural analyses of high-rise SPSW buildings,was established based on the above-mentioned tensional-compressional strip model.The efficiency of the proposed simplified analysis method was validated via the experimental data obtained from this thesis and the literature.