Performance Experiment And Structural Design Approach Of Self-centering Steel Plate Shear Wall

To improve the seismic resilience of the steel frame-steel plate shear wall structure,a new type of steel plate shear wall with self-centering energy dissipation brace(SPSW-SCEDB)was proposed.In this paper,the cooperative working mechanism of each component in this member is studied by low-cycle reversed loading tests.Based on the theoretical analysis,the ideal damage sequence of the SPSW-SCEDB steel frame structure is determined.Considering the influence law of SPSW-SCEDB design parameters on the hysteretic behavior of the overall structure,the design approach of the SPSW-SCEDB steel frame structure is established.By comparing the seismic responses of the steel frame with two-side connected steel plate shear wall and the SPSW-SCEDB steel frame,the feasibility and accuracy of the design approach are verified.The main conclusions are as follows:(1)The reasonably designed SPSW-SCEDB presents a full flag-shaped hysteretic response under the action of low-cycle reversed loading and has excellent energy dissipation and recentering capacities.The wall plate and pre-pressed disc spring self-centering energy dissipation(PS-SCED)braces in SPSW-SCEDB bear the horizontal load in parallel.As the loading displacement increases,the component that contributes the most of the bearing capacity gradually changes from the wall plate to PS-SCED braces.During the loading process,the energy dissipation capacity of the wall plate is greater than that of PS-SCED braces.The restoring force of the SPSW-SCEDB is fully provided by the PS-SCED braces.The recentering ability of the PS-SCED braces in the test specimen can completely overcome the residual displacement of the wall plate,so that the residual deformation ratio of the SPSW-SCEDB is less than 0.2%,achieving the goal of recentering.(2)Combined with the requirements of the code,the design of the SPSW-SCEDB steel frame structure should be based on the hinged steel frame structure with two-side connected steel plate shear wall considering the strength of the wall plate after yielding,and the two-side connected steel plate shear wall is replaced by the SPSW-SCEDB with the same lateral stiffness.25 SPSW-SCEDB steel frame structures with different design parameters are simulated to study the influence of design parameters on structural performance.Results indicate that the ratio of the width to span of the wall plate has the greatest impact on the bearing capacity,followed by the stiffness ratio of the brace.The ratio of the width to span of the wall plate and the percentage of pre-pressed force in the activation force have the greatest influence on the energy dissipation capacity.The ratio of the width to span of the wall plate has the greatest influence on the recentering ability of the structure,followed by the percentage of pre-pressed force in the activation force.Based on the design priority of the performance indices that is "recentering is first,energy dissipation is second,and ensuring bearing capacity",the value ranges of the design parameters are suggested as follows: the ratio of the width to span of the wall plate does not exceed 35%;the percentage of pre-pressed force in the activation force is not less than 80%;the percentage of stiffness of the wall palte in SPSW-SCEDB is not more than 35%;and the stiffness ratio of the brace is primarily selected as 5%.(3)Two steel prototype frame with two-side connected steel plate shear wall and the SPSW-SCEDB steel frame with the same main component and inter-story lateral stiffness are designed,and their dynamic responses under frequent,basis,rare and mega earthquakes are studied.Compared with the prototype structure,the inter-story drift response of the SPSW-SCEDB steel frame is reduced by 34%～45%.The residual displacement ratio of the SPSW-SCEDB steel frame structure is smaller than that of the prototype structure under basis,rare and mega earthquakes,and the degree of reduction increases with the increase of peak ground acceleration.The floor acceleration of the SPSW-SCEDB steel frame structure is larger,and its ratio of the two structures is 1.22:1under mega earthquake.The energy input into the structure by the ground motion is mainly converted into the elasticity potential energy,damping energy dissipation,kinetic energy and plastic energy dissipation.The kinetic energy of SPSW-SCEDB steel frame is increased by 2.5 times,and damping and plastic energy dissipation are increased by 65%～136% and 1.1～19.9 times,respectively.The elastic potential energy is reduced by 9%,and the total input energy of ground motion is increased by45%～180%.The SPSW-SCEDB steel frame structure has an excellent recentering capacity under mega earthquakes,but the beams and columns provide little plastic energy dissipation,ensuring the goal of replacement after earthquakes.