| As the building height increases,the requirements for the stiffness,ductility and overturning resistance of the lateral force-resistant structure increase.The coupled steel plate shear wall composed of two steel plate shear walls connected by steel connecting beams is a new type of lateral force resistance structure with high ductility and strong energy dissipation capacity.The coupled steel plate shear wall is arranged in the concrete-filled steel tubular frame to form a concrete-filled steel tubular frame-coupled steel plate shear wall structure system,this structure can play the synergistic effect of the frame and the shear wall to realize the goal of dual seismic defense line under large earthquake.In this paper,theoretical analysis and numerical simulation are combined to study the design method of the coupled steel plate shear wall structure and anti-seismic collapse performance of concrete-filled steel tubular frame-steel plate shear wall structure.The main research contents are:(1)The flexural contribution of the boundary frame and coupling beam to the system are considered in the calculation of the lateral force of the coupled steel plate shear wall,an equation is presented to quantify the relationship between the overstrength Ωk of the system and the percentage κi of the lateral seismic design force resisted by the web plates alone.This equation can be used in design to proportion the strength of web plates,the boundary frames,and the coupling beams to achieve the optimum design of the coupled steel plate shear wall.The correctness of the shear force distribution equation is initially verified through the analysis of a three-story coupled steel plate shear wall structure,and the results show that the coupled steel plate shear wall structure designed by this method can form the desired plastic damage mechanism.(2)The finite element software OpenSees was used to perform nonlinear numerical simulation on the test specimens of the coupled steel plate shear wall,and the analysis results were compared with the test results to verify the correctness of the modeling method.The results show that the load-displacement curves of the two are consistent,and the modeling method used in this paper can reflect the hysteretic performance of the coupled steel plate shear wall structure.(3)According to the optimum design method of the coupled steel plate shear wall proposed in this paper,16 CFST frame-coupled steel plate shear wall archetype were designed,the 16 archetypes are divided into two sets according to the degree of coupling DC(i.e.,DC≤0.4 and 0.4<DC<0.6),each archetype set contains archetypes with different aspect ratios and different stories.The above finite element modeling method is used to establish the analytical model of all archetypes,perform nonlinear static analysis,calculate the system overstrength Ω0 of the structure and the period-based ductility coefficient μT to evaluate the performance of the structure under seismic,and the plastic development of the structure is also analyzed.(4)Nonlinear incremental dynamic analysis(IDA)and collapse analysis are performed on the archetype structural models to obtain the IDA curves and median collapse spectrum acceleration sCT of the structures.Take the collapse point Sa(T1)on the IDA curve as the ground motion intensity index,establish the structural collapse vulnerability function,and then the collapse margin ratios CMR and the collapse probability under large earthquakes were calculated to assess the collapse performance.The results show that the CMR of each story structure when DC<0.4 is slightly larger than that when 0.4<DC<0.6,For 9-,12-and 20-story structures,the optimum design method(ie.,Ωk=1.0)can be used to design the coupled steel plate shear wall,while for structures with higher story(such as 30-story),the overstrength Qk needs to be increased to 1.35 to design the coupled steel plate shear wall. |
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