Research On Mechanical Property Of X-Shaped Planar Mega Steel Frame-Double Skin Composite Shear Wall System

Based on the research and application results of mega steel frame and double skin composite shear wall structures,a new type of super high-rise structure system,the mega steel frame-double skin composite shear wall structure system,is constructed by combining the mega steel frame structure,double skin composite shear wall and multilayer prefabricated secondary structure.The system is composed of several ‘structural groups’.The secondary structures in each group are independent of each other and have no influence on each other.Different Functional requirement of buildings can be realized in different structural groups,and the requirements of large bay of buildings without walls and columns can be realized.Considering that the X-shaped building plan is widely used in high-rise and super high-rise buildings,a systematic and comprehensive study is conducted on the static and dynamic performance of this new structural system in super high-rise buildings with X-shaped plans,as well as the static performance of key connection joints.Firstly,based on the actual engineering project of a super high-rise residential building with an X-shaped plane,three different shear wall layout plans are proposed,and elastic static analysis is conducted to select the optimal shear wall layout plan.Furthermore,based on the analysis results of the primary structural column and double skin composite shear wall section parameters,the optimal layout plan is optimized for steel consumption.Secondly,based on parameter analysis methods,the influence of secondary structures on the lateral stiffness and deformation of the overall structure in the new structural system is studied,and reasonable assumptions of secondary structures are proposed to simplify the calculation.Then,hinge and rigid connection models of the secondary structure and the primary structure,as well as general structural system models,are established.Elastic static analysis and elasto-plastic time history analysis are conducted on the three calculation models,and key performance indicators and component internal forces are compared.The mechanical properties of the new structural system and the general structural system are systematically studied.Finally,based on ABAQUS,a refined analysis model for the connection joints between secondary structural beam and double skin composite shear wall is established to analyze the static performance of different connection methods and provide appropriate connection methods.The analysis of the impact of secondary structures on structural stiffness and deformation shows that when simplifying the analysis,only considering the action of secondary structure floors can represent the stiffness and deformation of the overall structure.The elastic and elasto-plastic analysis results of the new structural system and the general structural system show that there is little difference in static performance between the two.The former has advantages in terms of elasto-plastic deformation and shear wall damage.The elastic and elastic-plastic analysis results of the secondary structure and the primary structure using rigid or hinge connection indicate that using hinge connections is more conducive to the stress distribution of double steel plate composite shear walls and the secondary structures.The finite element analysis results of the connection joints indicate that the deformation and stress of each component of the hinge connection model are smaller than those of the rigid connection model and the rigid ribbed connection model;The research results are applicable to X-shaped high-rise and super high-rise buildings,and can also provide reference for other plan layout buildings,and provide a new idea for the research of structural forms of highrise and super high-rise buildings.Finally,summarize the entire work and point out the focus of future research.