| The multi-ribbed composite shear wall with concrete-filled steel tubular columns(MRCW-CFSTs)is a new structural system that uses steel tube concrete columns as the edge components of the composite wall,and is connected by post cast concrete columns.It fully integrates the advantages of high strength,good plastic toughness,and seismic performance of steel tube concrete columns,as well as the energy dissipation and vibration reduction of the multi ribbed composite wall,multiple defense lines,ecological energy conservation,and rapid construction.Providing more forms of choices for building houses with frame shear wall and shear wall structural systems,with good economic benefits and environmental performance.Both can be prefabricated in advance,which is in line with the development trend of residential industrialization and has broad prospects for development and application.Based on this,this article adopts theoretical research and numerical analysis methods,combined with existing experimental data comparison and verification,to study the shear mechanism and compressive shear bearing performance of MRCW-CFSTs under monotonic and reciprocating loads,providing theoretical basis and technical support for the practical engineering application of new composite shear walls.The main job responsibilities are as follows:(1)Based on the shear mechanism and working performance of wall with concrete-filled steel tube(CFST),and based on the softened strut-and-tie model,the contribution of steel pipes,transverse bars,and longitudinal bars to the shear bearing capacity of the wall is considered.A calculation method for its shear bearing capacity is proposed,which is verified based on existing experimental results in literature.Compared with the calculation results recommended by domestic and foreign standards,the proposed formula in this paper has good calculation accuracy and rationality,and explore the main factors that affect the shear bearing capacity;Finally,considering the shear strength calculation model of the composite material of the middle wall,a formula for calculating the shear bearing capacity of MRCW-CFSTs was further derived.(2)Using the finite element analysis software ABAQUS,appropriate constitutive models,boundary conditions,and interface contacts were selected to conduct numerical analysis of the monotonic shear performance of MRCW-CFSTs.The simulation results were compared with the theoretical formula results proposed in this paper and found to be in good agreement,indicating the applicability of the softened tension compression rod model and the reliability of the finite element model;Breaking through the limitations of insufficient experimental data,a comparative study on the monotonic shear performance of composite shear walls based on key parameter changes was conducted using a finite element model,expanding the analysis of the influence of block form,steel pipe yield strength,concrete strength grade,and shear key form on the monotonic shear performance.(3)The numerical simulation analysis of the reciprocating shear performance of MRCWCFSTs was carried out using ABAQUS software,revealing the mechanical characteristics and collaborative working mechanism of the wall under horizontal reciprocating loads.The accuracy of the recommended formula was demonstrated by comparing the finite element results with the theoretical results of reciprocating shear capacity;Using CFST and ordinary multi ribbed composite walls(MRCW)as comparative specimens,analyze the failure forms,hysteresis characteristics,energy dissipation capacity,and stiffness degradation of three different types of walls.Research has shown that concrete filled steel tube frame columns can effectively improve the bearing capacity of shear walls,enhance structural energy dissipation capacity,and slow down the degradation process of stiffness and strength.This indicates that the deformation of various components of the wall is coordinated,and the overall load-bearing performance is good.(4)Based on the existing theory of computation models of CFST and MRCW,the formula for calculating the compression shear bearing capacity of MRCW-CFSTs is derived;Exploring the changes in the main properties of the specimen,such as peak load,ultimate load,and initial stiffness,under the influence of various parameters,and analyzing the influence characteristics of axial compression ratio,aspect ratio,steel pipe wall thickness,and block strength on the compressive shear performance of shear walls. |
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