Research On Lateral Resisting Performance Of Cold-formed Steel Framing Wall With Infilled Gypsum-based Lightweight Material

The lightweight gypsum-based modified material fills the cold-formed thin-walled steel wall to overcome the problem of knocking the cavity,which not only improves the strength,rigidity,stability,fire resistance and thermal insulation properties of the composite wall.And as a green and environmentally friendly building structure,the realization of waste recycling,in line with the sustainable development of the construction industry.In this paper,the lateral performance of lightweight gypsum-based modified materials filled with cold-formed steel composite wall is studied by experimental research,theoretical analysis and numerical simulation,and related design methods are proposed.In this paper,the low-cycle repeated loading test of 11 pieces of full-scale lightweight gypsum-based modified material filled with cold-formed thin-walled steel composite wall was carried out,and the force characteristics and failure modes of the composite wall specimen under horizontal load were observed.The seismic performance indexes such as bearing capacity,lateral stiffness,energy dissipation capacity and ductility of the composite wall are analyzed,and the influences of parameters such as filler material strength and column spacing on the seismic performance of the composite wall are studied.The test results show that all the composite wall specimens are mainly shear deformation,the failure characteristics of the cavity wall are the failure of the screw connection between the wall frame and the wall panel,and the filling wall is ineffective in removing the skin of the wall panel,pressure damage occurred in the corner of the filled plaster;compared with the cavity wall,the shear bearing capacity and the lateral stiffness of the filled wall are significantly improved,and gradually increase with the increase of the strength of the filling material and the spacing between columns;the energy dissipation coefficient and ductility of the infilled wall are higher than that of the cavity wall,and the bearing capacity is relatively stable.Secondly,monotonic loading and cyclic reciprocating loading tests were carried out on two sets of 16 cold-formed steel keel-tapping screws-wall panels,observed the force characteristics and failure mode of the specimen during loading.The performance indexes such as bearing capacity,shear stiffness,energy dissipation capacity and ductility of the screw-connected test pieces were analyzed.The effects of cladding type and thickness,screw diameter and other parameters on the mechanical properties and seismic performance of the screw connection system were studied.The test results show that the failure of the test piece is the failure of the screw connection between the column and the cladding;the bearing capacity and stiffness of the test piece increase with the increase of the screw diameter,keel and wall panel thickness;the test piece of the gypsum board was good in ductility,and the ductility of the test piece coated with the OSB board was poor,and the ductility of the test piece increased with the increase of the keel thickness and the screw diameter and the decrease of the panel thickness.Based on the experimental research,this paper takes cold-formed steel composite walls filled with gypsum-based lightweight material as the research object.Firstly,the finite element analysis software ABAQUS is used to simulate the lateral resistance of composite walls under monotonic loads.On the basis of verifying the correctness and reliability of the numerical model,the main factors affecting the lateral performance of composite walls are analyzed.The results show that the failure mode obtained by the finite element simulation is basically consistent with the failure characteristics of the test,and the simulation results agree well with the experimental results.The shear bearing capacity and stiffness of the composite wall increase with the strength of the filling material;increasing the column spacing,wall thickness,keel wall thickness and reducing the aspect ratio of the composite wall can improve the shear capacity and shear stiffness of the wall;the strength grade of the steel of the wall have little effect on the shear performance of the composite wall and can be neglected.For the numerical model of composite wall under hysteretic load,ABAQUS software can not accurately reflect the hysteretic characteristics of wall shrinkage and slip,so this paper uses macro-element analysis software OpenSEES to analyze.Finally,on the basis of experimental research and finite element analysis,an analytical model and calculation method for the lateral stiffness and shear bearing capacity based on the superposition method are proposed for the lightweight gypsum-based modified material filled with cold-formed steel composite wall.The results show that the error between the analysis value and the experimental value of the lateral stiffness(K)and the shear capacity of the composite wall are between 0.944?1.046 and 0.947?1.112,respectively,except for the error of the individual test pieces,which is slightly more than 10%.The error of the pieces is within 10%.The stiffness calculation model and the bearing capacity calculation model based on the superposition method proposed in this paper can better predict the lateral stiffness and shear capacity of the filled cold-formed steel composite wall.