Research On Mechanical Properties Of Steel Frame Structures With Different New Types Of Infill Walls

With the vigorous implementation of China's housing industrialization,steel structure residential system has become a preferred residential structure system.However,the infill walls to match it are not well-developed.In recent years,new infill walls to match steel frames are emerging increasingly and a large number of studies have shown that these new infill walls have different influence on the mechanical properties of steel frame structures under horizontal uniaxial loading,low cyclic loading and earthquakes.Nowadays there are few comparative studies on the influence of different new types of infill walls on the mechanical properties of steel frame structures.Differences between influence of different new infill walls on the mechanical properties of steel frames are still unknown and valuable selection schemes of new infill walls are few.The purpose of this paper is to study the influence of different new infill walls on the mechanical behavior of steel frame structures.The finite element analysis method is used to study the mechanical properties of the structural system under horizontal uniaxial loading,low cyclic loading and earthquakes.The main research results are as follows:(1)According to the experiments in the existing literature,the refined finite element model of steel frame structure with three different new infill walls was established respectively.The finite element calculation results were in good agreement with the experimental results.(2)Three basic models were obtained by filling three new infill walls into the same single-span and two-layer plane steel frame structure.By analyzing the loaddisplacement curves of three basic models under uniaxial loading and hysteresis curves,skeleton curves and stiffness degradation curves under low cyclic loading,differences of influence of different new infill walls on the bearing capacity,stiffness,energy dissipation capacity and ductility of plane steel frame structures are obtained.(3)Through the analysis of the influencing factors of the basic models,the influences of three key factors of axial compression ratio,high span ratio and wall thickness on the mechanical properties of three new infilled wall steel frame structures are found.(4)Based on the existing infill wall equivalent single lever model,we used the refined solid model and fitting method to correct the existing equivalent single lever effective width formula.The formula for calculating the effective width of the equivalent single lever diagonal bracing model suitable for steel frame structures with the new composite wallboard was obtained and it was verified by existing tests.(5)Based on the equivalent single lever model modified in this paper,selecting a steel frame residential to compare and analyze the influence of three new infill walls on the seismic performance of three-dimensional steel frame structures under rare earthquakes.Combining the two aspects of mechanical performance and cost,a new infill wall selection scheme was proposed for practical engineering reference.