Study On Flexural And Axial Compression Behavior Of Cold-Formed Thin-Walled Steel Framing(CTSF) Walls Infilled With Light Polymer Material

In recent years,with the transformation and upgrading of the construction industry,the assembly architecture has been developed and applied vigorously in china.In this paper,a new type of cold-formed thin-walled steel framing(CTSF)walls infilled with light polymer material was investigated,in which light thermal insulation materials are sprayed in region of the cold-formed thin-wall steel frame,light polymer insulation layer and panels are used on both sides of the wall.The CTSF wall infilled with light polymer material has good insulation,heat insulation and fire resistance.The wall fabrication is completed in the factory according to the standardized design and industrialized production,which improves the assembly rate of the housing and accords with the development trend of the fabricated buildings in china.The flexural and axial compression performance tests of cold-formed thin-walled steel framing(CTSF)walls infilled with light polymer material were carried out,and the test results were verified by finite element software,and the calculation methods of their ultimate bearing capacity were given.The main research has been done as follows:(1)The flexural performance tests of 6 CTSF walls infilled with light polymer material was carried out,and the failure mode and bending bearing capacity of the composite wall were studied.The results show that the buckling failure occurs in the middle span of the light steel studs under the lateral uniform load.The types of light polymer material affect the bending capacity of composite walls.The flexural bearing capacity of CTSF walls infilled with cement light polymer material is 7.7% larger than that of CTSF walls infilled with plaster light polymer material.The panels and light polymer insulation layer on both sides of the wall can improve the flexural capacity of the composite wall.(2)The flexural properties of CTSF walls infilled with light polymer material were numerically simulated by finite element software,which showed that the finite element results were in good agreement with the test results.The effect of steel yield strength,panel thickness,panel species and light polymer material strength on flexural behavior of the composite wall were studied.The results show that steel yield strength,panel thickness,panel species have great influence on the bending capacity of the walls,and the light polymer material strength has little influence on the bending performance of the composite walls.(3)The axial compression performance tests of 6 CTSF walls infilled with light polymer material was carried out,and the failure mode and bending bearing capacity of the composite wall were studied.The results show that the studs of CTSF walls infilled with plaster light polymer material was flexed around the weak axis and was accompanied by distortional buckling.The studs of CTSF walls infilled with cement light polymer material was flexed around the strong axis.Local buckling occurs in the bottom and middle sheetmetal screws of the studs of the composite wall with cement light polymer insulation layer and cement fiber board on both sides.The axial compression bearing capacity of CTSF walls infilled with cement light polymer material is 81.8% larger than that of CTSF walls infilled with plaster light polymer material.The panels and light polymer insulation layer on both sides of the wall can improve the axial compression bearing capacity of the composite wall.(4)The axial compression performance of CTSF walls infilled with light polymer material were numerically simulated by finite element software,which showed that the finite element results were in good agreement with the test results.The effect of panel thickness,panel species,stud spacing,sheetmetal screw spacing on flexural behavior of the composite wall were studied.The results show that panel thickness,panel species,sheetmetal screw spacing have great influence on the bending capacity of the walls,and the stud spacing has little influence on the bending performance of the composite walls.(5)Based on the experimental phenomena and the finite element analysis,The effective section method and the direct strength method were applied to calculate the flexural and axial bearing capacity of the CTSF wall column.Through calculation and analysis,the calculation formulas of the flexural and axial bearing capacity of the wall were put forward.The calculation methods suggested in this paper can be used for structural design of CTSF walls infilled with light polymer.It can also provide a reference for subsequent research and engineering application.