The Research On The Axial Compression Of Cold-formed Thin-walled C Steel Columns With Longtitudinal Rebal Strengthened

With the application of cold-formed thin-walled steel in the field of construction,buckling has been widely studied as an important factor affecting the bearing capacity of cold-formed thin-walled steel.Buckling will greatly reduce the ultimate bearing capacity of cold-formed thin-walled steel members.In order to reduce the influence of buckling bearing capacity of cold-formed thin-walled C steel column,the deformation characteristics of the axial compression buckling of web member,respectively in the flange and the edge along the medial axial reinforcement method,in order to improve the ultimate bearing capacity of members.In this paper,the fine model of cold-formed thin-walled C steel column is established by using finite element method,taking account of material nonlinearity and geometric nonlinearity.On this basis,the influences of the location of steel bars,the diameter of reinforcement,the slenderness ratio of members,the thickness ratio of C steel web and the location of spot welding on the axial compressive capacity of reinforced cold-formed thin-walled C steel columns are studied respectively.The results show that the local buckling of the specimen,through web flange reinforced paste steel bar can effectively improve the vertical ultimate bearing capacity of the specimen;whole buckling failure specimens by sticking steel bar longitudinal flange in the web can also effectively improve the ultimate bearing capacity of specimen;the distortion of the buckling failure of specimen.Based on the two edge vertical stick can effectively improve the bearing capacity of reinforced bar diameter is reinforced;strengthen the important influence factors of bearing capacity of steel column type C,with the increase of the bar diameter,after the ultimate load bearing capacity increases gradually increasing reinforcement;slenderness ratio,web depth thickness ratio and welding position of bearing capacity of cold-formed thin-walled C steel column reinforcement after a great influence.Finally,based on the direct strength method and 5 groups of 138 finite element models,the calculation method of axial compression capacity of cold-formed thin-walled C steel members is proposed.The calculation results of this method are compared with the results of finite element analysis.It is proved that the calculation method is reasonable and can be used by designers.