Study On Design Method Of Cold-formed Steel Beam With No Axis Of Symmetry Section

Container building is a temporary building,being widely used in rebuilding after disasters,construction site and exhibition room etc.it has many advantages,including Quick and easy disassembly and recycling.Bottom frame beam and top frame beam are mainly structural members of container building,with complicated,abroach and asymmetric section styles,this paper mainly describes the detailed study resulted on bending carrying capacity of cold-formed steel beam with no axis of symmetry section by tests and numerical analysis,and the corresponding integral stability coefficient design method is proposed.Firstly,the cold-formed steel beam with no axis of symmetry section building experimental models were tested,with different section styles and loading styles.This paper has completed 9 groups tests of torsion bending,and totally 18 specimens.testing method,testing apparatus,testing phenomenon and testing data processing were detailed introduced.and the working and destruction mechanism of beams is concluded in this part.Secondly,nonlinear finite element analysis involving geometric large deformation,materials nonlinear is used to simulate test models under bending load in this paper.From the comparison of ANSYS analysis with experimental results,the finite element model is more accurate.Then simplified finite element models of beams of bottom frame beam were set up,and the parametric study analysis was carried out to mainly determine the effect of the position of top flange stiffener,depth-thickness ratio of web.Contrastive analysis the failure mode and bending bearing capacity under two different loading conditions.Finally.based on the current theory,deducing the critical moment of asymmetric section under lateral loading,providing the formula of coefficient of integral stability,and compared with tests results.determined the simplified formula for engineering design.