Study On Seismic Behavior Of Cold-formed And Thin-walled Steel Composite Wall With Diagonal Bracing

The cold-formed thin-walled steel composite wall with diagonal bracing is a new type of composite wall that is merely involved in research at home or abroad.It improves the shear resistance of the wall by installing diagonal bracing members,which has a very good application value.However,the current researches on this new type of wall are not abundant.The calculation methods of its mechanical properties and bearing capacity still need further systematic research.In this paper,the experimental research and theoretical analysis of the seismic performance of the cold-formed thin-walled composite wall with bracing are investigated.The mechanical properties,failure modes,hysteretic properties,ductility and stiffness of the wall are evaluated.The influence of factors such as width ratio,panel screw spacing,steel material properties and length of the wall on the anti-seismic performance are also analyzed.Meanwhile,the design values of the shear capacity of such a wall in seismic design are determined according to domestic and international norms.Firstly,a low-cycle reciprocating loading test is carried out on a six-sided overlying OSB plate and a non-coated diagonally braced cold-formed thin-walled composite wall.The effects of the presence and absence of overlying panels and different aspect ratios on the seismic performance of the composite wall are studied.The failure modes,deformation characteristics and ultimate bearing capacity of the cold-formed thin-walled steel composite wall are investigated.The mechanical properties such as energy dissipation capacity,ductility and stiffness change of the composite wall are analyzed.At the same time,the shear connection test of the self-tapping screws is performed,and the mechanical properties of the self-tapping screw connectors with different connection methods were analyzed.Based on the experimental study,a finite element simulation analysis is performed on the test wall.The spring unit is used to simulate the screw and the actual connection of the self-tapping screw in the test was reduced.Through comparison with the test results,the rationality and effectiveness of the finite element analysis model are verified.Based on this,based on the analysis model,the parametric analysis is performed on the variable bracing cold-formed thin-wall steel composite wall.The factors such as aspect ratio,panel screw spacing,and steel material properties of the composite wall with braces are investigated.The effect of body performance and bearing capacity.Finally,according to the results of the test and finite element analysis,combined with the relevant regulations and theoretical backgrounds for the shear capacity of cold-formed thin-wall steels in the domestic and international specifications,the partial resistance coefficients of the cold-formed thin-walled steel composite wall with diagonal bracing are obtained.To determine the design value of the shear capacity of such walls under horizontal earthquakes,and provide reference for the application and research and development of the project.