Anti-Seismic Performance Study On Double-Wall Combinnation Of Cold-Formed Thin-Walled Steel

Cold-formed thin-walled steel residential housing system gradually increased in our country,the main components of the system in combination with the wall and floor beams are space bearing system,Current domestic and international research mainly focuses on the wall studs or floor joists alone,there are few data on double-wall combination.And the combination of the upper and lower walls of the connecting parts of the structure is a weak position,resulting in the entire wall is not continuous,can not be coordinated.In order to study the mechanical properties of the cold-formed thin-wall steel double-wall composite wall,six double-wall composite wall specimens were subjected to low-cycle reciprocating loading.Studying the effects of wall column cross-section,axial compression and different materials of wall panels on the mechanical properties of the wall,the failure characteristics,bearing capacity characteristics,ductility and stiffness degradation of the specimens were analyzed.And the various factors were analyzed and compared:(1)The failure mode of the wall is that the screws around the wall are obviously loosened,the connection is mostly failed,the panel is deformed or damaged.After the test,the pull significantly loosened,wall column column foot,side beams,floor beams,rail plastic deformation.(2)Cross-sectional size: the larger the cross-section of the wall column column specimen bearing capacity,the greater the energy dissipation,the smaller the ductility.(3)Axial pressure: for the OSB panel wall,the bearing capacity of the axial pressure wall is smaller than that of the non-axial compression wall,which has little influence on energy dissipation capacity and ductility.For the calcium silicate plate wall,the bearing capacity of the axial pressure wall is significantly larger than that of the non-axial pressure wall,and the energy dissipation capacity is reduced,and the ductility has little effect.(4)Different materials panel:without axial pressure,OSB wall get higher bearing capacity,lower energy dissipation than calcium silicate board wall,ductility less affected;with axial pressure,the bearing capacity of calcium: silicate board> gypsum board > OSB board,the energy bearing:gypsum board> calcium silicate board> OSB board,ductility: calcium silicate board>OSB board> gypsum board.The ANSYS finite element analysis software was used to simulate the cold-formed thin-walled steel double-walled composite wall.The finite element model was loaded according to the loading conditions of the specimen.The stress and displacement cloud patterns were obtained by solving the model.The simulation results were in good agreement with the experimental results.Affecting the combination of double wall shearperformance of the two factors in the parameters of the finite element analysis,it is concluded that:(1)It can effectively improve the shear bearing capacity of the double-layer composite wall and improve the weak link between the upper and lower composite wall and the connection of the floor.(2)Increasing the thickness of wall panel can improve the shear bearing capacity of the double-layer composite wall.Based on the simplified calculation model of anti-lateral stiffness of single-wall cold-formed steel frame wall and deduced theoretical calculation formula of anti-lateral displacement stiffness of wall,combined with the experimental data a,come to a practical formula of anti-sliding stiffness which considered load,horizontal earthquake and rare earthquake.