Research On Experimental Fragility And Hysteretic Behavior Of Cold-Formed Steel Gypsum Sheathed Partition Walls

As an important part of building non-structural components,cold-formed steelframed gypsum partition wall has been widely used in construction.However,there are few research on its fragility and hysteretic performance.Therefor,the quasi-static test of cold-formed steel-framed gypsum partition wall is carried out and the fragility and hysteretic performance are analyzed on the basis of the test.The main research contents and results are as follows:(1)Quasi-static experiments were carried out on 3m by 3m full-scale specimens of cold-formed steel-framed gypsum partition walls.According to different structural configurations,the specimens were divided into five groups,each group consisting of three identical specimens.A large number of data records of damage characteristics and hysteretic properties of partition walls were obtained.(2)Based on the observation of the damage process of the specimens during the test,the fragility curves of five groups of specimens are drawn.The results show that the track-slab connections is the weakness of the partition walls designed with the current design code,and the failure of trak-slab connections leads to the loss of the resistance of the partition walls.As the nails increases,the damage of the partition wall becomes obvious.Influenced by the shear strength of nails and track,there are two failure modes of the nail-slab connection: the tearing of the track and the cutting of the nails.A new configuration of track-slab connection with three-ply slab was tested.The preliminary results show that the cushion is helpful to improve the shear resistance of track.Another new configuration is replacing nail-slab connection with expansion bolts was tested,too.This method can completely solve the structural weakness of the insufficient nail-slab connection of cold-formed steel-framed gypsum partition wall,significantly improve the lateral resistance of partition wall,and enhance the synergistic effect of resistance on each part of cold-formed steel-framed gypsum partition wall.The results of failure curve analysis show that the failure curve of cold-formed steel-framed gypsum partition wall based on interstory drift have less affected by different configurations of track-slab connections.(3)The hysteretic behavior of cold-formed steel-framed gypsum partition walls was analyzed,and the Wayne Stewart hysteretic model parameters of each group of specimens are calculated.The results show that the backbone curve can be divided into four stages according to the characteristics of deformation.The hysteretic curve affected by configurations has four forms,and the hysteretic model parameters obviously affected by configurations are initial stiffness,yield force and capping force.Which have little relation with configurations change are: post-yield stiffness factor,post capping stiffness factor,unloading stiffness factor and intercept force.The simplified Wayne Stewart hysteretic model provides the necessary data for the numerical analysis of cold-formed steel-framed gypsum partition wall.