Experimental Study And Finite Element Analysis Of Steel Frame With Vertical Slit CCA Infill Wall

In the trend of housing industrialization,new type of infill wall in the application of steel frame structure is attracting more attention.In the traditional design of steel structure system,infill wall is regarded as a kind of building envelope regardless of its structure function.However,due to the coupling effect between the infill wall and steel frame,there are considerable variation between the steel frame with infill wall and bare steel frame in stress performance.Therefore,it is of great significance to study the failure modes and failure mechanisms of new type of infill wall.In order to mitigate CCA infill wall crack and reduce the stress concentration in the corner of the wallboard,one vertical slit was set in the middle of the wallboard,and one steel frame with vertical slit CCA infill wall was carried out in a pseudo static test,also one bare steel frame and one steel frame with CCA infill wall was designed,which were compared with the steel frame with vertical slit CCA infill wall.The failure modes and failure mechanisms of vertical slit CCA infill wall were main researched,as well as the effect of the vertical slit to the load-displacement hysteretic curves,the deformation capacity and stiffness degradation,energy dissipation of the specimen,and the results of the experiment was compared with the finite element software simulation results.Experimental studies show that vertical slit can reduce the stress concentration in the corner of the infill wall and retard the CCA infill wall crack effectively.The vertical slit altered the failure mode and stress mechanism of the infill wall.The failure mode of vertical slit CCA infill wall was inclined cracks at the upper and lower ends of vertical slit,the failure mode of CCA infill wall was cross cracks at the corner.Five opening CCA infill wall steel frames were studied by finite element simulation.The influence of opening ratio and opening location on crack form,stress concentration of CCA infill wall and the lateral stiffness of the steel frame were analyzed.The results indicated that the cracks in the opening CCA infill wall are distributed in the corner or near the opening.When the opening location were constant,the initial lateral stiffness of steel frames were decreased with the increase of opening ratio;When the opening ratio were constant,opening at the edge was greater than opening at the center in the initial stiffness of the specimen.Research results will provide theoretical basis for the development of steel frame with CCA infill walls.