Experimental Research On Seismic Performance Of Superimposed Concrete Wall Panels Node

At present,the development of superimposed concrete wall panels structure system in China has a mature theoretical foundation with the release of standards and atlas.This is of fundamental significance to the revision and promotion.The composite slab shear wallboard structure has begun to play a unique role,especially in projects with a prefabrication rate of more than 30%.The advantages in construction technology,on-site environmental protection,labor and time saving,visualization of concealed works acceptance,and so on have become increasingly prominent in the traditional cast-in-place mode environment with frequent contradictions.The core breakthrough point is to study the mechanical performance of relatively weak connection joints to make the integrity of composite slab structure achieve or even break through the effect of traditional cast-in-place mode.On this basis,the structure load level is more effective.Previously,there have been many experiments on the seismic performance of the horizontal and vertical joints of wall splicing before.However,there is a lack of exploration on the seismic performance of overlapping joints between the floor slab and the superimposed concrete wall at the floor position.Therefore,this paper conducts seismic tests on floor joints in composite slab structures.The main research contents and results:(1)We intercepted the floor structure formed by the upper and lower shear walls and the overlapping floor slab in the middle and set up two groups of comparative specimens of cast-in-place type and laminated slab type,nd described the cross-section,reinforcement design,and theoretical checking process of the shear wall slab.Hinge supports are arranged at the base of the floor slab and the bottom of the wall.The bending moment is effectively domain focus on nodes when subjected to horizontal load.Via the reciprocating stress of shear wallboard in different modes,this paper studies the difference of mechanical performance and failure mode between composite slab shear wallboard and traditional cast-in-place shear wallboard joints.Through the analysis of seismic indexes make a comprehensive evaluation of the seismic performance of the floor joints of superimposed concrete wall panels.At the same time,the finite element model calculation provide a reference for the nonlinear simulation analysis of this kind of structure.(2)During the test,the displacement of the wallboard and support is closely monitored and the data is collected.Two groups of wallboard specimens showed failure after applying low cyclic reciprocating load.The main concentrated areas of cracks are located at the joints of the wallboard.The cracks in the wall are X-shaped.Difference in pouring type shear wall panel wall body,plate crack is relatively evenly distributed in the ministries.There is no obvious bias in the cracks.Concrete falls off on both sides of slab crack joints of composite slab shear wall.Cracks in the plate body and wall body are concentrated on the outside of the root.There are fewer cracks in the middle part.The floor stably transfers horizontal force without obvious disconnection.The failure mode of the wall is a flexural shear failure,which is mainly bending failure.In terms of bearing capacity,the gap between the laminated plate specimens and the cast-in situ specimens is no more than12.23%,the ductility is good(both are greater than 2.8),the difference in initial stiffness measured is about 2%,the material degradation trend is similar,and the difference in viscous damping coefficient in the whole process is 0.01 ~ 0.02.It can be regarded that the laminated specimen has almost the same seismic performance as the cast-in-place specimen.(3)Considering the nonlinear behavior of floor joints and wallboard surface under stress.Finally,the simulation software is used to analyze the two groups of samples and set the corresponding definition,and the calculated results could effectively converge.Via the analysis and comparison of the simulation results with the test results,the damage of the wallboard core reflected by the stress the wallboard of core damage almost unanimously,which can accurately describe the failure mechanism of the shear wallboard under a complex load environment.In this paper,it can more accurately depict the destruction mechanism of shear wall under complex loading environment.In terms of the error between the ultimate bearing capacity and the test results,the full cast-in-place and laminated types are 3.5% and 10.1%,respectively.They can verify each other’s accuracy,which has reference value for setting parameters of laminated panel wallboard.Figure [36] table [8] reference [70]...