Experimental Study On Seismic Performance Of The Top Floor Joint Of Short Pier Shear Wall

In order to study the seismic behavior of the top node of short pier shear wall,in this paper,four short leg shear wall top node structural test models are designed based on different limb thickness ratio under the condition of constant wall thickness.The stress strain data of the core area of the joint are measured and the structural test models are observed and recorded during the test,the mechanical behavior and structural deformation rule of the short leg shear wall joint are obtained after processing and analyzing the test data.To compare with the results of the test,three full-scale structural analysis models with the same cross section shape and the same similarity ratio are established by using ANSYS finite element analysis software,the cyclic loading is similar to the structural test for the finite element analysis model.By changing the axial compression ratio,the seismic performance of the top node of short pier shear wall is further studied,and the results of the finite element analysis are compared with those of the structural test data,and the two are in good agreement.Combined with the model test data and finite element calculation results,the skeleton curve of the top node of short leg shear wall under horizontal cyclic loading is determined,and linear regression method is used to get the seventy percent off line restoring force model of the node.Considering the similarity between the top floor joints of special shaped columns and the top floor joints of short leg shear walls,in order to facilitate the unification of engineering application and calculation method,the results of structural test and finite element analysis are synthetically analyzed,and the formula of the top floor joint of the special shaped column is corrected with a magnifying coefficient,and the calculation formula of the shear capacity of the top floor joint of the short leg shear wall is obtained.Through the structural model test and ANSYS finite element analysis,the following achievements are accomplished:1?According to the scale of 1:3,four test models for the top story joints of T shaped short pier shear walls with the same wall thickness and the ratio of thickness is 5,6 and 7 are designed.The experimental data show that the area of the hysteresis loop of the top layer of the short leg shear wall is reduced with the increase of the thickness ratio of the wall limbs under the condition of constant thickness of the wall limbs.the increase of the ratio of the limb thickness reduces the energy dissipation performance of the top floor joint of the short leg shear wall in the case of the constant thickness of the wall limbs.2?In order to compare with the structural model test results,3 finite element structural analysis models are established with the help of ANSYS finite element analysis software.the axial compression ratio is 0.1,0.2,0.3 and 0.4 respectively,and then the increasing cyclic horizontal load is applied to the finite element analysis model.The finite element analysis shows that the increase of the axial compression ratio can increase the bearing capacity of the core area of the top layer of the short leg shear wall,but with the increase of the axial compression ratio,the energy dissipation capacity of the joints is reduced.3?The hysteretic curve and seventy percent off line restoring force model of the top node of short pier shear wall are obtained by using structural model test results and finite element analysis.4?By using a magnifying coefficient,the formula of the top floor joint of the special shaped column is modified,and the formula for calculating the shear capacity of the top wall and continuous beam joints of the short shear wall is obtained.