Seismic Performance Analysis Of Self-centering Joint Based On Energy Consumption Of Angle Steel

The self-centering prefabricated structure combines the characteristics of prefabricated structure and prestressed structure.It has the advantages of small residual deformation after earthquake and strong self-reset ability,so it is conducive to the realization of building industrialization and has broad prospects for development.The angle steel connection joint formed by connecting prefabricated members with energy-dissipating angle steel and prestressed tendons,belongs to one of self-centering prefabricated joints.Compared with other self-centering joints,it has the advantages of quick construction and easy repair after earthquake.At present,the domestic research on the angle steel connection joint lacks systematicity and pertinence,and there is no effective design method based on Chinese design codes.On the basis of summarizing the ACI 550.3-13 and the design method of the hybrid connection joint in the early stage of our team,this paper combines the stress characteristics of angle steel and existing research results,and proposes a design method and calculation process suitable for angle steel connection joint.Through the finite element software Abaqus,the static nonlinear models of hybrid connection joint and angle steel connection joint were established respectively.Then,the hysteretic curve,skeleton curve,energy dissipation capacity,self-centering performance,material damage and other seismic performance indexes of the angle steel connection joint are studied by using the method of comparative analysis with the hybrid connection joint.Finally,by changing the screw gauge distance of angle steel vertical leg,the measures to improve its energy consumption capacity are studied,and the mechanism of angle steel energy consumption joint is further explored.The main results of the paper are as follows:（1）With the increase of parameterΦ_des（the ratio of moment capacity provided by prestressed tendons to total moment capacity of section）,the residual deformation of hybrid connection joint and angle steel connection joint decreases,the self-centering capacity increases,and the energy dissipating capacity decreases.（2）For the sameΦ_des,the residual deformation of angle steel connection joint is smaller than that of the hybrid connection joint,and the self-centering ability is better.Even when the maximum displacement is applied to control the interlaminar displacement angle（θ=1/50）,the residual displacement does not need to be dealt with.（3）Under the maximum displacement load（θ=1/50）,the concrete crushing phenomenon of angle steel connection joint mainly occurs in the concrete cover at the end of the frame beam,and there is no crushing phenomenon in the core area of the frame beam.But,its energy consumption capacity is only half of that of the hybrid connection joint.（4）The energy consumption of the angle steel connection joint is mainly through the shear deformation of angle steel vertical leg.The deformation and damage areas of angle steel,are mainly concentrated in the horizontal strip of the turning horizontal line and the height of the bolt hole in the vertical limb.（5）Under the condition of keeping the prestressed tendons area,angle steel thickness and material parameters unchanged,as the vertical leg screw position of the angle steel decreases,it will reduceΦ_des and increase the moment capacity,thereby improving the energy consumption.