Study On Seismic Performance Of Self-Centering Joint Based On Multi-Stage Energy Dissapition

The self-centering structure can be resilient after earthquake,mainly composed of self-centering mechanism and energy dissipation mechanism.In this paper,when designing self-centering joints,a multi-stage energy dissipation mechanism is proposed based on the existing self-centering mechanism.The energy dissipation mechanism is realized by a new multi-stage energy dissipation damper.The main works of this paper are as follow:(1)A multi-stage energy dissipation damper is proposed.Based on the principle of different displacements at different radius points with the same rotation angle,the multi-stage yield energy dissipation of the damper is achieved by reasonably arranging the position of the energy dissipation plate in the damper.Firstly,the mechanical properties of a single energy dissipation plate in the damper are studied theoretically,and the formulas for calculating the relevant mechanical properties of the energy dissipation plate under shear are derived.On this basis,the restoring force model of multi-stage energy dissipation damper is proposed.The influence of the width and thickness of the energy dissipation plate on the mechanical properties of the damper is analyzed by using the finite element software.Four dampers with different number and arrangement of energy dissipation plates are designed by choosing reasonable size of energy dissipation plate.The numerical simulation of monotonic loading and reciprocating loading is carried out to verify the energy dissipation characteristics of the damper and to analyze the influence of different parameters on the energy dissipation capacity of the damper.(2)Theoretical analysis of self-centering joints with multi-stage energy dissipation dampers is carried out.Combining with the relevant theoretical formulas of structural mechanics,the deformation of beam end displacement is calculated.According to the force balance at the interface of beam and column and the mechanical properties of energy dissipation damper in stages,the relationship between load and displacement in each stage is deduced,and the restoring force model of energy dissipation and self-centering joints in stages is put forward.(3)The number of prestressed tendons and the yield stiffness of damper energy dissipation plate are analyzed for the energy dissipation self-centering joints in stages.Four joint specimens are modeled by finite element software ABAQUS.The hysteretic curve,skeleton curve,energy dissipation capacity,ductility,stiffness degradation and residual deformation of the specimens are obtained by numerical simulation under low cyclic load.By comparing the effects of different parameters on the seismic capacity of the joint specimens,the analysis shows that the residual deformation of the joint is smaller,the self-centering ability is better,and it has a certain energy dissipation performance,which can realize energy dissipation in multi-stage.