A Study On Seismic Performance Of The Post-tensioned Precast Concrete Frame With Additional Energy Dissipataters

With the rapid development of construction industrialization,the demand for the development of the precast structures is increasing.As a common fabricated structure,the post-tensioned precast concrete frame structure has good ductility and be able to avoid destructive residual deformation and difficulty in repairing of the traditional cast-in-place concrete frame after the earthquake.As the mechanism of the post-tensioned precast concrete frame,the precast concrete beams and columns are assembled by post-tensioned unbonded strands.Instead of connecting the beams and columns by the bonding force of the traditional cast-in-place concrete connection,the shear force between the beams and columns is mainly resisted by the friction force generated by the post-tensioned unbonded strands.Under the action of horizontal force,the beam-column joints of the post-tensioned precast concrete frame opens,and the plastic deformation of the structure is mainly concentrated in the beam-column joint zone.Due to the post-tensioned unbonded strands,the frame has good self-centering performance and small residual deformation.Compared with the cast-in-place structure,the energy dissipation capacity of the posttensioned precast concrete frame is weak,and additional energy dissipation dampers need to be equipped.The partially restrained energy dissipater is a kind of energy consumption damper with stable energy consumption performance,and has the advantages of no welding,no grouting and easy replacement.In order to improve of the energy dissipation capacity of the post-tensioned precast concrete frame,this paper equips the frame with the partially restrained energy dissipater as energy dissipation dampers and conducted systematically research to the Seismic Performance of the post-tensioned precast concrete frame with additional Energy dissipataters by means of combination of experimental analysis,numerical simulation and theoretical research.(1)Completed the whole process from overall frame design,detailed component design to the frame experiment: a single-story single-span post-tensioned precast concrete frame was designed,as well as the initial pre-stress and the partially restrained energy dissipater of the frame were designed at the component level,with a systematical design method introduced finally;A test was conducted to research the Seismic Performance of the post-tensioned precast concrete frame with additional energy dissipataters on the basis of the designed components.The research results show that the post-tensioned precast concrete frame has good self-centering performance,in addition,the additional energy dissipataters effectively improve the energy consumption capacity of the frame.Furthermore,the energy dissipater is easy to replace,which is conveniently for the frame to repair in time after the earthquake.(2)A two-dimensional three-degree-of-freedom plane numerical model of the post-tensioned precast concrete frame with additional energy dissipataters is established based on the Opensses finite element software,and the numerical results are in good agreement with the experimental results.Based on the numerical model,parametric analysis was carried out to research the effects of initial prestress,number of the partially restrained energy dissipaters,installation height of the partially restrained energy dissipater,and frame column axial compression ratio on the Seismic Performance of the frame structure.Based on the results of parametric analysis,the key parameters affecting the Seismic Performance of the frame are summarized and design suggestions for key parameters are given.(3)In order to further study the influence mechanism of subcomponents’ parameter of the post-tensioned precast concrete frame with additional energy dissipataters on the Seismic Performance of the frame,the mechanical performance and hysteresis characteristics of the frame are deeply studied,and the hysteretic restoring force model which explains the relationship between the lateral force and the lateral displacement of the frame are obtained further.Based on the analysis of the characteristic quantities and characteristic points of the hysteresis model,a algorithm-based procedural modeling method is established.The accuracy of the theoretical hysteresis model is verified by comparison with the experimental hysteresis result,which could provide provide a theoretical reference for the design calculation of post-tensioned precast concrete frame.