| Ductility,as one of the concerns in traditional seismic design,has long been considered to be helpful to reduce the seismic hazard of structures,but this is at the expense of structural damage and at the expense of the interes ts of building owners.Compared with the traditional structure,the self-centering structure has the characteristics of functional recovery and building industrialization,so the ductility demand is lower and it adapts to the needs of the times.Therefore,it has broad application prospect and great research value,but there are still some problems in practical application.Therefore,in this paper,the prestressed self-centering prefabricated concrete frame with rocking frame(PSCPC-RF)is proposed to overcome the disadvantages of poor energy dissipation,concentrated lateral deformation and yield failure of prestressed tendon of the prestressed self-centering prefabricated concrete(PSCPC)frame composed of hybrid connections.Through research on hybrid connection design and structural stress,the deformation mode and failure mode of the frame are optimized,and on this basis,the seismic performance of the PSCPC-RF frame is comprehensively evaluated.The specific work is as follows:(1)The accurate modeling of the hybrid connection is realized on the OpenSees simulation platform,and its rationality and applicability is verified by relevant domestic tests.(2)In the process of exploring and researching the design method of the hybrid connection,two design parameters,the prestressed strength ratio ? and the moment factor of beam ? proposed by this paper,are selected.Then the design method of rocking frame based on stiffness requirement is also verified,and the modeling of the overall frame is further completed.On the basis of the above work,sixty-one conditions are constructed.In order to facilitate the subsequent inductive analysis and research,the concept of ? level is put forward according to the number of prestressed tendons.(3)The ductility coefficients of PSCPC and PSCPC-RF frames with different conditions are obtained through pushover analysis,and their deformation mode and failure mode are identified,which are explained and analyzed in detail at the same time.On this basis,the effects of design parameters on ductility coefficient,deformation mode and failure mode of the frame is evaluated,and the improvement and control effect of rocking frame on PSCPC frame is evaluated.(4)The dynamic time-history analysis of RC,PSCPC and PSCPC-RF frame systems under the action of multiple,fortification and rare e arthquakes is carried out respectively.Furthermore,The distribution of drift concentration factor(DCF),most story drift angle and residual displacement with the design parameters is discussed.Taking the most story drift angle as the optimization objective,the optimization domain of design parameters of two self-centering frame systems is obtained.Then,according to the results of Pushover analysis and dynamic analysis,the connection is designed in a supplementary way,and the design parameters are suggested as follows:(1)Reduce the ? level as much as possible.(2)The value range of ? is 0.6~0.75,where the left limit is not strictly limited.(3)The value range of ? is 0.6~1.(5)Based on the optimized BASE model,the seismic performance of the PSCPC-RF frame system is comprehensively evaluated by comparing and analyzing the story drift,lateral displacement,residual displacement,prestressed tendon force and hysteretic energy dissipation of the RC,PSCPC and PSCPC-RF system under earthquake action.Through the above research,it is found that both the internal optimal structure design and the external additional rocking frame can effectively improve the seismic resilience of the self-centering structure,and the internal and external optimization has less influence on each other.Therefore,as a new structural system,the PSCPC-RF frame can have good functional recoverability and excellent seismic performance after reasonable design. |
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