| Traditional seismic design mainly relies on the strength and deformation ability of the beams and columns in the structure to resist earthquake action,but this method of completely relying on the deformation of the structure to absorb and consume seismic energy still cannot ensure the structure’s performance in the event of a huge earthquake.It is safe,so a new system with more significant seismic performance than traditional seismic systems—energy dissipation and damping technology is proposed.This technology can significantly improve the seismic performance of the structure by consuming the seismic energy transferred to the upper structure through the damper,but whether the damper can fully function depends on the design of the energy dissipating substructure,If the design bearing capacity of the energy dissipating substructure is insufficient,the energy dissipating substructure will be destroyed before the dampers are not functioning,so the application of damping design in the structure is meaningless.Therefore,the research on the design method of energy dissipation substructure is proposed to ensure that the damper can play a full role.In the technical specification for energy dissipation and vibration reduction,the design requirement for energy dissipation substructure is that the energy dissipation substructure should be designed based on bearing capacity and ductility,but the specific design index is not clear.At present,most of the energy dissipation substructure design is based on the design of bearing capacity,without considering the ductility.In this regard,this paper introduces the ductility design concept on the basis of ensuring the bearing capacity of the energy dissipator substructure,analyzes the ductility influencing factors of the reinforced concrete structure,and obtains the seismic performance test database of reinforced concrete columns from the Pacific Earthquake Research Center(PEER-Structural Performance Database)Extract the experimental data of reinforced concrete columns under low-cycle cyclic loading,and analyze the influence of ductility factors on reinforced concrete columns;Then,a three-story frame structure with mild steel damper is designed for damping.First,the structure is analyzed by Pushover analysis method,and then the ductility concept is introduced into the design of the energy dissipating substructure.By adjusting the cross-sectional size,material strength,and Reinforcement ratio,control the number of hinge-out steps,adjust the elastoplastic structure model under different hinge-out steps of the energy dissipation substructure: Plastic hinges appear in the energy dissipating substructure and the non-substructure at the same time(plastic hinges appear at the same time),the energy dissipating substructures have plastic hinges after the non-substructures(plastic hinge 1)and the energy dissipation substructures appear in the last three of the non-substructures.Step out of the plastic hinge(back out of the plastic hinge 2).The comparative analysis of three elastoplastic structural models shows that:(1)According to the analysis of the shear displacement curve,the lower the number of hinge steps of the energy dissipation substructure,the higher the base shear force,the displacement ductility coefficient and the overall ductility of the structure.(2)According to the seismic performance analysis,the lower the number of hinge steps of energy dissipation substructure,the smaller the top displacement of the structure,the smaller the inter story displacement angle of the structure,and the overall seismic performance of the structure is improved.(3)According to the analysis of three elastic-plastic models of the frame structure with mild steel dampers,the model of energy dissipation substructure after the non substructure step out of the hinge(after the hinge 1),after the non substructure failure,the energy dissipation substructure is followed by the failure,at this time,the energy dissipation of the damper is the best.(4)For frame structure with soft steel damper,when the curvature ductility coefficient ratio of non substructure and energy dissipation substructure is 0.65,the design of energy dissipation substructure is reasonable. |
