Bearing-energy Dissipated Joint And Optimization Of Earthquake Failure Mode For Fabricated Steel Frames

In recent years,performance-based design theory is recognized step by step,the study has become the present hot spot at earthquake engineering,and the theory has been developed maturely.Lately,the seismic design based on resilience has been the focus of the international earthquake engineering community.Compared with the traditional performance-based seismic design,the factors considered by it are comprehensive,and it is more in line with the actural needs of disaster-resistance in earthquakes.The current prefabricated construction of the building for the structural recovery of the structure provides a maneuverability.On that background,a new type of assembly bearing-energy dissipated joint was put forward.It has the dual characteristics of bearing and energy-dissipating,and has the characteristics of easy assembly and easy to replace.Based on that,this paper focuses on the bearing-energy dissipated joint of the assembled steel frame,analyzes the seismic performance of the joint and controls the failure mode of the structure based on the designability of the node.Main research contents are as follows:(1)Based on the small-deflection theory and the strength after buckling of thin plate,the restoring force model of joint is improved and the structural design idea of failure mode of steel frame "weak beam strong column" is put forward.(2)Based on Pushover method,the anti-seismic performance analysis and the failure mode optimization of the assembled steel frame and the o rdinary steel frame are carried out.Based on structural seismic performance study,structural optimization ideas are obtained.Three kinds of failure modes are obtained by three typical lateral force loads.The optimization scheme is proposed based on the assembled bearing-energy dissipated joint,and the designability of the joints is verified.(3)Based on nonlinear time history method,the anti-seismic performance analysis of the steel frame structures with bearing-energy dissipated joints and the common frames are analyzed.Combined with the results of Pushover analysis and the results of the dynamic elasto-plastic analysis,the assembled bearing-energy dissipated joint has excellent seismic performance.(4)Based on Incremental Dynamic Analysis(IDA),the weakest failure mode of structure is obtained,and four optimization schemes for improving the failure mode are proposed based on the bearing-energy dissipated joint.The energy consumption before and after the structural optimization is analyzed.It is proved that the failure mode of the structure can be controlled by bearing-energy dissipated joint and the overall seismic capacity of the structure can be improved,and the bearing-energy dissipated joint has good energy dissipation characteristics.