| Due to the large residual deformation of the traditional steel frame under strong earthquake,the repair cost of the building after earthquake increases greatly.In this paper,a new structural form of multi-layer steel frame joints is proposed,that is,a new phased energy dissipation self-resetting beam-column joints.The joints are provided with prestressed tendons to provide self-resetting capability and specially arranged mild steel components to provide energy dissipation capability.The new steel frame beam-column joint has simple structure,clear function and small residual deformation after the earthquake.It is expected to be restored after simple repair.The main research contents and results of this paper are as follows:Firstly,in view of the large residual deformation of the traditional joint after a large earthquake,a new type of phased energy dissipation self-resetting beam-column joint is proposed,and its structural form and working principle are described.Secondly,the nonlinear finite element modeling of the new phased energy-dissipated self-resetting beam-column node and the traditional beam-column node is carried out by using the finite element software ABAQUS.The mechanical properties of the hysteretic curves,skeleton curves and residual deformation curves of the two nodes are numerically simulated and analyzed,and the mechanical properties of the new node and the traditional node under earthquake are investigated.Then,in order to facilitate calculation,the connection element method is used to simplify the new node modeled by solid element to the fitting node modeled by line element,which requires the hysteresis curves of the two nodes to be consistent,laying a foundation for the next step of self-resetting steel frame modeling.Thirdly,the multi-layer self-resetting steel frame model with new node connection and the traditional rigid multi-layer steel frame model are established respectively,and the modal analysis is carried out to compare the natural vibration frequency and mode of the two frame models,and explore the influence of the installation of new nodes on the natural vibration period of the multi-layer steel frame.The seismic time-history analysis of the two frame models was carried out by inputting seismic waves with different peak accelerations.The seismic performance indexes of the two models,such as maximum inter-storey angular displacement,maximum acceleration and base shear,were compared,and the influence of the installation of new nodes on the seismic performance of the multi-storey steel frames was further investigated.Finally,in order to analyze the influence of the new node arrangement on the seismic performance of the multi-layer steel frame,the new nodes were arranged in different layers and different frames,and the seismic performance indexes of the steel frame models with different self-reset node arrangements were compared and analyzed.The optimal self-reset node arrangement scheme was obtained by combining the layout schemes with good seismic performance. |
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