Study Of Self-centering Steel Moment Frame With Bolted Top And Seat Angles

Post-tensioned self-centering steel moment frame can reduce the residualdeformation effectively the earthquake, caused great attention of scholars at home andabroad. This paper studied self-centering Steel Moment Frame with Bolted Top andSeat Angles.First of all, this paper puts forward a kind of theoretical approach tocalculate M-θrrelationship of self-centering steel connection with bolted top and seatangles.Based on the research of the connection failure mechanism, connection bearingcapacity is deduced by component method. Using the EUROCODE3and Kishi-Chenfunction model, this paper obtains the connection M-θrrelationship and presents thedesign principles at each stage. The theoretical model calculation results, finite elementanalysis results and some experiment results were compared, the validity of the methodwas proved. In finite element analysis, the connection reflects better self-centeringperformance. The stresses of column web in the vicinity of the rotation centerconcentrate significantly, and it should be reinforced with stiffening plate to ensure thelocal stability of elements. At the same time, the place anchoring prestressedreinforcement should be added cover plate to ensure local stability of plate and thenormal work of prestressed reinforcement.Based on connection research, studies the force and deformation of the influenceon the connection’s M-θrrelationship and beam of prestress effects under static load.Research shows that: when the self-centering moment frame in the smaller load, the force and deformation are similar to ordinary rigid structure; when the load is larger,Node rotation ability stronger, the force and deformation reflects the characteristics ofthe semi-rigid joints. Lateral stiffness of the structure is less than the ordinary rigidframe.In order to study in detail the seismic performance and failure mechanism ofself-centering steel moment frame, SAP2000is adopted to modal a traditional steelmoment-risistent frame and two self-centering steel moment frames on the basis ofnode’s research and frame static analysis. By comparing the results, we know thatdynamic response of self-centering steel moment frames is significantly smallercompared with traditional steel moment-risistent frame. In all conditions, the top floordisplacement, interstory drift, node force and base shear force (moment) ofself-centering steel moment frames were smaller than the general frame; Comparedwith the general frame, self-centering steel moment frames failure later or no structuralfailure, plastic hinge appears late, plastic damage is also lesser. Dynamic response ofself-centering steel moment frames which prestressed smaller is less than prestressedlarger one. In all conditions, the displacement of top floor, interstory drift, node forceand base shear force (moment) of prestressed smaller one were smaller than the largerone. Prestressed smaller one failure late or no structural failure, plastic hinge appearslate, plastic damage is also lesser. Do not consider nodes fully failure, the failuremechanism of self-centering structure is similar with the general frame that plastic hingappear at end of beam, also with the bottom column root. Elastic-plastic deformationcapacity, structural ductility and energy dissipation of self-centering structure is better.Failure form is the beam hinge mechanism or mixed hinge mechanism.Self-centeringstructure has a good balance between rigidness and flexibility, and seismicperformance is superior to the general frame.