| Buckling-restrained braced(BRB)as a new lateral resisting element that rely on the tension and compression yield of core unit to dissipate energy,which has a lot of advantages,such as the relatively simple structure,more sort,the good effect of damping,stable performance,etc.Its characteristics of yield under tensile and compressive working condition can solved the problem of the ordinary support buckling does not yield under compression,and reduced the section size of the structure of bearing component,improved the damping and the lateral stiffness of the structure,so as to achieve the effect of the seismic energy dissipation on structure.Because of its similarity of the application fields with steel support,BRB has been widely used in the steel frame structure system.However,the application of BRB does not reach its application degree in terms of the most widely used concrete frame structure system,the complexity and the ambiguity on force trans-mission mechanism of the beam-column joints in the concrete frame structure is the main reason.With the theoretical research and experimental research on support system for concrete frame structure developed,it has been emerging used in existing structure reinforcement.But,the research on connection joints between BRB and concrete beam-column is in early stage.According to the background of the above,The research in this paper have a good promotion effect and research value for support in the application of concrete frame structures with buckling constraints.Four kinds of connection form of beam-column joints-the angle steel embedded joint,the angle steel through type joint,the T-shaped steel embedded joint,the T-shaped steel through type joint are designed in this paper.In order to research the ultimate bearing capacity,the energy dissipation capacity,the failure mode and the bearing mechanism of the joint,the force states of all the members and research the influence on stiffness of the joint and beam rotation ability with the embedded parts,four joint are being modeled respectively by the finite element analysis software and loaded with monotonic loading and reciprocating loading to analyze the load-displacement curve,hysteresis curves,skeleton curves,the ductility and degradation stiffness of joints.With Comparative analysis on the advantages and disadvantages of the properties and the force mechanism of four joints,the optimizing order of embedded objects is given.The results show that:Four joints under monotonic loading and reciprocating loading have good work performances;the mechanics characteristics stages under monotonic loading is clear and have good ductility.There are some advantages,such as the full hysteretic curve under reciprocating loading,good ductility and seismic performance,stiffness degradation smoothly,and better energy dissipation;The failures of through type joints due to the concrete contact with plate in concrete beam be crushed and the transfer method of force is reasonable,which shows that embedded parts have good force performances and reliability;the bearing capacity of the embedded joints are mainly decided size of board,the research results in this paper proved that the T-shaped steel and angle steel as embedded parts of connection joints between BRB and concrete beam-column is practicability,which can provide the reference for the new concrete structures with BRB. |
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